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Jaisinghani N, Previti ML, Andrade J, Askenazi M, Ueberheide B, Seeliger JC. Proteomics from compartment-specific APEX2 labeling in Mycobacterium tuberculosis reveals Type VII secretion substrates in the cell wall. Cell Chem Biol 2024; 31:523-533.e4. [PMID: 37967559 PMCID: PMC11106752 DOI: 10.1016/j.chembiol.2023.10.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 07/20/2023] [Accepted: 10/13/2023] [Indexed: 11/17/2023]
Abstract
The cell wall of mycobacteria plays a key role in interactions with the environment. Its ability to act as a selective filter is crucial to bacterial survival. Proteins in the cell wall enable this function by mediating the import and export of diverse metabolites, from ions to lipids to proteins. Identifying cell wall proteins is an important step in assigning function, especially as many mycobacterial proteins lack functionally characterized homologues. Current methods for protein localization have inherent limitations that reduce accuracy. Here we showed that although chemical labeling of live cells did not exclusively label surface proteins, protein tagging by the engineered peroxidase APEX2 within live Mycobacterium tuberculosis accurately identified the cytosolic and cell wall proteomes. Our data indicate that substrates of the virulence-associated Type VII ESX secretion system are exposed to the periplasm, providing insight into the currently unknown mechanism by which these proteins cross the mycobacterial cell envelope.
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Affiliation(s)
- Neetika Jaisinghani
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY 11794, USA
| | - Mary L Previti
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY 11794, USA
| | - Joshua Andrade
- Proteomics Laboratory, New York University Grossman School of Medicine, New York, NY 10016, USA
| | | | - Beatrix Ueberheide
- Proteomics Laboratory, New York University Grossman School of Medicine, New York, NY 10016, USA; Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Jessica C Seeliger
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY 11794, USA.
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2
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Jaisinghani N, Previti ML, Andrade J, Askenazi M, Ueberheide B, Seeliger JC. Cell wall proteomics in live Mycobacterium tuberculosis uncovers exposure of ESX substrates to the periplasm. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.29.534792. [PMID: 37034674 PMCID: PMC10081232 DOI: 10.1101/2023.03.29.534792] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 04/16/2023]
Abstract
The cell wall of mycobacteria plays a key role in interactions with the environment and its ability to act as a selective filter is crucial to bacterial survival. Proteins in the cell wall enable this function by mediating the import and export of diverse metabolites from ions to lipids to proteins. Accurately identifying cell wall proteins is an important step in assigning function, especially as many mycobacterial proteins lack functionally characterized homologues. Current methods for protein localization have inherent limitations that reduce accuracy. Here we showed that protein tagging by the engineered peroxidase APEX2 within live Mycobacterium tuberculosis enabled the accurate identification of the cytosolic and cell wall proteomes. Our data indicate that substrates of the virulence-associated Type VII ESX secretion system are exposed to the Mtb periplasm, providing insight into the currently unknown mechanism by which these proteins cross the mycobacterial cell envelope.
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Affiliation(s)
- Neetika Jaisinghani
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, New York, USA
| | - Mary L Previti
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, New York, USA
| | - Joshua Andrade
- Proteomics Laboratory, New York University Grossman School of Medicine, New York, New York, USA
| | | | - Beatrix Ueberheide
- Proteomics Laboratory, New York University Grossman School of Medicine, New York, New York, USA
- Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, New York, USA
| | - Jessica C Seeliger
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, New York, USA
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3
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Shamma F, Rego EH, Boutte CC. Mycobacterial serine/threonine phosphatase PstP is phosphoregulated and localized to mediate control of cell wall metabolism. Mol Microbiol 2022; 118:47-60. [PMID: 35670057 PMCID: PMC10070032 DOI: 10.1111/mmi.14951] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 05/12/2022] [Accepted: 06/01/2022] [Indexed: 11/26/2022]
Abstract
The mycobacterial cell wall is profoundly regulated in response to environmental stresses, and this regulation contributes to antibiotic tolerance. The reversible phosphorylation of different cell wall regulatory proteins is a major mechanism of cell wall regulation. Eleven serine/threonine protein kinases phosphorylate many critical cell wall-related proteins in mycobacteria. PstP is the sole serine/ threonine phosphatase, but few proteins have been verified as PstP substrates. PstP is itself phosphorylated, but the role of its phosphorylation in regulating its activity has been unclear. In this study, we aim to discover novel substrates of PstP in Mycobacterium tuberculosis (Mtb). We show in vitro that PstP dephosphorylates two regulators of peptidoglycan in Mtb, FhaA, and Wag31. We also show that a phosphomimetic mutation of T137 on PstP negatively regulates its catalytic activity against the cell wall regulators FhaA, Wag31, CwlM, PknB, and PknA, and that the corresponding mutation in Mycobacterium smegmatis causes misregulation of peptidoglycan in vivo. We show that PstP is localized to the septum, which likely restricts its access to certain substrates. These findings on the regulation of PstP provide insight into the control of cell wall metabolism in mycobacteria.
