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Maciag T, Kozieł E, Otulak-Kozieł K, Jafra S, Czajkowski R. Looking for Resistance to Soft Rot Disease of Potatoes Facing Environmental Hypoxia. Int J Mol Sci 2024; 25:3757. [PMID: 38612570 PMCID: PMC11011919 DOI: 10.3390/ijms25073757] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2024] [Revised: 03/21/2024] [Accepted: 03/26/2024] [Indexed: 04/14/2024] Open
Abstract
Plants are exposed to various stressors, including pathogens, requiring specific environmental conditions to provoke/induce plant disease. This phenomenon is called the "disease triangle" and is directly connected with a particular plant-pathogen interaction. Only a virulent pathogen interacting with a susceptible plant cultivar will lead to disease under specific environmental conditions. This may seem difficult to accomplish, but soft rot Pectobacteriaceae (SRPs) is a group virulent of pathogenic bacteria with a broad host range. Additionally, waterlogging (and, resulting from it, hypoxia), which is becoming a frequent problem in farming, is a favoring condition for this group of pathogens. Waterlogging by itself is an important source of abiotic stress for plants due to lowered gas exchange. Therefore, plants have evolved an ethylene-based system for hypoxia sensing. Plant response is coordinated by hormonal changes which induce metabolic and physiological adjustment to the environmental conditions. Wetland species such as rice (Oryza sativa L.), and bittersweet nightshade (Solanum dulcamara L.) have developed adaptations enabling them to withstand prolonged periods of decreased oxygen availability. On the other hand, potato (Solanum tuberosum L.), although able to sense and response to hypoxia, is sensitive to this environmental stress. This situation is exploited by SRPs which in response to hypoxia induce the production of virulence factors with the use of cyclic diguanylate (c-di-GMP). Potato tubers in turn reduce their defenses to preserve energy to prevent the negative effects of reactive oxygen species and acidification, making them prone to soft rot disease. To reduce the losses caused by the soft rot disease we need sensitive and reliable methods for the detection of the pathogens, to isolate infected plant material. However, due to the high prevalence of SRPs in the environment, we also need to create new potato varieties more resistant to the disease. To reach that goal, we can look to wild potatoes and other Solanum species for mechanisms of resistance to waterlogging. Potato resistance can also be aided by beneficial microorganisms which can induce the plant's natural defenses to bacterial infections but also waterlogging. However, most of the known plant-beneficial microorganisms suffer from hypoxia and can be outcompeted by plant pathogens. Therefore, it is important to look for microorganisms that can withstand hypoxia or alleviate its effects on the plant, e.g., by improving soil structure. Therefore, this review aims to present crucial elements of potato response to hypoxia and SRP infection and future outlooks for the prevention of soft rot disease considering the influence of environmental conditions.
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Affiliation(s)
- Tomasz Maciag
- Department of Botany, Institute of Biology, Warsaw University of Life Sciences—SGGW, Nowoursynowska Street 159, 02-776 Warsaw, Poland;
| | - Edmund Kozieł
- Department of Botany, Institute of Biology, Warsaw University of Life Sciences—SGGW, Nowoursynowska Street 159, 02-776 Warsaw, Poland;
| | - Katarzyna Otulak-Kozieł
- Department of Botany, Institute of Biology, Warsaw University of Life Sciences—SGGW, Nowoursynowska Street 159, 02-776 Warsaw, Poland;
| | - Sylwia Jafra
- Laboratory of Plant Microbiology, Intercollegiate Faculty of Biotechnology UG and MUG, University of Gdansk, Antoniego Abrahama Street 58, 80-307 Gdansk, Poland;
| | - Robert Czajkowski
- Laboratory of Biologically Active Compounds, Intercollegiate Faculty of Biotechnology UG and MUG, University of Gdansk, Antoniego Abrahama Street 58, 80-307 Gdansk, Poland;
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2
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Schuelke-Sanchez A, Yennawar NH, Weinert EE. Oxygen-selective regulation of cyclic di-GMP synthesis by a globin coupled sensor with a shortened linking domain modulates Shewanella sp. ANA-3 biofilm. J Inorg Biochem 2024; 252:112482. [PMID: 38218138 DOI: 10.1016/j.jinorgbio.2024.112482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 01/03/2024] [Accepted: 01/04/2024] [Indexed: 01/15/2024]
Abstract
Bacteria utilize heme proteins, such as globin coupled sensors (GCSs), to sense and respond to oxygen levels. GCSs are predicted in almost 2000 bacterial species and consist of a globin domain linked by a central domain to a variety of output domains, including diguanylate cyclase domains that synthesize c-di-GMP, a major regulator of biofilm formation. To investigate the effects of middle domain length and heme edge residues on GCS diguanylate cyclase activity and cellular function, a putative diguanylate cyclase-containing GCS from Shewanella sp. ANA-3 (SA3GCS) was characterized. Binding of O2 to the heme resulted in activation of diguanylate cyclase activity, while NO and CO binding had minimal effects on catalysis, demonstrating that SA3GCS exhibits greater ligand selectivity for cyclase activation than many other diguanylate cyclase-containing GCSs. Small angle X-ray scattering analysis of dimeric SA3GCS identified movement of the cyclase domains away from each other, while maintaining the globin dimer interface, as a potential mechanism for regulating cyclase activity. Comparison of the Shewanella ANA-3 wild type and SA3GCS deletion (ΔSA3GCS) strains identified changes in biofilm formation, demonstrating that SA3GCS diguanylate cyclase activity modulates Shewanella phenotypes.
