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Moreno-Blanco A, Pluta R, Espinosa M, Ruiz-Cruz S, Bravo A. Promoter DNA recognition by the Enterococcus faecalis global regulator MafR. Front Mol Biosci 2023; 10:1294974. [PMID: 38192335 PMCID: PMC10773906 DOI: 10.3389/fmolb.2023.1294974] [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: 09/15/2023] [Accepted: 11/30/2023] [Indexed: 01/10/2024] Open
Abstract
When Enterococcus faecalis is exposed to changing environmental conditions, the expression of many genes is regulated at the transcriptional level. We reported previously that the enterococcal MafR protein causes genome-wide changes in the transcriptome. Here we show that MafR activates directly the transcription of the OG1RF_10478 gene, which encodes a hypothetical protein of 111 amino acid residues. We have identified the P10478 promoter and demonstrated that MafR enhances the efficiency of this promoter by binding to a DNA site that contains the -35 element. Moreover, our analysis of the OG1RF_10478 protein AlphaFold model indicates high similarity to 1) structures of EIIB components of the bacterial phosphoenolpyruvate:carbohydrate phosphotransferase system, and 2) structures of receiver domains that are found in response regulators of two-component signal transduction systems. However, unlike typical EIIB components, OG1RF_10478 lacks a Cys or His residue at the conserved phosphorylation site, and, unlike typical receiver domains, OG1RF_10478 lacks a conserved Asp residue at the position usually required for phosphorylation. Different from EIIB components and receiver domains, OG1RF_10478 contains an insertion between residues 10 and 30 that, according to ColabFold prediction, may serve as a dimerization interface. We propose that OG1RF_10478 could participate in regulatory functions by protein-protein interactions.
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Affiliation(s)
- Ana Moreno-Blanco
- Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
| | - Radoslaw Pluta
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Manuel Espinosa
- Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
| | - Sofía Ruiz-Cruz
- Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
| | - Alicia Bravo
- Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
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Marini E, Olivença C, Ramalhete S, Aguirre AM, Ingle P, Melo MN, Antunes W, Minton NP, Hernandez G, Cordeiro TN, Sorg JA, Serrano M, Henriques AO. A sporulation signature protease is required for assembly of the spore surface layers, germination and host colonization in Clostridioides difficile. PLoS Pathog 2023; 19:e1011741. [PMID: 37956166 PMCID: PMC10681294 DOI: 10.1371/journal.ppat.1011741] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 11/27/2023] [Accepted: 10/09/2023] [Indexed: 11/15/2023] Open
Abstract
A genomic signature for endosporulation includes a gene coding for a protease, YabG, which in the model organism Bacillus subtilis is involved in assembly of the spore coat. We show that in the human pathogen Clostridioidesm difficile, YabG is critical for the assembly of the coat and exosporium layers of spores. YabG is produced during sporulation under the control of the mother cell-specific regulators σE and σK and associates with the spore surface layers. YabG shows an N-terminal SH3-like domain and a C-terminal domain that resembles single domain response regulators, such as CheY, yet is atypical in that the conserved phosphoryl-acceptor residue is absent. Instead, the CheY-like domain carries residues required for activity, including Cys207 and His161, the homologues of which form a catalytic diad in the B. subtilis protein, and also Asp162. The substitution of any of these residues by Ala, eliminates an auto-proteolytic activity as well as interdomain processing of CspBA, a reaction that releases the CspB protease, required for proper spore germination. An in-frame deletion of yabG or an allele coding for an inactive protein, yabGC207A, both cause misassemby of the coat and exosporium and the formation of spores that are more permeable to lysozyme and impaired in germination and host colonization. Furthermore, we show that YabG is required for the expression of at least two σK-dependent genes, cotA, coding for a coat protein, and cdeM, coding for a key determinant of exosporium assembly. Thus, YabG also impinges upon the genetic program of the mother cell possibly by eliminating a transcriptional repressor. Although this activity has not been described for the B. subtilis protein and most of the YabG substrates vary among sporeformers, the general role of the protease in the assembly of the spore surface is likely to be conserved across evolutionary distance.
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Affiliation(s)
- Eleonora Marini
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Avenida da República EAN, Oeiras, Portugal
| | - Carmen Olivença
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Avenida da República EAN, Oeiras, Portugal
| | - Sara Ramalhete
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Avenida da República EAN, Oeiras, Portugal
| | - Andrea Martinez Aguirre
- Texas A&M University, Department of Biology, College Station, Texas, United States of America
| | - Patrick Ingle
- Clostridia Research Group, BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Manuel N Melo
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Avenida da República EAN, Oeiras, Portugal
| | - Wilson Antunes
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Avenida da República EAN, Oeiras, Portugal
| | - Nigel P Minton
- Clostridia Research Group, BBSRC/EPSRC Synthetic Biology Research Centre (SBRC), School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Guillem Hernandez
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Avenida da República EAN, Oeiras, Portugal
| | - Tiago N Cordeiro
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Avenida da República EAN, Oeiras, Portugal
| | - Joseph A Sorg
- Texas A&M University, Department of Biology, College Station, Texas, United States of America
| | - Mónica Serrano
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Avenida da República EAN, Oeiras, Portugal
| | - Adriano O Henriques
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Avenida da República EAN, Oeiras, Portugal
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3
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Tang J, Yao D, Zhou H, Wang M, Daroch M. Distinct Molecular Patterns of Two-Component Signal Transduction Systems in Thermophilic Cyanobacteria as Revealed by Genomic Identification. BIOLOGY 2023; 12:biology12020271. [PMID: 36829548 PMCID: PMC9953108 DOI: 10.3390/biology12020271] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 01/30/2023] [Accepted: 02/07/2023] [Indexed: 02/11/2023]
Abstract
Two-component systems (TCSs) play crucial roles in sensing and responding to environmental signals, facilitating the acclimation of cyanobacteria to hostile niches. To date, there is limited information on the TCSs of thermophilic cyanobacteria. Here, genome-based approaches were used to gain insights into the structure and architecture of the TCS in 17 well-described thermophilic cyanobacteria, namely strains from the genus Leptodesmis, Leptolyngbya, Leptothermofonsia, Thermoleptolyngbya, Thermostichus, and Thermosynechococcus. The results revealed a fascinating complexity and diversity of the TCSs. A distinct composition of TCS genes existed among these thermophilic cyanobacteria. A majority of TCS genes were classified as orphan, followed by the paired and complex cluster. A high proportion of histidine kinases (HKs) were predicted to be cytosolic subcellular localizations. Further analyses suggested diversified domain architectures of HK and response regulators (RRs), putatively in association with various functions. Comparative and evolutionary genomic analyses indicated that the horizontal gene transfer, as well as duplications events, might be involved in the evolutionary history of TCS genes in Thermostichus and Thermosynechococcus strains. A comparative analysis between thermophilic and mesophilic cyanobacteria indicated that one HK cluster and one RR cluster were uniquely shared by all the thermophilic cyanobacteria studied, while two HK clusters and one RR cluster were common to all the filamentous thermophilic cyanobacteria. These results suggested that these thermophile-unique clusters may be related to thermal characters and morphology. Collectively, this study shed light on the TCSs of thermophilic cyanobacteria, which may confer the necessary regulatory flexibility; these findings highlight that the genomes of thermophilic cyanobacteria have a broad potential for acclimations to environmental fluctuations.
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Affiliation(s)
- Jie Tang
- School of Food and Bioengineering, Chengdu University, Chengdu 610106, China
| | - Dan Yao
- School of Food and Bioengineering, Chengdu University, Chengdu 610106, China
| | - Huizhen Zhou
- School of Food and Bioengineering, Chengdu University, Chengdu 610106, China
| | - Mingcheng Wang
- School of Food and Bioengineering, Chengdu University, Chengdu 610106, China
| | - Maurycy Daroch
- School of Environment and Energy, Peking University Shenzhen Graduate School, 2199 Lishui Road, Shenzhen 518055, China
- Correspondence: ; Tel.: +86-0755-2603-2184
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4
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Leite Montalvão AP, Kersten B, Kim G, Fladung M, Müller NA. ARR17 controls dioecy in Populus by repressing B-class MADS-box gene expression. Philos Trans R Soc Lond B Biol Sci 2022; 377:20210217. [PMID: 35306887 PMCID: PMC8935312 DOI: 10.1098/rstb.2021.0217] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The number of dioecious species for which the genetic basis of sex determination has been resolved is rapidly increasing. Nevertheless, the molecular mechanisms downstream of the sex determinants remain largely elusive. Here, by RNA-sequencing early-flowering isogenic aspen (Populus tremula) lines differing exclusively for the sex switch gene ARR17, we show that a narrowly defined genetic network controls differential development of female and male flowers. Although ARR17 encodes a type-A response regulator supposedly involved in cytokinin (CK) hormone signalling, clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9-mediated arr17 knockout only affected the expression of a strikingly small number of genes, indicating a specific role in the regulation of floral development rather than a generic function in hormone signalling. Notably, the UNUSUAL FLORAL ORGANS (UFO) gene, encoding an F-box protein acting as a transcriptional cofactor with LEAFY (LFY) to activate B-class MADS-box gene expression, and the B-class gene PISTILLATA (PI), necessary for male floral organ development, were strongly de-repressed in the arr17 CRISPR mutants. Our data highlight a CK-independent role of the poplar response regulator ARR17 and further emphasize the minimal differences between female and male individuals. This article is part of the theme issue 'Sex determination and sex chromosome evolution in land plants'.
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Affiliation(s)
- Ana P Leite Montalvão
- Thünen Institute of Forest Genetics, Sieker Landstrasse 2, 22927 Grosshansdorf, Germany
| | - Birgit Kersten
- Thünen Institute of Forest Genetics, Sieker Landstrasse 2, 22927 Grosshansdorf, Germany
| | - Gihwan Kim
- Thünen Institute of Forest Genetics, Sieker Landstrasse 2, 22927 Grosshansdorf, Germany
| | - Matthias Fladung
- Thünen Institute of Forest Genetics, Sieker Landstrasse 2, 22927 Grosshansdorf, Germany
| | - Niels A Müller
- Thünen Institute of Forest Genetics, Sieker Landstrasse 2, 22927 Grosshansdorf, Germany
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5
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Phosphoproteomics Meets Chemical Genetics: Approaches for Global Mapping and Deciphering the Phosphoproteome. Int J Mol Sci 2020; 21:ijms21207637. [PMID: 33076458 PMCID: PMC7588962 DOI: 10.3390/ijms21207637] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Revised: 10/13/2020] [Accepted: 10/14/2020] [Indexed: 12/14/2022] Open
Abstract
Protein kinases are important enzymes involved in the regulation of various cellular processes. To function properly, each protein kinase phosphorylates only a limited number of proteins among the thousands present in the cell. This provides a rapid and dynamic regulatory mechanism that controls biological functions of the proteins. Despite the importance of protein kinases, most of their substrates remain unknown. Recently, the advances in the fields of protein engineering, chemical genetics, and mass spectrometry have boosted studies on identification of bona fide substrates of protein kinases. Among the various methods in protein kinase specific substrate identification, genetically engineered protein kinases and quantitative phosphoproteomics have become promising tools. Herein, we review the current advances in the field of chemical genetics in analog-sensitive protein kinase mutants and highlight selected strategies for identifying protein kinase substrates and studying the dynamic nature of protein phosphorylation.
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Barriot R, Latour J, Castanié-Cornet MP, Fichant G, Genevaux P. J-Domain Proteins in Bacteria and Their Viruses. J Mol Biol 2020; 432:3771-3789. [DOI: 10.1016/j.jmb.2020.04.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 04/10/2020] [Accepted: 04/14/2020] [Indexed: 02/06/2023]
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Krishnan J, Lu L, Alam Nazki A. The interplay of spatial organization and biochemistry in building blocks of cellular signalling pathways. J R Soc Interface 2020; 17:20200251. [PMID: 32453980 PMCID: PMC7276544 DOI: 10.1098/rsif.2020.0251] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Accepted: 04/24/2020] [Indexed: 12/14/2022] Open
Abstract
Biochemical pathways and networks are central to cellular information processing. While a broad range of studies have dissected multiple aspects of information processing in biochemical pathways, the effect of spatial organization remains much less understood. It is clear that space is central to intracellular organization, plays important roles in cellular information processing and has been exploited in evolution; additionally, it is being increasingly exploited in synthetic biology through the development of artificial compartments, in a variety of ways. In this paper, we dissect different aspects of the interplay between spatial organization and biochemical pathways, by focusing on basic building blocks of these pathways: covalent modification cycles and two-component systems, with enzymes which may be monofunctional or bifunctional. Our analysis of spatial organization is performed by examining a range of 'spatial designs': patterns of localization or non-localization of enzymes/substrates, theoretically and computationally. Using these well-characterized in silico systems, we analyse the following. (i) The effect of different types of spatial organization on the overall kinetics of modification, and the role of distinct modification mechanisms therein. (ii) How different information processing characteristics seen experimentally and studied from the viewpoint of kinetics are perturbed, or generated. (iii) How the activity of enzymes (bifunctional enzymes in particular) may be spatially manipulated, and the relationship between localization and activity. (iv) How transitions in spatial organization (encountered either through evolution or through the lifetime of cells, as seen in multiple model organisms) impacts the kinetic module (and pathway) behaviour, and how transitions in chemistry may be impacted by prior spatial organization. The basic insights which emerge are central to understanding the role of spatial organization in biochemical pathways in both bacteria and eukaryotes, and are of direct relevance to engineering spatial organization of pathways in bottom-up synthetic biology in cellular and cell-free systems.
