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Kasahara M, Suetsugu N, Urano Y, Yamamoto C, Ohmori M, Takada Y, Okuda S, Nishiyama T, Sakayama H, Kohchi T, Takahashi F. An adenylyl cyclase with a phosphodiesterase domain in basal plants with a motile sperm system. Sci Rep 2016; 6:39232. [PMID: 27982074 PMCID: PMC5159850 DOI: 10.1038/srep39232] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 11/18/2016] [Indexed: 01/03/2023] Open
Abstract
Adenylyl cyclase (AC), which produces the signalling molecule cAMP, has numerous important cellular functions in diverse organisms from prokaryotes to eukaryotes. Here we report the identification and characterization of an AC gene from the liverwort Marchantia polymorpha. The encoded protein has both a C-terminal AC catalytic domain similar to those of class III ACs and an N-terminal cyclic nucleotide phosphodiesterase (PDE) domain that degrades cyclic nucleotides, thus we designated the gene MpCAPE (COMBINED AC with PDE). Biochemical analyses of recombinant proteins showed that MpCAPE has both AC and PDE activities. In MpCAPE-promoter-GUS lines, GUS activity was specifically detected in the male sexual organ, the antheridium, suggesting MpCAPE and thus cAMP signalling may be involved in the male reproductive process. CAPE orthologues are distributed only in basal land plants and charophytes that use motile sperm as the male gamete. CAPE is a subclass of class III AC and may be important in male organ and cell development in basal plants.
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Affiliation(s)
- Masahiro Kasahara
- Graduate School of Life Sciences, Ritsumeikan University, Shiga 525-8577, Japan
- College of Life Sciences, Ritsumeikan University, Shiga 525-8577, Japan
| | - Noriyuki Suetsugu
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan
| | - Yuki Urano
- Graduate School of Life Sciences, Ritsumeikan University, Shiga 525-8577, Japan
| | - Chiaki Yamamoto
- College of Life Sciences, Ritsumeikan University, Shiga 525-8577, Japan
| | - Mikiya Ohmori
- College of Life Sciences, Ritsumeikan University, Shiga 525-8577, Japan
| | - Yuki Takada
- College of Life Sciences, Ritsumeikan University, Shiga 525-8577, Japan
| | - Shujiro Okuda
- Graduate School of Medical and Dental Sciences, Niigata University, Niigata 951-8510, Japan
| | - Tomoaki Nishiyama
- Advanced Science Research Center, Kanazawa University, Ishikawa 920-0934, Japan
| | - Hidetoshi Sakayama
- Department of Biology, Graduate School of Science, Kobe University, Hyogo 657-8501, Japan
| | - Takayuki Kohchi
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan
| | - Fumio Takahashi
- Graduate School of Life Sciences, Ritsumeikan University, Shiga 525-8577, Japan
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Structural insight into photoactivation of an adenylate cyclase from a photosynthetic cyanobacterium. Proc Natl Acad Sci U S A 2016; 113:6659-64. [PMID: 27247413 DOI: 10.1073/pnas.1517520113] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Cyclic-AMP is one of the most important second messengers, regulating many crucial cellular events in both prokaryotes and eukaryotes, and precise spatial and temporal control of cAMP levels by light shows great promise as a simple means of manipulating and studying numerous cell pathways and processes. The photoactivated adenylate cyclase (PAC) from the photosynthetic cyanobacterium Oscillatoria acuminata (OaPAC) is a small homodimer eminently suitable for this task, requiring only a simple flavin chromophore within a blue light using flavin (BLUF) domain. These domains, one of the most studied types of biological photoreceptor, respond to blue light and either regulate the activity of an attached enzyme domain or change its affinity for a repressor protein. BLUF domains were discovered through studies of photo-induced movements of Euglena gracilis, a unicellular flagellate, and gene expression in the purple bacterium Rhodobacter sphaeroides, but the precise details of light activation remain unknown. Here, we describe crystal structures and the light regulation mechanism of the previously undescribed OaPAC, showing a central coiled coil transmits changes from the light-sensing domains to the active sites with minimal structural rearrangement. Site-directed mutants show residues essential for signal transduction over 45 Å across the protein. The use of the protein in living human cells is demonstrated with cAMP-dependent luciferase, showing a rapid and stable response to light over many hours and activation cycles. The structures determined in this study will assist future efforts to create artificial light-regulated control modules as part of a general optogenetic toolkit.