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Affiliation(s)
- Ariel Schuelke-Sanchez
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA 16802, USA
| | - Neela H Yennawar
- The Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA 16802, USA
| | - Emily E Weinert
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA 16802, USA; Department of Chemistry, Pennsylvania State University, University Park, PA 16802, USA.
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3
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Anbalagan S. Heme-based oxygen gasoreceptors. Am J Physiol Endocrinol Metab 2024; 326:E178-E181. [PMID: 38231000 DOI: 10.1152/ajpendo.00004.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2024] [Accepted: 01/07/2024] [Indexed: 01/18/2024]
Abstract
To investigate gasocrine signaling, there is a critical need to identify gasoreceptors for the essential gasotransmitters like O2. Based on existing scientific literature, I propose that heme-based O2 sensors, featuring diverse signaling domains across genera, should be explicitly designated as O2 gasoreceptors. Acknowledging that O2 gasoreceptors are likely to belong to multiple protein classes with diverse signaling domains and pathways will facilitate a comprehensive search for O2 gasoreceptors in all organisms and across every cell type. This approach will broaden the investigation beyond specialized tissues or cells, encompassing a systemic exploration.
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Affiliation(s)
- Savani Anbalagan
- Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University, Poznań, Poland
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4
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Hoque NJ, Weinert EE. Control of bacterial second messenger signaling and motility by heme-based direct oxygen-sensing proteins. Curr Opin Microbiol 2023; 76:102396. [PMID: 37864983 DOI: 10.1016/j.mib.2023.102396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 09/15/2023] [Accepted: 09/21/2023] [Indexed: 10/23/2023]
Abstract
Bacteria sense and respond to their environment, allowing them to maximize their survival and growth under changing conditions, such as oxygen levels. Direct oxygen-sensing proteins allow bacteria to rapidly sense concentration changes and adapt by regulating signaling pathways and/or cellular machinery. Recent work has identified roles for direct oxygen-sensing proteins in controlling second messenger levels and motility machinery, as well as effects on biofilm formation, virulence, and motility. In this review, we discuss recent progress in understanding O2-dependent regulation of cyclic di-GMP signaling and motility and highlight the emerging importance in controlling bacterial physiology and behavior.
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Affiliation(s)
- Nushrat J Hoque
- Department of Chemistry, Penn State University, University Park, PA 16802, USA
| | - Emily E Weinert
- Department of Chemistry, Penn State University, University Park, PA 16802, USA; Department of Biochemistry & Molecular Biology, Penn State University, University Park, PA 16802, USA.