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Affiliation(s)
- J. Krishnan
- Department of Chemical Engineering, Centre for Process Systems Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ, UK
- Institute for Systems and Synthetic Biology, Imperial College London, South Kensington Campus, London SW7 2AZ, UK
| | - Lingjun Lu
- Department of Chemical Engineering, Centre for Process Systems Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ, UK
| | - Aiman Alam Nazki
- Department of Chemical Engineering, Centre for Process Systems Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ, UK
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Li R, Wang X, Wu L, Huang L, Qin Q, Yao J, Lu G, Tang J. Xanthomonas campestris sensor kinase HpaS co-opts the orphan response regulator VemR to form a branched two-component system that regulates motility. MOLECULAR PLANT PATHOLOGY 2020; 21:360-375. [PMID: 31919999 PMCID: PMC7036368 DOI: 10.1111/mpp.12901] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Revised: 11/26/2019] [Accepted: 12/04/2019] [Indexed: 05/07/2023]
Abstract
Xanthomonas campestris pv. campestris (Xcc) controls virulence and plant infection mechanisms via the activity of the sensor kinase and response regulator pair HpaS/hypersensitive response and pathogenicity G (HrpG). Detailed analysis of the regulatory role of HpaS has suggested the occurrence of further regulators besides HrpG. Here we used in vitro and in vivo approaches to identify the orphan response regulator VemR as another partner of HpaS and to characterize relevant interactions between components of this signalling system. Bacterial two-hybrid and protein pull-down assays revealed that HpaS physically interacts with VemR. Phos-tag SDS-PAGE analysis showed that mutation in hpaS reduced markedly the phosphorylation of VemR in vivo. Mutation analysis reveals that HpaS and VemR contribute to the regulation of motility and this relationship appears to be epistatic. Additionally, we show that VemR control of Xcc motility is due in part to its ability to interact and bind to the flagellum rotor protein FliM. Taken together, the findings describe the unrecognized regulatory role of sensor kinase HpaS and orphan response regulator VemR in the control of motility in Xcc and contribute to the understanding of the complex regulatory mechanisms used by Xcc during plant infection.
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Affiliation(s)
- Rui‐Fang Li
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐bioresourcesCollege of Life Science and TechnologyGuangxi UniversityNanningChina
- Guangxi Key Laboratory of Biology for Crop Diseases and Insect PestsPlant Protection Research InstituteGuangxi Academy of Agricultural SciencesNanningChina
| | - Xin‐Xin Wang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐bioresourcesCollege of Life Science and TechnologyGuangxi UniversityNanningChina
| | - Liu Wu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐bioresourcesCollege of Life Science and TechnologyGuangxi UniversityNanningChina
| | - Li Huang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐bioresourcesCollege of Life Science and TechnologyGuangxi UniversityNanningChina
| | - Qi‐Jian Qin
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐bioresourcesCollege of Life Science and TechnologyGuangxi UniversityNanningChina
| | - Jia‐Li Yao
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐bioresourcesCollege of Life Science and TechnologyGuangxi UniversityNanningChina
| | - Guang‐Tao Lu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐bioresourcesCollege of Life Science and TechnologyGuangxi UniversityNanningChina
| | - Ji‐Liang Tang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐bioresourcesCollege of Life Science and TechnologyGuangxi UniversityNanningChina
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Qi YH, Huang L, Liu GF, Leng M, Lu GT. PilG and PilH antagonistically control flagellum-dependent and pili-dependent motility in the phytopathogen Xanthomonas campestris pv. campestris. BMC Microbiol 2020; 20:37. [PMID: 32070276 PMCID: PMC7029496 DOI: 10.1186/s12866-020-1712-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Accepted: 01/27/2020] [Indexed: 12/27/2022] Open
Abstract
Background The virulence of the plant pathogen Xanthomonas campestris pv. campestris (Xcc) involves the coordinate expression of many virulence factors, including surface appendages flagellum and type IV pili, which are required for pathogenesis and the colonization of host tissues. Despite many insights gained on the structure and functions played by flagellum and pili in motility, biofilm formation, surface attachment and interactions with bacteriophages, we know little about how these appendages are regulated in Xcc. Results Here we present evidence demonstrating the role of two single domain response regulators PilG and PilH in the antagonistic control of flagellum-dependent (swimming) and pili-dependent (swarming) motility. Using informative mutagenesis, we reveal PilG positively regulates swimming motility while and negatively regulating swarming motility. Conversely, PilH negatively regulates swimming behaviour while and positively regulating swarming motility. By transcriptome analyses (RNA-seq and RT-PCR) we confirm these observations as PilG is shown to upregulate many genes involved chemotaxis and flagellar biosynthesis but these similar genes were downregulated by PilH. Co-immunoprecipitation, bacterial two-hybrid and pull-down analyses showed that PilH and PilG were able to interact with district subsets of proteins that potentially account for their regulatory impact. Additionally, we present evidence, using mutagenesis that PilG and PilH are involved in other cellular processes, including chemotaxis and virulence. Conclusions Taken together, we demonstrate that for the conditions tested PilG and PilH have inverse regulatory effects on flagellum-dependent and pili-dependent motility in Xcc and that this regulatory impact depends on these proteins influences on genes/proteins involved in flagellar biosynthesis and pilus assembly.
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Affiliation(s)
- Yan-Hua Qi
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, 530004, Guangxi, China
| | - Li Huang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, 530004, Guangxi, China
| | - Guo-Fang Liu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, 530004, Guangxi, China
| | - Ming Leng
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, 530004, Guangxi, China
| | - Guang-Tao Lu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning, 530004, Guangxi, China.
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10
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Vatlin AA, Bekker OB, Lysenkova LN, Shchekotikhin AE, Danilenko VN. Bioinformatics analysis of genes of Streptomyces xinghaiensis (fradiae) ATCC 19609 with a focus on mutations conferring resistance to oligomycin A and its derivatives. J Glob Antimicrob Resist 2020; 22:47-53. [PMID: 32061812 DOI: 10.1016/j.jgar.2020.01.026] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 01/21/2020] [Accepted: 01/25/2020] [Indexed: 10/25/2022] Open
Abstract
OBJECTIVES The aim of this study was to obtain Streptomyces xinghaiensis (fradiae) ATCC 19609 mutants resistant to oligomycin A and its derivatives and to identify the underlying mechanism of resistance. This study was based on the premise that S. xinghaiensis ATCC 19609 contains several oligomycin A biological targets, explaining why the strain remains supersensitive to oligomycin A despite all efforts to obtain resistant mutants using standard genetic methods. METHODS The method to obtain oligomycin A-resistant mutants was performed in two steps: first, mutants slightly resistant to an oligomycin A derivative with an attenuated effect were obtained; and second, oligomycin A-resistant mutants were obtained from those mutants obtained earlier. The genomes of the mutants were then sequenced and a bioinformatics analysis of the detected mutations was conducted. RESULTS Mutants with seven mutations were required to obtain oligomycin A-resistant mutant strains of S. xinghaiensis characterised by a level of resistance comparable with that of the model organism Streptomyces lividans. Five of these mutations caused amino acid substitutions in the well-known oligomycin A biological target, namely the F0F1-ATP synthase A subunit, and the others caused amino acid substitutions in unexplored biological targets, including RecB-like recombinase, type IV helicase, DNA ligase and single-domain response regulator. CONCLUSION A new oligomycin resistance mechanism involving a pathway that repairs double-strand breaks in DNA known as non-homologous end joining (NHEJ) was discovered.
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Affiliation(s)
- Aleksey A Vatlin
- Vavilov Institute of General Genetics, Russian Academy of Sciences, Gubkina str. 3, 119333 Moscow, Russia.
| | - Olga B Bekker
- Vavilov Institute of General Genetics, Russian Academy of Sciences, Gubkina str. 3, 119333 Moscow, Russia
| | - Ludmila N Lysenkova
- Gause Institute of New Antibiotics, Bolschaya Pirogovskaya str. 11/1, 119867 Moscow, Russia
| | - Andrey E Shchekotikhin
- Gause Institute of New Antibiotics, Bolschaya Pirogovskaya str. 11/1, 119867 Moscow, Russia
| | - Valery N Danilenko
- Vavilov Institute of General Genetics, Russian Academy of Sciences, Gubkina str. 3, 119333 Moscow, Russia
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11
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Gengenbacher A, Müller-Rudorf A, Poggio T, Gräßel L, Dumit VI, Kreutmair S, Lippert LJ, Duyster J, Illert AL. Proteomic Phosphosite Analysis Identified Crucial NPM-ALK-Mediated NIPA Serine and Threonine Residues. Int J Mol Sci 2019; 20:ijms20164060. [PMID: 31434245 PMCID: PMC6721280 DOI: 10.3390/ijms20164060] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 08/09/2019] [Accepted: 08/16/2019] [Indexed: 12/20/2022] Open
Abstract
Anaplastic large-cell lymphoma (ALCL) is an aggressive non-Hodgkin lymphoma that shows in 60% of cases a translocation t(2;5)(p23;q35), which leads to the expression of the oncogenic kinase NPM-ALK. The nuclear interaction partner of ALK (NIPA) defines an E3-SCF ligase that contributes to the timing of mitotic entry. It has been shown that co-expression of NIPA and NPM-ALK results in constitutive NIPA phosphorylation. By mass spectrometry-based proteomics we identified nine serine/threonine residues to be significantly upregulated in NIPA upon NPM-ALK expression. Generation of phospho-deficient mutants of the respective phospho-residues specified five serine/threonine residues (Ser-338, Ser-344, Ser-370, Ser-381 and Thr-387) as key phosphorylation sites involved in NPM-ALK-directed phosphorylation of NIPA. Analysis of the biological impact of NIPA phosphorylation by NPM-ALK demonstrated that the ALK-induced phosphorylation does not change the SCFNIPA-complex formation but may influence the localization of NIPA and NPM-ALK. Biochemical analyses with phospho-deficient mutants elucidated the importance of NIPA phosphorylation by NPM-ALK for the interaction of the two proteins and proliferation potential of respective cells: Silencing of the five crucial NIPA serine/threonine residues led to a highly enhanced NIPA-NPM-ALK binding capacity as well as a slightly reduced proliferation in Ba/F3 cells.
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Affiliation(s)
- Anina Gengenbacher
- Department of Hematology and Oncology, Freiburg University Medical Center, Albert-Ludwigs-University of Freiburg, 79106 Freiburg, Germany
| | - Alina Müller-Rudorf
- Department of Hematology and Oncology, Freiburg University Medical Center, Albert-Ludwigs-University of Freiburg, 79106 Freiburg, Germany
- German Cancer Consortium (DKTK) and German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Teresa Poggio
- Department of Hematology and Oncology, Freiburg University Medical Center, Albert-Ludwigs-University of Freiburg, 79106 Freiburg, Germany
| | - Linda Gräßel
- Department of Hematology and Oncology, Freiburg University Medical Center, Albert-Ludwigs-University of Freiburg, 79106 Freiburg, Germany
| | - Veronica I Dumit
- Center for Biological Systems Analysis (ZBSA), University of Freiburg, 79104 Freiburg, Germany
| | - Stefanie Kreutmair
- Department of Hematology and Oncology, Freiburg University Medical Center, Albert-Ludwigs-University of Freiburg, 79106 Freiburg, Germany
| | - Lena J Lippert
- Department of Hematology and Oncology, Freiburg University Medical Center, Albert-Ludwigs-University of Freiburg, 79106 Freiburg, Germany
| | - Justus Duyster
- Department of Hematology and Oncology, Freiburg University Medical Center, Albert-Ludwigs-University of Freiburg, 79106 Freiburg, Germany
- German Cancer Consortium (DKTK) and German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Anna L Illert
- Department of Hematology and Oncology, Freiburg University Medical Center, Albert-Ludwigs-University of Freiburg, 79106 Freiburg, Germany.
- German Cancer Consortium (DKTK) and German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany.
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12
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Gottschlich L, Geiser P, Bortfeld-Miller M, Field CM, Vorholt JA. Complex general stress response regulation in Sphingomonas melonis Fr1 revealed by transcriptional analyses. Sci Rep 2019; 9:9404. [PMID: 31253827 PMCID: PMC6599016 DOI: 10.1038/s41598-019-45788-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Accepted: 06/12/2019] [Indexed: 01/31/2023] Open
Abstract
The general stress response (GSR) represents an important trait to survive in the environment by leading to multiple stress resistance. In alphaproteobacteria, the GSR is under the transcriptional control of the alternative sigma factor EcfG. Here we performed transcriptome analyses to investigate the genes controlled by EcfG of Sphingomonas melonis Fr1 and the plasticity of this regulation under stress conditions. We found that EcfG regulates genes for proteins that are typically associated with stress responses. Moreover, EcfG controls regulatory proteins, which likely fine-tune the GSR. Among these, we identified a novel negative GSR feedback regulator, termed NepR2, on the basis of gene reporter assays, phenotypic analyses, and biochemical assays. Transcriptional profiling of signaling components upstream of EcfG under complex stress conditions showed an overall congruence with EcfG-regulated genes. Interestingly however, we found that the GSR is transcriptionally linked to the regulation of motility and biofilm formation via the single domain response regulator SdrG and GSR-activating histidine kinases. Altogether, our findings indicate that the GSR in S. melonis Fr1 underlies a complex regulation to optimize resource allocation and resilience in stressful and changing environments.