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Thiriet-Rupert S, Carrier G, Chénais B, Trottier C, Bougaran G, Cadoret JP, Schoefs B, Saint-Jean B. Transcription factors in microalgae: genome-wide prediction and comparative analysis. BMC Genomics 2016; 17:282. [PMID: 27067009 PMCID: PMC4827209 DOI: 10.1186/s12864-016-2610-9] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2015] [Accepted: 04/05/2016] [Indexed: 11/28/2022] Open
Abstract
Background Studying transcription factors, which are some of the key players in gene expression, is of outstanding interest for the investigation of the evolutionary history of organisms through lineage-specific features. In this study we performed the first genome-wide TF identification and comparison between haptophytes and other algal lineages. Results For TF identification and classification, we created a comprehensive pipeline using a combination of BLAST, HMMER and InterProScan software. The accuracy evaluation of the pipeline shows its applicability for every alga, plant and cyanobacterium, with very good PPV and sensitivity. This pipeline allowed us to identify and classified the transcription factor complement of the three haptophytes Tisochrysis lutea, Emiliania huxleyi and Pavlova sp.; the two stramenopiles Phaeodactylum tricornutum and Nannochloropsis gaditana; the chlorophyte Chlamydomonas reinhardtii and the rhodophyte Porphyridium purpureum. By using T. lutea and Porphyridium purpureum, this work extends the variety of species included in such comparative studies, allowing the detection and detailed study of lineage-specific features, such as the presence of TF families specific to the green lineage in Porphyridium purpureum, haptophytes and stramenopiles. Our comprehensive pipeline also allowed us to identify fungal and cyanobacterial TF families in the algal nuclear genomes. Conclusions This study provides examples illustrating the complex evolutionary history of algae, some of which support the involvement of a green alga in haptophyte and stramenopile evolution. Electronic supplementary material The online version of this article (doi:10.1186/s12864-016-2610-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Stanislas Thiriet-Rupert
- IFREMER, Physiology and Biotechnology of Algae Laboratory, rue de l'Ile d'Yeu, 44311, Nantes, France.
| | - Grégory Carrier
- IFREMER, Physiology and Biotechnology of Algae Laboratory, rue de l'Ile d'Yeu, 44311, Nantes, France
| | - Benoît Chénais
- MicroMar, Mer Molécules Santé, IUML - FR 3473 CNRS, University of Le Mans, Le Mans, France
| | - Camille Trottier
- IFREMER, Physiology and Biotechnology of Algae Laboratory, rue de l'Ile d'Yeu, 44311, Nantes, France
| | - Gaël Bougaran
- IFREMER, Physiology and Biotechnology of Algae Laboratory, rue de l'Ile d'Yeu, 44311, Nantes, France
| | - Jean-Paul Cadoret
- IFREMER, Physiology and Biotechnology of Algae Laboratory, rue de l'Ile d'Yeu, 44311, Nantes, France
| | - Benoît Schoefs
- MicroMar, Mer Molécules Santé, IUML - FR 3473 CNRS, University of Le Mans, Le Mans, France
| | - Bruno Saint-Jean
- IFREMER, Physiology and Biotechnology of Algae Laboratory, rue de l'Ile d'Yeu, 44311, Nantes, France
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NAD captureSeq indicates NAD as a bacterial cap for a subset of regulatory RNAs. Nature 2014; 519:374-7. [PMID: 25533955 DOI: 10.1038/nature14020] [Citation(s) in RCA: 179] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Accepted: 10/27/2014] [Indexed: 11/08/2022]
Abstract
A distinctive feature of prokaryotic gene expression is the absence of 5'-capped RNA. In eukaryotes, 5',5'-triphosphate-linked 7-methylguanosine protects messenger RNA from degradation and modulates maturation, localization and translation. Recently, the cofactor nicotinamide adenine dinucleotide (NAD) was reported as a covalent modification of bacterial RNA. Given the central role of NAD in redox biochemistry, posttranslational protein modification and signalling, its attachment to RNA indicates that there are unknown functions of RNA in these processes and undiscovered pathways in RNA metabolism and regulation. The unknown identity of NAD-modified RNAs has so far precluded functional analyses. Here we identify NAD-linked RNAs from bacteria by chemo-enzymatic capture and next-generation sequencing (NAD captureSeq). Among those identified, specific regulatory small RNAs (sRNAs) and sRNA-like 5'-terminal fragments of certain mRNAs are particularly abundant. Analogous to a eukaryotic cap, 5'-NAD modification is shown in vitro to stabilize RNA against 5'-processing by the RNA-pyrophosphohydrolase RppH and against endonucleolytic cleavage by ribonuclease (RNase) E. The nudix phosphohydrolase NudC decaps NAD-RNA and thereby triggers RNase-E-mediated RNA decay, while being inactive against triphosphate-RNA. In vivo, ∼13% of the abundant sRNA RNAI is NAD-capped in the presence, and ∼26% in the absence, of functional NudC. To our knowledge, this is the first description of a cap-like structure and a decapping machinery in bacteria.