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5
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Williams MT, Yee E, Larson GW, Apiche EA, Rama Damodaran A, Bhagi-Damodaran A. Metalloprotein enabled redox signal transduction in microbes. Curr Opin Chem Biol 2023; 76:102331. [PMID: 37311385 PMCID: PMC10524656 DOI: 10.1016/j.cbpa.2023.102331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 04/21/2023] [Accepted: 04/26/2023] [Indexed: 06/15/2023]
Abstract
Microbes utilize numerous metal cofactor-containing proteins to recognize and respond to constantly fluctuating redox stresses in their environment. Gaining an understanding of how these metalloproteins sense redox events, and how they communicate such information downstream to DNA to modulate microbial metabolism, is a topic of great interest to both chemists and biologists. In this article, we review recently characterized examples of metalloprotein sensors, focusing on the coordination and oxidation state of the metals involved, how these metals are able to recognize redox stimuli, and how the signal is transmitted beyond the metal center. We discuss specific examples of iron, nickel, and manganese-based microbial sensors, and identify gaps in knowledge in the field of metalloprotein-based signal transduction pathways.
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Affiliation(s)
- Murphi T Williams
- Department of Chemistry, University of Minnesota Twin Cities, 207 Pleasant St. SE, Minneapolis MN 55414, USA
| | - Eaindra Yee
- Department of Chemistry, University of Minnesota Twin Cities, 207 Pleasant St. SE, Minneapolis MN 55414, USA
| | - Grant W Larson
- Department of Chemistry, University of Minnesota Twin Cities, 207 Pleasant St. SE, Minneapolis MN 55414, USA
| | - Elizabeth A Apiche
- Department of Chemistry, University of Minnesota Twin Cities, 207 Pleasant St. SE, Minneapolis MN 55414, USA
| | - Anoop Rama Damodaran
- Department of Chemistry, University of Minnesota Twin Cities, 207 Pleasant St. SE, Minneapolis MN 55414, USA
| | - Ambika Bhagi-Damodaran
- Department of Chemistry, University of Minnesota Twin Cities, 207 Pleasant St. SE, Minneapolis MN 55414, USA.
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6
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Fekete FJ, Marotta NJ, Liu X, Weinert EE. An O 2-sensing diguanylate cyclase broadly affects the aerobic transcriptome in the phytopathogen Pectobacterium carotovorum. Front Microbiol 2023; 14:1134742. [PMID: 37485529 PMCID: PMC10360401 DOI: 10.3389/fmicb.2023.1134742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Accepted: 06/26/2023] [Indexed: 07/25/2023] Open
Abstract
Pectobacterium carotovorum is an important plant pathogen responsible for the destruction of crops through bacterial soft rot, which is modulated by oxygen (O2) concentration. A soluble globin coupled sensor protein, Pcc DgcO (also referred to as PccGCS) is one way through which P. carotovorum senses oxygen. DgcO contains a diguanylate cyclase output domain producing c-di-GMP. Synthesis of the bacterial second messenger c-di-GMP is increased upon oxygen binding to the sensory globin domain. This work seeks to understand regulation of function by DgcO at the transcript level. RNA sequencing and differential expression analysis revealed that the deletion of DgcO only affects transcript levels in cells grown under aerobic conditions. Differential expression analysis showed that DgcO deletion alters transcript levels for metal transporters. These results, followed by inductively coupled plasma-mass spectrometry showing decreased concentrations of six biologically relevant metals upon DgcO deletion, provide evidence that a globin coupled sensor can affect cellular metal content. These findings improve the understanding of the transcript level control of O2-dependent phenotypes in an important phytopathogen and establish a basis for further studies on c-di-GMP-dependent functions in P. carotovorum.