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Affiliation(s)
- Lisa Gottschlich
- Institute of Microbiology, Department of Biology, ETH Zurich, Vladimir-Prelog-Weg 1-5/10, 8093, Zurich, Switzerland
| | - Petra Geiser
- Institute of Microbiology, Department of Biology, ETH Zurich, Vladimir-Prelog-Weg 1-5/10, 8093, Zurich, Switzerland
| | - Miriam Bortfeld-Miller
- Institute of Microbiology, Department of Biology, ETH Zurich, Vladimir-Prelog-Weg 1-5/10, 8093, Zurich, Switzerland
| | - Christopher M Field
- Institute of Microbiology, Department of Biology, ETH Zurich, Vladimir-Prelog-Weg 1-5/10, 8093, Zurich, Switzerland
| | - Julia A Vorholt
- Institute of Microbiology, Department of Biology, ETH Zurich, Vladimir-Prelog-Weg 1-5/10, 8093, Zurich, Switzerland.
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13
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Zhu L, Gong T, Wood TL, Yamasaki R, Wood TK. σ 54 -Dependent regulator DVU2956 switches Desulfovibrio vulgaris from biofilm formation to planktonic growth and regulates hydrogen sulfide production. Environ Microbiol 2019; 21:3564-3576. [PMID: 31087603 DOI: 10.1111/1462-2920.14679] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2019] [Accepted: 05/11/2019] [Indexed: 11/30/2022]
Abstract
Microbiologically influenced corrosion causes $100 billion in damage per year, and biofilms formed by sulfate-reducing bacteria (SRB) are the major culprit. However, little is known about the regulation of SRB biofilm formation. Using Desulfovibrio vulgaris as a model SRB organism, we compared the transcriptomes of biofilm and planktonic cells and identified that the gene for σ54 -dependent regulator DVU2956 is repressed in biofilms. Utilizing a novel promoter that is primarily transcribed in biofilms (Pdvu0304 ), we found production of DVU2956 inhibits biofilm formation by 70%. Corroborating this result, deleting dvu2956 increased biofilm formation, and this biofilm phenotype could be complemented. By producing proteins in biofilms from genes controlled by DVU2956 (dvu2960 and dvu2962), biofilm formation was inhibited almost completely. A second round of RNA-seq for the production of DVU2956 revealed DVU2956 influences electron transport via an Hmc complex (high-molecular-weight cytochrome c encoded by dvu0531-dvu0536) and the Fe-only hydrogenase (encoded by dvu1769, hydA and dvu1770, hydB) to control H2 S production. Corroborating these results, producing DVU2956 in biofilms decreased H2 S production by half, deleting dvu2956 increased H2 S production by 131 ± 5%, and producing DVU2956 in the dvu2956 strain reduced H2 S production. Therefore, DVU2956 maintains SRB in the planktonic state and reduces H2 S formation.
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Affiliation(s)
- Lei Zhu
- Department of Chemical Engineering, Pennsylvania State University, University Park, State College, PA, 16802, USA
| | - Ting Gong
- Department of Chemical Engineering, Pennsylvania State University, University Park, State College, PA, 16802, USA
| | - Thammajun L Wood
- Department of Chemical Engineering, Pennsylvania State University, University Park, State College, PA, 16802, USA
| | - Ryota Yamasaki
- Department of Chemical Engineering, Pennsylvania State University, University Park, State College, PA, 16802, USA
| | - Thomas K Wood
- Department of Chemical Engineering, Pennsylvania State University, University Park, State College, PA, 16802, USA
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14
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Abstract
Complex chemosensory systems control multiple biological functions in bacteria, such as chemotaxis, gene regulation, and cell cycle progression. Many species contain more than one chemosensory system per genome, but little is known about their potential interplay. In this study, we reveal cross talk between two chemosensory pathways that modulate chemotaxis and biofilm formation in Comamonas testosteroni We demonstrate that some chemoreceptors that govern chemotaxis also contribute to biofilm formation and these chemoreceptors can physically interact with components of both pathways. Finally, we show that the chemotaxis histidine kinase CheA can phosphorylate not only its cognate response regulator CheY2 but also one of the response regulators from the pathway mediating biofilm formation, FlmD. The phosphoryl group transfer from CheA to CheY2 is much faster than that from CheA to FlmD, which is consistent with chemotaxis being a fast response and biofilm formation being a much slower developmental process. We propose that cross talk between chemosensory pathways may play a role in coordination of complex behaviors in bacteria.IMPORTANCE In many bacteria, two or more homologous chemosensory pathways control several cellular functions, such as motility and gene regulation, in response to changes in the cell's microenvironment. Cross talk between signal transduction systems is poorly understood; while generally it is considered to be undesired, in some instances it might be beneficial for coregulation of complex behaviors. We demonstrate that several receptors from the pathway controlling motility can physically interact with downstream components of the pathway controlling biofilm formation. We further show that a kinase from the pathway controlling motility can also phosphorylate a response regulator from the pathway controlling biofilm formation. We propose that cross talk between two chemosensory pathways might be involved in coordination of two types of cell behavior-chemotaxis and biofilm formation.
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15
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Wallmeroth N, Jeschke D, Slane D, Nägele J, Veerabagu M, Mira-Rodado V, Berendzen KW. ARR22 overexpression can suppress plant Two-Component Regulatory Systems. PLoS One 2019; 14:e0212056. [PMID: 30742656 PMCID: PMC6370222 DOI: 10.1371/journal.pone.0212056] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Accepted: 01/26/2019] [Indexed: 12/13/2022] Open
Abstract
In plants, several developmental processes are co-coordinated by cytokinins via phosphorylation dependent processes of the Two-Component System (TCS). An outstanding challenge is to track phosphorelay flow from cytokinin perception to its molecular outputs, of which gene activation plays a major role. To address this issue, a kinetic-based reporter system was expounded to track TCS phosphorelay activity in vivo that can distinguish between basal and cytokinin dependent effects of overexpressed TCS members. The TCS phosphorelay can be positively activated by cytokinin and inhibited by pharmaceuticals or naturally interfering components. In this case we took advantage of the phosphohistidine-phosphatase Arabidopsis Response Regulator (ARR) 22 and investigated its phosphocompetition with other TCS members in regulating promoters of ARR5 and WUS in Arabidopsis thaliana cell culture protoplasts. In congruency with the proposed function of ARR22, overexpression of ARR22 blocked the activation of all B-type ARRs in this study in a TCS dependent manner. Furthermore, this effect could not be mimicked by A-type response regulator overexpression or compensated by AHP overexpression. Compared to other reporter assays, ours mimicked effects previously observed only in transgenic plants for all of the TCS proteins studied, suggesting that it is possible to expose phosphocompetition. Thus, our approach can be used to investigate gene signaling networks involving the TCS by leveraging ARR22 as a TCS inhibitor along with B-type ARR overexpression.
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Affiliation(s)
- Niklas Wallmeroth
- Department of Plant Physiology at the Center for Plant Molecular Biology (ZMBP), University of Tübingen, Tübingen, Germany
| | - Daniel Jeschke
- Department of Plant Physiology at the Center for Plant Molecular Biology (ZMBP), University of Tübingen, Tübingen, Germany
| | - Daniel Slane
- Max-Planck Institute for Developmental Biology, Tübingen, Germany
| | - Janine Nägele
- Department of Plant Physiology at the Center for Plant Molecular Biology (ZMBP), University of Tübingen, Tübingen, Germany
| | - Manikandan Veerabagu
- Department of Plant Physiology at the Center for Plant Molecular Biology (ZMBP), University of Tübingen, Tübingen, Germany
| | - Virtudes Mira-Rodado
- Department of Plant Physiology at the Center for Plant Molecular Biology (ZMBP), University of Tübingen, Tübingen, Germany
| | - Kenneth Wayne Berendzen
- Department of Plant Physiology at the Center for Plant Molecular Biology (ZMBP), University of Tübingen, Tübingen, Germany
- Department of the Central Facilities at Center for Plant Molecular Biology (ZMBP), University of Tübingen, Tübingen, Germany
- * E-mail:
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16
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Feldheim YS, Zusman T, Kapach A, Segal G. The single-domain response regulator LerC functions as a connector protein in theLegionella pneumophilaeffectors regulatory network. Mol Microbiol 2018; 110:741-760. [DOI: 10.1111/mmi.14101] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Revised: 07/29/2018] [Accepted: 08/07/2018] [Indexed: 01/10/2023]
Affiliation(s)
- Yaron S. Feldheim
- Department of Molecular Microbiology and Biotechnology, School of Molecular Cell Biology and Biotechnology, George S. Wise Faculty of Life Sciences; Tel-Aviv University; Tel-Aviv Israel
| | - Tal Zusman
- Department of Molecular Microbiology and Biotechnology, School of Molecular Cell Biology and Biotechnology, George S. Wise Faculty of Life Sciences; Tel-Aviv University; Tel-Aviv Israel
| | - Anya Kapach
- Department of Molecular Microbiology and Biotechnology, School of Molecular Cell Biology and Biotechnology, George S. Wise Faculty of Life Sciences; Tel-Aviv University; Tel-Aviv Israel
| | - Gil Segal
- Department of Molecular Microbiology and Biotechnology, School of Molecular Cell Biology and Biotechnology, George S. Wise Faculty of Life Sciences; Tel-Aviv University; Tel-Aviv Israel
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17
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Regulation of Streptomyces Chitinases by Two-Component Signal Transduction Systems and their Post Translational Modifications: A Review. JOURNAL OF PURE AND APPLIED MICROBIOLOGY 2018. [DOI: 10.22207/jpam.12.3.45] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
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18
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Xia X, Katzenell S, Reinhart EF, Bauer KM, Pellegrini M, Ragusa MJ. A pseudo-receiver domain in Atg32 is required for mitophagy. Autophagy 2018; 14:1620-1628. [PMID: 29909755 DOI: 10.1080/15548627.2018.1472838] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022] Open
Abstract
Mitochondria are targeted for degradation by mitophagy, a selective form of autophagy. In Saccharomyces cerevisiae, mitophagy is dependent on the autophagy receptor, Atg32, an outer mitochondrial membrane protein. Once activated, Atg32 recruits the autophagy machinery to mitochondria, facilitating mitochondrial capture in phagophores, the precursors to autophagosomes. However, the mechanism of Atg32 activation remains poorly understood. To investigate this crucial step in mitophagy regulation, we examined the structure of Atg32. We have identified a structured domain in Atg32 that is essential for the initiation of mitophagy, as it is required for the proteolysis of the C-terminal domain of Atg32 and the subsequent recruitment of Atg11. The solution structure of this domain was determined by NMR spectroscopy, revealing that Atg32 contains a previously undescribed pseudo-receiver (PsR) domain. Our data suggests that the PsR domain of Atg32 regulates Atg32 activation and the initiation of mitophagy. ABBREVIATIONS AIM: Atg8-interacting motif; GFP: green fluorescent protein; LIR: LC3-interacting region; NMR: nuclear magnetic resonance; NOESY: nuclear Overhauser effect spectroscopy; PDB: protein data bank; PsR: pseudo-receiver; RMSD: root-mean-square deviation.
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Affiliation(s)
- Xue Xia
- a Department of Biochemistry & Cell Biology , Geisel School of Medicine at Dartmouth , Hanover , NH , USA
| | - Sarah Katzenell
- b Department of Chemistry , Dartmouth College , Hanover , NH , USA
| | - Erin F Reinhart
- b Department of Chemistry , Dartmouth College , Hanover , NH , USA
| | - Katherine M Bauer
- a Department of Biochemistry & Cell Biology , Geisel School of Medicine at Dartmouth , Hanover , NH , USA
| | - Maria Pellegrini
- b Department of Chemistry , Dartmouth College , Hanover , NH , USA
| | - Michael J Ragusa
- a Department of Biochemistry & Cell Biology , Geisel School of Medicine at Dartmouth , Hanover , NH , USA.,b Department of Chemistry , Dartmouth College , Hanover , NH , USA
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19
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A Single-Domain Response Regulator Functions as an Integrating Hub To Coordinate General Stress Response and Development in Alphaproteobacteria. mBio 2018; 9:mBio.00809-18. [PMID: 29789370 PMCID: PMC5964349 DOI: 10.1128/mbio.00809-18] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The alphaproteobacterial general stress response is governed by a conserved partner-switching mechanism that is triggered by phosphorylation of the response regulator PhyR. In the model organism Caulobacter crescentus, PhyR was proposed to be phosphorylated by the histidine kinase PhyK, but biochemical evidence in support of such a role of PhyK is missing. Here, we identify a single-domain response regulator, MrrA, that is essential for general stress response activation in C. crescentus We demonstrate that PhyK does not function as a kinase but accepts phosphoryl groups from MrrA and passes them on to PhyR, adopting the role of a histidine phosphotransferase. MrrA is phosphorylated by at least six histidine kinases that likely serve as stress sensors. MrrA also transfers phosphate to LovK, a histidine kinase involved in C. crescentus holdfast production and attachment, which also negatively regulates the general stress response. We show that LovK together with the response regulator LovR acts as a phosphate sink to redirect phosphate flux away from the PhyKR branch. In agreement with the biochemical data, an mrrA mutant is unable to activate the general stress response and shows a hyperattachment phenotype, which is linked to decreased expression of the major holdfast inhibitory protein HfiA. We propose that MrrA serves as a central phosphorylation hub that coordinates the general stress response with C. crescentus development and other adaptive behaviors. The characteristic bow-tie architecture of this phosphorylation network with MrrA as the central knot may expedite the evolvability and species-specific niche adaptation of this group of bacteria.IMPORTANCE Two-component systems (TCSs) consisting of a histidine kinase and a cognate response regulator are predominant signal transduction systems in bacteria. To avoid cross talk, TCSs are generally thought to be highly insulated from each other. However, this notion is based largely on studies of the HisKA subfamily of histidine kinases, while little information is available for the HWE and HisKA2 subfamilies. The latter have been implicated in the alphaproteobacterial general stress response. Here, we show that in the model organism Caulobacter crescentus an atypical FATGUY-type single-domain response regulator, MrrA, is highly promiscuous in accepting and transferring phosphoryl groups from and to multiple up- and downstream kinases, challenging the current view of strictly insulated TCSs. Instead, we propose that FATGUY response regulators have evolved in alphaproteobacteria as central phosphorylation hubs to broadly sample information and distribute phosphoryl groups between the general stress response pathway and other TCSs, thereby coordinating multiple cellular behaviors.