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Kulkarni PR, Jia T, Kuehne SA, Kerkering TM, Morris ER, Searle MS, Heeb S, Rao J, Kulkarni RV. A sequence-based approach for prediction of CsrA/RsmA targets in bacteria with experimental validation in Pseudomonas aeruginosa. Nucleic Acids Res 2014; 42:6811-25. [PMID: 24782516 PMCID: PMC4066749 DOI: 10.1093/nar/gku309] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
CsrA/RsmA homologs are an extensive family of ribonucleic acid (RNA)-binding proteins that function as global post-transcriptional regulators controlling important cellular processes such as secondary metabolism, motility, biofilm formation and the production and secretion of virulence factors in diverse bacterial species. While direct messenger RNA binding by CsrA/RsmA has been studied in detail for some genes, it is anticipated that there are numerous additional, as yet undiscovered, direct targets that mediate its global regulation. To assist in the discovery of these targets, we propose a sequence-based approach to predict genes directly regulated by these regulators. In this work, we develop a computer code (CSRA_TARGET) implementing this approach, which leads to predictions for several novel targets in Escherichia coli and Pseudomonas aeruginosa. The predicted targets in other bacteria, specifically Salmonella enterica serovar Typhimurium, Pectobacterium carotovorum and Legionella pneumophila, also include global regulators that control virulence in these pathogens, unraveling intricate indirect regulatory roles for CsrA/RsmA. We have experimentally validated four predicted RsmA targets in P. aeruginosa. The sequence-based approach developed in this work can thus lead to several testable predictions for direct targets of CsrA homologs, thereby complementing and accelerating efforts to unravel global regulation by this important family of proteins.
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Affiliation(s)
- Prajna R Kulkarni
- Department of Physics, University of Massachusetts Boston, Boston, MA 02125, USA
| | - Tao Jia
- Social Cognitive Networks Academic Research Center, and Department of Computer Science, Rensselaer Polytechnic Institute, Troy, NY 12180, USA
| | - Sarah A Kuehne
- School of Life Sciences, Centre for Biomolecular Sciences, University Park, University of Nottingham, Nottingham NG7 2RD, UK
| | - Thomas M Kerkering
- Section of Infectious Diseases, Carilion Clinic/Virginia Tech Carilion School of Medicine/Jefferson College of Health Sciences, Roanoke, VA 24013, USA
| | - Elizabeth R Morris
- School of Chemistry, Centre for Biomolecular Sciences, University Park, University of Nottingham, Nottingham NG7 2RD, UK
| | - Mark S Searle
- School of Chemistry, Centre for Biomolecular Sciences, University Park, University of Nottingham, Nottingham NG7 2RD, UK
| | - Stephan Heeb
- School of Life Sciences, Centre for Biomolecular Sciences, University Park, University of Nottingham, Nottingham NG7 2RD, UK
| | - Jayasimha Rao
- Section of Infectious Diseases, Carilion Clinic/Virginia Tech Carilion School of Medicine/Jefferson College of Health Sciences, Roanoke, VA 24013, USA
| | - Rahul V Kulkarni
- Department of Physics, University of Massachusetts Boston, Boston, MA 02125, USA
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6
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Seidl MF, Van den Ackerveken G, Govers F, Snel B. A domain-centric analysis of oomycete plant pathogen genomes reveals unique protein organization. PLANT PHYSIOLOGY 2011; 155:628-644. [PMID: 21119047 PMCID: PMC3032455 DOI: 10.1104/pp.110.167841] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2010] [Accepted: 11/24/2010] [Indexed: 05/29/2023]
Abstract
Oomycetes comprise a diverse group of organisms that morphologically resemble fungi but belong to the stramenopile lineage within the supergroup of chromalveolates. Recent studies have shown that plant pathogenic oomycetes have expanded gene families that are possibly linked to their pathogenic lifestyle. We analyzed the protein domain organization of 67 eukaryotic species including four oomycete and five fungal plant pathogens. We detected 246 expanded domains in fungal and oomycete plant pathogens. The analysis of genes differentially expressed during infection revealed a significant enrichment of genes encoding expanded domains as well as signal peptides linking a substantial part of these genes to pathogenicity. Overrepresentation and clustering of domain abundance profiles revealed domains that might have important roles in host-pathogen interactions but, as yet, have not been linked to pathogenicity. The number of distinct domain combinations (bigrams) in oomycetes was significantly higher than in fungi. We identified 773 oomycete-specific bigrams, with the majority composed of domains common to eukaryotes. The analyses enabled us to link domain content to biological processes such as host-pathogen interaction, nutrient uptake, or suppression and elicitation of plant immune responses. Taken together, this study represents a comprehensive overview of the domain repertoire of fungal and oomycete plant pathogens and points to novel features like domain expansion and species-specific bigram types that could, at least partially, explain why oomycetes are such remarkable plant pathogens.
