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Janssens A, Nguyen VS, Cecil AJ, Van der Verren SE, Timmerman E, Deghelt M, Pak AJ, Collet JF, Impens F, Remaut H. SlyB encapsulates outer membrane proteins in stress-induced lipid nanodomains. Nature 2024; 626:617-625. [PMID: 38081298 DOI: 10.1038/s41586-023-06925-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2021] [Accepted: 12/01/2023] [Indexed: 01/19/2024]
Abstract
The outer membrane in Gram-negative bacteria consists of an asymmetric phospholipid-lipopolysaccharide bilayer that is densely packed with outer-membrane β-barrel proteins (OMPs) and lipoproteins1. The architecture and composition of this bilayer is closely monitored and is essential to cell integrity and survival2-4. Here we find that SlyB, a lipoprotein in the PhoPQ stress regulon, forms stable stress-induced complexes with the outer-membrane proteome. SlyB comprises a 10 kDa periplasmic β-sandwich domain and a glycine zipper domain that forms a transmembrane α-helical hairpin with discrete phospholipid- and lipopolysaccharide-binding sites. After loss in lipid asymmetry, SlyB oligomerizes into ring-shaped transmembrane complexes that encapsulate β-barrel proteins into lipid nanodomains of variable size. We find that the formation of SlyB nanodomains is essential during lipopolysaccharide destabilization by antimicrobial peptides or acute cation shortage, conditions that result in a loss of OMPs and compromised outer-membrane barrier function in the absence of a functional SlyB. Our data reveal that SlyB is a compartmentalizing transmembrane guard protein that is involved in cell-envelope proteostasis and integrity, and suggest that SlyB represents a larger family of broadly conserved lipoproteins with 2TM glycine zipper domains with the ability to form lipid nanodomains.
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Affiliation(s)
- Arne Janssens
- Structural and Molecular Microbiology, VIB-VUB Center for Structural Biology, VIB, Brussels, Belgium
- Department of Bioengineering Sciences, Structural Biology Brussels, Vrije Universiteit Brussel, Brussels, Belgium
| | - Van Son Nguyen
- Structural and Molecular Microbiology, VIB-VUB Center for Structural Biology, VIB, Brussels, Belgium
- Department of Bioengineering Sciences, Structural Biology Brussels, Vrije Universiteit Brussel, Brussels, Belgium
| | - Adam J Cecil
- Chemical and Biological Engineering, Colorado School of Mines, Golden, CO, USA
| | - Sander E Van der Verren
- Structural and Molecular Microbiology, VIB-VUB Center for Structural Biology, VIB, Brussels, Belgium
- Department of Bioengineering Sciences, Structural Biology Brussels, Vrije Universiteit Brussel, Brussels, Belgium
| | - Evy Timmerman
- VIB Proteomics Core, Ghent, Belgium
- VIB-UGent Center for Medical Biotechnology, Ghent, Belgium
- Faculty of Medicine and Health Sciences, Department of Biochemistry, Ghent University, Ghent, Belgium
| | - Michaël Deghelt
- Walloon Excellence in Life Sciences and Biotechnology, WELBIO, Brussels, Belgium
- De Duve Institute, Université Catholique de Louvain, Brussels, Belgium
| | - Alexander J Pak
- Chemical and Biological Engineering, Colorado School of Mines, Golden, CO, USA
- Quantitative Biosciences and Engineering, Colorado School of Mines, Golden, CO, USA
| | - Jean-François Collet
- Walloon Excellence in Life Sciences and Biotechnology, WELBIO, Brussels, Belgium
- De Duve Institute, Université Catholique de Louvain, Brussels, Belgium
| | - Francis Impens
- VIB Proteomics Core, Ghent, Belgium
- VIB-UGent Center for Medical Biotechnology, Ghent, Belgium
- Faculty of Medicine and Health Sciences, Department of Biochemistry, Ghent University, Ghent, Belgium
| | - Han Remaut
- Structural and Molecular Microbiology, VIB-VUB Center for Structural Biology, VIB, Brussels, Belgium.
- Department of Bioengineering Sciences, Structural Biology Brussels, Vrije Universiteit Brussel, Brussels, Belgium.
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2
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Miyakoshi M. Multilayered regulation of amino acid metabolism in Escherichia coli. Curr Opin Microbiol 2024; 77:102406. [PMID: 38061078 DOI: 10.1016/j.mib.2023.102406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 11/08/2023] [Accepted: 11/09/2023] [Indexed: 02/12/2024]
Abstract
Amino acid metabolism in Escherichia coli has long been studied and has established the basis for regulatory mechanisms at the transcriptional, posttranscriptional, and posttranslational levels. In addition to the classical signal transduction cascade involving posttranslational modifications (PTMs), novel PTMs in the two primary nitrogen assimilation pathways have recently been uncovered. The regulon of the master transcriptional regulator NtrC is further expanded by a small RNA derived from the 3´UTR of glutamine synthetase mRNA, which coordinates central carbon and nitrogen metabolism. Furthermore, recent advances in sequencing technologies have revealed the global regulatory networks of transcriptional and posttranscriptional regulators, Lrp and GcvB. This review provides an update of the multilayered and interconnected regulatory networks governing amino acid metabolism in E. coli.
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Affiliation(s)
- Masatoshi Miyakoshi
- Department of Infection Biology, Institute of Medicine, University of Tsukuba, 305-8575 Ibaraki, Japan.
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3
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Coleman DJL, Keane P, Luque-Martin R, Chin PS, Blair H, Ames L, Kellaway SG, Griffin J, Holmes E, Potluri S, Assi SA, Bushweller J, Heidenreich O, Cockerill PN, Bonifer C. Gene regulatory network analysis predicts cooperating transcription factor regulons required for FLT3-ITD+ AML growth. Cell Rep 2023; 42:113568. [PMID: 38104314 PMCID: PMC10874628 DOI: 10.1016/j.celrep.2023.113568] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Revised: 11/03/2023] [Accepted: 11/27/2023] [Indexed: 12/19/2023] Open
Abstract
Acute myeloid leukemia (AML) is a heterogeneous disease caused by different mutations. Previously, we showed that each mutational subtype develops its specific gene regulatory network (GRN) with transcription factors interacting within multiple gene modules, many of which are transcription factor genes themselves. Here, we hypothesize that highly connected nodes within such networks comprise crucial regulators of AML maintenance. We test this hypothesis using FLT3-ITD-mutated AML as a model and conduct an shRNA drop-out screen informed by this analysis. We show that AML-specific GRNs predict crucial regulatory modules required for AML growth. Furthermore, our work shows that all modules are highly connected and regulate each other. The careful multi-omic analysis of the role of one (RUNX1) module by shRNA and chemical inhibition shows that this transcription factor and its target genes stabilize the GRN of FLT3-ITD+ AML and that its removal leads to GRN collapse and cell death.
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Affiliation(s)
- Daniel J L Coleman
- Institute of Cancer and Genomic Sciences, College of Medicine and Dentistry, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - Peter Keane
- Institute of Cancer and Genomic Sciences, College of Medicine and Dentistry, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK; School of Biosciences, University of Birmingham, Birmingham B15 2TT, U.K
| | - Rosario Luque-Martin
- Wolfson Childhood Cancer Research Centre, Translational and Clinical Research Institute, Newcastle University, Herschel Building, Level 6, Brewery Lane, Newcastle upon Tyne NE1 7RU, UK
| | - Paulynn S Chin
- Institute of Cancer and Genomic Sciences, College of Medicine and Dentistry, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - Helen Blair
- Wolfson Childhood Cancer Research Centre, Translational and Clinical Research Institute, Newcastle University, Herschel Building, Level 6, Brewery Lane, Newcastle upon Tyne NE1 7RU, UK
| | - Luke Ames
- Institute of Cancer and Genomic Sciences, College of Medicine and Dentistry, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - Sophie G Kellaway
- Institute of Cancer and Genomic Sciences, College of Medicine and Dentistry, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - James Griffin
- Institute of Cancer and Genomic Sciences, College of Medicine and Dentistry, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - Elizabeth Holmes
- Institute of Cancer and Genomic Sciences, College of Medicine and Dentistry, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - Sandeep Potluri
- Institute of Cancer and Genomic Sciences, College of Medicine and Dentistry, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - Salam A Assi
- Institute of Cancer and Genomic Sciences, College of Medicine and Dentistry, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - John Bushweller
- University of Virginia, 1340 Jefferson Park Avenue, Charlottesville, VA 22908, USA
| | - Olaf Heidenreich
- Wolfson Childhood Cancer Research Centre, Translational and Clinical Research Institute, Newcastle University, Herschel Building, Level 6, Brewery Lane, Newcastle upon Tyne NE1 7RU, UK; Prinses Máxima Centrum for Pediatric Oncology, Postbus 113, 3720 AC Bilthoven, Heidelberglaan 25, 3584CS Utrecht, the Netherlands.
| | - Peter N Cockerill
- Institute of Cancer and Genomic Sciences, College of Medicine and Dentistry, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK.
| | - Constanze Bonifer
- Institute of Cancer and Genomic Sciences, College of Medicine and Dentistry, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK.
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4
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Hidese R, Ohbayashi R, Kato Y, Matsuda M, Tanaka K, Imamura S, Ashida H, Kondo A, Hasunuma T. ppGpp accumulation reduces the expression of the global nitrogen homeostasis-modulating NtcA regulon by affecting 2-oxoglutarate levels. Commun Biol 2023; 6:1285. [PMID: 38145988 PMCID: PMC10749895 DOI: 10.1038/s42003-023-05632-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 11/23/2023] [Indexed: 12/27/2023] Open
Abstract
The cyanobacterium Synechococcus elongatus PCC 7942 accumulates alarmone guanosine tetraphosphate (ppGpp) under stress conditions, such as darkness. A previous study observed that artificial ppGpp accumulation under photosynthetic conditions led to the downregulation of genes involved in the nitrogen assimilation system, which is activated by the global nitrogen regulator NtcA, suggesting that ppGpp regulates NtcA activity. However, the details of this mechanism have not been elucidated. Here, we investigate the metabolic responses associated with ppGpp accumulation by heterologous expression of the ppGpp synthetase RelQ. The pool size of 2-oxoglutarate (2-OG), which activates NtcA, is significantly decreased upon ppGpp accumulation. De novo 13C-labeled CO2 assimilation into the Calvin-Benson-Bassham cycle and glycolytic intermediates continues irrespective of ppGpp accumulation, whereas the labeling of 2-OG is significantly decreased under ppGpp accumulation. The low 2-OG levels in the RelQ overexpression cells could be because of the inhibition of metabolic enzymes, including aconitase, which are responsible for 2-OG biosynthesis. We propose a metabolic rearrangement by ppGpp accumulation, which negatively regulates 2-OG levels to maintain carbon and nitrogen balance.
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Affiliation(s)
- Ryota Hidese
- Graduate School of Science, Innovation and Technology, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan
- Engineering Biology Research Center, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan
| | - Ryudo Ohbayashi
- Laboratory for Chemistry and Life Science Institute of Innovative Research, Tokyo Institute of Technology, Midori-ku, Yokohama, Japan
- Department of Biological Sciences, Faculty of Science, Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka, 422-8529, Japan
| | - Yuichi Kato
- Engineering Biology Research Center, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan
| | - Mami Matsuda
- Graduate School of Science, Innovation and Technology, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan
| | - Kan Tanaka
- Laboratory for Chemistry and Life Science Institute of Innovative Research, Tokyo Institute of Technology, Midori-ku, Yokohama, Japan
| | - Sousuke Imamura
- Laboratory for Chemistry and Life Science Institute of Innovative Research, Tokyo Institute of Technology, Midori-ku, Yokohama, Japan
- NTT Space Environment and Enegy Laboratories, Nippon Telegraph and Telephone Corporation, 3-9-11 Midori-cho, Musashino-shi, Tokyo, 180-8585, Japan
| | - Hiroki Ashida
- Graduate School of Human Development and Environment, Kobe University, 3-11 Tsurukabuto, Nada-Ku, Kobe, 657-8501, Japan
| | - Akihiko Kondo
- Graduate School of Science, Innovation and Technology, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan
- Engineering Biology Research Center, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan
- Research Center for Sustainable Resource Science, RIKEN, 1-7-22 Suehiro, Tsurumi, Yokohama, Kanagawa, 230-0045, Japan
| | - Tomohisa Hasunuma
- Graduate School of Science, Innovation and Technology, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan.
- Engineering Biology Research Center, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan.
- Research Center for Sustainable Resource Science, RIKEN, 1-7-22 Suehiro, Tsurumi, Yokohama, Kanagawa, 230-0045, Japan.
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5
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Milly TA, Renshaw CP, Tal-Gan Y. Developing multispecies quorum-sensing modulators based on the Streptococcus mitis competence-stimulating peptide. J Biol Chem 2023; 299:105448. [PMID: 37951305 PMCID: PMC10714334 DOI: 10.1016/j.jbc.2023.105448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Revised: 10/26/2023] [Accepted: 10/30/2023] [Indexed: 11/13/2023] Open
Abstract
Bacteria utilize quorum sensing (QS) to coordinate many group behaviors. As such, QS has attracted significant attention as a potential mean to attenuate bacterial infectivity without introducing selective pressure for resistance development. Streptococcus mitis, a human commensal, acts as a genetic diversity reservoir for Streptococcus pneumoniae, a prevalent human pathogen. S. mitis possesses a typical comABCDE competence regulon QS circuitry; however, the competence-stimulating peptide (CSP) responsible for QS activation and the regulatory role of the competence regulon QS circuitry in S. mitis are yet to be explored. We set out to delineate the competence regulon QS circuitry in S. mitis, including confirming the identity of the native CSP signal, evaluating the molecular mechanism that governs CSP interactions with histidine kinase receptor ComD leading to ComD activation, and defining the regulatory roles of the competence regulon QS circuitry in initiating various S. mitis phenotypes. Our analysis revealed important structure-activity relationship insights of the CSP signal and facilitated the development of novel CSP-based QS modulators. Our analysis also revealed the involvement of the competence regulon in modulating competence development and biofilm formation. Furthermore, our analysis revealed that the native S. mitis CSP signal can modulate QS response in S. pneumoniae. Capitalizing on this crosstalk, we developed a multispecies QS modulator that activates both the pneumococcus ComD receptors and the S. mitis ComD-2 receptor with high potencies. The novel scaffolds identified herein can be utilized to evaluate the effects temporal QS modulation has on S. mitis as it inhabits its natural niche.
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Affiliation(s)
- Tahmina A Milly
- Department of Chemistry, University of Nevada, Reno, Reno, Nevada, USA
| | - Clay P Renshaw
- Department of Chemistry, University of Nevada, Reno, Reno, Nevada, USA
| | - Yftah Tal-Gan
- Department of Chemistry, University of Nevada, Reno, Reno, Nevada, USA.
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6
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Müller-Dott S, Tsirvouli E, Vazquez M, Ramirez Flores R, Badia-i-Mompel P, Fallegger R, Türei D, Lægreid A, Saez-Rodriguez J. Expanding the coverage of regulons from high-confidence prior knowledge for accurate estimation of transcription factor activities. Nucleic Acids Res 2023; 51:10934-10949. [PMID: 37843125 PMCID: PMC10639077 DOI: 10.1093/nar/gkad841] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 08/08/2023] [Accepted: 09/22/2023] [Indexed: 10/17/2023] Open
Abstract
Gene regulation plays a critical role in the cellular processes that underlie human health and disease. The regulatory relationship between transcription factors (TFs), key regulators of gene expression, and their target genes, the so called TF regulons, can be coupled with computational algorithms to estimate the activity of TFs. However, to interpret these findings accurately, regulons of high reliability and coverage are needed. In this study, we present and evaluate a collection of regulons created using the CollecTRI meta-resource containing signed TF-gene interactions for 1186 TFs. In this context, we introduce a workflow to integrate information from multiple resources and assign the sign of regulation to TF-gene interactions that could be applied to other comprehensive knowledge bases. We find that the signed CollecTRI-derived regulons outperform other public collections of regulatory interactions in accurately inferring changes in TF activities in perturbation experiments. Furthermore, we showcase the value of the regulons by examining TF activity profiles in three different cancer types and exploring TF activities at the level of single-cells. Overall, the CollecTRI-derived TF regulons enable the accurate and comprehensive estimation of TF activities and thereby help to interpret transcriptomics data.