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20
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Sinha D, Mondal R, Mahapa A, Sau K, Chattopadhyaya R, Sau S. A staphylococcal anti-sigma factor possesses a single-domain, carries different denaturant-sensitive regions and unfolds via two intermediates. PLoS One 2018; 13:e0195416. [PMID: 29621342 PMCID: PMC5886543 DOI: 10.1371/journal.pone.0195416] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 03/21/2018] [Indexed: 11/26/2022] Open
Abstract
RsbW, an anti-sigma factor possessing kinase activity, is expressed by many Gram-positive bacteria including Staphylococcus aureus. To obtain clues about the domain structure and the folding-unfolding mechanism of RsbW, we have elaborately studied rRsbW, a recombinant S. aureus RsbW. Sequence analysis of the protein fragments, generated by the limited proteolysis of rRsbW, has proposed it to be a single-domain protein. The unfolding of rRsbW in the presence of GdnCl or urea was completely reversible in nature and occurred through the formation of at least two intermediates. The structure, shape, and the surface hydrophobicity of no intermediate completely matches with those of other intermediates or the native rRsbW. Interestingly, one of the intermediates, formed in the presence of less GdnCl concentrations, has a molten globule-like structure. Conversely, all of the intermediates, like native rRsbW, exist as dimers in aqueous solution. The putative molten globule and the urea-generated intermediates also have retained some kinase activity. Additionally, the putative ATP binding site/catalytic site of rRsbW shows higher denaturant sensitivity than the tentative dimerization region of this enzyme.
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Affiliation(s)
- Debabrata Sinha
- Department of Biochemistry, Bose Institute, Kolkata, West Bengal, India
| | - Rajkrishna Mondal
- Department of Biotechnology, Nagaland University, Dimapur, Nagaland, India
| | - Avisek Mahapa
- Department of Biotechnology, Haldia Institute of Technology, Haldia, West Bengal, India
| | - Keya Sau
- Department of Biotechnology, Haldia Institute of Technology, Haldia, West Bengal, India
| | | | - Subrata Sau
- Department of Biochemistry, Bose Institute, Kolkata, West Bengal, India
- * E-mail:
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21
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Abstract
Two-component systems (TCS) exist in bacteria and archaea. In contrast to the knowledge of bacterial TCSs, little information is available on their archaeal counterparts. In the current issue of Journal of Bacteriology, Galperin and coworkers present a bioinformatics analysis of TCS genes from archaeal genome sequences (M. Y. Galperin, K. S. Makarova, Y. I. Wolf, and E. V. Koonin, J Bacteriol 200:e00681-17, 2018, https://doi.org/10.1128/JB.00681-17). This study identifies different aspects in which TCS-mediated signaling differs in bacteria and archaea and forms a sound basis for the experimental design of studies to increase our knowledge of this poorly investigated protein family.
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22
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Phyletic Distribution and Lineage-Specific Domain Architectures of Archaeal Two-Component Signal Transduction Systems. J Bacteriol 2018; 200:JB.00681-17. [PMID: 29263101 PMCID: PMC5847659 DOI: 10.1128/jb.00681-17] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Accepted: 12/11/2017] [Indexed: 12/14/2022] Open
Abstract
The two-component signal transduction (TCS) machinery is a key mechanism of sensing environmental changes in the prokaryotic world. TCS systems have been characterized thoroughly in bacteria but to a much lesser extent in archaea. Here, we provide an updated census of more than 2,000 histidine kinases and response regulators encoded in 218 complete archaeal genomes, as well as unfinished genomes available from metagenomic data. We describe the domain architectures of the archaeal TCS components, including several novel output domains, and discuss the evolution of the archaeal TCS machinery. The distribution of TCS systems in archaea is strongly biased, with high levels of abundance in haloarchaea and thaumarchaea but none detected in the sequenced genomes from the phyla Crenarchaeota, Nanoarchaeota, and Korarchaeota The archaeal sensor histidine kinases are generally similar to their well-studied bacterial counterparts but are often located in the cytoplasm and carry multiple PAS and/or GAF domains. In contrast, archaeal response regulators differ dramatically from the bacterial ones. Most archaeal genomes do not encode any of the major classes of bacterial response regulators, such as the DNA-binding transcriptional regulators of the OmpR/PhoB, NarL/FixJ, NtrC, AgrA/LytR, and ActR/PrrA families and the response regulators with GGDEF and/or EAL output domains. Instead, archaea encode multiple copies of response regulators containing either the stand-alone receiver (REC) domain or combinations of REC with PAS and/or GAF domains. Therefore, the prevailing mechanism of archaeal TCS signaling appears to be via a variety of protein-protein interactions, rather than direct transcriptional regulation.IMPORTANCE Although the Archaea represent a separate domain of life, their signaling systems have been assumed to be closely similar to the bacterial ones. A study of the domain architectures of the archaeal two-component signal transduction (TCS) machinery revealed an overall similarity of archaeal and bacterial sensory modules but substantial differences in the signal output modules. The prevailing mechanism of archaeal TCS signaling appears to involve various protein-protein interactions rather than direct transcription regulation. The complete list of histidine kinases and response regulators encoded in the analyzed archaeal genomes is available online at http://www.ncbi.nlm.nih.gov/Complete_Genomes/TCSarchaea.html.
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23
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Liu WQ, Amara P, Mouesca JM, Ji X, Renoux O, Martin L, Zhang C, Zhang Q, Nicolet Y. 1,2-Diol Dehydration by the Radical SAM Enzyme AprD4: A Matter of Proton Circulation and Substrate Flexibility. J Am Chem Soc 2018; 140:1365-1371. [DOI: 10.1021/jacs.7b10501] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Wan-Qiu Liu
- Department
of Chemistry, Fudan University, Shanghai 200433, China
| | | | | | - Xinjian Ji
- Department
of Chemistry, Fudan University, Shanghai 200433, China
| | | | | | - Chen Zhang
- Department
of Chemistry, Fudan University, Shanghai 200433, China
| | - Qi Zhang
- Department
of Chemistry, Fudan University, Shanghai 200433, China
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24
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Bhatt P, Kumaresan V, Palanisamy R, Ravichandran G, Mala K, Amin SMN, Arshad A, Yusoff FM, Arockiaraj J. A mini review on immune role of chemokines and its receptors in snakehead murrel Channa striatus. FISH & SHELLFISH IMMUNOLOGY 2018; 72:670-678. [PMID: 29162541 DOI: 10.1016/j.fsi.2017.11.036] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Revised: 11/15/2017] [Accepted: 11/17/2017] [Indexed: 06/07/2023]
Abstract
Chemokines are ubiquitous cytokine molecules involved in migration of cells during inflammation and normal physiological processes. Though the study on chemokines in mammalian species like humans have been extensively studied, characterization of chemokines in teleost fishes is still in the early stage. The present review provides an overview of chemokines and its receptors in a teleost fish, Channa striatus. C. striatus is an air breathing freshwater carnivore, which has enormous economic importance. This species is affected by an oomycete fungus, Aphanomyces invadans and a Gram negative bacteria Aeromonas hydrophila is known to cause secondary infection. These pathogens impose immune changes in the host organism, which in turn mounts several immune responses. Of these, the role of cytokines in the immune response is immense, due to their involvement in several activities of inflammation such as cell trafficking to the site of inflammation and antigen presentation. Given that importance, chemokines in fishes do have significant role in the immunological and other physiological functions of the organism, hence there is a need to understand the characteristics, activities and performace of these small molecules in details.
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Affiliation(s)
- Prasanth Bhatt
- Division of Fisheries Biotechnology & Molecular Biology, Department of Biotechnology, Faculty of Science and Humanities, SRM University, Kattankulathur 603 203, Chennai, Tamil Nadu, India
| | - Venkatesh Kumaresan
- Division of Fisheries Biotechnology & Molecular Biology, Department of Biotechnology, Faculty of Science and Humanities, SRM University, Kattankulathur 603 203, Chennai, Tamil Nadu, India
| | - Rajesh Palanisamy
- Division of Fisheries Biotechnology & Molecular Biology, Department of Biotechnology, Faculty of Science and Humanities, SRM University, Kattankulathur 603 203, Chennai, Tamil Nadu, India
| | - Gayathri Ravichandran
- Division of Fisheries Biotechnology & Molecular Biology, Department of Biotechnology, Faculty of Science and Humanities, SRM University, Kattankulathur 603 203, Chennai, Tamil Nadu, India; SRM Research Institute, SRM University, Kattankulathur 603 203, Chennai, Tamil Nadu, India
| | - Kanchana Mala
- Medical College Hospital and Research Center, SRM University, Kattankulathur 603 203, Chennai, Tamil Nadu, India
| | - S M Nurul Amin
- Department of Aquaculture, Faculty of Agriculture, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia
| | - Aziz Arshad
- Department of Aquaculture, Faculty of Agriculture, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia; Laboratory of Marine Biotechnology, Institute of Bioscience, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor Darul Ehsan, Malaysia
| | - Fatimah Md Yusoff
- Department of Aquaculture, Faculty of Agriculture, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia; Laboratory of Marine Biotechnology, Institute of Bioscience, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor Darul Ehsan, Malaysia
| | - Jesu Arockiaraj
- Division of Fisheries Biotechnology & Molecular Biology, Department of Biotechnology, Faculty of Science and Humanities, SRM University, Kattankulathur 603 203, Chennai, Tamil Nadu, India; Laboratory of Marine Biotechnology, Institute of Bioscience, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor Darul Ehsan, Malaysia.
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25
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Class III Histidine Kinases: a Recently Accessorized Kinase Domain in Putative Modulators of Type IV Pilus-Based Motility. J Bacteriol 2017; 199:JB.00218-17. [PMID: 28484044 DOI: 10.1128/jb.00218-17] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Accepted: 04/28/2017] [Indexed: 01/02/2023] Open
Abstract
Histidine kinases are key components of regulatory systems that enable bacteria to respond to environmental changes. Two major classes of histidine kinases are recognized on the basis of their modular design: classical (HKI) and chemotaxis specific (HKII). Recently, a new type of histidine kinase that appeared to have features of both HKIs and HKIIs was identified and termed HKIII; however, the details of HKIII's relationship to other two classes of histidine kinases, their function, and evolutionary history remain unknown. Here, we carried out genomic, phylogenetic, and protein sequence analyses that allowed us to reveal the unusual evolutionary history of this protein family, formalize its distinctive features, and propose its putative function. HKIIIs are characterized by the presence of sensory domains and the lack of a dimerization domain, which is typically present in all histidine kinases. In addition to a single-domain response regulator, HKIII signal transduction systems utilize CheX phosphatase and, in many instances, an unorthodox soluble chemoreceptor that are usual components of chemotaxis signal transduction systems. However, many HKIII genes are found in genomes completely lacking chemotaxis genes, thus decoupling their function from chemotaxis. By contrast, all HKIII-containing genomes also contain pilT, a marker gene for bacterial type IV pilus-based motility, whose regulation is proposed as a putative function for HKIII. These signal transduction systems have a narrow phyletic distribution but are present in many emerging and opportunistic pathogens, thus offering an attractive potential target for future antimicrobial drug design.IMPORTANCE Bacteria adapt to their environment and their hosts by detecting signals and regulating their cellular functions accordingly. Here, we describe a largely unexplored family of signal transduction histidine kinases, called HKIII, that have a unique modular design. While they are currently identified in a relatively short list of bacterial species, this list contains many emerging pathogens. We show that HKIIIs likely control bacterial motility across solid surfaces, which is a key virulence factor in many bacteria, including those causing severe infections. Full understanding of this putative function may help in designing effective drugs against pathogens that will not affect the majority of the beneficial human microbiome.
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Gene expression and in silico analysis of snakehead murrel interleukin 8 and antimicrobial activity of C-terminal derived peptide WS12. Vet Immunol Immunopathol 2017; 190:1-9. [DOI: 10.1016/j.vetimm.2017.06.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Revised: 06/19/2017] [Accepted: 06/20/2017] [Indexed: 12/31/2022]
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Evolution of biosynthetic diversity. Biochem J 2017; 474:2277-2299. [DOI: 10.1042/bcj20160823] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Revised: 04/20/2017] [Accepted: 04/24/2017] [Indexed: 12/16/2022]
Abstract
Since the emergence of the last common ancestor from which all extant life evolved, the metabolite repertoire of cells has increased and diversified. Not only has the metabolite cosmos expanded, but the ways in which the same metabolites are made have diversified. Enzymes catalyzing the same reaction have evolved independently from different protein folds; the same protein fold can produce enzymes recognizing different substrates, and enzymes performing different chemistries. Genes encoding useful enzymes can be transferred between organisms and even between the major domains of life. Organisms that live in metabolite-rich environments sometimes lose the pathways that produce those same metabolites. Fusion of different protein domains results in enzymes with novel properties. This review will consider the major evolutionary mechanisms that generate biosynthetic diversity: gene duplication (and gene loss), horizontal and endosymbiotic gene transfer, and gene fusion. It will also discuss mechanisms that lead to convergence as well as divergence. To illustrate these mechanisms, one of the original metabolisms present in the last universal common ancestor will be employed: polyamine metabolism, which is essential for the growth and cell proliferation of archaea and eukaryotes, and many bacteria.