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Affiliation(s)
- Michael F Seidl
- Theoretical Biology and Bioinformatics , Department of Biology, Utrecht University, 3584 CH Utrecht, The Netherlands.
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7
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Zou Q, Yan X, Li B, Zeng X, Zhou J, Zhang J. Proteome analysis of sorbitol fermentation specific protein inVibrio cholerae by 2-DE and MS. Proteomics 2006; 6:1848-55. [PMID: 16525996 DOI: 10.1002/pmic.200401352] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Vibrio cholerae can be differentiated into epidemic and non-epidemic strains by sorbitol fermentation speed, but little research has been done on its mechanisms. In this study, we investigated differential protein expression of the two strains in response to sorbitol metabolism. V. cholerae strains were cultured in media with and without sorbitol, respectively. Proteins were separated by 2-DE, and those that showed different expression in the two media were identified by MALDI-TOF MS. Fifteen proteins in epidemic strains and 11 proteins in non-epidemic strains showed a different expression in sorbitol medium. Among them, 4 proteins were common to epidemic and non-epidemic strains. Gene sequence analysis showed that some mutations occurred in these proteins between the two strains. Potential functions of these proteins included sugar uptake, amino acid uptake, electron transport, sulfate and thiosulfate transport.
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Affiliation(s)
- QingHua Zou
- National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, PR China
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8
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Saavedra L, Sesma F. Atypical Genetic Locus Associated with the zwf Gene Encoding the Glucose 6-Phosphate Dehydrogenase from Enterococcus mundtii CRL35. Curr Microbiol 2005; 51:148-52. [PMID: 16091851 DOI: 10.1007/s00284-004-4454-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2004] [Accepted: 10/20/2004] [Indexed: 11/29/2022]
Abstract
The zwf gene encoding glucose 6-phosphate dehydrogenase (G6PD, EC.1.1.1.49) from Enterococcus mundtii CRL35 was cloned as a 4921 bp EcoRI fragment and analyzed. The predicted zwf gene product consists of 506 residues with a molecular mass of 58.4 kDa, and is fully active in Escherichia coli as demonstrated by its heterologous expression in the zwf-negative mutant E. coli Su294. It shows a high degree of sequence identity (40-60%) to G6PDs described in other bacteria. Upstream of the zwf gene, a homolog of the DtxR family was identified (ORF D). Analysis of the 5' sequence of ORF D revealed a potential promoter sequence, which would suggest the presence of an operon-like structure between ORF D and the zwf gene. Finally, it was found that Fe2+ levels have an important role as a modulator of G6PD activity. This is the first report of this type of regulation of G6PD activity. A possible involvement in oxidative stress is discussed.
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Affiliation(s)
- Lucila Saavedra
- Centro de Referencia para Lactobacilos (CONICET), Chacabuco , 145 (4000), Tucumán, Argentina
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9
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Abstract
This map is an update of the edition 9 map by Berlyn et al. (M. K. B. Berlyn, K. B. Low, and K. E. Rudd, p. 1715-1902, in F. C. Neidhardt et al., ed., Escherichia coli and Salmonella: cellular and molecular biology, 2nd ed., vol. 2, 1996). It uses coordinates established by the completed sequence, expressed as 100 minutes for the entire circular map, and adds new genes discovered and established since 1996 and eliminates those shown to correspond to other known genes. The latter are included as synonyms. An alphabetical list of genes showing map location, synonyms, the protein or RNA product of the gene, phenotypes of mutants, and reference citations is provided. In addition to genes known to correspond to gene sequences, other genes, often older, that are described by phenotype and older mapping techniques and that have not been correlated with sequences are included.
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Affiliation(s)
- M K Berlyn
- Department of Biology and School of Forestry and Environmental Studies, Yale University, New Haven, Connecticut 06520-8104, USA.
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Willis LB, Walker GC. The phbC (poly-beta-hydroxybutyrate synthase) gene of Rhizobium (Sinorhizobium) meliloti and characterization of phbC mutants. Can J Microbiol 1998; 44:554-64. [PMID: 9734305 DOI: 10.1139/w98-033] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Defined insertion mutations have been constructed in the Rhizobium (Sinorhizobium) meliloti phbC gene, which encodes poly-beta-hydroxybutyrate (PHB) synthase. The locus was isolated and subcloned from a genomic library of R. meliloti Rm1021 by complementation of phbC mutation of Alcaligenes eutrophus. PHB production was detected in wild-type R. meliloti under nutrient-limited conditions but not in rich medium. No PHB production was detected in the R. meliloti phbC mutants. The DNA sequence of the R. meliloti phbC gene was determined. The deduced polypeptide sequence is homologous to previously identified PhbCs from other bacteria. The R. meliloti phbC locus maps to pRmeSU47a, the smaller of the two megaplasmids in this strain.