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Affiliation(s)
- Farah Shamma
- Department of Biology, University of Texas at Arlington, Arlington, Texas, USA
| | - E Hesper Rego
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Cara C Boutte
- Department of Biology, University of Texas at Arlington, Arlington, Texas, USA
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4
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Ulrych A, Fabrik I, Kupčík R, Vajrychová M, Doubravová L, Branny P. Cell Wall Stress Stimulates the Activity of the Protein Kinase StkP of Streptococcus pneumoniae, Leading to Multiple Phosphorylation. J Mol Biol 2021; 433:167319. [PMID: 34688688 DOI: 10.1016/j.jmb.2021.167319] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 10/06/2021] [Accepted: 10/15/2021] [Indexed: 12/28/2022]
Abstract
Streptococcus pneumoniae is an opportunistic human pathogen that encodes a single eukaryotic-type Ser/Thr protein kinase StkP and its functional counterpart, the protein phosphatase PhpP. These signaling enzymes play critical roles in coordinating cell division and growth in pneumococci. In this study, we determined the proteome and phosphoproteome profiles of relevant mutants. Comparison of those with the wild-type provided a representative dataset of novel phosphoacceptor sites and StkP-dependent substrates. StkP phosphorylates key proteins involved in cell division and cell wall biosynthesis in both the unencapsulated laboratory strain Rx1 and the encapsulated virulent strain D39. Furthermore, we show that StkP plays an important role in triggering an adaptive response induced by a cell wall-directed antibiotic. Phosphorylation of the sensor histidine kinase WalK and downregulation of proteins of the WalRK core regulon suggest crosstalk between StkP and the WalRK two-component system. Analysis of proteomic profiles led to the identification of gene clusters regulated by catabolite control mechanisms, indicating a tight coupling of carbon metabolism and cell wall homeostasis. The imbalance of steady-state protein phosphorylation in the mutants as well as after antibiotic treatment is accompanied by an accumulation of the global Spx regulator, indicating a Spx-mediated envelope stress response. In summary, StkP relays the perceived signal of cell wall status to key cell division and regulatory proteins, controlling the cell cycle and cell wall homeostasis.
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Affiliation(s)
- Aleš Ulrych
- Institute of Microbiology, v.v.i., Czech Academy of Sciences, Vídeňská 1083, 142 20 Prague, Czech Republic.
| | - Ivo Fabrik
- Biomedical Research Center, University Hospital Hradec Králové, Sokolská 581, 500 05 Hradec Králové, Czech Republic.
| | - Rudolf Kupčík
- Biomedical Research Center, University Hospital Hradec Králové, Sokolská 581, 500 05 Hradec Králové, Czech Republic.
| | - Marie Vajrychová
- Biomedical Research Center, University Hospital Hradec Králové, Sokolská 581, 500 05 Hradec Králové, Czech Republic.
| | - Linda Doubravová
- Institute of Microbiology, v.v.i., Czech Academy of Sciences, Vídeňská 1083, 142 20 Prague, Czech Republic.
| | - Pavel Branny
- Institute of Microbiology, v.v.i., Czech Academy of Sciences, Vídeňská 1083, 142 20 Prague, Czech Republic.