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Oliveira J, Costa M, de Almeida MSC, da Cruz e Silva OA, Henriques AG. Protein Phosphorylation is a Key Mechanism in Alzheimer’s Disease. J Alzheimers Dis 2017; 58:953-978. [DOI: 10.3233/jad-170176] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Joana Oliveira
- Department of Medical Sciences, Neuroscience and Signalling Laboratory, iBiMED, University of Aveiro, Aveiro, Portugal
| | - Márcio Costa
- Department of Medical Sciences, Neuroscience and Signalling Laboratory, iBiMED, University of Aveiro, Aveiro, Portugal
| | | | - Odete A.B. da Cruz e Silva
- Department of Medical Sciences, Neuroscience and Signalling Laboratory, iBiMED, University of Aveiro, Aveiro, Portugal
| | - Ana Gabriela Henriques
- Department of Medical Sciences, Neuroscience and Signalling Laboratory, iBiMED, University of Aveiro, Aveiro, Portugal
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Bardy SL, Briegel A, Rainville S, Krell T. Recent advances and future prospects in bacterial and archaeal locomotion and signal transduction. J Bacteriol 2017; 199:e00203-17. [PMID: 28484047 PMCID: PMC5573076 DOI: 10.1128/jb.00203-17] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Unraveling the structure and function of two-component and chemotactic signaling along with different aspects related to motility of bacteria and archaea are key research areas in modern microbiology. Escherichia coli is the traditional model organism to study chemotaxis signaling and motility. However, the recent study of a wide range of bacteria and even some archaea with different lifestyles has provided new insight into the eco-physiology of chemotaxis, which is essential for the host establishment of different pathogens or beneficial bacteria. The expanded range of model organisms has also permitted the study of chemosensory pathways unrelated to chemotaxis, multiple chemotaxis pathways within an organism, and new types of chemoreceptors. This research has greatly benefitted from technical advances in the field of cryo-microscopy that continues to reveal with increasing resolution the complexity and diversity of large protein complexes like the flagellar motor or chemoreceptor arrays. In addition, sensitive instruments now allow for an increasing number of experiments to be conducted at the single-cell level, thereby revealing information that is beginning to bridge the gap between individual cells and population behavior. Evidence has also accumulated showing that bacteria have evolved different mechanisms for surface sensing, which appears to be mediated by flagella and possibly type IV pili, and that the downstream signaling involves chemosensory pathways and two-component system based processes. Herein we summarize the recent advances and research tendencies in this field as presented at the latest Bacterial Locomotion and Signal Transduction (BLAST XIV) conference.
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Affiliation(s)
- Sonia L. Bardy
- University of Wisconsin—Milwaukee, Biological Sciences, Milwaukee, Wisconsin, USA
| | | | - Simon Rainville
- Laval University, Department of Physics, Engineering Physics and Optics, Quebec City, Québec, Canada
| | - Tino Krell
- Estación Experimental del Zaidín, Granada, Spain
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Subramanian K, Tyson JJ. Spatiotemporal Models of the Asymmetric Division Cycle of Caulobacter crescentus. Results Probl Cell Differ 2017; 61:23-48. [PMID: 28409299 DOI: 10.1007/978-3-319-53150-2_2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The spatial localization of proteins within the cytoplasm of bacteria is an underappreciated but critical aspect of cell cycle regulation for many prokaryotes. In Caulobacter crescentus-a model organism for the study of asymmetric cell reproduction in prokaryotes-heterogeneous localization of proteins has been identified as the underlying cause of asymmetry in cell morphology, DNA replication, and cell division. However, significant questions remain. Firstly, the mechanisms by which proteins localize in the organelle-free prokaryotic cytoplasm remain obscure. Furthermore, how variations in the spatial and temporal dynamics of cell fate determinants regulate signaling pathways and orchestrate the complex programs of asymmetric cell division and differentiation are subjects of ongoing research. In this chapter, we review current efforts in investigating these two questions. We describe how mathematical models of spatiotemporal protein dynamics are being used to generate and test competing hypotheses and provide complementary insight about the control mechanisms that regulate asymmetry in protein localization and cell division.
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Affiliation(s)
- Kartik Subramanian
- Laboratory of Systems Pharmacology, Department of Systems Biology, Harvard Medical School, Boston, MA, 02115, USA.
| | - John J Tyson
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, 24061, USA
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Wallmeroth N, Anastasia AK, Harter K, Berendzen KW, Mira-Rodado V. Arabidopsis response regulator 22 inhibits cytokinin-regulated gene transcription in vivo. PROTOPLASMA 2017; 254:597-601. [PMID: 26769709 DOI: 10.1007/s00709-016-0944-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Accepted: 01/06/2016] [Indexed: 05/24/2023]
Abstract
Cytokinin signaling in Arabidopsis is carried out by a two-component system (TCS) multi-step phosphorelay mechanism that involves three different protein families: histidine kinases (AHKs), phosphotransfer proteins (AHPs), and response regulators (ARRs) that are in turn, subdivided into A-, B- and C-type ARRs depending on their function and structure. Upon cytokinin perception, AHK proteins autophosphorylate; this phosphate is then transferred from the AHKs to the AHPs to finally reach the ARRs. When B-type ARRs are activated by phosphorylation, they function as transcription factors that regulate the expression of cytokinin-dependent genes such as the A-type ARRs, among many others. In cytokinin signaling, while A- and B-type ARR function is well understood, it is still unclear if C-type ARRs (ARR22 and ARR24) play a role in this mechanism. Here, we describe a novel method suitable to study TCS activity natively as an in vivo system. We also show that ARR22 inhibits gene transcription of an A-type ARR upon cytokinin treatment in vivo. Consequently, we propose that ARR22, by acting as a phosphatase on specific AHPs, disrupts the TCS phosphorelay and prevents B-type ARR phosphorylation, and thus their activation as transcription factors, explaining the observed deactivation of cytokinin-responsive genes.
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Affiliation(s)
- Niklas Wallmeroth
- Center for Plant Molecular Biology (ZMBP), Department of Plant Physiology, University of Tübingen, Auf der Morgenstelle 32, D-72076, Tübingen, Germany
| | - Anna Katharina Anastasia
- Center for Plant Molecular Biology (ZMBP), Department of Plant Physiology, University of Tübingen, Auf der Morgenstelle 32, D-72076, Tübingen, Germany
| | - Klaus Harter
- Center for Plant Molecular Biology (ZMBP), Department of Plant Physiology, University of Tübingen, Auf der Morgenstelle 32, D-72076, Tübingen, Germany
| | - Kenneth Wayne Berendzen
- Center for Plant Molecular Biology (ZMBP), Central Facilities, University of Tübingen, Auf der Morgenstelle 32, D-72076, Tübingen, Germany.
| | - Virtudes Mira-Rodado
- Center for Plant Molecular Biology (ZMBP), Department of Plant Physiology, University of Tübingen, Auf der Morgenstelle 32, D-72076, Tübingen, Germany.
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Amigo N, Zhang Q, Amadio A, Zhang Q, Silva WM, Cui B, Chen Z, Larzabal M, Bei J, Cataldi A. Overexpressed Proteins in Hypervirulent Clade 8 and Clade 6 Strains of Escherichia coli O157:H7 Compared to E. coli O157:H7 EDL933 Clade 3 Strain. PLoS One 2016; 11:e0166883. [PMID: 27880834 PMCID: PMC5120812 DOI: 10.1371/journal.pone.0166883] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2016] [Accepted: 11/04/2016] [Indexed: 11/19/2022] Open
Abstract
Escherichia coli O157:H7 is responsible for severe diarrhea and hemolytic uremic syndrome (HUS), and predominantly affects children under 5 years. The major virulence traits are Shiga toxins, necessary to develop HUS and the Type III Secretion System (T3SS) through which bacteria translocate effector proteins directly into the host cell. By SNPs typing, E. coli O157:H7 was separated into nine different clades. Clade 8 and clade 6 strains were more frequently associated with severe disease and HUS. In this study, we aimed to identify differentially expressed proteins in two strains of E. coli O157:H7 (clade 8 and clade 6), obtained from cattle and compared them with the well characterized reference EDL933 strain (clade 3). Clade 8 and clade 6 strains show enhanced pathogenicity in a mouse model and virulence-related properties. Proteins were extracted and analyzed using the TMT-6plex labeling strategy associated with two dimensional liquid chromatography and mass spectrometry in tandem. We detected 2241 proteins in the cell extract and 1787 proteins in the culture supernatants. Attention was focused on the proteins related to virulence, overexpressed in clade 6 and 8 strains compared to EDL933 strain. The proteins relevant overexpressed in clade 8 strain were the curli protein CsgC, a transcriptional activator (PchE), phage proteins, Stx2, FlgM and FlgD, a dienelactone hydrolase, CheW and CheY, and the SPATE protease EspP. For clade 6 strain, a high overexpression of phage proteins was detected, mostly from Stx2 encoding phage, including Stx2, flagellin and the protease TagA, EDL933_p0016, dienelactone hydrolase, and Haemolysin A, amongst others with unknown function. Some of these proteins were analyzed by RT-qPCR to corroborate the proteomic data. Clade 6 and clade 8 strains showed enhanced transcription of 10 out of 12 genes compared to EDL933. These results may provide new insights in E. coli O157:H7 mechanisms of pathogenesis.
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Affiliation(s)
- Natalia Amigo
- Institute of Biotechnology, CICVyA, National Institute of Agricultural Technology. Hurlingham, Buenos Aires, Argentina
| | - Qi Zhang
- AGRO-Biological Gene Research Center, Guangdong `Academy of Agricultural Sciences (GDAAS), Guangzhou, China
| | - Ariel Amadio
- Rafaela Experimental Station, National Institute of Agricultural Technology. Rafaela, Santa Fe, Argentina
| | - Qunjie Zhang
- AGRO-Biological Gene Research Center, Guangdong `Academy of Agricultural Sciences (GDAAS), Guangzhou, China
| | - Wanderson M. Silva
- Institute of Biotechnology, CICVyA, National Institute of Agricultural Technology. Hurlingham, Buenos Aires, Argentina
| | - Baiyuan Cui
- AGRO-Biological Gene Research Center, Guangdong `Academy of Agricultural Sciences (GDAAS), Guangzhou, China
| | - Zhongjian Chen
- AGRO-Biological Gene Research Center, Guangdong `Academy of Agricultural Sciences (GDAAS), Guangzhou, China
| | - Mariano Larzabal
- Institute of Biotechnology, CICVyA, National Institute of Agricultural Technology. Hurlingham, Buenos Aires, Argentina
| | - Jinlong Bei
- AGRO-Biological Gene Research Center, Guangdong `Academy of Agricultural Sciences (GDAAS), Guangzhou, China
- * E-mail:
| | - Angel Cataldi
- Institute of Biotechnology, CICVyA, National Institute of Agricultural Technology. Hurlingham, Buenos Aires, Argentina
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Campagne S, Dintner S, Gottschlich L, Thibault M, Bortfeld-Miller M, Kaczmarczyk A, Francez-Charlot A, Allain FHT, Vorholt JA. Role of the PFXFATG[G/Y] Motif in the Activation of SdrG, a Response Regulator Involved in the Alphaproteobacterial General Stress Response. Structure 2016; 24:1237-1247. [PMID: 27396826 DOI: 10.1016/j.str.2016.05.015] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Revised: 05/23/2016] [Accepted: 05/23/2016] [Indexed: 11/19/2022]
Abstract
Two-component systems are major signal transduction pathways, which consist of histidine kinases and response regulators that communicate through phosphorylation. Here, we highlight a distinct class of single-domain response regulators containing the PFXFATG[G/Y] motif that are activated by a mechanism distinct from the Y-T coupling described for prototypical receiver domains. We first solved the structures of inactive and active SdrG, a representative of the FAT GUY family, and then biochemically and genetically characterized variants in which residues in this motif were mutated. Our results support a model of activation mainly driven by a conserved lysine and reveal that the rotation of the threonine induces the reorganization of several aromatic residues in and around the PFXFATG[G/Y] motif to generate intermediates resembling those occurring during classical Y-T coupling. Overall, this helps define a new subfamily of response regulators that emerge as important players in physiological adaptation.
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Affiliation(s)
- Sébastien Campagne
- Institute of Microbiology, ETH Zurich, Vladimir-Prelog-Weg 1-5/10, 8093 Zürich, Switzerland; Institute of Molecular Biology and Biophysics, ETH Zurich, Hönggerbergring 64, 8093 Zürich, Switzerland.
| | - Sebastian Dintner
- Institute of Microbiology, ETH Zurich, Vladimir-Prelog-Weg 1-5/10, 8093 Zürich, Switzerland
| | - Lisa Gottschlich
- Institute of Microbiology, ETH Zurich, Vladimir-Prelog-Weg 1-5/10, 8093 Zürich, Switzerland
| | - Maxence Thibault
- Institute of Molecular Biology and Biophysics, ETH Zurich, Hönggerbergring 64, 8093 Zürich, Switzerland
| | - Miriam Bortfeld-Miller
- Institute of Microbiology, ETH Zurich, Vladimir-Prelog-Weg 1-5/10, 8093 Zürich, Switzerland
| | - Andreas Kaczmarczyk
- Institute of Microbiology, ETH Zurich, Vladimir-Prelog-Weg 1-5/10, 8093 Zürich, Switzerland
| | - Anne Francez-Charlot
- Institute of Microbiology, ETH Zurich, Vladimir-Prelog-Weg 1-5/10, 8093 Zürich, Switzerland
| | - Frédéric H-T Allain
- Institute of Molecular Biology and Biophysics, ETH Zurich, Hönggerbergring 64, 8093 Zürich, Switzerland
| | - Julia A Vorholt
- Institute of Microbiology, ETH Zurich, Vladimir-Prelog-Weg 1-5/10, 8093 Zürich, Switzerland
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Li F, Subramanian K, Chen M, Tyson JJ, Cao Y. A stochastic spatiotemporal model of a response-regulator network in the Caulobacter crescentus cell cycle. Phys Biol 2016; 13:035007. [PMID: 27345750 DOI: 10.1088/1478-3975/13/3/035007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The asymmetric cell division cycle in Caulobacter crescentus is controlled by an elaborate molecular mechanism governing the production, activation and spatial localization of a host of interacting proteins. In previous work, we proposed a deterministic mathematical model for the spatiotemporal dynamics of six major regulatory proteins. In this paper, we study a stochastic version of the model, which takes into account molecular fluctuations of these regulatory proteins in space and time during early stages of the cell cycle of wild-type Caulobacter cells. We test the stochastic model with regard to experimental observations of increased variability of cycle time in cells depleted of the divJ gene product. The deterministic model predicts that overexpression of the divK gene blocks cell cycle progression in the stalked stage; however, stochastic simulations suggest that a small fraction of the mutants cells do complete the cell cycle normally.