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Affiliation(s)
- Sophia Müller-Dott
- Heidelberg University, Faculty of Medicine, and Heidelberg University Hospital, Institute for Computational Biomedicine, Bioquant, Heidelberg, Germany
| | - Eirini Tsirvouli
- Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway
- Department of Biology, Norwegian University of Science and Technology, Trondheim, Norway
| | | | - Ricardo O Ramirez Flores
- Heidelberg University, Faculty of Medicine, and Heidelberg University Hospital, Institute for Computational Biomedicine, Bioquant, Heidelberg, Germany
| | - Pau Badia-i-Mompel
- Heidelberg University, Faculty of Medicine, and Heidelberg University Hospital, Institute for Computational Biomedicine, Bioquant, Heidelberg, Germany
| | - Robin Fallegger
- Heidelberg University, Faculty of Medicine, and Heidelberg University Hospital, Institute for Computational Biomedicine, Bioquant, Heidelberg, Germany
| | - Dénes Türei
- Heidelberg University, Faculty of Medicine, and Heidelberg University Hospital, Institute for Computational Biomedicine, Bioquant, Heidelberg, Germany
| | - Astrid Lægreid
- Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway
| | - Julio Saez-Rodriguez
- Heidelberg University, Faculty of Medicine, and Heidelberg University Hospital, Institute for Computational Biomedicine, Bioquant, Heidelberg, Germany
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7
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Wang B, van der Kloet F, Hamoen LW. Induction of the CtsR regulon improves Xylanase production in Bacillus subtilis. Microb Cell Fact 2023; 22:231. [PMID: 37946188 PMCID: PMC10633939 DOI: 10.1186/s12934-023-02239-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Accepted: 10/27/2023] [Indexed: 11/12/2023] Open
Abstract
BACKGROUND The bacterium Bacillus subtilis is extensively used for the commercial production of enzymes due to its efficient protein secretion capacity. However, the efficiency of secretion varies greatly between enzymes, and despite many years of research, optimization of enzyme production is still largely a matter of trial-and-error. Genome-wide transcriptome analysis seems a useful tool to identify relevant secretion bottlenecks, yet to this day, only a limited number of transcriptome studies have been published that focus on enzyme secretion in B. subtilis. Here, we examined the effect of high-level expression of the commercially important enzyme endo-1,4-β-xylanase XynA on the B. subtilis transcriptome using RNA-seq. RESULTS Using the novel gene-set analysis tool GINtool, we found a reduced activity of the CtsR regulon when XynA was overproduced. This regulon comprises several protein chaperone genes, including clpC, clpE and clpX, and is controlled by transcriptional repression. CtsR levels are directly controlled by regulated proteolysis, involving ClpC and its cognate protease ClpP. When we abolished this negative feedback, by inactivating the repressor CtsR, the XynA production increased by 25%. CONCLUSIONS Overproduction of enzymes can reduce the pool of Clp protein chaperones in B. subtilis, presumably due to negative feedback regulation. Breaking this feedback can improve enzyme production yields. Considering the conserved nature of Clp chaperones and their regulation, this method might benefit high-yield enzyme production in other organisms.
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Affiliation(s)
- Biwen Wang
- Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, C3.108, 1098 XH, Amsterdam, The Netherlands
| | - Frans van der Kloet
- Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, C3.108, 1098 XH, Amsterdam, The Netherlands
| | - Leendert W Hamoen
- Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, C3.108, 1098 XH, Amsterdam, The Netherlands.
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8
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Hatch ND, Ouellette SP. Identification of the alternative sigma factor regulons of Chlamydia trachomatis using multiplexed CRISPR interference. mSphere 2023; 8:e0039123. [PMID: 37747235 PMCID: PMC10597470 DOI: 10.1128/msphere.00391-23] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Accepted: 08/07/2023] [Indexed: 09/26/2023] Open
Abstract
Chlamydia trachomatis is a developmentally regulated, obligate intracellular bacterium that encodes three sigma factors: σ66, σ54, and σ28. σ66 is the major sigma factor controlling most transcription initiation during early- and mid-cycle development as the infectious elementary body (EB) transitions to the non-infectious reticulate body (RB) that replicates within an inclusion inside the cell. The roles of the minor sigma factors, σ54 and σ28, have not been well characterized to date; however, there are data to suggest each functions in late-stage development and secondary differentiation as RBs transition to EBs. As the process of secondary differentiation itself is poorly characterized, clarifying the function of these alternative sigma factors by identifying the genes regulated by them will further our understanding of chlamydial differentiation. We hypothesize that σ54 and σ28 have non-redundant and essential functions for initiating late gene transcription thus mediating secondary differentiation in Chlamydia. Here, we demonstrate the necessity of each minor sigma factor in successfully completing the developmental cycle. We have implemented and validated multiplexed Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) interference techniques, novel to the chlamydial field to examine the effects of knocking down each alternative sigma factor individually and simultaneously. In parallel, we also overexpressed each sigma factor. Altering transcript levels for either or both alternative sigma factors resulted in a severe defect in EB production as compared to controls. Furthermore, RNA sequencing identified differentially expressed genes during alternative sigma factor dysregulation, indicating the putative regulons of each. These data demonstrate that the levels of alternative sigma factors must be carefully regulated to facilitate chlamydial growth and differentiation. IMPORTANCE Chlamydia trachomatis is a significant human pathogen in both developed and developing nations. Due to the organism's unique developmental cycle and intracellular niche, basic research has been slow and arduous. However, recent advances in chlamydial genetics have allowed the field to make significant progress in experimentally interrogating the basic physiology of Chlamydia. Broadly speaking, the driving factors of chlamydial development are poorly understood, particularly regarding how the later stages of development are regulated. Here, we employ a novel genetic tool for use in Chlamydia while investigating the effects of dysregulating the two alternative sigma factors in the organism that help control transcription initiation. We provide further evidence for both sigma factors' essential roles in late-stage development and their potential regulons, laying the foundation for deeper experimentation to uncover the molecular pathways involved in chlamydial differentiation.
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Affiliation(s)
- Nathan D. Hatch
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Scot P. Ouellette
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska, USA
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9
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Drummond IY, DePaolo A, Krieger M, Driscoll H, Eckstrom K, Spatafora GA. Small regulatory RNAs are mediators of the Streptococcus mutans SloR regulon. J Bacteriol 2023; 205:e0017223. [PMID: 37695854 PMCID: PMC10521355 DOI: 10.1128/jb.00172-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Accepted: 08/08/2023] [Indexed: 09/13/2023] Open
Abstract
Dental caries is among the most prevalent chronic diseases worldwide. Streptococcus mutans, the chief causative agent of caries, uses a 25-kDa manganese-dependent SloR protein to coordinate the uptake of essential manganese with the transcription of its virulence attributes. Small non-coding RNAs (sRNAs) can either enhance or repress gene expression, and reports in the literature ascribe an emerging role for sRNAs in the environmental stress response. Herein, we focused our attention on 18-50 nt sRNAs as mediators of the S. mutans SloR and manganese regulons. Specifically, the results of RNA sequencing revealed 19 sRNAs in S. mutans, which were differentially transcribed in the SloR-proficient UA159 and SloR-deficient GMS584 strains, and 10 sRNAs that were differentially expressed in UA159 cells grown in the presence of low vs high manganese. We describe SmsR1532 and SmsR1785 as SloR- and manganese-responsive sRNAs that are processed from large transcripts and that bind SloR directly in their promoter regions. The predicted targets of these sRNAs include regulators of metal ion transport, growth management via a toxin-antitoxin operon, and oxidative stress tolerance. These findings support a role for sRNAs in coordinating intracellular metal ion homeostasis with virulence gene control in an important oral cariogen. IMPORTANCE Small regulatory RNAs (sRNAs) are critical mediators of environmental signaling, particularly in bacterial cells under stress, but their role in Streptococcus mutans is poorly understood. S. mutans, the principal causative agent of dental caries, uses a 25-kDa manganese-dependent protein, called SloR, to coordinate the regulated uptake of essential metal ions with the transcription of its virulence genes. In the present study, we identified and characterized sRNAs that are both SloR and manganese responsive. Taken together, this research can elucidate the details of regulatory networks that engage sRNAs in an important oral pathogen and that can enable the development of an effective anti-caries therapeutic.
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Affiliation(s)
| | | | - Madeline Krieger
- Department of Restorative Dentistry, School of Dentistry, Oregon Health and Science University, Portland, Oregon, USA
| | - Heather Driscoll
- Department of Biology, Vermont Biomedical Research Network, Norwich University, Northfield, Vermont, USA
| | - Korin Eckstrom
- Department of Microbiology and Molecular Genetics, The Robert Larner, M.D. College of Medicine, University of Vermont, Burlington, Vermont, USA
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10
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Abstract
Small regulatory RNA (sRNAs) are key mediators of posttranscriptional gene control in bacteria. Assisted by RNA-binding proteins, a single sRNA often modulates the expression of dozens of genes, and thus sRNAs frequently adopt central roles in regulatory networks. Posttranscriptional regulation by sRNAs comes with several unique features that cannot be achieved by transcriptional regulators. However, for optimal network performance, transcriptional and posttranscriptional control mechanisms typically go hand-in-hand. This view is reflected by the ever-growing class of mixed network motifs involving sRNAs and transcription factors, which are ubiquitous in biology and whose regulatory properties we are beginning to understand. In addition, sRNA activity can be antagonized by base-pairing with sponge RNAs, adding yet another layer of complexity to these networks. In this article, we summarize the regulatory concepts underlying sRNA-mediated gene control in bacteria and discuss how sRNAs shape the output of a network, focusing on several key examples.
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Affiliation(s)
- Kai Papenfort
- Institute of Microbiology, Friedrich Schiller University Jena, Jena, Germany;
- Microverse Cluster, Friedrich Schiller University Jena, Jena, Germany
| | - Sahar Melamed
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel;
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Song J, Fan J, Fan C, He N, Ye X, Cao M, Yuan J. A Layered Genetic Design Enables the Yeast Galactose Regulon to Respond to Cyanamide. ACS Synth Biol 2023; 12:2783-2788. [PMID: 37603344 DOI: 10.1021/acssynbio.3c00241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/22/2023]
Abstract
The commonly used expression systems in Saccharomyces cerevisiae typically rely on either constitutive or galactose-regulated promoters. The lack of inducible systems in S. cerevisiae limits the precise temporal regulation of protein function and yeast metabolism. We herein repurposed the galactose-regulated system to make it respond to cyanamide. By using a cyanamide-inducible DDI2 promoter to control Gal4 expression in CEN.PK2-1C with Δgal80, a tight and graded cyanamide-inducible GAL system with an enhanced signal output was constructed. Subsequently, we demonstrated that the cyanamide-inducible GAL system was capable of tightly regulating the pentafunctional Aro1 protein to achieve conditional shikimate pathway activity. Taken together, the cyanamide-inducible GAL system could be implemented for both fundamental research and applied biotechnology.
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Affiliation(s)
- Jingya Song
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Fujian 361102, China
| | - Jian Fan
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Fujian 361102, China
| | - Cong Fan
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Fujian 361102, China
| | - Nike He
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Fujian 361102, China
| | - Xixi Ye
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Fujian 361102, China
| | - Mingfeng Cao
- College of Chemistry and Chemical Engineering, Xiamen University, Fujian 361005, China
| | - Jifeng Yuan
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Fujian 361102, China
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12
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Ku RH, Li LH, Liu YF, Hu EW, Lin YT, Lu HF, Yang TC. Implication of the σ E Regulon Members OmpO and σ N in the Δ ompA299-356-Mediated Decrease of Oxidative Stress Tolerance in Stenotrophomonas maltophilia. Microbiol Spectr 2023; 11:e0108023. [PMID: 37284772 PMCID: PMC10433810 DOI: 10.1128/spectrum.01080-23] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Accepted: 05/16/2023] [Indexed: 06/08/2023] Open
Abstract
Outer membrane protein A (OmpA) is the most abundant porin in bacterial outer membranes. KJΔOmpA299-356, an ompA C-terminal in-frame deletion mutant of Stenotrophomonas maltophilia KJ, exhibits pleiotropic defects, including decreased tolerance to menadione (MD)-mediated oxidative stress. Here, we elucidated the underlying mechanism of the decreased MD tolerance mediated by ΔompA299-356. The transcriptomes of wild-type S. maltophilia and the KJΔOmpA299-356 mutant strain were compared, focusing on 27 genes known to be associated with oxidative stress alleviation; however, no significant differences were identified. OmpO was the most downregulated gene in KJΔOmpA299-356. KJΔOmpA299-356 complementation with the chromosomally integrated ompO gene restored MD tolerance to the wild-type level, indicating the role of OmpO in MD tolerance. To further clarify the possible regulatory circuit involved in ompA defects and ompO downregulation, σ factor expression levels were examined based on the transcriptome results. The expression levels of three σ factors were significantly different (downregulated levels of rpoN and upregulated levels of rpoP and rpoE) in KJΔOmpA299-356. Next, the involvement of the three σ factors in the ΔompA299-356-mediated decrease in MD tolerance was evaluated using mutant strains and complementation assays. rpoN downregulation and rpoE upregulation contributed to the ΔompA299-356-mediated decrease in MD tolerance. OmpA C-terminal domain loss induced an envelope stress response. Activated σE decreased rpoN and ompO expression levels, in turn decreasing swimming motility and oxidative stress tolerance. Finally, we revealed both the ΔompA299-356-rpoE-ompO regulatory circuit and rpoE-rpoN cross regulation. IMPORTANCE The cell envelope is a morphological hallmark of Gram-negative bacteria. It consists of an inner membrane, a peptidoglycan layer, and an outer membrane. OmpA, an outer membrane protein, is characterized by an N-terminal β-barrel domain that is embedded in the outer membrane and a C-terminal globular domain that is suspended in the periplasmic space and connected to the peptidoglycan layer. OmpA is crucial for the maintenance of envelope integrity. Stress resulting from the destruction of envelope integrity is sensed by extracytoplasmic function (ECF) σ factors, which induce responses to various stressors. In this study, we revealed that loss of the OmpA-peptidoglycan (PG) interaction causes peptidoglycan and envelope stress while simultaneously upregulating σP and σE expression levels. The outcomes of σP and σE activation are different and are linked to β-lactam and oxidative stress tolerance, respectively. These findings establish that outer membrane proteins (OMPs) play a critical role in envelope integrity and stress tolerance.
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Affiliation(s)
- Ren-Hsuan Ku
- Department of Biotechnology and Laboratory Science in Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Li-Hua Li
- Department of Pathology and Laboratory Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
- School of Medical Laboratory Science and Biotechnology, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan
| | - Yi-Fu Liu
- Department of Biotechnology and Laboratory Science in Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - En-Wei Hu
- Department of Biotechnology and Laboratory Science in Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Yi-Tsung Lin
- Division of Infectious Diseases, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
- Department of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Hsu-Feng Lu
- Department of Medical Laboratory Science and Biotechnology, Asia University, Taichung, Taiwan
| | - Tsuey-Ching Yang
- Department of Biotechnology and Laboratory Science in Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan
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13
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Mauritzen JJ, Søndberg E, Kalatzis PG, Roager L, Gram L, Svenningsen SL, Middelboe M. Strain-specific quorum-sensing responses determine virulence properties in Vibrio anguillarum. Environ Microbiol 2023; 25:1344-1362. [PMID: 36807464 DOI: 10.1111/1462-2920.16356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Accepted: 02/16/2023] [Indexed: 02/23/2023]
Abstract
Bacterial populations communicate using quorum-sensing (QS) molecules and switch on QS regulation to engage in coordinated behaviour such as biofilm formation or virulence. The marine fish pathogen Vibrio anguillarum harbours several QS systems, and our understanding of its QS regulation is still fragmentary. Here, we identify the VanT-QS regulon and explore the diversity and trajectory of traits under QS regulation in Vibrio anguillarum through comparative transcriptomics of two wildtype strains and their corresponding mutants artificially locked in QS-on (ΔvanO) or QS-off (ΔvanT) states. Intriguingly, the two wildtype populations showed different QS responses to cell density changes and operated primarily in the QS-on and QS-off spectrum, respectively. Examining 27 V. anguillarum strains revealed that ~11% were QS-negative, and GFP-reporter measurements of nine QS-positive strains revealed a highly strain-specific nature of the QS responses. We showed that QS controls a plethora of genes involved in processes such as central metabolism, biofilm formation, competence, T6SS, and virulence properties in V. anguillarum, with large strain-specific differences. Moreover, we demonstrated that the QS state is an important driver of virulence towards fish larvae in one of two V. anguillarum strains. We speculate that infections by mixed-strain communities spanning diverse QS strategies optimize the infection efficiency of the pathogen.