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Affiliation(s)
- Florian J. Fekete
- Department of Biochemistry and Molecular Biology, Penn State University, University Park, PA, United States
| | - Nick J. Marotta
- Graduate Program in Molecular, Cellular, and Integrative Biosciences, Penn State University, University Park, PA, United States
| | - Xuanyu Liu
- Department of Biochemistry and Molecular Biology, Penn State University, University Park, PA, United States
| | - Emily E. Weinert
- Department of Biochemistry and Molecular Biology, Penn State University, University Park, PA, United States
- Department of Chemistry, Penn State University, University Park, PA, United States
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7
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Yu Z, Zhang W, Yang H, Chou SH, Galperin MY, He J. Gas and light: triggers of c-di-GMP-mediated regulation. FEMS Microbiol Rev 2023; 47:fuad034. [PMID: 37339911 PMCID: PMC10505747 DOI: 10.1093/femsre/fuad034] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 06/01/2023] [Accepted: 06/17/2023] [Indexed: 06/22/2023] Open
Abstract
The widespread bacterial second messenger c-di-GMP is responsible for regulating many important physiological functions such as biofilm formation, motility, cell differentiation, and virulence. The synthesis and degradation of c-di-GMP in bacterial cells depend, respectively, on diguanylate cyclases and c-di-GMP-specific phosphodiesterases. Since c-di-GMP metabolic enzymes (CMEs) are often fused to sensory domains, their activities are likely controlled by environmental signals, thereby altering cellular c-di-GMP levels and regulating bacterial adaptive behaviors. Previous studies on c-di-GMP-mediated regulation mainly focused on downstream signaling pathways, including the identification of CMEs, cellular c-di-GMP receptors, and c-di-GMP-regulated processes. The mechanisms of CME regulation by upstream signaling modules received less attention, resulting in a limited understanding of the c-di-GMP regulatory networks. We review here the diversity of sensory domains related to bacterial CME regulation. We specifically discuss those domains that are capable of sensing gaseous or light signals and the mechanisms they use for regulating cellular c-di-GMP levels. It is hoped that this review would help refine the complete c-di-GMP regulatory networks and improve our understanding of bacterial behaviors in changing environments. In practical terms, this may eventually provide a way to control c-di-GMP-mediated bacterial biofilm formation and pathogenesis in general.
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Affiliation(s)
- Zhaoqing Yu
- National Key Laboratory of Agricultural Microbiology and Hubei Hongshan Laboratory, College of Life Science and Technology, Huazhong Agricultural University, 1 Shizishan Street, Wuhan, Hubei 430070, PR China
- Institute of Agro-Product Processing, Jiangsu Academy of Agricultural Sciences, 50 Zhongling Street, Nanjing, Jiangsu 210014, PR China
| | - Wei Zhang
- National Key Laboratory of Agricultural Microbiology and Hubei Hongshan Laboratory, College of Life Science and Technology, Huazhong Agricultural University, 1 Shizishan Street, Wuhan, Hubei 430070, PR China
| | - He Yang
- National Key Laboratory of Agricultural Microbiology and Hubei Hongshan Laboratory, College of Life Science and Technology, Huazhong Agricultural University, 1 Shizishan Street, Wuhan, Hubei 430070, PR China
| | - Shan-Ho Chou
- National Key Laboratory of Agricultural Microbiology and Hubei Hongshan Laboratory, College of Life Science and Technology, Huazhong Agricultural University, 1 Shizishan Street, Wuhan, Hubei 430070, PR China
| | - Michael Y Galperin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, 8600 Rockville Pike, Bethesda, MD 20894, USA
| | - Jin He
- National Key Laboratory of Agricultural Microbiology and Hubei Hongshan Laboratory, College of Life Science and Technology, Huazhong Agricultural University, 1 Shizishan Street, Wuhan, Hubei 430070, PR China
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8
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Snyder SN, Chiura T, Mak PJ. Resonance Raman Characterization of O 2-Binding Heme Proteins. Methods Mol Biol 2023; 2648:27-41. [PMID: 37039983 DOI: 10.1007/978-1-0716-3080-8_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
Abstract
A vast array of critical in vivo processes and pathways are dependent on a multitude of O2-binding heme proteins which contain a diverse range of functions. Resonance Raman (rR) spectroscopy is an ideal technique for structural investigation of these proteins, providing information about the geometry of the Fe-O-O fragment and its electrostatic interactions with the distal active site. Characterization of these oxy adducts is an endeavor that is complicated by their instability for many heme proteins in solution, an obstacle which can be overcome by applying the rR technique to cryogenically frozen samples. We describe here how to measure rR spectra of heme proteins with stable oxy forms, as well as the technical adaptations required to measure unstable samples at 77 K.
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Affiliation(s)
- Samuel N Snyder
- Department of Chemistry, Saint Louis University, Saint Louis, MO, USA
| | - Tapiwa Chiura
- Department of Chemistry, Saint Louis University, Saint Louis, MO, USA
| | - Piotr J Mak
- Department of Chemistry, Saint Louis University, Saint Louis, MO, USA.