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Affiliation(s)
- Fei Li
- Departments of Computer Science, Virginia Tech, Blacksburg, VA 24061,USA
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Stranava M, Martínek V, Man P, Fojtikova V, Kavan D, Vaněk O, Shimizu T, Martinkova M. Structural characterization of the heme-based oxygen sensor, AfGcHK, its interactions with the cognate response regulator, and their combined mechanism of action in a bacterial two-component signaling system. Proteins 2016; 84:1375-89. [PMID: 27273553 DOI: 10.1002/prot.25083] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Revised: 05/19/2016] [Accepted: 05/30/2016] [Indexed: 01/11/2023]
Abstract
The oxygen sensor histidine kinase AfGcHK from the bacterium Anaeromyxobacter sp. Fw 109-5 forms a two-component signal transduction system together with its cognate response regulator (RR). The binding of oxygen to the heme iron of its N-terminal sensor domain causes the C-terminal kinase domain of AfGcHK to autophosphorylate at His183 and then transfer this phosphate to Asp52 or Asp169 of the RR protein. Analytical ultracentrifugation revealed that AfGcHK and the RR protein form a complex with 2:1 stoichiometry. Hydrogen-deuterium exchange coupled to mass spectrometry (HDX-MS) suggested that the most flexible part of the whole AfGcHK protein is a loop that connects the two domains and that the heme distal side of AfGcHK, which is responsible for oxygen binding, is the only flexible part of the sensor domain. HDX-MS studies on the AfGcHK:RR complex also showed that the N-side of the H9 helix in the dimerization domain of the AfGcHK kinase domain interacts with the helix H1 and the β-strand B2 area of the RR protein's Rec1 domain, and that the C-side of the H8 helix region in the dimerization domain of the AfGcHK protein interacts mostly with the helix H5 and β-strand B6 area of the Rec1 domain. The Rec1 domain containing the phosphorylable Asp52 of the RR protein probably has a significantly higher affinity for AfGcHK than the Rec2 domain. We speculate that phosphorylation at Asp52 changes the overall structure of RR such that the Rec2 area containing the second phosphorylation site (Asp169) can also interact with AfGcHK. Proteins 2016; 84:1375-1389. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Martin Stranava
- Department of Biochemistry, Charles University in Prague, Hlavova (Albertov) 2030-8, Prague 2, Czech Republic
| | - Václav Martínek
- Department of Biochemistry, Charles University in Prague, Hlavova (Albertov) 2030-8, Prague 2, Czech Republic.,Department of Chemical Education, Faculty of Science, Charles University in Prague, Hlavova (Albertov) 2030-8, Prague 2, Czech Republic
| | - Petr Man
- Department of Biochemistry, Charles University in Prague, Hlavova (Albertov) 2030-8, Prague 2, Czech Republic.,Laboratory of Structure Biology and Cell Signalling, BioCeV - Institute of Microbiology, Czech Academy of Sciences, V.V.I, Prumyslova 595, Vestec, Czech Republic
| | - Veronika Fojtikova
- Department of Biochemistry, Charles University in Prague, Hlavova (Albertov) 2030-8, Prague 2, Czech Republic
| | - Daniel Kavan
- Department of Biochemistry, Charles University in Prague, Hlavova (Albertov) 2030-8, Prague 2, Czech Republic.,Laboratory of Structure Biology and Cell Signalling, BioCeV - Institute of Microbiology, Czech Academy of Sciences, V.V.I, Prumyslova 595, Vestec, Czech Republic
| | - Ondřej Vaněk
- Department of Biochemistry, Charles University in Prague, Hlavova (Albertov) 2030-8, Prague 2, Czech Republic
| | - Toru Shimizu
- Department of Biochemistry, Charles University in Prague, Hlavova (Albertov) 2030-8, Prague 2, Czech Republic
| | - Marketa Martinkova
- Department of Biochemistry, Charles University in Prague, Hlavova (Albertov) 2030-8, Prague 2, Czech Republic.
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Albarracín VH, Gärtner W, Farias ME. Forged Under the Sun: Life and Art of Extremophiles from Andean Lakes. Photochem Photobiol 2015; 92:14-28. [PMID: 26647770 DOI: 10.1111/php.12555] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Revised: 10/09/2015] [Accepted: 11/05/2015] [Indexed: 12/25/2022]
Abstract
High-altitude Andean lakes (HAAL) are a treasure chest for microbiological research in South America. Their indigenous microbial communities are exposed to extremely high UV irradiation and to multiple chemical extremes (Arsenic, high salt content, alkalinity). Microbes are found both, free-living or associated into microbial mats with different degrees of mineralization and lithification, including unique modern stromatolites located at 3570 m above sea level. Characterization of these polyextremophilic microbes began only recently, employing morphological and phylogenetic methods as well as high-throughput sequencing and proteomics approach. Aside from providing a general overview on microbial communities, special attention is given to various survival strategies; HAAL's microbes present a complex system of shared genetic and physiological mechanisms (UV-resistome) based on UV photoreceptors and stress sensors with their corresponding response regulators, UV avoidance and protection strategies, damage tolerance and UV damage repair. Molecular information will be provided for what is, so far the most studied HAAL molecule, a CPD-Class I photolyase from Acinetobacter Ver3 (Laguna Verde, 4400 m). This work further proposes some strategies that make an appeal for the preservation of HAAL, a highly fragile environment that offers promising and ample research possibilities.
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Affiliation(s)
- Virginia Helena Albarracín
- Planta Piloto de Procesos Industriales y Microbiológicos (PROIMI), CCT, CONICET, Tucumán, Argentina.,Facultad de Ciencias Naturales e Instituto Miguel Lillo, Universidad Nacional de Tucumán, Tucumán, Argentina
| | - Wolfgang Gärtner
- Max-Planck-Institute for Chemical Energy Conversion, Mülheim, Germany
| | - María Eugenia Farias
- Planta Piloto de Procesos Industriales y Microbiológicos (PROIMI), CCT, CONICET, Tucumán, Argentina
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Arockiaraj J, Bhatt P, Kumaresan V, Dhayanithi NB, Arshad A, Harikrishnan R, Arasu MV, Al-Dhabi NA. Fish chemokines 14, 20 and 25: A comparative statement on computational analysis and mRNA regulation upon pathogenic infection. FISH & SHELLFISH IMMUNOLOGY 2015; 47:221-230. [PMID: 26363233 DOI: 10.1016/j.fsi.2015.09.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Revised: 09/05/2015] [Accepted: 09/07/2015] [Indexed: 06/05/2023]
Abstract
In this study, we reported a molecular characterization of three CC chemokines namely, CsCC-Chem14, CsCC-Chem20 and CsCC-Chem25 which are were identified from the established cDNA library of striped murrel Channa striatus. Multiple sequence alignment of all the three chemokines revealed the presence of gene specific domains and motifs including small cytokine domain, IL8 like domain, receptor binding site and glycosaminoglycan (GAG) binding sites. Three dimensional structures of the chemokines under study showed an important facet on their anti-microbial property. Tissue specific mRNA expression showed that the CsCC-Chem14 is highly expressed in spleen, CsCC-Chem20 in liver and CsCC-Chem25 in trunk kidney. On challenge C. striatus with oomycete fungus Aphanomyces invadans, both CsCC-Chem20 and CsCC-Chem25 showed significant (P < 0.05) up-regulation compared to CsCC-Chem14. The increase in the expression levels of CsCC-Chem20 and CsCC-Chem25 due to infection showed that they are antimicrobial proteins. But considering the CsCC-Chem14 expression, it is found to be a constitutive chemokine and is involved in homeostatic function in spleen of C. striatus. C. striatus challenged with bacteria Aeromonas hydrophila also exhibited different up-regulation pattern in all the three chemokines at various time points. However, extensive studies are required to determine the functional activities of CsCC-Chem14, CsCC-Chem20 and CsCC-Chem25 in vitro and in vivo to gain more knowledge at the molecular and proteomic levels.
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Affiliation(s)
- Jesu Arockiaraj
- Division of Fisheries Biotechnology & Molecular Biology, Department of Biotechnology, Faculty of Science and Humanities, SRM University, Kattankulathur, 603 203 Chennai, Tamil Nadu, India.
| | - Prasanth Bhatt
- Division of Fisheries Biotechnology & Molecular Biology, Department of Biotechnology, Faculty of Science and Humanities, SRM University, Kattankulathur, 603 203 Chennai, Tamil Nadu, India
| | - Venkatesh Kumaresan
- Division of Fisheries Biotechnology & Molecular Biology, Department of Biotechnology, Faculty of Science and Humanities, SRM University, Kattankulathur, 603 203 Chennai, Tamil Nadu, India
| | | | - Aziz Arshad
- Department of Aquaculture, Faculty of Agriculture, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia
| | - Ramasamy Harikrishnan
- Department of Zoology, Pachaiyappa's College for Men, Kanchipuram 631 501, Tamil Nadu, India
| | - Mariadhas Valan Arasu
- Department of Botany and Microbiology, Addiriyah Chair for Environmental Studies, College of Science, King Saud University, P. O. Box 2455, Riyadh 11451, Saudi Arabia
| | - Naif Abdullah Al-Dhabi
- Department of Botany and Microbiology, Addiriyah Chair for Environmental Studies, College of Science, King Saud University, P. O. Box 2455, Riyadh 11451, Saudi Arabia
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Borland S, Oudart A, Prigent-Combaret C, Brochier-Armanet C, Wisniewski-Dyé F. Genome-wide survey of two-component signal transduction systems in the plant growth-promoting bacterium Azospirillum. BMC Genomics 2015; 16:833. [PMID: 26489830 PMCID: PMC4618731 DOI: 10.1186/s12864-015-1962-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Accepted: 09/29/2015] [Indexed: 01/05/2023] Open
Abstract
Background Two-component systems (TCS) play critical roles in sensing and responding to environmental cues. Azospirillum is a plant growth-promoting rhizobacterium living in the rhizosphere of many important crops. Despite numerous studies about its plant beneficial properties, little is known about how the bacterium senses and responds to its rhizospheric environment. The availability of complete genome sequenced from four Azospirillum strains (A. brasilense Sp245 and CBG 497, A. lipoferum 4B and Azospirillum sp. B510) offers the opportunity to conduct a comprehensive comparative analysis of the TCS gene family. Results Azospirillum genomes harbour a very large number of genes encoding TCS, and are especially enriched in hybrid histidine kinases (HyHK) genes compared to other plant-associated bacteria of similar genome sizes. We gained further insight into HyHK structure and architecture, revealing an intriguing complexity of these systems. An unusual proportion of TCS genes were orphaned or in complex clusters, and a high proportion of predicted soluble HKs compared to other plant-associated bacteria are reported. Phylogenetic analyses of the transmitter and receiver domains of A. lipoferum 4B HyHK indicate that expansion of this family mainly arose through horizontal gene transfer but also through gene duplications all along the diversification of the Azospirillum genus. By performing a genome-wide comparison of TCS, we unraveled important ‘genus-defining’ and ‘plant-specifying’ TCS. Conclusions This study shed light on Azospirillum TCS which may confer important regulatory flexibility. Collectively, these findings highlight that Azospirillum genomes have broad potential for adaptation to fluctuating environments. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-1962-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Stéphanie Borland
- Université de Lyon, Université Lyon 1, CNRS, UMR5557, Laboratoire d'Ecologie Microbienne, 43 7 boulevard du 11 novembre 1918, F-69622, Villeurbanne, France.
| | - Anne Oudart
- Université de Lyon, Université Lyon 1, CNRS, UMR5558, Laboratoire de Biométrie et Biologie Evolutive, 43 boulevard du 11 novembre 1918, F-69622, Villeurbanne, France.
| | - Claire Prigent-Combaret
- Université de Lyon, Université Lyon 1, CNRS, UMR5557, Laboratoire d'Ecologie Microbienne, 43 7 boulevard du 11 novembre 1918, F-69622, Villeurbanne, France.
| | - Céline Brochier-Armanet
- Université de Lyon, Université Lyon 1, CNRS, UMR5558, Laboratoire de Biométrie et Biologie Evolutive, 43 boulevard du 11 novembre 1918, F-69622, Villeurbanne, France.
| | - Florence Wisniewski-Dyé
- Université de Lyon, Université Lyon 1, CNRS, UMR5557, Laboratoire d'Ecologie Microbienne, 43 7 boulevard du 11 novembre 1918, F-69622, Villeurbanne, France.