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Affiliation(s)
- Jesper Juel Mauritzen
- Marine Biological Section, Department of Biology, University of Copenhagen, Helsingør, Denmark
| | - Emilie Søndberg
- Section for Biomolecular Sciences, Department of Biology, University of Copenhagen, Copenhagen N, Denmark
| | - Panos G Kalatzis
- Marine Biological Section, Department of Biology, University of Copenhagen, Helsingør, Denmark
| | - Line Roager
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Lone Gram
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Sine Lo Svenningsen
- Section for Biomolecular Sciences, Department of Biology, University of Copenhagen, Copenhagen N, Denmark
| | - Mathias Middelboe
- Marine Biological Section, Department of Biology, University of Copenhagen, Helsingør, Denmark
- Department of Biology, University of Southern Denmark, Odense, Denmark
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14
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Fitzgerald DM, Stringer AM, Smith C, Lapierre P, Wade JT. Genome-Wide Mapping of the Escherichia coli PhoB Regulon Reveals Many Transcriptionally Inert, Intragenic Binding Sites. mBio 2023; 14:e0253522. [PMID: 37067422 PMCID: PMC10294691 DOI: 10.1128/mbio.02535-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Accepted: 03/23/2023] [Indexed: 04/18/2023] Open
Abstract
Genome-scale analyses have revealed many transcription factor binding sites within, rather than upstream of, genes, raising questions as to the function of these binding sites. Here, we use complementary approaches to map the regulon of the Escherichia coli transcription factor PhoB, a response regulator that controls transcription of genes involved in phosphate homeostasis. Strikingly, the majority of PhoB binding sites are located within genes, but these intragenic sites are not associated with detectable transcription regulation and are not evolutionarily conserved. Many intragenic PhoB sites are located in regions bound by H-NS, likely due to shared sequence preferences of PhoB and H-NS. However, these PhoB binding sites are not associated with transcription regulation even in the absence of H-NS. We propose that for many transcription factors, including PhoB, binding sites not associated with promoter sequences are transcriptionally inert and hence are tolerated as genomic "noise." IMPORTANCE Recent studies have revealed large numbers of transcription factor binding sites within the genes of bacteria. The function, if any, of the vast majority of these binding sites has not been investigated. Here, we map the binding of the transcription factor PhoB across the Escherichia coli genome, revealing that the majority of PhoB binding sites are within genes. We show that PhoB binding sites within genes are not associated with regulation of the overlapping genes. Indeed, our data suggest that bacteria tolerate the presence of large numbers of nonregulatory, intragenic binding sites for transcription factors and that these binding sites are not under selective pressure.
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Affiliation(s)
- Devon M. Fitzgerald
- Wadsworth Center, New York State Department of Health, Albany, New York, USA
- Department of Biomedical Sciences, School of Public Health, University at Albany, Albany, New York, USA
| | - Anne M. Stringer
- Wadsworth Center, New York State Department of Health, Albany, New York, USA
| | - Carol Smith
- Wadsworth Center, New York State Department of Health, Albany, New York, USA
| | - Pascal Lapierre
- Wadsworth Center, New York State Department of Health, Albany, New York, USA
| | - Joseph T. Wade
- Wadsworth Center, New York State Department of Health, Albany, New York, USA
- Department of Biomedical Sciences, School of Public Health, University at Albany, Albany, New York, USA
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15
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Toraih EA, Ruiz E, Ning B, Tortelote GG, Hilliard S, Moroz K, Hu T, Fawzy MS, Kandil E. Chromatin-Accessible miRNA Regulons Driving Thyroid Tumorigenesis and Progression. J Am Coll Surg 2023; 236:732-750. [PMID: 36728308 DOI: 10.1097/xcs.0000000000000541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
BACKGROUND Although papillary thyroid cancer can remain indolent, associated lymph node metastases and recurrence rates are approximately 50% and 20%, respectively. Omics-based medicine has led to the discovery of predictive biomarkers that can be used to predict tumor progression and clinical outcomes. We aimed to develop a noninvasive omics-driven blood test to allow accurate risk stratification and help tailor individual patient treatment plans. STUDY DESIGN RNA sequencing (seq) and microRNA analysis of The Cancer Genome Atlas and Gene Expression Omnibus datasets were employed to identify an epigenetic prognostic panel. Integrated bulk assay for transposase-accessible chromatin-seq and RNA-seq experiments confirmed the results. Sixty-two paired tumor and adjacent control thyroid tissues and 67 blood samples (62 papillary thyroid cancer and 5 controls) were analyzed for validation using sequencing and real-time polymerase chain reaction and correlated to clinical outcomes. A liposome-exosome fusion clustered regularly interspaced short palindromic repeats (CRISPR)-fluorescent detection system miRNA assay was developed. A predictive risk nomogram was generated and tested for performance. RESULTS Our miRNA panel (miR-146b-5p and miR-221-3p) from tissue and blood was associated with aggressive features and was located within accessible chromatin regions. The miRNA risk score and prognostic nomogram showed higher accuracy in predicting lymph node metastases (miR-146b: area under the curve [AUC] 0.816, sensitivity 76.9%; miR-221: AUC 0.740, sensitivity 79.5%) and recurrence (miR-146b: AUC 0.921, sensitivity 75.0%; miR-221: AUC 0.756, sensitivity 70.0%; p < 0.001) than staging and American Thyroid Association risk stratification. CRISPR-based miRNA assays showed upregulation in the blood of cancer cohorts. CONCLUSIONS CRISPR-based detection of miR-146b and miR-221 in the blood of thyroid cancer patients is a reliable and noninvasive tool for real-time assessment and prognostication that has great potential to provide a direct impact on the care of these patients.
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Affiliation(s)
- Eman A Toraih
- From the Division of General Endocrine and Oncologic Surgery, Department of Surgery (Toraih, Kandil), Tulane University School of Medicine, New Orleans, LA
- the Medical Genetics Unit, Department of Histology and Cell Biology (Toraih); Department of Medical Biochemistry and Molecular Biology, Faculty of Medicine, and Suez Canal University, Ismailia, Egypt
| | - Emmanuelle Ruiz
- the Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA (Ruiz)
| | - Bo Ning
- Department of Biochemistry and Molecular Biology (Ning, Hu), Tulane University School of Medicine, New Orleans, LA
| | - Giovane G Tortelote
- Section of Pediatric Nephrology, Department of Pediatrics (Tortelote, Hilliard), Tulane University School of Medicine, New Orleans, LA
| | - Sylvia Hilliard
- Section of Pediatric Nephrology, Department of Pediatrics (Tortelote, Hilliard), Tulane University School of Medicine, New Orleans, LA
| | - Krzysztof Moroz
- Department of Pathology and Laboratory Medicine (Moroz), Tulane University School of Medicine, New Orleans, LA
| | - Tony Hu
- Department of Biochemistry and Molecular Biology (Ning, Hu), Tulane University School of Medicine, New Orleans, LA
| | - Manal S Fawzy
- the Department of Biochemistry, Faculty of Medicine, Northern Border University, Arar, Saudi Arabia (Fawzy)
| | - Emad Kandil
- From the Division of General Endocrine and Oncologic Surgery, Department of Surgery (Toraih, Kandil), Tulane University School of Medicine, New Orleans, LA
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16
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Simcox BS, Tomlinson BR, Shaw LN, Rohde KH. Mycobacterium abscessus DosRS two-component system controls a species-specific regulon required for adaptation to hypoxia. Front Cell Infect Microbiol 2023; 13:1144210. [PMID: 36968107 PMCID: PMC10034137 DOI: 10.3389/fcimb.2023.1144210] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Accepted: 02/15/2023] [Indexed: 03/12/2023] Open
Abstract
Mycobacterium abscessus (Mab), an emerging opportunistic pathogen, predominantly infects individuals with underlying pulmonary diseases such as cystic fibrosis (CF). Current treatment outcomes for Mab infections are poor due to Mab's inherent antibiotic resistance and unique host interactions that promote phenotypic tolerance and hinder drug access. The hypoxic, mucus-laden airways in the CF lung and antimicrobial phagosome within macrophages represent hostile niches Mab must overcome via alterations in gene expression for survival. Regulatory mechanisms important for the adaptation and long-term persistence of Mab within the host are poorly understood, warranting further genetic and transcriptomics study of this emerging pathogen. DosRS Mab , a two-component signaling system (TCS), is one proposed mechanism utilized to subvert host defenses and counteract environmental stress such as hypoxia. The homologous TCS of Mycobacterium tuberculosis (Mtb), DosRS Mtb , is known to induce a ~50 gene regulon in response to hypoxia, carbon monoxide (CO) and nitric oxide (NO) in vitro and in vivo. Previously, a small DosR Mab regulon was predicted using bioinformatics based on DosR Mtb motifs however, the role and regulon of DosRS Mab in Mab pathogenesis have yet to be characterized in depth. To address this knowledge gap, our lab generated a Mab dosRS knockout strain (MabΔdosRS) to investigate differential gene expression, and phenotype in an in vitro hypoxia model of dormancy. qRT-PCR and lux reporter assays demonstrate Mab_dosR and 6 predicted downstream genes are induced in hypoxia. In addition, RNAseq revealed induction of a much larger hypoxia response comprised of >1000 genes, including 127 differentially expressed genes in a dosRS mutant strain. Deletion of DosRS Mab led to attenuated growth under low oxygen conditions, a shift in morphotype from smooth to rough, and down-regulation of 216 genes. This study provides the first look at the global transcriptomic response of Mab to low oxygen conditions encountered in the airways of CF patients and within macrophage phagosomes. Our data also demonstrate the importance of DosRS Mab for adaptation of Mab to hypoxia, highlighting a distinct regulon (compared to Mtb) that is significantly larger than previously described, including both genes conserved across mycobacteria as well as Mab-specific genes.
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Affiliation(s)
- Breven S. Simcox
- Division of Immunology and Pathogenesis, Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL, United States
| | - Brooke R. Tomlinson
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, Tampa, FL, United States
| | - Lindsey N. Shaw
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, Tampa, FL, United States
| | - Kyle H. Rohde
- Division of Immunology and Pathogenesis, Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL, United States
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17
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Sun X, Yu J, Zhu C, Mo X, Sun Q, Yang D, Su C, Lu Y. Recognition of galactose by a scaffold protein recruits a transcriptional activator for the GAL regulon induction in Candida albicans. eLife 2023; 12:84155. [PMID: 36723430 PMCID: PMC9925049 DOI: 10.7554/elife.84155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Accepted: 01/31/2023] [Indexed: 02/02/2023] Open
Abstract
The GAL pathway of yeasts has long served as a model system for understanding of how regulatory mode of eukaryotic metabolic pathways evolves. While Gal4 mode has been well-characterized in Saccharomycetaceae clade, little is known about the regulation of the GAL pathway in other yeasts. Here, we find that Rep1, a Ndt80-like family transcription factor, serves as a galactose sensor in the commensal-pathogenic fungus Candida albicans. It is presented at the GAL gene promoters independent of the presence of galactose. Rep1 recognizes galactose via a direct physical interaction. The net result of this interaction is the recruitment of a transcriptional activator Cga1 (Candida galactose gene activator, orf19.4959) and transcription of the GAL genes proceeds. Rep1 and Cga1 are conserved across the CTG species. Rep1 itself does not possess transcriptional activity. Instead, it provides a scaffold to recruit different factors for transcriptional regulation. Rep1-Cga1 mode of regulation represents a new example of network rewiring in fungi, which provides insight into how C. albicans evolves transcriptional programs to colonize diverse host niches.
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Affiliation(s)
- Xun Sun
- College of Life Sciences, TaiKang Center for Life and Medical Sciences, Wuhan UniversityWuhanChina
| | - Jing Yu
- Hubei Key Laboratory of Cell Homeostasis, Wuhan UniversityWuhanChina
| | - Cheng Zhu
- Tianjin Key Laboratory of Function and Application of Biological Macromolecular Structures, Tianjin UniversityTianjinChina
| | - Xinreng Mo
- Hubei Key Laboratory of Cell Homeostasis, Wuhan UniversityWuhanChina
| | - Qiangqiang Sun
- Hubei Key Laboratory of Cell Homeostasis, Wuhan UniversityWuhanChina
| | - Dandan Yang
- College of Life Sciences, TaiKang Center for Life and Medical Sciences, Wuhan UniversityWuhanChina
| | - Chang Su
- Hubei Key Laboratory of Cell Homeostasis, Wuhan UniversityWuhanChina
| | - Yang Lu
- College of Life Sciences, TaiKang Center for Life and Medical Sciences, Wuhan UniversityWuhanChina
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18
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Van Riet S, Tadesse W, Mortier J, Schlegel S, Simoens K, Bernaerts K, Dal Co A, Aertsen A. Heterogeneity and Evolutionary Tunability of Escherichia coli Resistance against Extreme Acid Stress. Microbiol Spectr 2022; 10:e0375722. [PMID: 36453903 PMCID: PMC9769608 DOI: 10.1128/spectrum.03757-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Accepted: 10/27/2022] [Indexed: 12/05/2022] Open
Abstract
Since acidic environments often serve as an important line of defense against bacterial pathogens, it is important to fully understand how the latter manage to mount and evolve acid resistance mechanisms. Escherichia coli, a species harboring many pathovars, is typically equipped with the acid fitness island (AFI), a genomic region encoding the GadE master regulator together with several GadE-controlled functions to counter acid stress. This study reveals that gadE and consequently AFI functions are heterogeneously expressed even in the absence of any prior acid stress, thereby preemptively creating acid-resistant subpopulations within a clonal E. coli population. Directed evolution efforts selecting for modulated gadE expression confirm that a gain-of-function mutation in the EvgS sensor kinase can constitutively upregulate gadE expression and concomitant acid resistance. However, we reveal that such upregulation of EvgS also causes cross-resistance to heat stress because of SafA-mediated cross-activation of the PhoPQ regulon. Surprisingly, loss of function of the serC gene (encoding phosphoserine/phosphohydroxythreonine aminotransferase) can also significantly upregulate gadE expression, acid resistance, and heat cross-resistance, although via a currently cryptic mechanism. As such, our data reveal a noisy expression of gadE in E. coli that is functional for the survival of sudden acid stress and that can readily be genetically tuned. IMPORTANCE Acidic environments constitute one of the most important stresses for enteric bacteria and can be encountered in both natural (e.g., host gastrointestinal tract) and manmade (e.g., food processing) environments. The enteric species Escherichia coli harbors many pathovars and is well known for its ability to cope with acid stress. In this study, we uncover that E. coli's acid fitness island (AFI), a genomic region that encodes important functions to deal with acid stress, is by default expressed in a heterogeneous manner. In fact, using microfluidics-based single-cell approaches, we further demonstrate that this heterogeneity preemptively creates a clonal subpopulation that is much better equipped to survive a sudden acid shock. In addition, we reveal that environments with recurring acid stress can readily select for mutants displaying a higher fraction of AFI-expressing cells. These new insights are important to properly understand and anticipate the survival characteristics of E. coli.
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Affiliation(s)
- Stefanie Van Riet
- Department of Molecular and Microbial Systems, KU Leuven, Leuven, Belgium
| | - Wubishet Tadesse
- Department of Molecular and Microbial Systems, KU Leuven, Leuven, Belgium
| | - Julien Mortier
- Department of Molecular and Microbial Systems, KU Leuven, Leuven, Belgium
| | - Susan Schlegel
- Department of Environmental Microbiology, Eawag, Dübendorf, Switzerland
- Department of Environmental Systems Science, ETH Zurich, Zurich, Switzerland
| | - Kenneth Simoens
- Department of Chemical Engineering, KU Leuven, Leuven, Belgium
| | | | - Alma Dal Co
- Department of Environmental Microbiology, Eawag, Dübendorf, Switzerland
- Department of Environmental Systems Science, ETH Zurich, Zurich, Switzerland
| | - Abram Aertsen
- Department of Molecular and Microbial Systems, KU Leuven, Leuven, Belgium
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19
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Kendrick R, Chotewutmontri P, Belcher S, Barkan A. Correlated retrograde and developmental regulons implicate multiple retrograde signals as coordinators of chloroplast development in maize. Plant Cell 2022; 34:4897-4919. [PMID: 36073948 PMCID: PMC9709983 DOI: 10.1093/plcell/koac276] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 09/02/2022] [Indexed: 05/09/2023]
Abstract
Signals emanating from chloroplasts influence nuclear gene expression, but roles of retrograde signals during chloroplast development are unclear. To address this gap, we analyzed transcriptomes of non-photosynthetic maize mutants and compared them to transcriptomes of stages of normal leaf development. The transcriptomes of two albino mutants lacking plastid ribosomes resembled transcriptomes at very early stages of normal leaf development, whereas the transcriptomes of two chlorotic mutants with thylakoid targeting or plastid transcription defects resembled those at a slightly later stage. We identified ∼2,700 differentially expressed genes, which fall into six major categories based on the polarity and mutant-specificity of the change. Downregulated genes were generally expressed late in normal development and were enriched in photosynthesis genes, whereas upregulated genes act early and were enriched for functions in chloroplast biogenesis and cytosolic translation. We showed further that target-of-rapamycin (TOR) signaling was elevated in mutants lacking plastid ribosomes and declined in concert with plastid ribosome buildup during normal leaf development. Our results implicate three plastid signals as coordinators of photosynthetic differentiation. One signal requires plastid ribosomes and activates photosynthesis genes. A second signal reflects attainment of chloroplast maturity and represses chloroplast biogenesis genes. A third signal, the consumption of nutrients by developing chloroplasts, represses TOR, promoting termination of cell proliferation during leaf development.