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Cabarca S, Frazão de Souza M, Albert de Oliveira A, Vignoli Muniz GS, Lamy MT, Vinicius Dos Reis C, Takarada J, Effer B, Souza LS, Iriarte de la Torre L, Couñago R, Pinto Oliveira CL, Balan A. Structure of the Mycobacterium tuberculosis cPknF and conformational changes induced in forkhead-associated regulatory domains. Curr Res Struct Biol 2021; 3:165-178. [PMID: 34382010 PMCID: PMC8339232 DOI: 10.1016/j.crstbi.2021.07.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 07/15/2021] [Accepted: 07/19/2021] [Indexed: 11/26/2022] Open
Abstract
Mycobacterium tuberculosis (Mtb) has 11 Serine-Threonine Protein Kinases (STPK) that control numerous physiological processes, including cell growth, cell division, metabolic flow, and transcription. PknF is one of the 11 Mtb STPKs that has, among other substrates, two FHA domains (FHA-1 and FHA-2) of the ATP-Binding Cassette (ABC) transporter Rv1747. Phosphorylation in T152 and T210 located in a non-structured linker that connects Rv1747 FHA domains is considerate to be the regulatory mechanism of the transporter. In this work, we resolved the three-dimensional structure of the PknF catalytic domain (cPknF) in complex with the human kinase inhibitor IKK16. cPknF is conserved when compared to other STPKs but shows specific residues in the binding site where the inhibitor is positioned. In addition, using Small Angle X-Ray Scattering analysis we monitored the behavior of the wild type and three FHA-phosphomimetic mutants in solution, and measured the cPknF affinity for these domains. The kinase showed higher affinity for the non-phosphorylated wild type domain and preference for phosphorylation of T152 inducing the rapprochement of the domains and significant structural changes. The results shed some light on the process of regulating the transporter's activity by phosphorylation and arises important questions about evolution and importance of this mechanism for the bacillus. Rv1747 is an ABC transporter which activity is regulated by PknF. cPknF is a typical Serine/Threonine Protein Kinase that can be explored as drug target. The higher affinity of cPknF for FHA-2 is important for further conformational changes. Rv1747 activation model reveals a concatenated activity essential for the system.
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Affiliation(s)
- Sindy Cabarca
- Programa de Pós-graduação em Genética, Universidade Estadual de Campinas, Campinas, 13083-862, SP, Brazil.,Laboratório de Biologia Estrutural Aplicada LBEA, Departamento de Microbiologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, 05508-000, São Paulo, SP, Brazil.,Grupo Investigaciones Biomédicas, Universidad de Sucre, Sincelejo, 700001, Sucre, Colombia
| | - Maximilia Frazão de Souza
- Grupo de Fluidos Complexos, Departamento de Física Experimental, Instituto de Física, Universidade de São Paulo, São Paulo, 05508-090, SP, Brazil
| | - Andrew Albert de Oliveira
- Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, 14049-900, SP, Brazil
| | - Gabriel S Vignoli Muniz
- Departamento de Física Geral, Instituto de Física, Universidade de São Paulo, São Paulo, 05508-090, Brazil
| | - M Teresa Lamy
- Departamento de Física Geral, Instituto de Física, Universidade de São Paulo, São Paulo, 05508-090, Brazil
| | - Caio Vinicius Dos Reis
- Structural Genomics Consortium, Universidade Estadual de Campinas, Campinas, 13083-886, São Paulo, Brazil
| | - Jessica Takarada
- Structural Genomics Consortium, Universidade Estadual de Campinas, Campinas, 13083-886, São Paulo, Brazil
| | - Brian Effer
- Center of Excellence in Traslational Medicine (CEMT) and Scientific and Technological Bioresource Nucleus (BIOREN), Universidad de la Frontera, Temuco, 01145, Chile
| | - Lucas Santos Souza
- Laboratório de Biologia Estrutural Aplicada LBEA, Departamento de Microbiologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, 05508-000, São Paulo, SP, Brazil
| | - Lilia Iriarte de la Torre
- Programa de Pós-graduação em Genética, Universidade Estadual de Campinas, Campinas, 13083-862, SP, Brazil.,Laboratório de Biologia Estrutural Aplicada LBEA, Departamento de Microbiologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, 05508-000, São Paulo, SP, Brazil.,Grupo Investigaciones Biomédicas, Universidad de Sucre, Sincelejo, 700001, Sucre, Colombia
| | - Rafael Couñago
- Structural Genomics Consortium, Universidade Estadual de Campinas, Campinas, 13083-886, São Paulo, Brazil
| | - Cristiano Luis Pinto Oliveira
- Grupo de Fluidos Complexos, Departamento de Física Experimental, Instituto de Física, Universidade de São Paulo, São Paulo, 05508-090, SP, Brazil
| | - Andrea Balan
- Laboratório de Biologia Estrutural Aplicada LBEA, Departamento de Microbiologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, 05508-000, São Paulo, SP, Brazil
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6
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Qu D, Zhao X, Sun Y, Wu FL, Tao SC. Mycobacterium tuberculosis Thymidylyltransferase RmlA Is Negatively Regulated by Ser/Thr Protein Kinase PknB. Front Microbiol 2021; 12:643951. [PMID: 33868202 PMCID: PMC8044546 DOI: 10.3389/fmicb.2021.643951] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Accepted: 02/28/2021] [Indexed: 11/13/2022] Open
Abstract
Ser/Thr phosphorylation by serine/threonine protein kinases (STPKs) plays significant roles in molecular regulation, which allows Mycobacteria to adapt their cell wall structure in response to the environment changes. Identifying direct targets of STPKs and determining their activities are therefore critical to revealing their function in Mycobacteria, for example, in cell wall formation and virulence. Herein, we reported that RmlA, a crucial L-rhamnose biosynthesis enzyme, is a substrate of STPK PknB in Mycobacterium tuberculosis (M. tuberculosis). Mass spectrometry analysis revealed that RmlA is phosphorylated at Thr-12, Thr-54, Thr-197, and Thr-12 is located close to the catalytic triad of RmlA. Biochemical and phenotypic analysis of two RmlA mutants, T12A/T12D, showed that their activities were reduced, and cell wall formation was negatively affected. Moreover, virulence of RmlA T12D mutant was attenuated in a macrophage model. Overall, these results provide the first evidence for the role of PknB-dependent RmlA phosphorylation in regulating cell wall formation in Mycobacteria, with significant implications for pathogenicity.