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Affiliation(s)
- L B Willis
- Department of Biology, Massachusetts Institute of Technology, Cambridge 02139, USA
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Cook GM, Membrillo-Hernández J, Poole RK. Transcriptional regulation of the cydDC operon, encoding a heterodimeric ABC transporter required for assembly of cytochromes c and bd in Escherichia coli K-12: regulation by oxygen and alternative electron acceptors. J Bacteriol 1997; 179:6525-30. [PMID: 9335308 PMCID: PMC179575 DOI: 10.1128/jb.179.20.6525-6530.1997] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The expression of the cydDC operon was investigated by using a chromosomal phi(cydD-lacZ) transcriptional fusion and primer extension analysis. A single transcriptional start site was found for cydD located 68 bp upstream of the translational start site, and Northern blot analysis confirmed that cydDC is transcribed as a polycistronic message independently of the upstream gene trxB. cydDC was highly expressed under aerobic growth conditions and during anaerobic growth with alternative electron acceptors. Aerobic expression was independent of ArcA and Fnr, but induction of cydDC by nitrate and nitrite was dependent on NarL and Fnr.
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Affiliation(s)
- G M Cook
- Department of Molecular Biology and Biotechnology, The Krebs Institute for Biomolecular Research, The University of Sheffield, United Kingdom
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12
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Membrillo-Hernández J, Kim SO, Cook GM, Poole RK. Paraquat regulation of hmp (flavohemoglobin) gene expression in Escherichia coli K-12 is SoxRS independent but modulated by sigma S. J Bacteriol 1997; 179:3164-70. [PMID: 9150210 PMCID: PMC179093 DOI: 10.1128/jb.179.10.3164-3170.1997] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
We report the first example of a gene, hmp, encoding a soluble flavohemoglobin in Escherichia coli K-12, which is up-regulated by paraquat in a SoxRS-independent manner. Unlike what is found for other paraquat-inducible genes, high concentrations of paraquat (200 microM) were required to increase the level of hmp expression, and maximal induction was observed only after 20 min of exposure to paraquat. Neither a mutation in soxS nor one in soxR prevented the paraquat-dependent increase in phi(hmp-lacZ) expression, but either mutant allele delayed full expression of phi(hmp-lacZ) activity after paraquat addition. Induction of hmp by paraquat was demonstrated in aerobically grown cultures during exponential growth and the stationary phase, thus revealing two Sox-independent regulatory mechanisms. Induction of hmp by paraquat in the stationary phase was dependent on the global regulator of stationary-phase gene expression, RpoS (sigma S). However, a mutation in rpoS did not prevent an increase in hmp expression by paraquat in exponentially growing cells. Induction of sigma S in the exponential phase by heat shock also induced phi(hmp-lacZ) expression in the presence of paraquat, supporting the role of sigma S in one of the regulatory mechanisms. Mutations in oxyR or rob, known regulators of several stress promoters in E. coli, had no effect on the induction of hmp by paraquat. Other known superoxide-generating agents (plumbagin, menadione, and phenazine methosulfate) were not effective in inducing hmp expression.
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Affiliation(s)
- J Membrillo-Hernández
- Krebs Institute for Biomolecular Research, Department of Molecular Biology and Biotechnology, The University of Sheffield, United Kingdom
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13
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Arn EA, Abelson JN. The 2'-5' RNA ligase of Escherichia coli. Purification, cloning, and genomic disruption. J Biol Chem 1996; 271:31145-53. [PMID: 8940112 DOI: 10.1074/jbc.271.49.31145] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
An RNA ligase previously detected in extracts of Escherichia coli is capable of joining Saccharomyces cerevisiae tRNA splicing intermediates in the absence of ATP to form a 2'-5' phosphodiester linkage (Greer, C., Javor, B., and Abelson, J. (1983) Cell 33, 899-906). This enzyme specifically ligates tRNA half-molecules containing nucleoside base modifications and shows a preference among different tRNA species. In order to investigate the function of this enzyme in RNA metabolism, the ligase was purified to homogeneity from E. coli lysate utilizing chromatographic techniques and separation of proteins by SDS-polyacrylamide gel electrophoresis. A single polypeptide of approximately 20 kilodaltons exhibited RNA ligase activity. The amino terminus of this protein was sequenced, and the open reading frame (ORF) encoding it was identified by a data base search. This ORF, which encodes a novel protein with a predicted molecular mass of 19.9 kDa, was amplified from E. coli genomic DNA and cloned. ORFs coding for highly similar proteins were detected in Methanococcus jannaschii and Bacillus stearothermophilus. The chromosomal gene encoding RNA ligase in E. coli was disrupted, abolishing ligase activity in cell lysates. Cells lacking ligase activity grew normally under laboratory conditions. However, moderate overexpression of the ligase protein led to slower growth rates and a temperature-sensitive phenotype in both wild-type and RNA ligase knockout strains. The RNA ligase reaction was studied in vitro using purified enzyme and was found to be reversible, indicating that this enzyme may perform cleavage or ligation in vivo.