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Affiliation(s)
- Rennie Kendrick
- Institute of Molecular Biology, University of Oregon, Eugene, Oregon 97403, USA
| | | | - Susan Belcher
- Institute of Molecular Biology, University of Oregon, Eugene, Oregon 97403, USA
| | - Alice Barkan
- Institute of Molecular Biology, University of Oregon, Eugene, Oregon 97403, USA
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20
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Crosby JR, Laemthong T, Bing RG, Zhang K, Tanwee TNN, Lipscomb GL, Rodionov DA, Zhang Y, Adams MWW, Kelly RM. Biochemical and Regulatory Analyses of Xylanolytic Regulons in Caldicellulosiruptor bescii Reveal Genus-Wide Features of Hemicellulose Utilization. Appl Environ Microbiol 2022; 88:e0130222. [PMID: 36218355 PMCID: PMC9642015 DOI: 10.1128/aem.01302-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Accepted: 09/19/2022] [Indexed: 11/20/2022] Open
Abstract
Caldicellulosiruptor species scavenge carbohydrates from runoff containing plant biomass that enters hot springs and from grasses that grow in more moderate parts of thermal features. While only a few Caldicellulosiruptor species can degrade cellulose, all known species are hemicellulolytic. The most well-characterized species, Caldicellulosiruptor bescii, decentralizes its hemicellulase inventory across five different genomic loci and two isolated genes. Transcriptomic analyses, comparative genomics, and enzymatic characterization were utilized to assign functional roles and determine the relative importance of its six putative endoxylanases (five glycoside hydrolase family 10 [GH10] enzymes and one GH11 enzyme) and two putative exoxylanases (one GH39 and one GH3) in C. bescii. Two genus-wide conserved xylanases, C. bescii XynA (GH10) and C. bescii Xyl3A (GH3), had the highest levels of sugar release on oat spelt xylan, were in the top 10% of all genes transcribed by C. bescii, and were highly induced on xylan compared to cellulose. This indicates that a minimal set of enzymes are used to drive xylan degradation in the genus Caldicellulosiruptor, complemented by hemicellulolytic inventories that are tuned to specific forms of hemicellulose in available plant biomasses. To this point, synergism studies revealed that the pairing of specific GH family proteins (GH3, -11, and -39) with C. bescii GH10 proteins released more sugar in vitro than mixtures containing five different GH10 proteins. Overall, this work demonstrates the essential requirements for Caldicellulosiruptor to degrade various forms of xylan and the differences in species genomic inventories that are tuned for survival in unique biotopes with variable lignocellulosic substrates. IMPORTANCE Microbial deconstruction of lignocellulose for the production of biofuels and chemicals requires the hydrolysis of heterogeneous hemicelluloses to access the microcrystalline cellulose portion. This work extends previous in vivo and in vitro efforts to characterize hemicellulose utilization by integrating genomic reconstruction, transcriptomic data, operon structures, and biochemical characteristics of key enzymes to understand the deployment and functionality of hemicellulases by the extreme thermophile Caldicellulosiruptor bescii. Furthermore, comparative genomics of the genus revealed both conserved and divergent mechanisms for hemicellulose utilization across the 15 sequenced species, thereby paving the way to connecting functional enzyme characterization with metabolic engineering efforts to enhance lignocellulose conversion.
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Affiliation(s)
- James R. Crosby
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina, USA
| | - Tunyaboon Laemthong
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina, USA
| | - Ryan G. Bing
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina, USA
| | - Ke Zhang
- Department of Cell and Molecular Biology, College of the Environmental and Life Sciences, University of Rhode Island, Kinston, Rhode Island, USA
| | - Tania N. N. Tanwee
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia, USA
| | - Gina L. Lipscomb
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia, USA
| | - Dmitry A. Rodionov
- Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California, USA
| | - Ying Zhang
- Department of Cell and Molecular Biology, College of the Environmental and Life Sciences, University of Rhode Island, Kinston, Rhode Island, USA
| | - Michael W. W. Adams
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia, USA
| | - Robert M. Kelly
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina, USA
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21
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Bredel M, Kim H, Bonner JA. An ErbB Lineage Co- Regulon Harbors Potentially Co-Druggable Targets for Multimodal Precision Therapy in Head and Neck Squamous Cell Carcinoma. Int J Mol Sci 2022; 23:ijms232113497. [PMID: 36362284 PMCID: PMC9658814 DOI: 10.3390/ijms232113497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Revised: 10/26/2022] [Accepted: 10/26/2022] [Indexed: 11/06/2022] Open
Abstract
The ErbB lineage of oncogenic receptor tyrosine kinases is frequently overexpressed in head and neck squamous cell carcinomas. A common co-regulon triggered by the ErbB proteins; involving shared signaling circuitries; may harbor co-druggable targets or response biomarkers for potential future multimodal precision therapy in ErbB-driven head and neck squamous cell carcinoma. We here present a cohort-based; genome-wide analysis of 488 head and neck squamous cell carcinomas curated as part of The Cancer Genome Atlas Project to characterize genes that are significantly positively co-regulated with the four ErbB proteins and those that are shared among all ErbBs denoting a common ErbB co-regulon. Significant positive gene correlations involved hundreds of genes that were co-expressed with the four ErbB family members (q < 0.05). A common; overlapping co-regulon consisted of a core set of 268 genes that were uniformly co-regulated with all four ErbB genes and highly enriched for functions in chromatin organization and histone modifications. This high-priority set of genes contained ten putative antineoplastic drug-gene interactions. The nature and directionality of these ten drug-gene associations was an inhibiting interaction for seven (PIK3CB; PIK3C2B; HDAC4; FRK; PRKCE; EPHA4; and DYRK1A) of them in which the drug decreases the biological activity or expression of the gene target. For three (CHD4; ARID1A; and PBRM1) of the associations; the directionality of the interaction was such that the gene predicted sensitivit y to the drug suggesting utility as potential response biomarkers. Drug-gene interactions that predicted the gene product to be reduced by the drug included a variety of potential targeted molecular agent classes. This unbiased genome-wide analysis identified a target-rich environment for multimodal therapeutic approaches in tumors that are putatively ErbB-driven. The results of this study require preclinical validation before ultimately devising lines of combinatorial treatment strategies for ErbB-dependent head and neck squamous cell carcinomas that incorporate these findings.
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Affiliation(s)
- Markus Bredel
- Department of Radiation Oncology, O’Neal Comprehensive Cancer Center, Heersink School of Medicine, The University of Alabama at Birmingham, Birmingham, AL 35294, USA
- Correspondence: (M.B.); (J.A.B.)
| | - Hyunsoo Kim
- Lineberger Comprehensive Cancer Center, University of Northern Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - James A. Bonner
- Department of Radiation Oncology, O’Neal Comprehensive Cancer Center, Heersink School of Medicine, The University of Alabama at Birmingham, Birmingham, AL 35294, USA
- Correspondence: (M.B.); (J.A.B.)
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22
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Bhatt P, Sharma M, Prakash Sharma P, Rathi B, Sharma S. Mycobacterium tuberculosis dormancy regulon proteins Rv2627c and Rv2628 as Toll like receptor agonist and as potential adjuvant. Int Immunopharmacol 2022; 112:109238. [PMID: 36116151 DOI: 10.1016/j.intimp.2022.109238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2022] [Revised: 09/02/2022] [Accepted: 09/05/2022] [Indexed: 11/19/2022]
Abstract
During latency, DosR proteins of Mycobacterium tuberculosis (M.tb) get activated and help the bacterium to remain dormant. We have shown earlier that 2 such proteins Rv2627c and Rv2628 are immunogenic and induce a TH1 kind of immune response. In this study, through in-vitro experiments we have confirmed that Rv2627c and Rv2628 proteins act as protein Toll-Like Receptor (TLR) agonist-adjuvant. Rv2627c and Rv2628 stimulated THP-1 macrophages showed an increased expression of TLR2, TLR4 and co-stimulatory molecules CD40, CD80, CD86 and antigen presenting molecule HLA-DR. Further studies also found enhanced expression of downstream signaling molecules of TLR activation like MyD88, NF-κB-p65 and pro-inflammatory cytokines. Inhibition studies using TLR blocking antibodies decreased the expression of co-stimulatory molecules, MyD88, NF-κB-p65, and pro-inflammatory cytokines. Rv2627c and Rv2628 stimulation of HEK-TLR2 reporter cell line confirmed the interaction of these proteins with TLR2. Moreover, molecular docking and simulations of Rv2627c and Rv2628 proteins with TLR2 and TLR4 showed stable interactions. The adjuvant activity of Rv2628 was further validated by a protein adjuvanted with pre-clinically validated peptides as multi-epitope vaccine construct which showed good binding with TLR2 and TLR4 and activate dendritic cells and induce sustained pro-inflammatory cytokine response by C-ImmSim analysis. We propose that our vaccine construct will produce a better immune response than BCG and can be taken up as a post-exposure therapeutic subunit vaccine along with standard TB therapy. We also anticipate that our construct can be taken up as a protein adjuvant with other vaccine candidates as these can activate macrophages through TLR signaling.
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Affiliation(s)
- Parul Bhatt
- DSKC BioDiscovery Lab, Department of Zoology, Miranda House, University of Delhi, Delhi 110007, India.
| | - Monika Sharma
- DSKC BioDiscovery Lab, Department of Zoology, Miranda House, University of Delhi, Delhi 110007, India
| | - Prem Prakash Sharma
- Laboratory for Translational Chemistry and Drug Discovery, Department of Chemistry, Hansraj College, University of Delhi, Delhi 110007, India
| | - Brijesh Rathi
- Laboratory for Translational Chemistry and Drug Discovery, Department of Chemistry, Hansraj College, University of Delhi, Delhi 110007, India
| | - Sadhna Sharma
- DSKC BioDiscovery Lab, Department of Zoology, Miranda House, University of Delhi, Delhi 110007, India.
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23
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Abdelhamed H, Ramachandran R, Narayanan L, Islam S, Ozan O, Freitag N, Lawrence ML. Role of FruR transcriptional regulator in virulence of Listeria monocytogenes and identification of its regulon. PLoS One 2022; 17:e0274005. [PMID: 36054213 PMCID: PMC9439231 DOI: 10.1371/journal.pone.0274005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Accepted: 08/19/2022] [Indexed: 11/29/2022] Open
Abstract
Listeria monocytogenes is a ubiquitous opportunistic foodborne pathogen capable of survival in various adverse environmental conditions. Pathogenesis of L. monocytogenes is tightly controlled by a complex regulatory network of transcriptional regulators that are necessary for survival and adaptations to harsh environmental conditions both inside and outside host cells. Among these regulatory pathways are members of the DeoR-family transcriptional regulators that are known to play a regulatory role in sugar metabolism. In this study, we deciphered the role of FruR, a DeoR family protein, which is a fructose operon transcriptional repressor protein, in L. monocytogenes pathogenesis and growth. Following intravenous (IV) inoculation in mice, a mutant strain with deletion of fruR exhibited a significant reduction in bacterial burden in liver and spleen tissues compared to the parent strain. Further, the ΔfruR strain had a defect in cell-to-cell spread in L2 fibroblast monolayers. Constitutive activation of PrfA, a pleiotropic activator of L. monocytogenes virulence factors, did not restore virulence to the ΔfruR strain, suggesting that the attenuation was not a result of impaired PrfA activation. Transcriptome analysis revealed that FruR functions as a positive regulator for genes encoding enzymes involved in the pentose phosphate pathway (PPP) and as a repressor for genes encoding enzymes in the glycolysis pathway. These results suggested that FruR may function to facilitate NADPH regeneration, which is necessary for full protection from oxidative stress. Interestingly, deletion of fruR increased sensitivity of L. monocytogenes to H2O2, confirming a role for FruR in survival of L. monocytogenes during oxidative stress. Using anti-mouse neutrophil/monocyte monoclonal antibody RB6-8C5 (RB6) in an in vivo infection model, we found that FruR has a specific function in protecting L. monocytogenes from neutrophil/monocyte-mediated killing. Overall, this work clarifies the role of FruR in controlling L. monocytogenes carbon flow between glycolysis and PPP for NADPH homeostasis, which provides a new mechanism allowing metabolic adaptation of L. monocytogenes to oxidative stress.
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Affiliation(s)
- Hossam Abdelhamed
- Department of Comparative Biomedical Sciences, College of Veterinary Medicine, Mississippi State University, Starkville, MS, United States of America
- * E-mail:
| | - Reshma Ramachandran
- Department of Comparative Biomedical Sciences, College of Veterinary Medicine, Mississippi State University, Starkville, MS, United States of America
- Department of Poultry Science, Mississippi State University, Starkville, MS, United States of America
| | - Lakshmi Narayanan
- Department of Comparative Biomedical Sciences, College of Veterinary Medicine, Mississippi State University, Starkville, MS, United States of America
| | - Shamima Islam
- Department of Comparative Biomedical Sciences, College of Veterinary Medicine, Mississippi State University, Starkville, MS, United States of America
| | - Ozdemir Ozan
- Department of Comparative Biomedical Sciences, College of Veterinary Medicine, Mississippi State University, Starkville, MS, United States of America
| | - Nancy Freitag
- Department of Pharmaceutical Sciences, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Mark L. Lawrence
- Department of Comparative Biomedical Sciences, College of Veterinary Medicine, Mississippi State University, Starkville, MS, United States of America
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24
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Letizia M, Mellini M, Fortuna A, Visca P, Imperi F, Leoni L, Rampioni G. PqsE Expands and Differentially Modulates the RhlR Quorum Sensing Regulon in Pseudomonas aeruginosa. Microbiol Spectr 2022; 10:e0096122. [PMID: 35604161 PMCID: PMC9241726 DOI: 10.1128/spectrum.00961-22] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 05/02/2022] [Indexed: 12/22/2022] Open
Abstract
In the opportunistic pathogen Pseudomonas aeruginosa, many virulence traits are finely regulated by quorum sensing (QS), an intercellular communication system that allows the cells of a population to coordinate gene expression in response to cell density. The key aspects underlying the functionality of the complex regulatory network governing QS in P. aeruginosa are still poorly understood, including the interplay between the effector protein PqsE and the transcriptional regulator RhlR in controlling the QS regulon. Different studies have focused on the characterization of PqsE- and RhlR-controlled genes in genetic backgrounds in which RhlR activity can be modulated by PqsE and pqsE expression is controlled by RhlR, thus hampering identification of the distinct regulons controlled by PqsE and RhlR. In this study, a P. aeruginosa PAO1 mutant strain with deletion of multiple QS elements and inducible expression of pqsE and/or rhlR was generated and validated. Transcriptomic analyses performed on this genetic background allowed us to unambiguously define the regulons controlled by PqsE and RhlR when produced alone or in combination. Transcriptomic data were validated via reverse transcription-quantitative PCR (RT-qPCR) and transcriptional fusions. Overall, our results showed that PqsE has a negligible effect on the P. aeruginosa transcriptome in the absence of RhlR, and that multiple RhlR subregulons exist with distinct dependency on PqsE. Overall, this study contributes to untangling the regulatory link between the pqs and rhl QS systems mediated by PqsE and RhlR and clarifying the impact of these QS elements on the P. aeruginosa transcriptome. IMPORTANCE The ability of Pseudomonas aeruginosa to cause difficult-to-treat infections relies on its capacity to fine-tune the expression of multiple virulence traits via the las, rhl, and pqs QS systems. Both the pqs effector protein PqsE and the rhl transcriptional regulator RhlR are required for full production of key virulence factors in vitro and pathogenicity in vivo. While it is known that PqsE can stimulate the ability of RhlR to control some virulence factors, no data are available to allow clear discrimination of the PqsE and RhlR regulons. The data produced in this study demonstrate that PqsE mainly impacts the P. aeruginosa transcriptome via an RhlR-dependent pathway and splits the RhlR regulon into PqsE-dependent and PqsE-independent subregulons. Besides contributing to untangling of the complex QS network of P. aeruginosa, our data confirm that both PqsE and RhlR are suitable targets for the development of antivirulence drugs.