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9
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Patterson DC, Ruiz MP, Yoon H, Walker JA, Armache JP, Yennawar NH, Weinert EE. Differential ligand-selective control of opposing enzymatic activities within a bifunctional c-di-GMP enzyme. Proc Natl Acad Sci U S A 2021; 118:e2100657118. [PMID: 34475207 PMCID: PMC8433548 DOI: 10.1073/pnas.2100657118] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Accepted: 08/02/2021] [Indexed: 01/23/2023] Open
Abstract
Cyclic dimeric guanosine monophosphate (c-di-GMP) serves as a second messenger that modulates bacterial cellular processes, including biofilm formation. While proteins containing both c-di-GMP synthesizing (GGDEF) and c-di-GMP hydrolyzing (EAL) domains are widely predicted in bacterial genomes, it is poorly understood how domains with opposing enzymatic activity are regulated within a single polypeptide. Herein, we report the characterization of a globin-coupled sensor protein (GCS) from Paenibacillus dendritiformis (DcpG) with bifunctional c-di-GMP enzymatic activity. DcpG contains a regulatory sensor globin domain linked to diguanylate cyclase (GGDEF) and phosphodiesterase (EAL) domains that are differentially regulated by gas binding to the heme; GGDEF domain activity is activated by the Fe(II)-NO state of the globin domain, while EAL domain activity is activated by the Fe(II)-O2 state. The in vitro activity of DcpG is mimicked in vivo by the biofilm formation of P. dendritiformis in response to gaseous environment, with nitric oxide conditions leading to the greatest amount of biofilm formation. The ability of DcpG to differentially control GGDEF and EAL domain activity in response to ligand binding is likely due to the unusual properties of the globin domain, including rapid ligand dissociation rates and high midpoint potentials. Using structural information from small-angle X-ray scattering and negative stain electron microscopy studies, we developed a structural model of DcpG, providing information about the regulatory mechanism. These studies provide information about full-length GCS protein architecture and insight into the mechanism by which a single regulatory domain can selectively control output domains with opposing enzymatic activities.
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Affiliation(s)
- Dayna C Patterson
- Department of Chemistry, The Pennsylvania State University, University Park, PA 16802
| | - Myrrh Perez Ruiz
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802
| | - Hyerin Yoon
- Department of Chemistry, Emory University, Atlanta, GA 30322
| | | | - Jean-Paul Armache
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802
- The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA 16802
| | - Neela H Yennawar
- The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA 16802
| | - Emily E Weinert
- Department of Chemistry, The Pennsylvania State University, University Park, PA 16802;
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802
- The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA 16802
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10
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π-Helix controls activity of oxygen-sensing diguanylate cyclases. Biosci Rep 2021; 40:222070. [PMID: 32039439 PMCID: PMC7033309 DOI: 10.1042/bsr20193602] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Revised: 02/04/2020] [Accepted: 02/07/2020] [Indexed: 11/18/2022] Open
Abstract
The ability of organisms to sense and adapt to oxygen levels in their environment leads to changes in cellular phenotypes, including biofilm formation and virulence. Globin coupled sensors (GCSs) are a family of heme proteins that regulate diverse functions in response to O2 levels, including modulating synthesis of cyclic dimeric guanosine monophosphate (c-di-GMP), a bacterial second messenger that regulates biofilm formation. While GCS proteins have been demonstrated to regulate O2-dependent pathways, the mechanism by which the O2 binding event is transmitted from the globin domain to the cyclase domain is unknown. Using chemical cross-linking and subsequent liquid chromatography-tandem mass spectrometry, diguanylate cyclase (DGC)-containing GCS proteins from Bordetella pertussis (BpeGReg) and Pectobacterium carotovorum (PccGCS) have been demonstrated to form direct interactions between the globin domain and a middle domain π-helix. Additionally, mutation of the π-helix caused major changes in oligomerization and loss of DGC activity. Furthermore, results from assays with isolated globin and DGC domains found that DGC activity is affected by the cognate globin domain, indicating unique interactions between output domain and cognate globin sensor. Based on these studies a compact GCS structure, which depends on the middle domain π-helix for orienting the three domains, is needed for DGC activity and allows for direct sensor domain interactions with both middle and output domains to transmit the O2 binding signal. The insights from the present study improve our understanding of DGC regulation and provide insight into GCS signaling that may lead to the ability to rationally control O2-dependent GCS activity.