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Affiliation(s)
- E A Arn
- Division of Biology 147-75, California Institute of Technology, Pasadena, California 91125, USA.
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14
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Poole RK, Anjum MF, Membrillo-Hernández J, Kim SO, Hughes MN, Stewart V. Nitric oxide, nitrite, and Fnr regulation of hmp (flavohemoglobin) gene expression in Escherichia coli K-12. J Bacteriol 1996; 178:5487-92. [PMID: 8808940 PMCID: PMC178372 DOI: 10.1128/jb.178.18.5487-5492.1996] [Citation(s) in RCA: 201] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Escherichia coli possesses a soluble flavohemoglobin, with an unknown function, encoded by the hmp gene. A monolysogen containing an hmp-lacZ operon fusion was constructed to determine how the hmp promoter is regulated in response to heme ligands (O2, NO) or the presence of anaerobically utilized electron acceptors (nitrate, nitrite). Expression of the phi (hmp-lacZ)1 fusion was similar during aerobic growth in minimal medium containing glucose, glycerol, maltose, or sorbitol as a carbon source. Mutations in cya (encoding adenylate cyclase) or changes in medium pH between 5 and 9 were without effect on aerobic expression. Levels of aerobic and anaerobic expression in glucose-containing minimal media were similar; both were unaffected by an arcA mutation. Anaerobic, but not aerobic, expression of phi (hmp-lacZ)1 was stimulated three- to four-fold by an fnr mutation; an apparent Fnr-binding site is present in the hmp promoter. Iron depletion of rich broth medium by the chelator 2'2'-dipyridyl (0.1 mM) enhanced hmp expression 40-fold under anaerobic conditions, tentatively attributed to effects on Fnr. At a higher chelator concentration (0.4 mM), hmp expression was also stimulated aerobically. Anaerobic expression was stimulated 6-fold by the presence of nitrate and 25-fold by the presence of nitrite. Induction by nitrate or nitrite was unaffected by narL and/or narP mutations, demonstrating regulation of hmp by these ions via mechanisms alternative to those implicated in the regulation of other respiratory genes. Nitric oxide (10 to 20 microM) stimulated aerobic phi (hmp-lacZ)1 activity by up to 19-fold; soxS and soxR mutations only slightly reduced the NO effect. We conclude that hmp expression is negatively regulated by Fnr under anaerobic conditions and that additional regulatory mechanisms are involved in the responses to oxygen, nitrogen compounds, and iron availability. Hmp is implicated in reactions with small nitrogen compounds.
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Affiliation(s)
- R K Poole
- Division of Life Sciences, King's College London, United Kingdom
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15
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Yashiro K, Sakamoto T, Ohmori M. Molecular characterization of an adenylate cyclase gene of the cyanobacterium Spirulina platensis. PLANT MOLECULAR BIOLOGY 1996; 31:175-181. [PMID: 8704152 DOI: 10.1007/bf00020618] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
A cyaA gene, encoding an adenylate cyclase, was isolated from a filamentous cyanobacterium, Spirulina platensis, by functional complementation of a cya mutant of Escherichia coli, defective in adenylate cyclase activity. The predicted gene product of cyaA contains a signal peptide-like domain, a putative sensor domain similar to the gene product of vsrA of Pseudomonas solanacearum, a putative membrane-spanning domain and an adenylate cyclase-like catalytic domain. Two other positive clones that complemented the E. coli mutant were isolated from the same cyanobacterium, suggesting that several cya genes are functioning in S. platensis.