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Affiliation(s)
| | - Marta Mellini
- Department of Science, Roma Tre University, Rome, Italy
| | | | - Paolo Visca
- Department of Science, Roma Tre University, Rome, Italy
- IRCCS Fondazione Santa Lucia, Rome, Italy
| | - Francesco Imperi
- Department of Science, Roma Tre University, Rome, Italy
- IRCCS Fondazione Santa Lucia, Rome, Italy
| | - Livia Leoni
- Department of Science, Roma Tre University, Rome, Italy
| | - Giordano Rampioni
- Department of Science, Roma Tre University, Rome, Italy
- IRCCS Fondazione Santa Lucia, Rome, Italy
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25
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Sevalkar RR, Glasgow JN, Pettinati M, Marti MA, Reddy VP, Basu S, Alipour E, Kim-Shapiro DB, Estrin DA, Lancaster JR, Steyn AJC. Mycobacterium tuberculosis DosS binds H 2S through its Fe 3+ heme iron to regulate the DosR dormancy regulon. Redox Biol 2022; 52:102316. [PMID: 35489241 PMCID: PMC9062744 DOI: 10.1016/j.redox.2022.102316] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 04/06/2022] [Accepted: 04/16/2022] [Indexed: 01/14/2023] Open
Abstract
Mycobacterium tuberculosis (Mtb) senses and responds to host-derived gasotransmitters NO and CO via heme-containing sensor kinases DosS and DosT and the response regulator DosR. Hydrogen sulfide (H2S) is an important signaling molecule in mammals, but its role in Mtb physiology is unclear. We have previously shown that exogenous H2S can modulate expression of genes in the Dos dormancy regulon via an unknown mechanism(s). Here, we test the hypothesis that Mtb senses and responds to H2S via the DosS/T/R system. Using UV-Vis and EPR spectroscopy, we show that H2S binds directly to the ferric (Fe3+) heme of DosS (KDapp = 5.30 μM) but not the ferrous (Fe2+) form. No interaction with DosT(Fe2+-O2) was detected. We found that the binding of sulfide can slowly reduce the DosS heme iron to the ferrous form. Steered Molecular Dynamics simulations show that H2S, and not the charged HS- species, can enter the DosS heme pocket. We also show that H2S increases DosS autokinase activity and subsequent phosphorylation of DosR, and H2S-mediated increases in Dos regulon gene expression is lost in Mtb lacking DosS. Finally, we demonstrate that physiological levels of H2S in macrophages can induce DosR regulon genes via DosS. Overall, these data reveal a novel mechanism whereby Mtb senses and responds to a third host gasotransmitter, H2S, via DosS(Fe3+). These findings highlight the remarkable plasticity of DosS and establish a new paradigm for how bacteria can sense multiple gasotransmitters through a single heme sensor kinase.
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Affiliation(s)
- Ritesh R Sevalkar
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Joel N Glasgow
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, USA.
| | - Martín Pettinati
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Química Inorgánica, Analítica y Química Física, Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires, Instituto de Química Física de los Materiales, Medio Ambiente y Energía (INQUIMAE), Buenos Aires, Argentina
| | - Marcelo A Marti
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Química Biológica, Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires, Instituto de Química Biológica (IQUIBICEN), Buenos Aires, Argentina
| | - Vineel P Reddy
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Swati Basu
- Department of Physics, Wake Forest University, Winston-Salem, NC, USA
| | - Elmira Alipour
- Department of Physics, Wake Forest University, Winston-Salem, NC, USA
| | | | - Dario A Estrin
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Química Inorgánica, Analítica y Química Física, Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires, Instituto de Química Física de los Materiales, Medio Ambiente y Energía (INQUIMAE), Buenos Aires, Argentina
| | - Jack R Lancaster
- Department of Pharmacology & Chemical Biology, Vascular Medicine Institute, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Adrie J C Steyn
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, USA; Centers for AIDS Research and Free Radical Biology, University of Alabama at Birmingham, Birmingham, AL, USA; Africa Health Research Institute, University of KwaZulu-Natal, Durban, South Africa.
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26
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Cai Z, Yang F, Shao X, Yue Z, Li Z, Song Y, Pan X, Jin Y, Cheng Z, Ha UH, Feng J, Yang L, Deng X, Wu W, Bai F. ECF Sigma Factor HxuI Is Critical for In Vivo Fitness of Pseudomonas aeruginosa during Infection. Microbiol Spectr 2022; 10:e0162021. [PMID: 35044199 PMCID: PMC8768829 DOI: 10.1128/spectrum.01620-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Accepted: 01/04/2022] [Indexed: 11/22/2022] Open
Abstract
The opportunistic pathogen Pseudomonas aeruginosa often adapts to its host environment and causes recurrent nosocomial infections. The extracytoplasmic function (ECF) sigma factor enables bacteria to alter their gene expression in response to host environmental stimuli. Here, we report an ECF sigma factor, HxuI, which is rapidly induced once P. aeruginosa encounters the host. Host stresses such as iron limitation, oxidative stress, low oxygen, and nitric oxide induce the expression of hxuI. By combining RNA-seq and promoter-lacZ reporter fusion analysis, we reveal that HxuI can activate the expression of diverse metabolic and virulence pathways which are critical to P. aeruginosa infections, including iron acquisition, denitrification, pyocyanin synthesis, and bacteriocin production. Most importantly, overexpression of the hxuI in the laboratory strain PAO1 promotes its colonization in both murine lung and subcutaneous infections. Together, our findings show that HxuI, a key player in host stress-response, controls the in vivo adaptability and virulence of P. aeruginosa during infection. IMPORTANCE P. aeruginosa has a strong ability to adapt to diverse environments, making it capable of causing recurrent and multisite infections in clinics. Understanding host adaptive mechanisms plays an important guiding role in the development of new anti-infective agents. Here, we demonstrate that an ECFσ factor of P. aeruginosa response to the host-inflicted stresses, which promotes the bacterial in vivo fitness and pathogenicity. Furthermore, our findings may help explain the emergence of highly transmissible strains of P. aeruginosa and the acute exacerbations during chronic infections.
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Affiliation(s)
- Zeqiong Cai
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, College of Life Sciences, Nankai University, Tianjin, China
| | - Fan Yang
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, College of Life Sciences, Nankai University, Tianjin, China
| | - Xiaolong Shao
- Department of Biomedical Sciences, City University of Hong Kong, Kowloon Tong, Hong Kong SAR, China
| | - Zhuo Yue
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, College of Life Sciences, Nankai University, Tianjin, China
| | - Zhenpeng Li
- School of Laboratory Medicine, Key Laboratory of Clinical Laboratory Diagnostics in Universities of Shandong, Weifang Medical University, Weifang, Shandong, China
| | - Yuqin Song
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Xiaolei Pan
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, College of Life Sciences, Nankai University, Tianjin, China
| | - Yongxin Jin
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, College of Life Sciences, Nankai University, Tianjin, China
| | - Zhihui Cheng
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, College of Life Sciences, Nankai University, Tianjin, China
| | - Un-Hwan Ha
- Department of Biotechnology and Bioinformatics, Korea University, Sejong, Republic of Korea
| | - Jie Feng
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Liang Yang
- School of Medicine, Southern University of Science and Technology (SUSTec), Shenzhen, China
| | - Xin Deng
- Department of Biomedical Sciences, City University of Hong Kong, Kowloon Tong, Hong Kong SAR, China
| | - Weihui Wu
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, College of Life Sciences, Nankai University, Tianjin, China
| | - Fang Bai
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, College of Life Sciences, Nankai University, Tianjin, China
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27
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Pais P, Oliveira J, Viana R, Costa IV, Sá-Correia I, Monteiro PT, Teixeira MC. Prediction of Gene and Genomic Regulation in Candida Species, Using the PathoYeastract Database: A Comparative Genomics Approach. Methods Mol Biol 2022; 2477:419-437. [PMID: 35524130 DOI: 10.1007/978-1-0716-2257-5_23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The ability of living organisms to survive changing environmental conditions is dependent on the implementation of gene expression programs underlying adaptation and fitness. Transcriptional networks can be exceptionally complex: a single transcription factor (TF) may regulate hundreds of genes, and multiple TFs may regulate a single gene-depending on the environmental conditions. Moreover, the same TF may act as an activator or repressor in distinct conditions. In turn, the activity of regulators themselves may be dependent on other TFs, as well as posttranscriptional and posttranslational regulation. These traits greatly contribute to the intricate networks governing gene expression programs.In this chapter, a step-by-step guide of how to use PathoYeastract, one of several interconnecting databases within the YEASTRACT+ portal, to predict gene and genomic regulation in Candida spp. is provided. PathoYeastract contains a set of analysis tools to study regulatory associations in human pathogenic yeasts, enabling: (1) the prediction and ranking of TFs that contribute to the regulation of individual genes; (2) the prediction of the genes regulated by a given TF; and (3) the prediction and ranking of TFs that regulate a genome-wide transcriptional response. These capabilities are illustrated, respectively, with the analysis of: (1) the TF network controlling the C. glabrata QDR2 gene; (2) the regulon controlled by the C. glabrata TF Rpn4; and (3) the regulatory network controlling the C. glabrata transcriptome-wide changes induced upon exposure to the antifungal drug fluconazole. The newest potentialities of this information system are explored, including cross-species network comparison. The results are discussed considering the performed queries and integrated with the current knowledge on the biological data for each case-study.
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Affiliation(s)
- Pedro Pais
- iBB-Institute for Bioengineering and Biosciences, Biological Sciences Research Group, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
- Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
| | - Jorge Oliveira
- INESC-ID, Knowledge Discovery and Bioinformatics Group, Lisbon, Portugal
- Department of Computer Science and Engineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
| | - Romeu Viana
- iBB-Institute for Bioengineering and Biosciences, Biological Sciences Research Group, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
- Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
| | - Inês V Costa
- iBB-Institute for Bioengineering and Biosciences, Biological Sciences Research Group, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
- Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
| | - Isabel Sá-Correia
- iBB-Institute for Bioengineering and Biosciences, Biological Sciences Research Group, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
- Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
| | - Pedro T Monteiro
- INESC-ID, Knowledge Discovery and Bioinformatics Group, Lisbon, Portugal
- Department of Computer Science and Engineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
| | - Miguel C Teixeira
- iBB-Institute for Bioengineering and Biosciences, Biological Sciences Research Group, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal.
- Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal.
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Płachetka M, Krawiec M, Zakrzewska-Czerwińska J, Wolański M. AdpA Positively Regulates Morphological Differentiation and Chloramphenicol Biosynthesis in Streptomyces venezuelae. Microbiol Spectr 2021; 9:e0198121. [PMID: 34878326 PMCID: PMC8653842 DOI: 10.1128/spectrum.01981-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Accepted: 10/29/2021] [Indexed: 11/22/2022] Open
Abstract
In members of genus Streptomyces, AdpA is a master transcriptional regulator that controls the expression of hundreds of genes involved in morphological differentiation, secondary metabolite biosynthesis, chromosome replication, etc. However, the function of AdpASv, an AdpA ortholog of Streptomyces venezuelae, is unknown. This bacterial species is a natural producer of chloramphenicol and has recently become a model organism for studies on Streptomyces. Here, we demonstrate that AdpASv is essential for differentiation and antibiotic biosynthesis in S. venezuelae and provide evidence suggesting that AdpASv positively regulates its own gene expression. We speculate that the different modes of AdpA-dependent transcriptional autoregulation observed in S. venezuelae and other Streptomyces species reflect the arrangement of AdpA binding sites in relation to the transcription start site. Lastly, we present preliminary data suggesting that AdpA may undergo a proteolytic processing and we speculate that this may potentially constitute a novel regulatory mechanism controlling cellular abundance of AdpA in Streptomyces. IMPORTANCEStreptomyces are well-known producers of valuable secondary metabolites which include a large variety of antibiotics and important model organisms for developmental studies in multicellular bacteria. The conserved transcriptional regulator AdpA of Streptomyces exerts a pleiotropic effect on cellular processes, including the morphological differentiation and biosynthesis of secondary metabolites. Despite extensive studies, the function of AdpA in these processes remains elusive. This work provides insights into the role of a yet unstudied AdpA ortholog of Streptomyces venezuelae, now considered a novel model organism. We found that AdpA plays essential role in morphological differentiation and biosynthesis of chloramphenicol, a broad-spectrum antibiotic. We also propose that AdpA may undergo a proteolytic processing that presumably constitutes a novel mechanism regulating cellular abundance of this master regulator.
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Affiliation(s)
| | - Michał Krawiec
- Faculty of Biotechnology, University of Wrocław, Wrocław, Poland
| | | | - Marcin Wolański
- Faculty of Biotechnology, University of Wrocław, Wrocław, Poland
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Van Loi V, Busche T, Fritsch VN, Weise C, Gruhlke MCH, Slusarenko AJ, Kalinowski J, Antelmann H. The two-Cys-type TetR repressor GbaA confers resistance under disulfide and electrophile stress in Staphylococcus aureus. Free Radic Biol Med 2021; 177:120-131. [PMID: 34678418 PMCID: PMC8693949 DOI: 10.1016/j.freeradbiomed.2021.10.024] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2021] [Revised: 10/15/2021] [Accepted: 10/18/2021] [Indexed: 12/12/2022]
Abstract
Staphylococcus aureus has to cope with oxidative and electrophile stress during host-pathogen interactions. The TetR-family repressor GbaA was shown to sense electrophiles, such as N-ethylmaleimide (NEM) via monothiol mechanisms of the two conserved Cys55 or Cys104 residues in vitro. In this study, we further investigated the regulation and function of the GbaA repressor and its Cys residues in S. aureus COL. The GbaA-controlled gbaAB-SACOL2595-97 and SACOL2592-nmrA-2590 operons were shown to respond only weakly 3-10-fold to oxidants, electrophiles or antibiotics in S. aureus COL, but are 57-734-fold derepressed in the gbaA deletion mutant, indicating that the physiological inducer is still unknown. Moreover, the gbaA mutant remained responsive to disulfide and electrophile stress, pointing to additional redox control mechanisms of both operons. Thiol-stress induction of the GbaA regulon was strongly diminished in both single Cys mutants, supporting that both Cys residues are required for redox-sensing in vivo. While GbaA and the single Cys mutants are reversible oxidized under diamide and allicin stress, these thiol switches did not affect the DNA binding activity. The repressor activity of GbaA could be only partially inhibited with NEM in vitro. Survival assays revealed that the gbaA mutant confers resistance under diamide, allicin, NEM and methylglyoxal stress, which was mediated by the SACOL2592-90 operon encoding for a putative glyoxalase and oxidoreductase. Altogether, our results support that the GbaA repressor functions in the defense against oxidative and electrophile stress in S. aureus. GbaA represents a 2-Cys-type redox sensor, which requires another redox-sensing regulator and an unknown thiol-reactive ligand for full derepression of the GbaA regulon genes.
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Affiliation(s)
- Vu Van Loi
- Freie Universität Berlin, Institute of Biology-Microbiology, D-14195, Berlin, Germany
| | - Tobias Busche
- Center for Biotechnology, Bielefeld University, D-33594, Bielefeld, Germany
| | - Verena Nadin Fritsch
- Freie Universität Berlin, Institute of Biology-Microbiology, D-14195, Berlin, Germany
| | - Christoph Weise
- Freie Universität Berlin, Institute of Chemistry and Biochemistry, D-14195, Berlin, Germany
| | | | - Alan John Slusarenko
- Department of Plant Physiology, RWTH Aachen University, D-52056, Aachen, Germany
| | - Jörn Kalinowski
- Center for Biotechnology, Bielefeld University, D-33594, Bielefeld, Germany
| | - Haike Antelmann
- Freie Universität Berlin, Institute of Biology-Microbiology, D-14195, Berlin, Germany.
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Song Y, Zhang X, Li M, Yang H, Fu D, Lv J, Ding Y, Gong Z, Shi Y, Yang S. The direct targets of CBFs: In cold stress response and beyond. J Integr Plant Biol 2021; 63:1874-1887. [PMID: 34379362 DOI: 10.1111/jipb.13161] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2021] [Accepted: 08/10/2021] [Indexed: 06/13/2023]
Abstract
Cold acclimation in Arabidopsis thaliana triggers a significant transcriptional reprogramming altering the expression patterns of thousands of cold-responsive (COR) genes. Essential to this process is the C-repeat binding factor (CBF)-dependent pathway, involving the activity of AP2/ERF (APETALA2/ethylene-responsive factor)-type CBF transcription factors required for plant cold acclimation. In this study, we performed chromatin immunoprecipitation assays followed by deep sequencing (ChIP-seq) to determine the genome-wide binding sites of the CBF transcription factors. Cold-induced CBF proteins specifically bind to the conserved C-repeat (CRT)/dehydration-responsive elements (CRT/DRE; G/ACCGAC) of their target genes. A Gene Ontology enrichment analysis showed that 1,012 genes are targeted by all three CBFs. Combined with a transcriptional analysis of the cbf1,2,3 triple mutant, we define 146 CBF regulons as direct CBF targets. In addition, the CBF-target genes are significantly enriched in functions associated with hormone, light, and circadian rhythm signaling, suggesting that the CBFs act as key integrators of endogenous and external environmental cues. Our findings not only define the genome-wide binding patterns of the CBFs during the early cold response, but also provide insights into the role of the CBFs in regulating multiple biological processes of plants.