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11
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Identification and characterization of virulence-attenuated mutants in Ralstonia solanacearum as potential biocontrol agents against bacterial wilt of Pogostemon cablin. Microb Pathog 2020; 147:104418. [PMID: 32739402 DOI: 10.1016/j.micpath.2020.104418] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2020] [Revised: 06/30/2020] [Accepted: 07/23/2020] [Indexed: 12/31/2022]
Abstract
Ralstonia solanacearum is a soil-borne pathogen that causes bacterial wilt worldwide. The virulence-attenuated mutants were able to combat the soil-borne plant diseases. In this study, we screened the virulence-attenuated mutant PRS-84-4-49 of Ralstonia solanacearum and demonstrated that this strain showed a significant biocontrol effect against patchouli bacterial wilt. Three putative virulence-attenuated mutants obtained in our previous preliminary screen were individually tested for their pathogenicity to patchouli plants. Mutant PRS-84-4-49 showed significantly less virulence to patchouli plants than the other investigated mutants. The virulence-attenuated mutant PRS-84-4-49 was then evaluated for its potential to control patchouli bacterial wilt. The results revealed that the biocontrol treatment significantly reduced disease severity compared with the inoculated control plants, their highest disease incidence were 33% and 63%, respectively, at 5 days post-inoculation. Mutant PRS-84-4-49 exhibited less motility and produced fewer biofilms than the wild-type strain. Therefore, our results demonstrate that virulence-attenuated mutant of Ralstonia solanacearum has potential as biological control agent capable of suppressing patchouli bacterial wilt.
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12
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Skalova T, Lengalova A, Dohnalek J, Harlos K, Mihalcin P, Kolenko P, Stranava M, Blaha J, Shimizu T, Martínková M. Disruption of the dimerization interface of the sensing domain in the dimeric heme-based oxygen sensor AfGcHK abolishes bacterial signal transduction. J Biol Chem 2020; 295:1587-1597. [PMID: 31914416 PMCID: PMC7008379 DOI: 10.1074/jbc.ra119.011574] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 12/30/2019] [Indexed: 12/17/2022] Open
Abstract
The heme-based oxygen sensor protein AfGcHK is a globin-coupled histidine kinase in the soil bacterium Anaeromyxobacter sp. Fw109-5. Its C-terminal functional domain exhibits autophosphorylation activity induced by oxygen binding to the heme-Fe(II) complex located in the oxygen-sensing N-terminal globin domain. A detailed understanding of the signal transduction mechanisms in heme-containing sensor proteins remains elusive. Here, we investigated the role of the globin domain's dimerization interface in signal transduction in AfGcHK. We present a crystal structure of a monomeric imidazole-bound AfGcHK globin domain at 1.8 Å resolution, revealing that the helices of the WT globin dimer are under tension and suggesting that Tyr-15 plays a role in both this tension and the globin domain's dimerization. Biophysical experiments revealed that whereas the isolated WT globin domain is dimeric in solution, the Y15A and Y15G variants in which Tyr-15 is replaced with Ala or Gly, respectively, are monomeric. Additionally, we found that although the dimerization of the full-length protein is preserved via the kinase domain dimerization interface in all variants, full-length AfGcHK variants bearing the Y15A or Y15G substitutions lack enzymatic activity. The combined structural and biophysical results presented here indicate that Tyr-15 plays a key role in the dimerization of the globin domain of AfGcHK and that globin domain dimerization is essential for internal signal transduction and autophosphorylation in this protein. These findings provide critical insights into the signal transduction mechanism of the histidine kinase AfGcHK from Anaeromyxobacter.
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Affiliation(s)
- Tereza Skalova
- Institute of Biotechnology of the Czech Academy of Sciences, v.v.i., Biocev, Vestec, 252 50 Czech Republic
| | - Alzbeta Lengalova
- Department of Biochemistry, Faculty of Science, Charles University, Prague 2, 128 43 Czech Republic
| | - Jan Dohnalek
- Institute of Biotechnology of the Czech Academy of Sciences, v.v.i., Biocev, Vestec, 252 50 Czech Republic
| | - Karl Harlos
- Division of Structural Biology, The Wellcome Trust Centre for Human Genetics, University of Oxford, OX3 7BN Oxford, United Kingdom
| | - Peter Mihalcin
- Department of Biochemistry, Faculty of Science, Charles University, Prague 2, 128 43 Czech Republic
| | - Petr Kolenko
- Institute of Biotechnology of the Czech Academy of Sciences, v.v.i., Biocev, Vestec, 252 50 Czech Republic; FNSPE, Czech Technical University in Prague, Brehova 7, Prague 1, 115 19 Czech Republic
| | - Martin Stranava
- Department of Biochemistry, Faculty of Science, Charles University, Prague 2, 128 43 Czech Republic
| | - Jan Blaha
- Department of Biochemistry, Faculty of Science, Charles University, Prague 2, 128 43 Czech Republic
| | - Toru Shimizu
- Department of Biochemistry, Faculty of Science, Charles University, Prague 2, 128 43 Czech Republic
| | - Markéta Martínková
- Department of Biochemistry, Faculty of Science, Charles University, Prague 2, 128 43 Czech Republic.