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Affiliation(s)
- K Yashiro
- Department of Biology, Graduate School of Arts and Sciences, University of Tokyo, Japan
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16
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Bass S, Gu Q, Christen A. Multicopy suppressors of prc mutant Escherichia coli include two HtrA (DegP) protease homologs (HhoAB), DksA, and a truncated R1pA. J Bacteriol 1996; 178:1154-61. [PMID: 8576052 PMCID: PMC177779 DOI: 10.1128/jb.178.4.1154-1161.1996] [Citation(s) in RCA: 125] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
We have isolated three multicopy suppressors of the conditional lethal phenotype of a prc (tsp) null strain of Escherichia coli. One of these suppressors included two novel putative protease genes in tandem that map to 3400 kb or 72.5 centisomes on the chromosome. We propose the names hhoA and hhoB, for htrA homolog, to denote that these genes encode proteins that are 58 and 35% identical, respectively, to the HtrA (DegP) serine protease and 36% identical to each other. The HhoA and HhoB proteins are predicted to be 455 and 355 amino acids, respectively, in length. The mature HhoA protein is periplasmic in location, and amino-terminal sequencing shows that it arises following cleavage of a 27-amino-acid signal peptide. Searches of the protein and DNA databases reveal a rapidly growing family of homologous genes in a variety of other bacteria, including several which are required for virulence in their host. Deletion of the hhoAB genes shows that they are not required for viability at high temperatures like the homologous htrA but grow more slowly than wild-type strains. A second multicopy prc suppressor is the dksA (dnaK suppressor) gene, which is also a multicopy suppressor of defects in the heat shock genes dnaK, dnaJ, and grpE. The dksA gene was independently isolated as a multicopy suppressor of a mukB mutation, which is required for chromosomal partitioning. A third dosage-dependent prc suppressor includes a truncated rare lipoprotein A (rlpA) gene.
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Affiliation(s)
- S Bass
- Department of Molecular Biology, Genentech Inc, South San Francisco, California 94080-4990, USA
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17
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Abstract
A new set of cloning vectors derived from pBlueScript (Stratagene, La Jolla, CA, USA) is presented. The ampicillin-resistance-encoding gene (ApR) of pBlueScript has been replaced by genes encoding resistance to either kanamycin (KmR) or tetracycline (TcR). The origin of DNA replication (ori), conferring to pBlueScript a very high-copy-number (500-700 copies/chromosome), has been replaced by the pBR322 ori (15-20 copies/chromosome) or the P15A ori (10-12 copies/chromosome) [Sambrook et al.: Molecular Cloning. A Laboratory Manual, 2nd ed. Cold Spring Harbor Laboratory Press, Cold Spring Harbor, NY, 1989]. Therefore, eight new vectors with different drug selection markers and low, medium or high plasmid copy-number were created which are compatible with each other (ColE1 ori and P15A ori) and can be selected to replace one another. These vectors were further modified by the insertion of an expression cassette based on the promoter and AraC repressor/activator of the ara operon, which allows high-level expression, extremely tight regulation and very inexpensive induction. High-level expression of one or two genes within the same cell is demonstrated.
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Affiliation(s)
- M P Mayer
- Departement de Biochimie Médicale, Centre Médical Universitaire, Genève 4, Switzerland
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18
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Katayama M, Wada Y, Ohmori M. Molecular cloning of the cyanobacterial adenylate cyclase gene from the filamentous cyanobacterium Anabaena cylindrica. J Bacteriol 1995; 177:3873-8. [PMID: 7601856 PMCID: PMC177110 DOI: 10.1128/jb.177.13.3873-3878.1995] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Molecular cloning of the structural gene for adenylate cyclase (cya) of the cyanobacterium Anabaena cylindrica was carried out by complementation of an Escherichia coli strain defective in the cya gene. The cya-defective strain produced significant amounts of cyclic AMP when it was transformed with the cya gene isolated from A. cylindrica. This gene encodes a polypeptide consisting of 502 amino acid residues (molecular weight, 55,300). The deduced primary protein structure showed that the carboxyl-terminal region of the adenylate cyclase of A. cylindrica shows strong structural similarity to the conserved regions of the adenylate cyclases of various eukaryotes. No similarity was found between the amino acid sequences of the cya gene of A. cylindrica and that of E. coli. A hydropathy plot suggests that this protein has two hydrophobic regions, a transmembrane span and a signal peptide. An antiserum specific to this adenylate cyclase was prepared by immunizing a rabbit with a glutathione S-transferase-adenylate cyclase fusion protein expressed in E. coli. This antiserum recognized a 55-kDa protein in Anabaena cell lysates. Subcellular fractionation analysis showed that A. cylindrica adenylate cyclase localized in the thylakoid membrane.
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Affiliation(s)
- M Katayama
- Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, Japan
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19
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Wei P, Stewart CR. Genes that protect against the host-killing activity of the E3 protein of Bacillus subtilis bacteriophage SPO1. J Bacteriol 1995; 177:2933-7. [PMID: 7751311 PMCID: PMC176973 DOI: 10.1128/jb.177.10.2933-2937.1995] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
A cloned rpoB gene, specifying an apparently mutant RNA polymerase beta subunit, protected Escherichia coli against the cytocidal effects of the E3 protein of bacteriophage SPO1, suggesting that RNA polymerase is the primary cellular target of the E3 protein. Two segments of the wild-type E. coli genome, one of which specifies a suppressor of dnaK mutations, and thus, possibly, a molecular chaperone, also provided protection when overexpressed, but wild-type rpoB did not.