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Affiliation(s)
- Yue Song
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Xiaoyan Zhang
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Minze Li
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Hao Yang
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Diyi Fu
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Jian Lv
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Yanglin Ding
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Zhizhong Gong
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Yiting Shi
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Shuhua Yang
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
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Cho SY, Jung SJ, Kim KD, Roe JH. Non-mitochondrial aconitase regulates the expression of iron-uptake genes by controlling the RNA turnover process in fission yeast. J Microbiol 2021; 59:1075-1082. [PMID: 34705258 DOI: 10.1007/s12275-021-1438-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 09/13/2021] [Accepted: 09/16/2021] [Indexed: 11/29/2022]
Abstract
Aconitase, a highly conserved protein across all domains of life, functions in converting citrate to isocitrate in the tricarboxylic acid cycle. Cytosolic aconitase is also known to act as an iron regulatory protein in mammals, binding to the RNA hairpin structures known as iron-responsive elements within the untranslated regions of specific RNAs. Aconitase-2 (Aco2) in fission yeast is a fusion protein consisting of an aconitase and a mitochondrial ribosomal protein, bL21, residing not only in mitochondria but also in cytosol and the nucleus. To investigate the role of Aco2 in the nucleus and cytoplasm of fission yeast, we analyzed the transcriptome of aco2ΔN mutant that is deleted of nuclear localization signal (NLS). RNA sequencing revealed that the aco2ΔN mutation caused increase in mRNAs encoding iron uptake transporters, such as Str1, Str3, and Shu1. The half-lives of mRNAs for these genes were found to be significantly longer in the aco2ΔN mutant than the wild-type strain, suggesting the role of Aco2 in mRNA turnover. The three conserved cysteines required for the catalytic activity of aconitase were not necessary for this role. The UV cross-linking RNA immunoprecipitation analysis revealed that Aco2 directly bound to the mRNAs of iron uptake transporters. Aco2-mediated degradation of iron-uptake mRNAs appears to utilize exoribonuclease pathway that involves Rrp6 as evidenced by genetic interactions. These results reveal a novel role of non-mitochondrial aconitase protein in the mRNA turnover in fission yeast to fine-tune iron homeostasis, independent of regulation by transcriptional repressor Fep1.
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Affiliation(s)
- Soo-Yeon Cho
- Department of Systems Biotechnology, Chung-Ang University, Anseong, 17546, Republic of Korea
- School of Biological Sciences, Seoul National University, Seoul, 08826, Republic of Korea
| | - Soo-Jin Jung
- School of Biological Sciences, Seoul National University, Seoul, 08826, Republic of Korea
- Center for RNA Research, Institute for Basic Science, Seoul, 02841, Republic of Korea
| | - Kyoung-Dong Kim
- Department of Systems Biotechnology, Chung-Ang University, Anseong, 17546, Republic of Korea.
| | - Jung-Hye Roe
- School of Biological Sciences, Seoul National University, Seoul, 08826, Republic of Korea.
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Son B, Patterson-West J, Arroyo-Mendoza M, Ramachandran R, Iben J, Zhu J, Rao V, Dimitriadis E, Hinton D. A phage-encoded nucleoid associated protein compacts both host and phage DNA and derepresses H-NS silencing. Nucleic Acids Res 2021; 49:9229-9245. [PMID: 34365505 PMCID: PMC8450097 DOI: 10.1093/nar/gkab678] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 07/20/2021] [Accepted: 08/06/2021] [Indexed: 12/23/2022] Open
Abstract
Nucleoid Associated Proteins (NAPs) organize the bacterial chromosome within the nucleoid. The interaction of the NAP H-NS with DNA also represses specific host and xenogeneic genes. Previously, we showed that the bacteriophage T4 early protein MotB binds to DNA, co-purifies with H-NS/DNA, and improves phage fitness. Here we demonstrate using atomic force microscopy that MotB compacts the DNA with multiple MotB proteins at the center of the complex. These complexes differ from those observed with H-NS and other NAPs, but resemble those formed by the NAP-like proteins CbpA/Dps and yeast condensin. Fluorescent microscopy indicates that expression of motB in vivo, at levels like that during T4 infection, yields a significantly compacted nucleoid containing MotB and H-NS. motB overexpression dysregulates hundreds of host genes; ∼70% are within the hns regulon. In infected cells overexpressing motB, 33 T4 late genes are expressed early, and the T4 early gene repEB, involved in replication initiation, is up ∼5-fold. We postulate that MotB represents a phage-encoded NAP that aids infection in a previously unrecognized way. We speculate that MotB-induced compaction may generate more room for T4 replication/assembly and/or leads to beneficial global changes in host gene expression, including derepression of much of the hns regulon.
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Affiliation(s)
- Bokyung Son
- Gene Expression and Regulation Section, Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Jennifer Patterson-West
- Gene Expression and Regulation Section, Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Melissa Arroyo-Mendoza
- Gene Expression and Regulation Section, Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Revathy Ramachandran
- Laboratory of Biochemistry and Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - James R Iben
- Molecular Genomics Core, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - Jingen Zhu
- Department of Biology, The Catholic University of America, Washington, DC, USA
| | - Venigalla Rao
- Department of Biology, The Catholic University of America, Washington, DC, USA
| | - Emilios K Dimitriadis
- Trans-NIH Shared Resource on Biomedical Engineering and Physical Science, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD, USA
| | - Deborah M Hinton
- Gene Expression and Regulation Section, Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
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de Araújo HL, Martins BP, Vicente AM, Lorenzetti APR, Koide T, Marques MV. Cold Regulation of Genes Encoding Ion Transport Systems in the Oligotrophic Bacterium Caulobacter crescentus. Microbiol Spectr 2021; 9:e0071021. [PMID: 34479415 PMCID: PMC8552747 DOI: 10.1128/spectrum.00710-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Accepted: 07/21/2021] [Indexed: 12/02/2022] Open
Abstract
In this study, we characterize the response of the free-living oligotrophic alphaproteobacterium Caulobacter crescentus to low temperatures by global transcriptomic analysis. Our results showed that 656 genes were upregulated and 619 were downregulated at least 2-fold after a temperature downshift. The identified differentially expressed genes (DEG) belong to several functional categories, notably inorganic ion transport and metabolism, and a subset of these genes had their expression confirmed by reverse transcription quantitative real-time PCR (RT-qPCR). Several genes belonging to the ferric uptake regulator (Fur) regulon were downregulated, indicating that iron homeostasis is relevant for adaptation to cold. Several upregulated genes encode proteins that interact with nucleic acids, particularly RNA: cspA, cspB, and the DEAD box RNA helicases rhlE, dbpA, and rhlB. Moreover, 31 small regulatory RNAs (sRNAs), including the cell cycle-regulated noncoding RNA (ncRNA) CcnA, were upregulated, indicating that posttranscriptional regulation is important for the cold stress response. Interestingly, several genes related to transport were upregulated under cold stress, including three AcrB-like cation/multidrug efflux pumps, the nitrate/nitrite transport system, and the potassium transport genes kdpFABC. Further characterization showed that kdpA is upregulated in a potassium-limited medium and at a low temperature in a SigT-independent way. kdpA mRNA is less stable in rho and rhlE mutant strains, but while the expression is positively regulated by RhlE, it is negatively regulated by Rho. A kdpA-deleted strain was generated, and its viability in response to osmotic, acidic, or cold stresses was determined. The implications of such variation in the gene expression for cold adaptation are discussed. IMPORTANCE Low-temperature stress is an important factor for nucleic acid stability and must be circumvented in order to maintain the basic cell processes, such as transcription and translation. The oligotrophic lifestyle presents further challenges to ensure the proper nutrient uptake and osmotic balance in an environment of slow nutrient flow. Here, we show that in Caulobacter crescentus, the expression of the genes involved in cation transport and homeostasis is altered in response to cold, which could lead to a decrease in iron uptake and an increase in nitrogen and high-affinity potassium transport by the Kdp system. This previously uncharacterized regulation of the Kdp transporter has revealed a new mechanism for adaptation to low temperatures that may be relevant for oligotrophic bacteria.
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Affiliation(s)
- Hugo L. de Araújo
- Departamento de Microbiologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brazil
| | - Bianca P. Martins
- Departamento de Microbiologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brazil
| | - Alexandre M. Vicente
- Departamento de Microbiologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brazil
| | - Alan P. R. Lorenzetti
- Departamento de Bioquímica e Imunologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Tie Koide
- Departamento de Bioquímica e Imunologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Marilis V. Marques
- Departamento de Microbiologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brazil
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Minnullina L, Kostennikova Z, Evtugin V, Akosah Y, Sharipova M, Mardanova A. Diversity in the swimming motility and flagellar regulon structure of uropathogenic Morganella morganii strains. Int Microbiol 2021; 25:111-122. [PMID: 34363151 DOI: 10.1007/s10123-021-00197-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 07/20/2021] [Accepted: 07/21/2021] [Indexed: 10/20/2022]
Abstract
In current times, the opportunistic pathogen Morganella morganii is increasingly becoming a cause of urinary tract infections. The condition has been further complicated by the multiple drug resistance of most isolates. Swimming motility plays an important role in the development of urinary tract infections, allowing bacteria to colonize the upper urinary tract. We determined the differences between the growth, swimming motility, and biofilm formation of two M. morganii strains MM 1 and MM 190 isolated from the urine of patients who had community-acquired urinary tract infections. MM 190 showed a lower growth rate but better-formed biofilms in comparison to MM 1. In addition, MM 190 possessed autoaggregation abilities. It was found that a high temperature (37 °C) inhibits the flagellation of strains and makes MM 190 less motile. At the same time, the MM 1 strain maintained its rate of motility at this temperature. We demonstrated that urea at a concentration of 1.5% suppresses the growth and swimming motility of both strains. Genome analysis showed that MM 1 has a 17.7-kb-long insertion in flagellar regulon between fliE and glycosyltransferase genes, which was not identified in corresponding loci of MM 190 and 9 other M. morganii strains with whole genomes. Both strains carry two genes encoding flagellin, which may indicate flagellar antigen phase variation. However, the fliC2 genes have only 91% identity to each other and exhibit some variability in the regulatory region. We assume that all these differences influence the swimming motility of the strains.
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Affiliation(s)
- Leyla Minnullina
- Institute of Fundamental Medicine and Biology, Kazan (Volga region) Federal University, Kazan, Russia.
| | - Zarina Kostennikova
- Institute of Fundamental Medicine and Biology, Kazan (Volga region) Federal University, Kazan, Russia
| | - Vladimir Evtugin
- Interdisciplinary Center for Analytical Microscopy, Kazan (Volga region) Federal University, Kazan, Russia
| | - Yaw Akosah
- Institute of Fundamental Medicine and Biology, Kazan (Volga region) Federal University, Kazan, Russia
| | - Margarita Sharipova
- Institute of Fundamental Medicine and Biology, Kazan (Volga region) Federal University, Kazan, Russia
| | - Ayslu Mardanova
- Institute of Fundamental Medicine and Biology, Kazan (Volga region) Federal University, Kazan, Russia
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Katoh-Kurasawa M, Hrovatin K, Hirose S, Webb A, Ho HI, Zupan B, Shaulsky G. Transcriptional milestones in Dictyostelium development. Genome Res 2021; 31:1498-1511. [PMID: 34183452 PMCID: PMC8327917 DOI: 10.1101/gr.275496.121] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Accepted: 06/23/2021] [Indexed: 02/02/2023]
Abstract
Dictyostelium development begins with single-cell starvation and ends with multicellular fruiting bodies. Developmental morphogenesis is accompanied by sweeping transcriptional changes, encompassing nearly half of the 13,000 genes in the genome. We performed time-series RNA-sequencing analyses of the wild type and 20 mutants to explore the relationships between transcription and morphogenesis. These strains show developmental arrest at different stages, accelerated development, or atypical morphologies. Considering eight major morphological transitions, we identified 1371 milestone genes whose expression changes sharply between consecutive transitions. We also identified 1099 genes as members of 21 regulons, which are groups of genes that remain coordinately regulated despite the genetic, temporal, and developmental perturbations. The gene annotations in these groups validate known transitions and reveal new developmental events. For example, DNA replication genes are tightly coregulated with cell division genes, so they are expressed in mid-development although chromosomal DNA is not replicated. Our data set includes 486 transcriptional profiles that can help identify new relationships between transcription and development and improve gene annotations. We show its utility by showing that cycles of aggregation and disaggregation in allorecognition-defective mutants involve dedifferentiation. We also show sensitivity to genetic and developmental conditions in two commonly used actin genes, act6 and act15, and robustness of the coaA gene. Finally, we propose that gpdA is a better mRNA quantitation standard because it is less sensitive to external conditions than commonly used standards. The data set is available for democratized exploration through the web application dictyExpress and the data mining environment Orange.
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Affiliation(s)
- Mariko Katoh-Kurasawa
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Karin Hrovatin
- Faculty of Computer and Information Science, University of Ljubljana, SI-1000 Ljubljana, Slovenia
| | - Shigenori Hirose
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Amanda Webb
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Hsing-I Ho
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Blaž Zupan
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA
- Faculty of Computer and Information Science, University of Ljubljana, SI-1000 Ljubljana, Slovenia
| | - Gad Shaulsky
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA
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Buckley SJ, Harvey RJ, Shan Z. Application of the random forest algorithm to Streptococcus pyogenes response regulator allele variation: from machine learning to evolutionary models. Sci Rep 2021; 11:12687. [PMID: 34135390 PMCID: PMC8209152 DOI: 10.1038/s41598-021-91941-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Accepted: 05/27/2021] [Indexed: 02/07/2023] Open
Abstract
Group A Streptococcus (GAS) is a globally significant bacterial pathogen. The GAS genotyping gold standard characterises the nucleotide variation of emm, which encodes a surface-exposed protein that is recombinogenic and under immune-based selection pressure. Within a supervised learning methodology, we tested three random forest (RF) algorithms (Guided, Ordinary, and Regularized) and 53 GAS response regulator (RR) allele types to infer six genomic traits (emm-type, emm-subtype, tissue and country of sample, clinical outcomes, and isolate invasiveness). The Guided, Ordinary, and Regularized RF classifiers inferred the emm-type with accuracies of 96.7%, 95.7%, and 95.2%, using ten, three, and four RR alleles in the feature set, respectively. Notably, we inferred the emm-type with 93.7% accuracy using only mga2 and lrp. We demonstrated a utility for inferring emm-subtype (89.9%), country (88.6%), invasiveness (84.7%), but not clinical (56.9%), or tissue (56.4%), which is consistent with the complexity of GAS pathophysiology. We identified a novel cell wall-spanning domain (SF5), and proposed evolutionary pathways depicting the 'contrariwise' and 'likewise' chimeric deletion-fusion of emm and enn. We identified an intermediate strain, which provides evidence of the time-dependent excision of mga regulon genes. Overall, our workflow advances the understanding of the GAS mga regulon and its plasticity.
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Affiliation(s)
- Sean J Buckley
- School of Health and Behavioural Sciences, University of the Sunshine Coast, Locked Bag 4, Maroochydore DC, QLD, 4558, Australia.
| | - Robert J Harvey
- School of Health and Behavioural Sciences, University of the Sunshine Coast, Locked Bag 4, Maroochydore DC, QLD, 4558, Australia
- Sunshine Coast Health Institute, Birtinya, QLD, 4575, Australia
| | - Zack Shan
- Thompson Institute, University of the Sunshine Coast, Birtinya, QLD, 4575, Australia
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Zhang J, Liu B, Gu D, Hao Y, Chen M, Ma Y, Zhou X, Reverter D, Zhang Y, Wang Q. Binding site profiles and N-terminal minor groove interactions of the master quorum-sensing regulator LuxR enable flexible control of gene activation and repression. Nucleic Acids Res 2021; 49:3274-3293. [PMID: 33693882 PMCID: PMC8034623 DOI: 10.1093/nar/gkab150] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 02/19/2021] [Accepted: 02/23/2021] [Indexed: 12/19/2022] Open
Abstract
LuxR is a TetR family master quorum sensing (QS) regulator activating or repressing expression of hundreds of genes that control collective behaviors in Vibrios with underlying mechanism unknown. To illuminate how this regulator controls expression of various target genes, we applied ChIP-seq and DNase I-seq technologies. Vibrio alginolyticus LuxR controls expression of ∼280 genes that contain either symmetric palindrome (repDNA) or asymmetric (actDNA) binding motifs with different binding profiles. The median number of LuxR binding sites for activated genes are nearly double for that of repressed genes. Crystal structures of LuxR in complex with the respective repDNA and actDNA motifs revealed a new mode of LuxR DNA binding that involves contacts of its N-terminal extension to the minor groove. The N-terminal contacts mediated by Arginine-9 and Arginine-11 differ when LuxR binds to repDNA vs actDNA, leading to higher binding affinity at repressed targets. Moreover, modification of LuxR binding sites, binding profiles, and N-terminal extension have important consequences on QS-regulated phenotypes. These results facilitate fundamental understanding of the high flexibility of mechanisms of LuxR control of gene activation and repression in Vibrio QS, which may facilitate to design QS inhibiting chemicals that interfere with LuxR regulation to effectively control pathogens.