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Affiliation(s)
- Dehui Qu
- Key Laboratory of Molecular Module-Based Breeding of High Yield and Abiotic Resistant Plants in Universities of Shandong, School of Agriculture, Ludong University, Yantai, China.,State Key Laboratory of Microbial Metabolism and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Xiaohui Zhao
- Key Laboratory of Molecular Module-Based Breeding of High Yield and Abiotic Resistant Plants in Universities of Shandong, School of Agriculture, Ludong University, Yantai, China
| | - Yao Sun
- Key Laboratory of Molecular Module-Based Breeding of High Yield and Abiotic Resistant Plants in Universities of Shandong, School of Agriculture, Ludong University, Yantai, China
| | - Fan-Lin Wu
- Key Laboratory of Molecular Module-Based Breeding of High Yield and Abiotic Resistant Plants in Universities of Shandong, School of Agriculture, Ludong University, Yantai, China
| | - Sheng-Ce Tao
- Key Laboratory of Systems Biomedicine (Ministry of Education), Shanghai Center for Systems Biomedicine, Shanghai Jiao Tong University, Shanghai, China
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7
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Djorić D, Minton NE, Kristich CJ. The enterococcal PASTA kinase: A sentinel for cell envelope stress. Mol Oral Microbiol 2020; 36:132-144. [PMID: 32945615 DOI: 10.1111/omi.12313] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 09/05/2020] [Accepted: 09/08/2020] [Indexed: 12/12/2022]
Abstract
Enterococci are Gram-positive, opportunistic pathogens that reside throughout the gastrointestinal tracts of most terrestrial organisms. Enterococci are resistant to many antibiotics, which makes enterococcal infections difficult to treat. Enterococci are also particularly hardy bacteria that can tolerate a variety of environmental stressors. Understanding how enterococci sense and respond to the extracellular environment to enact adaptive biological responses may identify new targets that can be exploited for development of treatments for enterococcal infections. Bacterial eukaryotic-like serine/threonine kinases (eSTKs) and cognate phosphatases (STPs) are important signaling systems that mediate biological responses to extracellular stimuli. Some bacterial eSTKs are transmembrane proteins that contain a series of extracellular repeats of the penicillin-binding and Ser/Thr kinase-associated (PASTA) domain, leading to their designation as "PASTA kinases." Enterococcal genomes encode a single PASTA kinase and its cognate phosphatase. Investigations of the enterococcal PASTA kinase revealed its importance in resistance to antibiotics and other cell wall stresses, in enterococcal colonization of the mammalian gut, clues about its mechanism of signal transduction, and its integration with other enterococcal signal transduction systems. In this review, we describe the current state of knowledge of PASTA kinase signaling in enterococci and describe important gaps that still need to be addressed to provide a better understanding of this important signaling system.