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Abstract
The Alphaproteobacteria uniquely integrate features of two-component signal transduction and alternative σ factor regulation to control transcription of genes that ensure growth and survival across a range of stress conditions. Research over the past decade has led to the discovery of the key molecular players of this general stress response (GSR) system, including the sigma factor σ(EcfG), its anti-σ factor NepR, and the anti-anti-σ factor PhyR. The central molecular event of GSR activation entails aspartyl phosphorylation of PhyR, which promotes its binding to NepR and thereby releases σ(EcfG) to associate with RNAP and direct transcription. Recent studies are providing a new understanding of complex, multilayered sensory networks that activate and repress this central protein partner switch. This review synthesizes our structural and functional understanding of the core GSR regulatory proteins and highlights emerging data that are defining the systems that regulate GSR transcription in a variety of species.
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Affiliation(s)
- Aretha Fiebig
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, Illinois 60637;
| | - Julien Herrou
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, Illinois 60637;
| | - Jonathan Willett
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, Illinois 60637;
| | - Sean Crosson
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, Illinois 60637;
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Zhou X, Qian G, Chen Y, Du L, Liu F, Yuen GY. PilG is Involved in the Regulation of Twitching Motility and Antifungal Antibiotic Biosynthesis in the Biological Control Agent Lysobacter enzymogenes. PHYTOPATHOLOGY 2015; 105:1318-1324. [PMID: 26360465 DOI: 10.1094/phyto-12-14-0361-r] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Lysobacter enzymogenes strain C3 is a gliding bacterium which produces the antifungal secondary metabolite heat-stable antifungal factor (HSAF) and type IV pilus (T4P) as important mechanisms in biological control activity against fungal pathogens. To date, the regulators that control HSAF biosynthesis and T4P-dependent twitching motility in L. enzymogenes are poorly explored. In the present study, we addressed the role of pilG in the regulation of these two traits in L. enzymogenes. PilG of L. enzymogenes was found to be a response regulator, commonly known as a component of a two-component transduction system. Mutation of pilG in strain C3 abolished its ability to display spreading colony phenotype and cell movement at the colony margin, which is indicative of twitching motility; hence, PilG positively regulates twitching motility in L. enzymogenes. Mutation of pilG also enhanced HSAF production and the transcription of its key biosynthetic gene hsaf pks/nrps, suggesting that PilG plays a negative regulatory role in HSAF biosynthesis. This finding represents the first demonstration of the regulator PilG having a role in secondary metabolite biosynthesis in bacteria. Collectively, our results suggest that key ecological functions (HSAF production and twitching motility) in L. enzymogenes strain C3 are regulated in opposite directions by the same regulatory protein, PilG.
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Affiliation(s)
- Xue Zhou
- First, second, third, and fifth authors: College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China/Key Laboratory of Integrated Management of Crop Diseases and Pests (Nanjing Agricultural University), Ministry of Education; fourth author: Department of Chemistry, University of Nebraska-Lincoln, 68588; fifth author: Institute of Plant Protection, Jiangsu Academy of Agricultural Science, Nanjing 210014, P.R. China; and sixth author: Department of Plant Pathology, University of Nebraska-Lincoln
| | - Guoliang Qian
- First, second, third, and fifth authors: College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China/Key Laboratory of Integrated Management of Crop Diseases and Pests (Nanjing Agricultural University), Ministry of Education; fourth author: Department of Chemistry, University of Nebraska-Lincoln, 68588; fifth author: Institute of Plant Protection, Jiangsu Academy of Agricultural Science, Nanjing 210014, P.R. China; and sixth author: Department of Plant Pathology, University of Nebraska-Lincoln
| | - Yuan Chen
- First, second, third, and fifth authors: College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China/Key Laboratory of Integrated Management of Crop Diseases and Pests (Nanjing Agricultural University), Ministry of Education; fourth author: Department of Chemistry, University of Nebraska-Lincoln, 68588; fifth author: Institute of Plant Protection, Jiangsu Academy of Agricultural Science, Nanjing 210014, P.R. China; and sixth author: Department of Plant Pathology, University of Nebraska-Lincoln
| | - Liangcheng Du
- First, second, third, and fifth authors: College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China/Key Laboratory of Integrated Management of Crop Diseases and Pests (Nanjing Agricultural University), Ministry of Education; fourth author: Department of Chemistry, University of Nebraska-Lincoln, 68588; fifth author: Institute of Plant Protection, Jiangsu Academy of Agricultural Science, Nanjing 210014, P.R. China; and sixth author: Department of Plant Pathology, University of Nebraska-Lincoln
| | - Fengquan Liu
- First, second, third, and fifth authors: College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China/Key Laboratory of Integrated Management of Crop Diseases and Pests (Nanjing Agricultural University), Ministry of Education; fourth author: Department of Chemistry, University of Nebraska-Lincoln, 68588; fifth author: Institute of Plant Protection, Jiangsu Academy of Agricultural Science, Nanjing 210014, P.R. China; and sixth author: Department of Plant Pathology, University of Nebraska-Lincoln
| | - Gary Y Yuen
- First, second, third, and fifth authors: College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China/Key Laboratory of Integrated Management of Crop Diseases and Pests (Nanjing Agricultural University), Ministry of Education; fourth author: Department of Chemistry, University of Nebraska-Lincoln, 68588; fifth author: Institute of Plant Protection, Jiangsu Academy of Agricultural Science, Nanjing 210014, P.R. China; and sixth author: Department of Plant Pathology, University of Nebraska-Lincoln
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Salvado B, Vilaprinyo E, Sorribas A, Alves R. A survey of HK, HPt, and RR domains and their organization in two-component systems and phosphorelay proteins of organisms with fully sequenced genomes. PeerJ 2015; 3:e1183. [PMID: 26339559 PMCID: PMC4558063 DOI: 10.7717/peerj.1183] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Accepted: 07/23/2015] [Indexed: 12/17/2022] Open
Abstract
Two Component Systems and Phosphorelays (TCS/PR) are environmental signal transduction cascades in prokaryotes and, less frequently, in eukaryotes. The internal domain organization of proteins and the topology of TCS/PR cascades play an important role in shaping the responses of the circuits. It is thus important to maintain updated censuses of TCS/PR proteins in order to identify the various topologies used by nature and enable a systematic study of the dynamics associated with those topologies. To create such a census, we analyzed the proteomes of 7,609 organisms from all domains of life with fully sequenced and annotated genomes. To begin, we survey each proteome searching for proteins containing domains that are associated with internal signal transmission within TCS/PR: Histidine Kinase (HK), Response Regulator (RR) and Histidine Phosphotranfer (HPt) domains, and analyze how these domains are arranged in the individual proteins. Then, we find all types of operon organization and calculate how much more likely are proteins that contain TCS/PR domains to be coded by neighboring genes than one would expect from the genome background of each organism. Finally, we analyze if the fusion of domains into single TCS/PR proteins is more frequently observed than one might expect from the background of each proteome. We find 50 alternative ways in which the HK, HPt, and RR domains are observed to organize into single proteins. In prokaryotes, TCS/PR coding genes tend to be clustered in operons. 90% of all proteins identified in this study contain just one of the three domains, while 8% of the remaining proteins combine one copy of an HK, a RR, and/or an HPt domain. In eukaryotes, 25% of all TCS/PR proteins have more than one domain. These results might have implications for how signals are internally transmitted within TCS/PR cascades. These implications could explain the selection of the various designs in alternative circumstances.
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Affiliation(s)
- Baldiri Salvado
- Departament de Cienciès Mèdiques Bàsiques, Universitat de Lleida , Lleida, Catalonya , Spain
| | - Ester Vilaprinyo
- Departament de Cienciès Mèdiques Bàsiques, Universitat de Lleida , Lleida, Catalonya , Spain ; IRBLleida , Lleida, Catalonya , Spain
| | - Albert Sorribas
- Departament de Cienciès Mèdiques Bàsiques, Universitat de Lleida , Lleida, Catalonya , Spain
| | - Rui Alves
- Departament de Cienciès Mèdiques Bàsiques, Universitat de Lleida , Lleida, Catalonya , Spain
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Fojtikova V, Stranava M, Vos MH, Liebl U, Hranicek J, Kitanishi K, Shimizu T, Martinkova M. Kinetic Analysis of a Globin-Coupled Histidine Kinase, AfGcHK: Effects of the Heme Iron Complex, Response Regulator, and Metal Cations on Autophosphorylation Activity. Biochemistry 2015. [PMID: 26212354 DOI: 10.1021/acs.biochem.5b00517] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The globin-coupled histidine kinase, AfGcHK, is a part of the two-component signal transduction system from the soil bacterium Anaeromyxobacter sp. Fw109-5. Activation of its sensor domain significantly increases its autophosphorylation activity, which targets the His183 residue of its functional domain. The phosphate group of phosphorylated AfGcHK is then transferred to the cognate response regulator. We investigated the effects of selected variables on the autophosphorylation reaction's kinetics. The kcat values of the heme Fe(III)-OH(-), Fe(III)-cyanide, Fe(III)-imidazole, and Fe(II)-O2 bound active AfGcHK forms were 1.1-1.2 min(-1), and their Km(ATP) values were 18.9-35.4 μM. However, the active form bearing a CO-bound Fe(II) heme had a kcat of 1.0 min(-1) but a very high Km(ATP) value of 357 μM, suggesting that its active site structure differs strongly from the other active forms. The Fe(II) heme-bound inactive form had kcat and Km(ATP) values of 0.4 min(-1) and 78 μM, respectively, suggesting that its low activity reflects a low affinity for ATP relative to that of the Fe(III) form. The heme-free form exhibited low activity, with kcat and Km(ATP) values of 0.3 min(-1) and 33.6 μM, respectively, suggesting that the heme iron complex is essential for high catalytic activity. Overall, our results indicate that the coordination and oxidation state of the sensor domain heme iron profoundly affect the enzyme's catalytic activity because they modulate its ATP binding affinity and thus change its kcat/Km(ATP) value. The effects of the response regulator and different divalent metal cations on the autophosphorylation reaction are also discussed.
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Affiliation(s)
| | | | - Marten H Vos
- §Laboratoire d'Optique et Biosciences, INSERM U1182-CNRS UMR7645, Ecole Polytechnique, 91128 Palaiseau Cedex, France
| | - Ursula Liebl
- §Laboratoire d'Optique et Biosciences, INSERM U1182-CNRS UMR7645, Ecole Polytechnique, 91128 Palaiseau Cedex, France
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Subramanian K, Paul MR, Tyson JJ. Dynamical Localization of DivL and PleC in the Asymmetric Division Cycle of Caulobacter crescentus: A Theoretical Investigation of Alternative Models. PLoS Comput Biol 2015; 11:e1004348. [PMID: 26186202 PMCID: PMC4505887 DOI: 10.1371/journal.pcbi.1004348] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Accepted: 05/20/2015] [Indexed: 11/18/2022] Open
Abstract
Cell-fate asymmetry in the predivisional cell of Caulobacter crescentus requires that the regulatory protein DivL localizes to the new pole of the cell where it up-regulates CckA kinase, resulting in a gradient of CtrA~P across the cell. In the preceding stage of the cell cycle (the "stalked" cell), DivL is localized uniformly along the cell membrane and maintained in an inactive form by DivK~P. It is unclear how DivL overcomes inhibition by DivK~P in the predivisional cell simply by changing its location to the new pole. It has been suggested that co-localization of DivL with PleC phosphatase at the new pole is essential to DivL's activity there. However, there are contrasting views on whether the bifunctional enzyme, PleC, acts as a kinase or phosphatase at the new pole. To explore these ambiguities, we formulated a mathematical model of the spatiotemporal distributions of DivL, PleC and associated proteins (DivJ, DivK, CckA, and CtrA) during the asymmetric division cycle of a Caulobacter cell. By varying localization profiles of DivL and PleC in our model, we show how the physiologically observed spatial distributions of these proteins are essential for the transition from a stalked cell to a predivisional cell. Our simulations suggest that PleC is a kinase in predivisional cells, and that, by sequestering DivK~P, the kinase form of PleC enables DivL to be reactivated at the new pole. Hence, co-localization of PleC kinase and DivL is essential to establishing cellular asymmetry. Our simulations reproduce the experimentally observed spatial distribution and phosphorylation status of CtrA in wild-type and mutant cells. Based on the model, we explore novel combinations of mutant alleles, making predictions that can be tested experimentally.
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Affiliation(s)
- Kartik Subramanian
- Graduate Program in Genetics, Bioinformatics and Computational Biology, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, United States of America
| | - Mark R. Paul
- Department of Mechanical Engineering, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, United States of America
| | - John J. Tyson
- Department of Biological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, United States of America
- Virginia Bioinformatics Institute, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, United States of America
- * E-mail:
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Kurth D, Belfiore C, Gorriti MF, Cortez N, Farias ME, Albarracín VH. Genomic and proteomic evidences unravel the UV-resistome of the poly-extremophile Acinetobacter sp. Ver3. Front Microbiol 2015; 6:328. [PMID: 25954258 PMCID: PMC4406064 DOI: 10.3389/fmicb.2015.00328] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Accepted: 04/01/2015] [Indexed: 12/20/2022] Open
Abstract
Ultraviolet radiation can damage biomolecules, with detrimental or even lethal effects for life. Even though lower wavelengths are filtered by the ozone layer, a significant amount of harmful UV-B and UV-A radiation reach Earth's surface, particularly in high altitude environments. high-altitude Andean lakes (HAALs) are a group of disperse shallow lakes and salterns, located at the Dry Central Andes region in South America at altitudes above 3,000 m. As it is considered one of the highest UV-exposed environments, HAAL microbes constitute model systems to study UV-resistance mechanisms in environmental bacteria at various complexity levels. Herein, we present the genome sequence of Acinetobacter sp. Ver3, a gammaproteobacterium isolated from Lake Verde (4,400 m), together with further experimental evidence supporting the phenomenological observations regarding this bacterium ability to cope with increased UV-induced DNA damage. Comparison with the genomes of other Acinetobacter strains highlighted a number of unique genes, such as a novel cryptochrome. Proteomic profiling of UV-exposed cells identified up-regulated proteins such as a specific cytoplasmic catalase, a putative regulator, and proteins associated to amino acid and protein synthesis. Down-regulated proteins were related to several energy-generating pathways such as glycolysis, beta-oxidation of fatty acids, and electronic respiratory chain. To the best of our knowledge, this is the first report on a genome from a polyextremophilic Acinetobacter strain. From the genomic and proteomic data, an "UV-resistome" was defined, encompassing the genes that would support the outstanding UV-resistance of this strain.