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Affiliation(s)
| | | | | | - Yuan Hao
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Mo Chen
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Yue Ma
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Xiaohui Zhou
- Department of Pathobiology and Veterinary Science, University of Connecticut, Storrs, CT 06269, USA
| | - David Reverter
- Correspondence may also be addressed to David Reverter. Tel: +34 93 5868955;
| | - Yuanxing Zhang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China
- Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), 519000 Zhuhai, China
- Shanghai Engineering Research Center of Maricultured Animal Vaccines, Shanghai, China
| | - Qiyao Wang
- To whom correspondence should be addressed. Tel: +86 21 64253306;
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Mejía-Almonte C, Busby SJW, Wade JT, van Helden J, Arkin AP, Stormo GD, Eilbeck K, Palsson BO, Galagan JE, Collado-Vides J. Redefining fundamental concepts of transcription initiation in bacteria. Nat Rev Genet 2020; 21:699-714. [PMID: 32665585 PMCID: PMC7990032 DOI: 10.1038/s41576-020-0254-8] [Citation(s) in RCA: 76] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/29/2020] [Indexed: 12/15/2022]
Abstract
Despite enormous progress in understanding the fundamentals of bacterial gene regulation, our knowledge remains limited when compared with the number of bacterial genomes and regulatory systems to be discovered. Derived from a small number of initial studies, classic definitions for concepts of gene regulation have evolved as the number of characterized promoters has increased. Together with discoveries made using new technologies, this knowledge has led to revised generalizations and principles. In this Expert Recommendation, we suggest precise, updated definitions that support a logical, consistent conceptual framework of bacterial gene regulation, focusing on transcription initiation. The resulting concepts can be formalized by ontologies for computational modelling, laying the foundation for improved bioinformatics tools, knowledge-based resources and scientific communication. Thus, this work will help researchers construct better predictive models, with different formalisms, that will be useful in engineering, synthetic biology, microbiology and genetics.
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Affiliation(s)
- Citlalli Mejía-Almonte
- Programa de Genómica Computacional, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Morelos, Cuernavaca, México
| | | | - Joseph T Wade
- Division of Genetics, Wadsworth Center, New York State Department of Health, Albany, NY, USA
| | - Jacques van Helden
- Aix-Marseille University, INSERM UMR S 1090, Theory and Approaches of Genome Complexity (TAGC), Marseille, France
- CNRS, Institut Français de Bioinformatique, IFB-core, UMS 3601, Evry, France
| | - Adam P Arkin
- Department of Bioengineering, University of California, Berkeley, Berkeley, CA, USA
| | - Gary D Stormo
- Department of Genetics, Washington University School of Medicine, St Louis, MO, USA
| | - Karen Eilbeck
- Department of Biomedical Informatics, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Bernhard O Palsson
- Department of Bioengineering, University of California, San Diego, La Jolla, CA, USA
| | - James E Galagan
- Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Julio Collado-Vides
- Programa de Genómica Computacional, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Morelos, Cuernavaca, México.
- Department of Biomedical Engineering, Boston University, Boston, MA, USA.
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Sanchez AM, Garg A, Shuman S, Schwer B. Genetic interactions and transcriptomics implicate fission yeast CTD prolyl isomerase Pin1 as an agent of RNA 3' processing and transcription termination that functions via its effects on CTD phosphatase Ssu72. Nucleic Acids Res 2020; 48:4811-4826. [PMID: 32282918 PMCID: PMC7229847 DOI: 10.1093/nar/gkaa212] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Revised: 03/19/2020] [Accepted: 03/24/2020] [Indexed: 01/05/2023] Open
Abstract
The phosphorylation pattern of Pol2 CTD Y1S2P3T4S5P6S7 repeats comprises an informational code coordinating transcription and RNA processing. cis-trans isomerization of CTD prolines expands the scope of the code in ways that are not well understood. Here we address this issue via analysis of fission yeast peptidyl-prolyl isomerase Pin1. A pin1Δ allele that does not affect growth per se is lethal in the absence of cleavage-polyadenylation factor (CPF) subunits Ppn1 and Swd22 and elicits growth defects absent CPF subunits Ctf1 and Dis2 and termination factor Rhn1. Whereas CTD S2A, T4A, and S7A mutants thrive in combination with pin1Δ, a Y1F mutant does not, nor do CTD mutants in which half the Pro3 or Pro6 residues are replaced by alanine. Phosphate-acquisition genes pho1, pho84 and tgp1 are repressed by upstream lncRNAs and are sensitive to changes in lncRNA 3' processing/termination. pin1Δ hyper-represses PHO gene expression and erases the de-repressive effect of CTD-S7A. Transcriptional profiling delineated sets of 56 and 22 protein-coding genes that are down-regulated and up-regulated in pin1Δ cells, respectively, 77% and 100% of which are downregulated/upregulated when the cis-proline-dependent Ssu72 CTD phosphatase is inactivated. Our results implicate Pin1 as a positive effector of 3' processing/termination that acts via Ssu72.
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Affiliation(s)
- Ana M Sanchez
- Dept. of Microbiology and Immunology, Weill Cornell Medical College, New York, NY 10065, USA
- Gerstner Sloan Kettering Graduate School of Biomedical Sciences, New York, NY 10065, USA
| | - Angad Garg
- Molecular Biology Program, Sloan-Kettering Institute, New York, NY 10065, USA
| | - Stewart Shuman
- Molecular Biology Program, Sloan-Kettering Institute, New York, NY 10065, USA
- To whom correspondence should be addressed. Tel: +1 212 639 7145;
| | - Beate Schwer
- Dept. of Microbiology and Immunology, Weill Cornell Medical College, New York, NY 10065, USA
- Correspondence may also be addressed to Beate Schwer. Tel: +1 212 746 6518;
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Abstract
Yu and colleagues combined computational and experimental techniques to identify a new post-transcriptional regulator of metastatic potential in colon cancer. This study reveals that the RNA-binding protein RBMS1 is a positive regulator of mRNA stability for multiple genes, including the tumor suppressor AKAP12 and a WNT pathway interacting protein, SDCBP, and its loss is a common event associated with poor prognosis.See related article by Yu et al., p. 1410.
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Affiliation(s)
- Hannah Carter
- Division of Medical Genetics, Department of Medicine, University of California, San Diego, La Jolla, California.
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Cross AR, Csatary EE, Raghuram V, Diggle FL, Whiteley M, Wuest WM, Goldberg JB. The histone-like protein AlgP regulon is distinct in mucoid and nonmucoid Pseudomonas aeruginosa and does not include alginate biosynthesis genes. Microbiology (Reading) 2020; 166:861-866. [PMID: 32634088 DOI: 10.1099/mic.0.000923] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The opportunistic bacterial pathogen Pseudomonas aeruginosa causes acute and chronic infections that are notoriously difficult to treat. In people with cystic fibrosis, P. aeruginosa can cause lifelong lung infections, and isolation of mucoid P. aeruginosa, resulting from the overproduction of alginate, is associated with chronic infection. The histone-like protein AlgP has previously been implicated in the control of alginate gene expression in mucoid strains, but this regulation is unclear. To explore AlgP in further detail, we deleted algP in mucoid strains and demonstrated that the deletion of algP did not result in a nonmucoid phenotype or a decrease in alginate production. We showed that the algP promoter is expressed by both the nonmucoid strain PAO1 and the isogenic mucoid strain PDO300, suggesting that there may be genes that are differentially regulated between these strains. In support of this, using RNA sequencing, we identified a small AlgP regulon that has no significant overlap between PAO1 and PDO300 and established that alginate genes were not differentially regulated by the deletion of algP. Of note, we found that deleting algP in PAO1 increased expression of the nitric oxide operon norCBD and the nitrous oxide reductase genes nosRZ and subsequently promoted growth of PAO1 under anaerobic conditions. Altogether, we have defined a narrow regulon of genes controlled by AlgP and provided evidence that alginate production is not greatly affected by AlgP, countering the long-standing premise in the field.
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Affiliation(s)
- Ashley R Cross
- Emory+Children's Center for Cystic Fibrosis and Airway Disease Research, Emory University School of Medicine, Atlanta, GA, USA
- Division of Pulmonary, Allergy and Immunology, Cystic Fibrosis and Sleep, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA
| | - Erika E Csatary
- Department of Chemistry, Emory University, Atlanta GA, USA
- Emory+Children's Center for Cystic Fibrosis and Airway Disease Research, Emory University School of Medicine, Atlanta, GA, USA
| | - Vishnu Raghuram
- Emory+Children's Center for Cystic Fibrosis and Airway Disease Research, Emory University School of Medicine, Atlanta, GA, USA
- Division of Pulmonary, Allergy and Immunology, Cystic Fibrosis and Sleep, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA
| | - Frances L Diggle
- Emory+Children's Center for Cystic Fibrosis and Airway Disease Research, Emory University School of Medicine, Atlanta, GA, USA
- Center for Microbial Dynamics and Infection, Georgia Institute of Technology, Atlanta GA, USA
- School of Biological Sciences, Georgia Institute of Technology, Atlanta GA, USA
| | - Marvin Whiteley
- Center for Microbial Dynamics and Infection, Georgia Institute of Technology, Atlanta GA, USA
- School of Biological Sciences, Georgia Institute of Technology, Atlanta GA, USA
- Emory+Children's Center for Cystic Fibrosis and Airway Disease Research, Emory University School of Medicine, Atlanta, GA, USA
| | - William M Wuest
- Department of Chemistry, Emory University, Atlanta GA, USA
- Emory+Children's Center for Cystic Fibrosis and Airway Disease Research, Emory University School of Medicine, Atlanta, GA, USA
| | - Joanna B Goldberg
- Emory+Children's Center for Cystic Fibrosis and Airway Disease Research, Emory University School of Medicine, Atlanta, GA, USA
- Division of Pulmonary, Allergy and Immunology, Cystic Fibrosis and Sleep, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA
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Liu Y, Shi Y, Zhu N, Zhong S, Bouzayen M, Li Z. SlGRAS4 mediates a novel regulatory pathway promoting chilling tolerance in tomato. Plant Biotechnol J 2020; 18:1620-1633. [PMID: 31916348 PMCID: PMC7292549 DOI: 10.1111/pbi.13328] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 12/14/2019] [Accepted: 12/25/2019] [Indexed: 05/08/2023]
Abstract
Tomato (Solanum lycopersicum L.) plants are cold-sensitive, and the fruit are susceptible to postharvest chilling injury when stored at low temperature. However, the mechanisms underlying cold stress responses in tomato are poorly understood. We demonstrate that SlGRAS4, encoding a transcription factor induced by low temperature, promotes chilling tolerance in tomato leaves and fruit. Combined genome-wide ChIP-seq and RNA-seq approaches identified among cold stress-associated genes those being direct targets of SlGRAS4 and protein studies revealed that SlGRAS4 forms a homodimer to self-activate its own promoter. SlGRAS4 can also directly bind tomato SlCBF promoters to activate their transcription without inducing any growth retardation. The study identifies the SlGRAS4-regulon as a new cold response pathway conferring cold stress tolerance in tomato independently of the ICE1-CBF pathway. This provides new track for breeding strategies aiming to improve chilling tolerance of cultivated tomatoes and to preserve sensory qualities of tomato fruit often deteriorated by storage at low temperatures.
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Affiliation(s)
- Yudong Liu
- Key Laboratory of Plant Hormones and Development Regulation of ChongqingSchool of Life SciencesChongqing UniversityChongqingChina
- Center of Plant Functional GenomicsInstitute of Advanced Interdisciplinary StudiesChongqing UniversityChongqingChina
| | - Yuan Shi
- Key Laboratory of Plant Hormones and Development Regulation of ChongqingSchool of Life SciencesChongqing UniversityChongqingChina
- Center of Plant Functional GenomicsInstitute of Advanced Interdisciplinary StudiesChongqing UniversityChongqingChina
| | - Ning Zhu
- State Key Laboratory of AgrobiotechnologySchool of Life SciencesChinese University of Hong KongHong KongChina
| | - Silin Zhong
- State Key Laboratory of AgrobiotechnologySchool of Life SciencesChinese University of Hong KongHong KongChina
| | - Mondher Bouzayen
- Center of Plant Functional GenomicsInstitute of Advanced Interdisciplinary StudiesChongqing UniversityChongqingChina
- UMR990 INRA/INP‐ENSATUniversité de ToulouseCastanet‐TolosanFrance
| | - Zhengguo Li
- Key Laboratory of Plant Hormones and Development Regulation of ChongqingSchool of Life SciencesChongqing UniversityChongqingChina
- Center of Plant Functional GenomicsInstitute of Advanced Interdisciplinary StudiesChongqing UniversityChongqingChina
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Andreozzi E, Uhlich GA. PchE Regulation of Escherichia coli O157:H7 Flagella, Controlling the Transition to Host Cell Attachment. Int J Mol Sci 2020; 21:ijms21134592. [PMID: 32605187 PMCID: PMC7369912 DOI: 10.3390/ijms21134592] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Revised: 06/24/2020] [Accepted: 06/26/2020] [Indexed: 11/16/2022] Open
Abstract
Shiga toxins and intimate adhesion controlled by the locus of enterocyte effacement are major enterohemorrhagic Escherichia coli (EHEC) virulence factors. Curli fimbriae also contribute to cell adhesion and are essential biofilm components. The transcriptional regulator PchE represses the expression of curli and their adhesion to HEp-2 cells. Past studies indicate that pchE also represses additional adhesins that contribute to HEp-2 cell attachment. In this study, we tested for pchE regulation of several tissue adhesins and their regulators. Three adhesin-encoding genes (eae, lpfA1, fliC) and four master regulators (csgD, stpA, ler, flhDC) were controlled by pchE. pchE over-expression strongly up-regulated fliC but the marked flagella induction reduced the attachment of O157:H7 clinical isolate PA20 to HEp-2 cells, indicating that flagella were blocking cell attachments rather than functioning as an adhesin. Chemotaxis, motor, structural, and regulatory genes in the flagellar operons were all increased by pchE expression, as was PA20 motility. This study identifies new members in the pchE regulon and shows that pchE stimulates flagellar motility while repressing cell adhesion, likely to support EHEC movement to the intestinal surface early in infection. However, induced or inappropriate pchE-dependent flagellar expression could block cell attachments later during disease progression.