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Affiliation(s)
- Dušanka Djorić
- Department of Microbiology and Immunology, Center for Infectious Disease Research, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Nicole E Minton
- Department of Microbiology and Immunology, Center for Infectious Disease Research, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Christopher J Kristich
- Department of Microbiology and Immunology, Center for Infectious Disease Research, Medical College of Wisconsin, Milwaukee, WI, USA
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Bellinzoni M, Wehenkel AM, Durán R, Alzari PM. Novel mechanistic insights into physiological signaling pathways mediated by mycobacterial Ser/Thr protein kinases. Microbes Infect 2019; 21:222-229. [PMID: 31254628 DOI: 10.1016/j.micinf.2019.06.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Accepted: 04/02/2019] [Indexed: 12/11/2022]
Abstract
Protein phosphorylation is known to be one of the keystones of signal sensing and transduction in all living organisms. Once thought to be essentially confined to the eukaryotic kingdoms, reversible phosphorylation on serine, threonine and tyrosine residues, has now been shown to play a major role in many prokaryotes, where the number of Ser/Thr protein kinases (STPKs) equals or even exceeds that of two component systems. Mycobacterium tuberculosis, the etiological agent of tuberculosis, is one of the most studied organisms for the role of STPK-mediated signaling in bacteria. Driven by the interest and tractability of these enzymes as potential therapeutic targets, extensive studies revealed the remarkable conservation of protein kinases and their cognate phosphatases across evolution, and their involvement in bacterial physiology and virulence. Here, we present an overview of the current knowledge of mycobacterial STPKs structures and kinase activation mechanisms, and we then focus on PknB and PknG, two well-characterized STPKs that are essential for the intracellular survival of the bacillus. We summarize the mechanistic evidence that links PknB to the regulation of peptidoglycan synthesis in cell division and morphogenesis, and the major findings that establishes PknG as a master regulator of central carbon and nitrogen metabolism. Two decades after the discovery of STPKs in M. tuberculosis, the emerging landscape of O-phosphosignaling is starting to unveil how eukaryotic-like kinases can be engaged in unique, non-eukaryotic-like, signaling mechanisms in mycobacteria.
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Affiliation(s)
- Marco Bellinzoni
- Unit of Structural Microbiology, Department of Structural Biology and Chemistry, Institut Pasteur, CNRS UMR 3528 & Université Paris Diderot, 25 rue du Docteur Roux, 75724 Paris cedex 15, France
| | - Anne Marie Wehenkel
- Unit of Structural Microbiology, Department of Structural Biology and Chemistry, Institut Pasteur, CNRS UMR 3528 & Université Paris Diderot, 25 rue du Docteur Roux, 75724 Paris cedex 15, France
| | - Rosario Durán
- Unidad de Bioquímica y Proteómica Analíticas, Institut Pasteur de Montevideo, Instituto de Investigaciones Biológicas Clemente Estable, Mataojo 2020, Montevideo 11400, Uruguay
| | - Pedro M Alzari
- Unit of Structural Microbiology, Department of Structural Biology and Chemistry, Institut Pasteur, CNRS UMR 3528 & Université Paris Diderot, 25 rue du Docteur Roux, 75724 Paris cedex 15, France.
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9
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Labbe BD, Hall CL, Kellogg SL, Chen Y, Koehn O, Pickrum AM, Mirza SP, Kristich CJ. Reciprocal Regulation of PASTA Kinase Signaling by Differential Modification. J Bacteriol 2019; 201:e00016-19. [PMID: 30858297 PMCID: PMC6482931 DOI: 10.1128/jb.00016-19] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Accepted: 03/01/2019] [Indexed: 12/20/2022] Open
Abstract
Transmembrane Ser/Thr kinases containing extracellular PASTA (penicillin-binding protein [PBP] and Ser/Thr-associated) domains are ubiquitous among Actinobacteria and Firmicutes species. Such PASTA kinases regulate critical bacterial processes, including antibiotic resistance, cell division, cell envelope homeostasis, and virulence, and are sometimes essential for viability. Previous studies of purified PASTA kinase fragments revealed they are capable of autophosphorylation in vitro, typically at multiple sites on the kinase domain. Autophosphorylation of a specific structural element of the kinase known as the activation loop is thought to enhance kinase activity in response to stimuli. However, the role of kinase phosphorylation at other sites is largely unknown. Moreover, the mechanisms by which PASTA kinases are deactivated once their stimulus has diminished are poorly understood. Enterococcus faecalis is a Gram-positive intestinal bacterium and a major antibiotic-resistant opportunistic pathogen. In E. faecalis, the PASTA kinase IreK drives intrinsic resistance to cell wall-active antimicrobials, and such antimicrobials trigger enhanced phosphorylation of IreK in vivo Here we identify multiple sites of phosphorylation on IreK and evaluate their function in vivo and in vitro While phosphorylation of the IreK activation loop is required for kinase activity, we found that phosphorylation at a site distinct from the activation loop reciprocally modulates IreK activity in vivo, leading to diminished activity (and diminished antimicrobial resistance). Moreover, this site is important for deactivation of IreK in vivo upon removal of an activating stimulus. Our results are consistent with a model in which phosphorylation of IreK at distinct sites reciprocally regulates IreK activity in vivo to promote adaptation to cell wall stresses.IMPORTANCE Transmembrane Ser/Thr kinases containing extracellular PASTA domains are ubiquitous among Actinobacteria and Firmicutes species and regulate critical processes, including antibiotic resistance, cell division, and cell envelope homeostasis. Previous studies of PASTA kinase fragments revealed autophosphorylation at multiple sites. However, the functional role of autophosphorylation and the relative impacts of phosphorylation at distinct sites are poorly understood. The PASTA kinase of Enterococcus faecalis, IreK, regulates intrinsic resistance to antimicrobials. Here we identify multiple sites of phosphorylation on IreK and show that modification of IreK at distinct sites reciprocally regulates IreK activity and antimicrobial resistance in vivo Thus, these results provide new insights into the mechanisms by which PASTA kinases can regulate critical physiological processes in a wide variety of bacterial species.