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13
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Kuang S, Yuan Y, Wu Z, Peng R. Expression, purification and characterization of diguanylate cyclase from Rhodococcus ruber. Protein Expr Purif 2019; 163:105441. [PMID: 31195084 DOI: 10.1016/j.pep.2019.06.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 06/06/2019] [Accepted: 06/06/2019] [Indexed: 12/28/2022]
Abstract
Diguanylate cyclases (DGCs) were responsible for the synthesis of second messenger cyclic di-guanosine monophosphate (c-di-GMP), which were involved in various physiological activities of bacterial species. Here, a full-length DGC from Rhodococcus ruber SD3 fused with glutathione-S-transferase (GST) was expressed in E. coli and purified by glutathione agarose resin. The apparent molecular mass of one subunit of the purified diguanylate cyclase with GST tag (GST-DGC) was estimated to be 71.9 kDa by SDS-PAGE, which was approximately in accordance with the theoretical value of 73.0 kDa. The sequence of GST-DGC was confirmed by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). The blue native PAGE indicated that GST-DGC formed octamer. The optimum pH and temperature for GST-DGC activity were 8.0 and 47 °C, respectively. The fusion protein exhibited high thermostability, and 94% of activity was retained when the protein was incubated at 87 °C for 1 h. Moreover, the fusion protein showed pH stability. The Km, Vmax and Kcat values for GST-DGC enzyme were 9.8 μM, 0.7 μM/min and 1.3 S-1. Some ions such as Zn2+, Mn2+, Fe2+, Ni2+ and Co2+ had inhibitory effects on the activity of the protein, while other ions such as Mg2+, K+ and Na+ slightly activated the protein. The fusion protein also showed rather high stability in the presence of toluene, cyclohexane and n-hexane.
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Affiliation(s)
- Sufang Kuang
- College of Life Science, Jiangxi Normal University, Nanchang, Jiangxi, People's Republic of China
| | - Yuan Yuan
- College of Life Science, Jiangxi Normal University, Nanchang, Jiangxi, People's Republic of China
| | - Zhonghao Wu
- College of Life Science, Jiangxi Normal University, Nanchang, Jiangxi, People's Republic of China
| | - Ren Peng
- College of Life Science, Jiangxi Normal University, Nanchang, Jiangxi, People's Republic of China.
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14
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Rivera S, Young PG, Hoffer ED, Vansuch GE, Metzler CL, Dunham CM, Weinert EE. Structural Insights into Oxygen-Dependent Signal Transduction within Globin Coupled Sensors. Inorg Chem 2018; 57:14386-14395. [PMID: 30378421 DOI: 10.1021/acs.inorgchem.8b02584] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
In order to respond to external stimuli, bacteria have evolved sensor proteins linking external signals to intracellular outputs that can then regulate downstream pathways and phenotypes. Globin coupled sensor proteins (GCSs) serve to link environmental O2 levels to cellular processes by coupling a heme-containing sensor globin domain to a catalytic output domain. However, the mechanism by which O2 binding activates these proteins is currently unknown. To provide insights into the signaling mechanism, two distinct dimeric complexes of the isolated globin domain of the GCS from Bordetella pertussis ( BpeGlobin) were solved via X-ray crystallography in which differences in ligand-bound states were observed. Both monomers of one dimer contain Fe(II)-O2 states, while the other dimer consists of the Fe(III)-H2O and Fe(II)-O2 states. These data provide the first molecular insights into the heme pocket conformation of the active Fe(II)-O2 form of these enzymes. In addition, heme distortion modes and heme-protein interactions were found to correlate with the ligation state of the globin, suggesting that these conformational changes play a role in O2-dependent signaling. Fourier transform infrared spectroscopy (FTIR) of the full-length GCS from B. pertussis ( BpeGReg) and the closely related GCS from Pectobacterium carotovorum ssp. carotovorum ( PccGCS) confirmed the importance of an ordered water within the heme pocket and two distal residues (Tyr43 and Ser68) as hydrogen-bond donors. Taken together, this work provides mechanistic insights into BpeGReg O2 sensing and the signaling mechanisms of diguanylate cyclase-containing GCS proteins.