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Affiliation(s)
- Daniel Kurth
- Laboratorio de Investigaciones Microbiologicas Lagunas Andinas, Centro Científico Tecnológico, Planta Piloto de Procesos Industriales Microbiológicos - Consejo Nacional de Investigaciones Científicas y Técnicas, San Miguel de Tucumán Argentina
| | - Carolina Belfiore
- Laboratorio de Investigaciones Microbiologicas Lagunas Andinas, Centro Científico Tecnológico, Planta Piloto de Procesos Industriales Microbiológicos - Consejo Nacional de Investigaciones Científicas y Técnicas, San Miguel de Tucumán Argentina
| | - Marta F Gorriti
- Laboratorio de Investigaciones Microbiologicas Lagunas Andinas, Centro Científico Tecnológico, Planta Piloto de Procesos Industriales Microbiológicos - Consejo Nacional de Investigaciones Científicas y Técnicas, San Miguel de Tucumán Argentina
| | - Néstor Cortez
- Centro Científico Tecnológico, IBR - CONICET, Universidad Nacional de Rosario Rosario, Argentina
| | - María E Farias
- Laboratorio de Investigaciones Microbiologicas Lagunas Andinas, Centro Científico Tecnológico, Planta Piloto de Procesos Industriales Microbiológicos - Consejo Nacional de Investigaciones Científicas y Técnicas, San Miguel de Tucumán Argentina
| | - Virginia H Albarracín
- Laboratorio de Investigaciones Microbiologicas Lagunas Andinas, Centro Científico Tecnológico, Planta Piloto de Procesos Industriales Microbiológicos - Consejo Nacional de Investigaciones Científicas y Técnicas, San Miguel de Tucumán Argentina ; Facultad de Ciencias Naturales e Instituto Miguel Lillo, Universidad Nacional de Tucumán, San Miguel de Tucumán Argentina
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Ocasio VJ, Corrêa F, Gardner KH. Ligand-induced folding of a two-component signaling receiver domain. Biochemistry 2015; 54:1353-63. [PMID: 25629646 DOI: 10.1021/bi501143b] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
To survive and adapt to environmental changes, bacteria commonly use two-component signaling systems. Minimally, these pathways use histidine kinases (HKs) to detect environmental signals, harnessing these to control phosphorylation levels of receiver (REC) domains of downstream response regulators that convert this signal into physiological responses. Studies of several prototypical REC domains suggest that phosphorylation shifts these proteins between inactive and active structures that are globally similar and well-folded. However, it is unclear how globally these findings hold within REC domains in general, particularly when they are considered within full-length proteins. Here, we present EL_LovR, a full-length REC-only protein that is phosphorylated in response to blue light in the marine α-proteobacterium, Erythrobacter litoralis HTCC2594. Notably, EL_LovR is similar to comparable REC-only proteins used in bacterial general stress responses, where genetic evidence suggests that their potent phosphatase activity is important to shut off such systems. Size exclusion chromatography, light scattering, and solution NMR experiments show that EL_LovR is monomeric and unfolded in solution under conditions routinely used for other REC structure determinations. Addition of Mg(2+) and phosphorylation induce progressively greater degrees of tertiary structure stabilization, with the solution structure of the fully activated EL_LovR adopting the canonical receiver domain fold. Parallel functional assays show that EL_LovR has a fast dephosphorylation rate, consistent with its proposed function as a phosphate sink that depletes the HK phosphoryl group, promoting the phosphatase activity of this enzyme. Our findings demonstrate that EL_LovR undergoes substantial ligand-dependent conformational changes that have not been reported for other RRs, expanding the scope of conformational changes and regulation used by REC domains, critical components of bacterial signaling systems.
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Affiliation(s)
- Victor J Ocasio
- Departments of Biophysics and Biochemistry, UT Southwestern Medical Center , Dallas, Texas 75390-8816, United States
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Li J, Zheng X, Guo X, Qi L, Dong X. Characterization of an archaeal two-component system that regulates methanogenesis in Methanosaeta harundinacea. PLoS One 2014; 9:e95502. [PMID: 24748383 PMCID: PMC3991700 DOI: 10.1371/journal.pone.0095502] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2013] [Accepted: 03/27/2014] [Indexed: 02/02/2023] Open
Abstract
Two-component signal transduction systems (TCSs) are a major mechanism used by bacteria in response to environmental changes. Although many sequenced archaeal genomes encode TCSs, they remain poorly understood. Previously, we reported that a methanogenic archaeon, Methanosaeta harundinacea, encodes FilI, which synthesizes carboxyl-acyl homoserine lactones, to regulate transitions of cellular morphology and carbon metabolic fluxes. Here, we report that filI, the cotranscribed filR2, and the adjacent filR1 constitute an archaeal TCS. FilI possesses a cytoplasmic kinase domain (histidine kinase A and histidine kinase-like ATPase) and its cognate response regulator. FilR1 carries a receiver (REC) domain coupled with an ArsR-related domain with potential DNA-binding ability, while FilR2 carries only a REC domain. In a phosphorelay assay, FilI was autophosphorylated and specifically transferred the phosphoryl group to FilR1 and FilR2, confirming that the three formed a cognate TCS. Through chromatin immunoprecipitation-quantitative polymerase chain reaction (ChIP-qPCR) using an anti-FilR1 antibody, FilR1 was shown to form in vivo associations with its own promoter and the promoter of the filI-filR2 operon, demonstrating a regulatory pattern common among TCSs. ChIP-qPCR also detected FilR1 associations with key genes involved in acetoclastic methanogenesis, acs4 and acs1. Electrophoretic mobility shift assays confirmed the in vitro tight binding of FilR1 to its own promoter and those of filI-filR2, acs4, and mtrABC. This also proves the DNA-binding ability of the ArsR-related domain, which is found primarily in Archaea. The archaeal promoters of acs4, filI, acs1, and mtrABC also initiated FilR1-modulated expression in an Escherichia coli lux reporter system, suggesting that FilR1 can up-regulate both archaeal and bacterial transcription. In conclusion, this work identifies an archaeal FilI/FilRs TCS that regulates the methanogenesis of M. harundinacea.
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Affiliation(s)
- Jie Li
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Xin Zheng
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Xiaopeng Guo
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Lei Qi
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Xiuzhu Dong
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- * E-mail:
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Essential role for the response regulator PmrA in Coxiella burnetii type 4B secretion and colonization of mammalian host cells. J Bacteriol 2014; 196:1925-40. [PMID: 24610709 DOI: 10.1128/jb.01532-14] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Successful host cell colonization by the Q fever pathogen, Coxiella burnetii, requires translocation of effector proteins into the host cytosol by a Dot/Icm type 4B secretion system (T4BSS). In Legionella pneumophila, the two-component system (TCS) PmrAB regulates the Dot/Icm T4BSS and several additional physiological processes associated with pathogenesis. Because PmrA consensus regulatory elements are associated with some dot/icm and substrate genes, a similar role for PmrA in regulation of the C. burnetii T4BSS has been proposed. Here, we constructed a C. burnetii pmrA deletion mutant to directly probe PmrA-mediated gene regulation. Compared to wild-type bacteria, C. burnetii ΔpmrA exhibited severe intracellular growth defects that coincided with failed secretion of effector proteins. Luciferase gene reporter assays demonstrated PmrA-dependent expression of 5 of 7 dot/icm operons and 9 of 11 effector-encoding genes with a predicted upstream PmrA regulatory element. Mutational analysis verified consensus sequence nucleotides required for PmrA-directed transcription. RNA sequencing and whole bacterial cell mass spectrometry of wild-type C. burnetii and the ΔpmrA mutant uncovered new components of the PmrA regulon, including several genes lacking PmrA motifs that encoded Dot/Icm substrates. Collectively, our results indicate that the PmrAB TCS is a critical virulence factor that regulates C. burnetii Dot/Icm secretion. The presence of PmrA-responsive genes lacking PmrA regulatory elements also suggests that the PmrAB TCS controls expression of regulatory systems associated with the production of additional C. burnetii proteins involved in host cell parasitism.
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48
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Sheftic SR, White E, Gage DJ, Alexandrescu AT. NMR structure of the HWE kinase associated response regulator Sma0114 in its activated state. Biochemistry 2014; 53:311-22. [PMID: 24364624 DOI: 10.1021/bi401497h] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Bacterial receiver domains modulate intracellular responses to external stimuli in two-component systems. Sma0114 is the first structurally characterized representative from the family of receiver domains that are substrates for histidine-tryptophan-glutamate (HWE) kinases. We report the NMR structure of Sma0114 bound by Ca(2+) and BeF3(-), a phosphate analogue that stabilizes the activated state. Differences between the NMR structures of the inactive and activated states occur in helix α1, the active site loop that connects strand β3 and helix α3, and in the segment from strand β5 to helix α5 of the 455 (α4-β5-α5) face. Structural rearrangements of the 455 face typically make receiver domains competent for binding downstream target molecules. In Sma0114 the structural changes accompanying activation result in a more negatively charged surface for the 455 face. Coupling between the 455 face and active site phosphorylation is usually mediated through the rearrangement of a threonine and tyrosine residue, in a mechanism called Y-T coupling. The NMR structure indicates that Sma0114 lacks Y-T coupling and that communication between the active site and the 455 face is achieved through a conserved lysine residue that stabilizes the acyl phosphate in receiver domains. (15)N-NMR relaxation experiments were used to investigate the backbone dynamics of the Sma0114 apoprotein, the binary Sma0114·Ca(2+) complex, and the ternary Sma0114·Ca(2+)·BeF3(-) complex. The loss of entropy due to ligand binding at the active site is compensated by increased flexibility in the 455 face. The dynamic character of the 455 face in Sma0114, which results in part from the replacement of helix α4 by a flexible loop, may facilitate induced-fit recognition of target molecules.
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Affiliation(s)
- Sarah R Sheftic
- Department of Molecular and Cellular Biology, University of Connecticut, Storrs , Connecticut, United States
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Abstract
Cytokinins are N (6) substituted adenine derivatives that affect many aspects of plant growth and development, including cell division, shoot initiation and growth, leaf senescence, apical dominance, sink/source relationships, nutrient uptake, phyllotaxis, and vascular, gametophyte, and embryonic development, as well as the response to biotic and abiotic factors. Molecular genetic studies in Arabidopsis have helped elucidate the mechanisms underlying the function of this phytohormone in plants. Here, we review our current understanding of cytokinin biosynthesis and signaling in Arabidopsis, the latter of which is similar to bacterial two-component phosphorelays. We discuss the perception of cytokinin by the ER-localized histidine kinase receptors, the role of the AHPs in mediating the transfer of the phosphoryl group from the receptors to the response regulators (ARRs), and finally the role of the large ARR family in cytokinin function. The identification and genetic manipulation of the genes involved in cytokinin metabolism and signaling have helped illuminate the roles of cytokinins in Arabidopsis. We discuss these diverse roles, and how other signaling pathways influence cytokinin levels and sensitivity though modulation of the expression of cytokinin signaling and metabolic genes.
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Affiliation(s)
- Joseph J Kieber
- University of North Carolina, Biology Department, Chapel Hill, NC 27599-3280
| | - G Eric Schaller
- Dartmouth College, Department of Biological Sciences, Hanover, NH 03755
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Mikkelsen H, Hui K, Barraud N, Filloux A. The pathogenicity island encoded PvrSR/RcsCB regulatory network controls biofilm formation and dispersal in Pseudomonas aeruginosa PA14. Mol Microbiol 2013; 89:450-63. [PMID: 23750818 PMCID: PMC3842833 DOI: 10.1111/mmi.12287] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/03/2013] [Indexed: 01/14/2023]
Abstract
Pseudomonas aeruginosa biofilm formation is linked to persistent infections in humans. Biofilm formation is facilitated by extracellular appendages, some of which are assembled by the Chaperone Usher Pathway (Cup). The cupD gene cluster is located on the PAPI-1 pathogenicity island of strain PA14 and has probably been acquired together with four genes encoding two-component signal transduction proteins. We have previously showed that the RcsB response regulator activates expression of the cupD genes, which leads to the production of CupD fimbriae and increased attachment. Here we show that RcsB activity is tightly modulated by two sensors, RcsC and PvrS. While PvrS acts as a kinase that enhances RcsB activity, RcsC has a dual function, first as a phosphorelay, and second as a phosphatase. We found that, under certain growth conditions, overexpression of RcsB readily induces biofilm dispersal. Microarray analysis shows that RcsB positively controls expression of pvrR that encodes the phosphodiesterase required for this dispersal process. Finally, in addition to the PAPI-1 encoded cupD genes, RcsB controls several genes on the core genome, some of which encode orphan response regulators. We thus discovered that RcsB is central to a large regulatory network that fine-tunes the switch between biofilm formation and dispersal.
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Affiliation(s)
- Helga Mikkelsen
- Imperial College London, Department of Life Sciences, MRC Centre for Molecular Bacteriology and Infection, South Kensington Campus, Flowers Building, SW7 2AZ, London, UK
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