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Janssen KH, Corley JM, Djapgne L, Cribbs JT, Voelker D, Slusher Z, Nordell R, Regulski EE, Kazmierczak BI, McMackin EW, Yahr TL. Hfq and sRNA 179 Inhibit Expression of the Pseudomonas aeruginosa cAMP-Vfr and Type III Secretion Regulons. mBio 2020; 11:e00363-20. [PMID: 32546612 PMCID: PMC7298702 DOI: 10.1128/mbio.00363-20] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Accepted: 05/08/2020] [Indexed: 12/23/2022] Open
Abstract
Pseudomonas aeruginosa is a Gram-negative opportunistic pathogen causing skin and soft tissue, respiratory, and bloodstream infections. The type III secretion system (T3SS) is one important virulence factor. Production of the T3SS is controlled by ExsA, a transcription factor that activates expression of the entire T3SS regulon. Global regulators including Vfr, RsmA, and Hfq also contribute to regulation of the T3SS. Vfr is a cAMP-responsive transcription factor that activates exsA transcription. RsmA, an RNA-binding protein, inversely controls expression of the T3SS and the type VI secretion system (T6SS). Hfq is an RNA chaperone that functions by stabilizing small noncoding RNAs (sRNAs) and/or facilitating base pairing between sRNAs and mRNA targets. A previous study identified sRNA 1061, which directly targets the exsA mRNA and likely inhibits ExsA synthesis. In this study, we screened an sRNA expression library and identified sRNA 179 as an Hfq-dependent inhibitor of T3SS gene expression. Further characterization revealed that sRNA 179 inhibits the synthesis of both ExsA and Vfr. The previous finding that RsmA stimulates ExsA and Vfr synthesis suggested that sRNA 179 impacts the Gac/Rsm system. Consistent with that idea, the inhibitory activity of sRNA 179 is suppressed in a mutant lacking rsmY and rsmZ, and sRNA 179 expression stimulates rsmY transcription. RsmY and RsmZ are small noncoding RNAs that sequester RsmA from target mRNAs. Our combined findings show that Hfq and sRNA 179 indirectly regulate ExsA and Vfr synthesis by reducing the available pool of RsmA, leading to reduced expression of the T3SS and cAMP-Vfr regulons.IMPORTANCE Control of gene expression by small noncoding RNA (sRNA) is well documented but underappreciated. Deep sequencing of mRNA preparations from Pseudomonas aeruginosa suggests that >500 sRNAs are generated. Few of those sRNAs have defined roles in gene expression. To address that knowledge gap, we constructed an sRNA expression library and identified sRNA 179 as a regulator of the type III secretion system (T3SS) and the cAMP-Vfr regulons. The T3SS- and cAMP-Vfr-controlled genes are critical virulence factors. Increased understanding of the signals and regulatory mechanisms that control these important factors will enhance our understanding of disease progression and reveal potential approaches for therapeutic intervention.
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Affiliation(s)
- Kayley H Janssen
- Department of Microbiology and Immunology, University of Iowa, Iowa City, Iowa, USA
| | - Jodi M Corley
- Department of Microbiology and Immunology, University of Iowa, Iowa City, Iowa, USA
| | - Louise Djapgne
- Department of Microbiology and Immunology, University of Iowa, Iowa City, Iowa, USA
| | - J T Cribbs
- Department of Microbiology and Immunology, University of Iowa, Iowa City, Iowa, USA
| | - Deven Voelker
- Department of Microbiology and Immunology, University of Iowa, Iowa City, Iowa, USA
| | - Zachary Slusher
- Department of Microbiology and Immunology, University of Iowa, Iowa City, Iowa, USA
| | - Robert Nordell
- Department of Microbiology and Immunology, University of Iowa, Iowa City, Iowa, USA
| | - Elizabeth E Regulski
- Department of Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Barbara I Kazmierczak
- Department of Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, USA
| | | | - Timothy L Yahr
- Department of Microbiology and Immunology, University of Iowa, Iowa City, Iowa, USA
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Abstract
Staphylococcus aureus colonizes or causes infection in a multitude of niches within a mammalian host. Many of these niches are acidic, yet specific pH resistance mechanisms that facilitate survival have not been thoroughly investigated. This review discusses recent studies documenting known acid resistance mechanisms in S. aureus and other staphylococcal species. However, studies that clearly define the regulation of the acid resistance regulon and potential interactions with weak organic acids in specific niches of the host including the skin and gut are yet to be defined.
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Affiliation(s)
- Chunyi Zhou
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska, United States
| | - Paul D Fey
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska, United States.
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Millan-Oropeza A, Henry C, Lejeune C, David M, Virolle MJ. Expression of genes of the Pho regulon is altered in Streptomyces coelicolor. Sci Rep 2020; 10:8492. [PMID: 32444655 PMCID: PMC7244524 DOI: 10.1038/s41598-020-65087-w] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Accepted: 04/24/2020] [Indexed: 12/30/2022] Open
Abstract
Most currently used antibiotics originate from Streptomycetes and phosphate limitation is an important trigger of their biosynthesis. Understanding the molecular processes underpinning such regulation is of crucial importance to exploit the great metabolic diversity of these bacteria and get a better understanding of the role of these molecules in the physiology of the producing bacteria. To contribute to this field, a comparative proteomic analysis of two closely related model strains, Streptomyces lividans and Streptomyces coelicolor was carried out. These strains possess identical biosynthetic pathways directing the synthesis of three well-characterized antibiotics (CDA, RED and ACT) but only S. coelicolor expresses them at a high level. Previous studies established that the antibiotic producer, S. coelicolor, is characterized by an oxidative metabolism and a reduced triacylglycerol content compared to the none producer, S. lividans, characterized by a glycolytic metabolism. Our proteomic data support these findings and reveal that these drastically different metabolic features could, at least in part, due to the weaker abundance of proteins of the two component system PhoR/PhoP in S. coelicolor compared to S. lividans. In condition of phosphate limitation, PhoR/PhoP is known to control positively and negatively, respectively, phosphate and nitrogen assimilation and our study revealed that it might also control the expression of some genes of central carbon metabolism. The tuning down of the regulatory role of PhoR/PhoP in S. coelicolor is thus expected to be correlated with low and high phosphate and nitrogen availability, respectively and with changes in central carbon metabolic features. These changes are likely to be responsible for the observed differences between S. coelicolor and S. lividans concerning energetic metabolism, triacylglycerol biosynthesis and antibiotic production. Furthermore, a novel view of the contribution of the bio-active molecules produced in this context, to the regulation of the energetic metabolism of the producing bacteria, is proposed and discussed.
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Affiliation(s)
- Aaron Millan-Oropeza
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France
- PAPPSO, Micalis Institute, INRAE, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, France
| | - Céline Henry
- PAPPSO, Micalis Institute, INRAE, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, France
| | - Clara Lejeune
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France
| | - Michelle David
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France
| | - Marie-Joelle Virolle
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France.
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Andreassen PR, Trappetti C, Minhas V, Nielsen FD, Pakula K, Paton JC, Jørgensen MG. Host-glycan metabolism is regulated by a species-conserved two-component system in Streptococcus pneumoniae. PLoS Pathog 2020; 16:e1008332. [PMID: 32130269 PMCID: PMC7075642 DOI: 10.1371/journal.ppat.1008332] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2019] [Revised: 03/16/2020] [Accepted: 01/18/2020] [Indexed: 12/16/2022] Open
Abstract
Pathogens of the Streptococcus genus inhabit many different environmental niches during the course of an infection in a human host and the bacteria must adjust their metabolism according to available nutrients. Despite their lack of the citric-acid cycle, some streptococci proliferate in niches devoid of a readily available carbohydrate source. Instead they rely on carbohydrate scavenging for energy acquisition, which are obtained from the host. Here we discover a two-component system (TCS07) of Streptococcus pneumoniae that responds to glycoconjugated structures on proteins present on the host cells. Using next-generation RNA sequencing we find that the uncharacterized TCS07 regulon encodes proteins important for host-glycan processing and transporters of the released glycans, as well as intracellular carbohydrate catabolizing enzymes. We find that a functional TCS07 allele is required for growth on the glycoconjugated model protein fetuin. Consistently, we see a TCS07-dependent activation of the glycan degradation pathway. Thus, we pinpoint the molecular constituents responsible for sensing host derived glycans and link this to the induction of the proteins necessary for glycan degradation. Furthermore, we connect the TCS07 regulon to virulence in a mouse model, thereby establishing that host-derived glycan-metabolism is important for infection in vivo. Finally, a comparative phylogenomic analysis of strains from the Streptococcus genus reveal that TCS07 and most of its regulon is specifically conserved in species that utilize host-glycans for growth. Worldwide, Streptococcus pneumoniae is the most common cause of community acquired pneumonia with high mortality rates. Interestingly, S. pneumoniae strictly relies on carbohydrate scavenging for energy acquisition, which are obtained from the host. This is a critical step in pathogenesis and a common mechanism among Streptococcal species. In this study, we discover an uncharacterized two-component system that responds to the carbohydrate structures present on the host cells. These are important findings as we describe the molecular mechanism responsible for sensing these host derived glycans, and how this mechanism is linked to virulence, thus highlighting that glycan metabolism is important for infection in vivo, thereby posing a novel target for intervention. Our phylogenetic analysis reveals that the two-component system and the genetic regulon co-occur and are specifically conserved among Streptococcal species capable of degrading host-glycans.
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Affiliation(s)
| | - Claudia Trappetti
- Department of Molecular and Biomedical Science, University of Adelaide, Adelaide, Australia
| | - Vikrant Minhas
- Department of Molecular and Biomedical Science, University of Adelaide, Adelaide, Australia
| | | | - Kevin Pakula
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | - James C. Paton
- Department of Molecular and Biomedical Science, University of Adelaide, Adelaide, Australia
| | - Mikkel Girke Jørgensen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
- * E-mail:
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Zuo ZF, Kang HG, Hong QC, Park MY, Sun HJ, Kim J, Song PS, Lee HY. A novel basic helix-loop-helix transcription factor, ZjICE2 from Zoysia japonica confers abiotic stress tolerance to transgenic plants via activating the DREB/CBF regulon and enhancing ROS scavenging. Plant Mol Biol 2020; 102:447-462. [PMID: 31898148 DOI: 10.1007/s11103-019-00957-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Accepted: 12/26/2019] [Indexed: 05/21/2023]
Abstract
ZjICE2 works as a positive regulator in abiotic stress responses and ZjICE2 is a valuable genetic resource to improve abiotic stress tolerance in the molecular breeding program of Zoysia japonica. The basic helix-loop-helix (bHLH) family transcription factors (TFs) play an important role in response to biotic or abiotic stresses in plants. However, the functions of bHLH TFs in Zoysia japonica, one of the warm-season turfgrasses, remain poorly understood. Here, we identified ZjICE2 from Z. japonica, a novel MYC-type bHLH transcription factor that was closely related to ICE homologs in the phylogenetic tree, and its expression was regulated by various abiotic stresses. Transient expression of ZjICE2-GFP in onion epidermal cells revealed that ZjICE2 was a nuclear-localized protein. Also, ZjICE2 bound the MYC cis-element in the promoter of dehydration responsive element binding 1 of Z. japonica (ZjDREB1) using yeast one-hybrid assay. A phenotypic analysis showed that overexpression of the ZjICE2 in Arabidopsis enhanced tolerance to cold, drought, and salt stresses. The transgenic Arabidopsis and Z. japonica accumulated more transcripts of cold-responsive DREB/CBFs and their downstream genes than the wild type (WT) after cold treatment. Furthermore, the transgenic plants exhibited an enhanced Reactive oxygen species (ROS) scavenging ability, which resulted in an efficient maintenance of oxidant-antioxidant homeostasis. In addition, overexpression of the ZjICE2 in Z. japonica displayed intensive cold tolerance with increases in chlorophyll contents and photosynthetic efficiency. Our study suggests that ZjICE2 works as a positive regulator in abiotic stress responses and the ICE-DREB/CBFs response pathway involved in cold stress tolerance is also conserved in Z. japonica. These results provide a valuable genetic resource for the molecular breeding program especially for warm-season grasses as well as other leaf crop plants.
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Affiliation(s)
- Zhi-Fang Zuo
- Department of Biotechnology, Jeju National University, Jeju, Korea
- Subtropical Horticulture Research Institute, Jeju National University, Jeju, Korea
| | - Hong-Gyu Kang
- Subtropical Horticulture Research Institute, Jeju National University, Jeju, Korea.
| | - Quan-Chun Hong
- Department of Life Science, Shangqiu Normal University, Henan, China
| | - Mi-Young Park
- Subtropical Horticulture Research Institute, Jeju National University, Jeju, Korea
| | - Hyeon-Jin Sun
- Subtropical Horticulture Research Institute, Jeju National University, Jeju, Korea
| | - Jeongsik Kim
- Faculty of Science Education, Jeju National University, Jeju, Korea
| | - Pill-Soon Song
- Subtropical Horticulture Research Institute, Jeju National University, Jeju, Korea
| | - Hyo-Yeon Lee
- Department of Biotechnology, Jeju National University, Jeju, Korea.
- Subtropical Horticulture Research Institute, Jeju National University, Jeju, Korea.
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Zhang H, Wei J, Qian W, Deng C. Analysis of HrpG regulons and HrpG-interacting proteins by ChIP-seq and affinity proteomics in Xanthomonas campestris. Mol Plant Pathol 2020; 21:388-400. [PMID: 31916392 PMCID: PMC7036363 DOI: 10.1111/mpp.12903] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 11/06/2019] [Accepted: 11/27/2019] [Indexed: 06/02/2023]
Abstract
Gamma-proteobacteria Xanthomonas spp. cause at least 350 different plant diseases among important agricultural crops, which result in serious yield losses. Xanthomonas spp. rely mainly on the type III secretion system (T3SS) to infect their hosts and induce a hypersensitive response in nonhosts. HrpG, the master regulator of the T3SS, plays the dominant role in bacterial virulence. In this study, we used chromatin immunoprecipitation followed by sequencing (ChIP-seq) and tandem affinity purification (TAP) to systematically characterize the HrpG regulon and HrpG interacting proteins in vivo. We obtained 186 candidate HrpG downstream genes from the ChIP-seq analysis, which represented the genomic-wide regulon spectrum. A consensus HrpG-binding motif was obtained and three T3SS genes, hpa2, hrcU, and hrpE, were confirmed to be directly transcriptionally activated by HrpG in the inducing medium. A total of 273 putative HrpG interacting proteins were identified from the TAP data and the DNA-binding histone-like HU protein of Xanthomonas campestris pv. campestris (HUxcc ) was proved to be involved in bacterial virulence by increasing the complexity and intelligence of the bacterial signalling pathways in the T3SS.
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Affiliation(s)
- Hong‐Yu Zhang
- State Key Laboratory of Plant GenomicsInstitute of MicrobiologyChinese Academy of SciencesBeijingChina
- College of Life SciencesUniversity of Chinese Academy of SciencesBeijingChina
| | - Jin‐Wei Wei
- State Key Laboratory of Plant GenomicsInstitute of MicrobiologyChinese Academy of SciencesBeijingChina
- College of Life SciencesUniversity of Chinese Academy of SciencesBeijingChina
| | - Wei Qian
- State Key Laboratory of Plant GenomicsInstitute of MicrobiologyChinese Academy of SciencesBeijingChina
| | - Chao‐Ying Deng
- State Key Laboratory of Plant GenomicsInstitute of MicrobiologyChinese Academy of SciencesBeijingChina
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Peterson MA, Grice AN, Hare JM. A corepressor participates in LexA-independent regulation of error-prone polymerases in Acinetobacter. Microbiology (Reading) 2020; 166:212-226. [PMID: 31687925 PMCID: PMC7273328 DOI: 10.1099/mic.0.000866] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Accepted: 10/07/2019] [Indexed: 01/03/2023]
Abstract
The DNA damage response of the multidrug-resistant pathogen Acinetobacter baumannii, which induces mutagenic UmuD'2C error-prone polymerases, differs from that of many bacteria. Acinetobacter species lack a LexA repressor, but induce gene transcription after DNA damage. One regulator, UmuDAb, binds to and represses the promoters of the multiple A. baumannii ATCC 17978 umuDC alleles and the divergently transcribed umuDAb and ddrR genes. ddrR is unique to the genus Acinetobacter and of unknown function. 5' RACE (rapid amplification of cDNA ends) PCR mapping of the umuDAb and ddrR transcriptional start sites revealed that their -35 promoter elements overlapped the UmuDAb binding site, suggesting that UmuDAb simultaneously repressed expression of both genes by blocking polymerase access. This coordinated control of ddrR and umuDAb suggested that ddrR might also regulate DNA damage-inducible gene transcription. RNA-sequencing experiments in 17 978 ddrR- cells showed that ddrR regulated approximately 25 % (n=39) of the mitomycin C-induced regulon, with umuDAb coregulating 17 of these ddrR-regulated genes. Eight genes (the umuDC polymerases, umuDAb and ddrR) were de-repressed in the absence of DNA damage, and nine genes were uninduced in the presence of DNA damage, in both ddrR and umuDAb mutant strains. These data suggest ddrR has multiple roles, both as a co-repressor and as a positive regulator of DNA damage-inducible gene transcription. Additionally, 57 genes were induced by mitomycin C in the ddrR mutant but not in wild-type cells. This regulon contained multiple genes for DNA replication, recombination and repair, transcriptional regulators, RND efflux, and transport. This study uncovered another regulator of the atypical DNA damage response of this genus, to help describe how this pathogen acquires drug resistance through its expression of the error-prone polymerases under DdrR and UmuDAb control.
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Affiliation(s)
- Megan A. Peterson
- Department of Biology and Chemistry, Morehead State University, Morehead, KY 40351, USA
| | - Alison N. Grice
- Department of Biology and Chemistry, Morehead State University, Morehead, KY 40351, USA
- Office of Information Technology, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Janelle M. Hare
- Department of Biology and Chemistry, Morehead State University, Morehead, KY 40351, USA
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