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Affiliation(s)
- P Wei
- Department of Biochemistry and Cell Biology, Rice University, Houston, Texas 77005-1892, USA
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20
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Utsumi R, Katayama S, Taniguchi M, Horie T, Ikeda M, Igaki S, Nakagawa H, Miwa A, Tanabe H, Noda M. Newly identified genes involved in the signal transduction of Escherichia coli K-12. Gene X 1994; 140:73-7. [PMID: 8125343 DOI: 10.1016/0378-1119(94)90733-1] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
We cloned and sequenced two Escherichia coli genes which are members of a family of an environmentally responsive two-component system. The nucleotide (nt) and deduced amino-acid sequences of these two genes were found to be homologous to those of the Bordetella pertussis bvgA and bvgS genes. They were mapped at 51 min (clones 6B9 to 7G9 of the Kohara miniset library of the E. coli chromosome). Both proteins, deduced from their nt sequences, were identified in the coupled in vitro transcription-translation system; their molecular masses were consistent with BvgA and BvgS (23 and 135 kDa, respectively). Furthermore, when these genes were expressed on a multicopy plasmid in an envZ deletion strain, ompC expression was induced. This expression was found to be regulated by low temperature, MgSO4 and nicotinic acid, factors known to control the virulence of B. pertussis via BvgA and BvgS. These results indicate that the newly cloned genes were structurally and functionally similar to bvgA and bvgS, and we designated these genes evgA and evgS.
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Affiliation(s)
- R Utsumi
- Department of Agricultural Chemistry, Kinki University, Nara, Japan
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21
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Autexier C, DuBow MS. The Escherichia coli Mu/D108 phage ner homologue gene (nlp) is transcribed and evolutionarily conserved among the Enterobacteriaceae. Gene 1992; 114:13-8. [PMID: 1534062 DOI: 10.1016/0378-1119(92)90701-p] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The Escherichia coli nlp gene is highly homologous to the regulatory ner genes of transposable coliphages, Mu and D108. It was discovered, via its action when overexpressed, as a positive activator of mal gene expression in a cya- crp*1 strain. Chromosomal disruption of the nlp gene by insertion of a promoterless luxAB reporter gene revealed that nlp is nonessential for E. coli viability. Light measurements from the resulting nlp::luxAB transcriptional fusion, plus RNA dot blot analysis, suggest that nlp is transcribed. Southern-blot analyses of DNAs from several bacterial species were performed and indicate that nlp is evolutionarily conserved, but only among closely related Enterobacteriaceae.
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Affiliation(s)
- C Autexier
- Department of Microbiology and Immunology, McGill University, Montréal, Québec, Canada
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22
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New nucleotide sequence data on the EMBL File Server. Nucleic Acids Res 1991; 19:5455-79. [PMID: 1923842 PMCID: PMC328939 DOI: 10.1093/nar/19.19.5455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
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23
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DeVault JD, Hendrickson W, Kato J, Chakrabarty AM. Environmentally regulated algD promoter is responsive to the cAMP receptor protein in Escherichia coli. Mol Microbiol 1991; 5:2503-9. [PMID: 1665196 DOI: 10.1111/j.1365-2958.1991.tb02096.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The environmentally activated algD promoter of Pseudomonas aeruginosa has been shown to be influenced by DNA supercoiling. It is believed that protein-induced bending or looping is required for this activation. We studied the role of Escherichia coli cAMP-CRP on algD promoter activation in E. coli and show that a functional CRP is required for this activation. We also demonstrate that the algD promoter is sensitive to glucose repression both in E. coli and P. aeruginosa. Deletion of a putative consensus CRP binding sequence upstream of the algD promoter renders the promoter non-responsive to glucose repression. The involvement of cAMP-CRP complex in the activation of the algD promoter in E. coli has been demonstrated directly through binding of a 255 base pair DNA fragment containing the putative consensus CRP binding sequence. Other fragments, upstream or downstream but without any consensus CRP binding sequence, did not show any binding with CRP. A CRP-like analogue, similar to that in Xanthomonas campestris, but capable of activating genes without forming a complex with cAMP, is believed to allow glucose repression in P. aeruginosa.
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Affiliation(s)
- J D DeVault
- Department of Microbiology and Immunology (M/C 790), University of Illinois College of Medicine, Chicago 60612
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