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Affiliation(s)
- Shannon Rivera
- Department of Chemistry , Emory University , Atlanta , Georgia 30322 , United States
| | - Paul G Young
- Department of Chemistry , Emory University , Atlanta , Georgia 30322 , United States
| | - Eric D Hoffer
- Department of Biochemistry , Emory University , Atlanta , Georgia 30322 , United States
| | - Gregory E Vansuch
- Department of Chemistry , Emory University , Atlanta , Georgia 30322 , United States
| | - Carmen L Metzler
- Department of Chemistry , Emory University , Atlanta , Georgia 30322 , United States
| | - Christine M Dunham
- Department of Biochemistry , Emory University , Atlanta , Georgia 30322 , United States
| | - Emily E Weinert
- Department of Chemistry , Emory University , Atlanta , Georgia 30322 , United States
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15
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Bretl DJ, Ladd KM, Atkinson SN, Müller S, Kirby JR. Suppressor mutations reveal an NtrC-like response regulator, NmpR, for modulation of Type-IV Pili-dependent motility in Myxococcus xanthus. PLoS Genet 2018; 14:e1007714. [PMID: 30346960 PMCID: PMC6211767 DOI: 10.1371/journal.pgen.1007714] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 11/01/2018] [Accepted: 09/26/2018] [Indexed: 12/03/2022] Open
Abstract
Two-component signaling systems (TCS) regulate bacterial responses to environmental signals through the process of protein phosphorylation. Specifically, sensor histidine kinases (SK) recognize signals and propagate the response via phosphorylation of a cognate response regulator (RR) that functions to initiate transcription of specific genes. Signaling within a single TCS is remarkably specific and cross-talk between TCS is limited. However, regulation of the flow of information through complex signaling networks that include closely related TCS remains largely unknown. Additionally, many bacteria utilize multi-component signaling networks which provide additional genetic and biochemical interactions that must be regulated for signaling fidelity, input and output specificity, and phosphorylation kinetics. Here we describe the characterization of an NtrC-like RR that participates in regulation of Type-IV pilus-dependent motility of Myxococcus xanthus and is thus named NmpR, NtrC Modulator of Pili Regulator. A complex multi-component signaling system including NmpR was revealed by suppressor mutations that restored motility to cells lacking PilR, an evolutionarily conserved RR required for expression of pilA encoding the major Type-IV pilus monomer found in many bacterial species. The system contains at least four signaling proteins: a SK with a protoglobin sensor domain (NmpU), a hybrid SK (NmpS), a phospho-sink protein (NmpT), and an NtrC-like RR (NmpR). We demonstrate that ΔpilR bypass suppressor mutations affect regulation of the NmpRSTU multi-component system, such that NmpR activation is capable of restoring expression of pilA in the absence of PilR. Our findings indicate that pilus gene expression in M. xanthus is regulated by an extended network of TCS which interact to refine control of pilus function.
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Affiliation(s)
- Daniel J. Bretl
- Department of Microbiology and Immunology, Medical College of Wisconsin, Milwaukee, WI, United States of America
| | - Kayla M. Ladd
- Department of Biochemistry, University of Iowa, Iowa City, Iowa, United States of America
| | - Samantha N. Atkinson
- Department of Microbiology and Immunology, Medical College of Wisconsin, Milwaukee, WI, United States of America
- Department of Bioinformatics, University of Iowa, Iowa City, Iowa, United States of America
| | - Susanne Müller
- Department of Microbiology and Immunology, Medical College of Wisconsin, Milwaukee, WI, United States of America
| | - John R. Kirby
- Department of Microbiology and Immunology, Medical College of Wisconsin, Milwaukee, WI, United States of America
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