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Affiliation(s)
- Benjamin D Labbe
- Department of Microbiology and Immunology, Center for Infectious Disease Research, Medical College of Wisconsin-Milwaukee, Milwaukee, Wisconsin, USA
| | - Cherisse L Hall
- Department of Microbiology and Immunology, Center for Infectious Disease Research, Medical College of Wisconsin-Milwaukee, Milwaukee, Wisconsin, USA
| | - Stephanie L Kellogg
- Department of Microbiology and Immunology, Center for Infectious Disease Research, Medical College of Wisconsin-Milwaukee, Milwaukee, Wisconsin, USA
| | - Yao Chen
- Department of Microbiology and Immunology, Center for Infectious Disease Research, Medical College of Wisconsin-Milwaukee, Milwaukee, Wisconsin, USA
| | - Olivia Koehn
- Department of Microbiology and Immunology, Center for Infectious Disease Research, Medical College of Wisconsin-Milwaukee, Milwaukee, Wisconsin, USA
| | - Adam M Pickrum
- Department of Microbiology and Immunology, Center for Infectious Disease Research, Medical College of Wisconsin-Milwaukee, Milwaukee, Wisconsin, USA
| | - Shama P Mirza
- Department of Microbiology and Immunology, Center for Infectious Disease Research, Medical College of Wisconsin-Milwaukee, Milwaukee, Wisconsin, USA
| | - Christopher J Kristich
- Department of Microbiology and Immunology, Center for Infectious Disease Research, Medical College of Wisconsin-Milwaukee, Milwaukee, Wisconsin, USA
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10
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Bellinzoni M, Wehenkel AM, Durán R, Alzari PM. Novel mechanistic insights into physiological signaling pathways mediated by mycobacterial Ser/Thr protein kinases. Genes Immun 2019; 20:383-393. [DOI: 10.1038/s41435-019-0069-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Accepted: 04/02/2019] [Indexed: 12/16/2022]
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11
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New substrates and interactors of the mycobacterial Serine/Threonine protein kinase PknG identified by a tailored interactomic approach. J Proteomics 2019; 192:321-333. [DOI: 10.1016/j.jprot.2018.09.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Revised: 07/27/2018] [Accepted: 09/25/2018] [Indexed: 11/18/2022]
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12
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Turapov O, Forti F, Kadhim B, Ghisotti D, Sassine J, Straatman-Iwanowska A, Bottrill AR, Moynihan PJ, Wallis R, Barthe P, Cohen-Gonsaud M, Ajuh P, Vollmer W, Mukamolova GV. Two Faces of CwlM, an Essential PknB Substrate, in Mycobacterium tuberculosis. Cell Rep 2018; 25:57-67.e5. [PMID: 30282038 PMCID: PMC6180346 DOI: 10.1016/j.celrep.2018.09.004] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Revised: 06/11/2018] [Accepted: 08/31/2018] [Indexed: 11/26/2022] Open
Abstract
Tuberculosis claims >1 million lives annually, and its causative agent Mycobacterium tuberculosis is a highly successful pathogen. Protein kinase B (PknB) is reported to be critical for mycobacterial growth. Here, we demonstrate that PknB-depleted M. tuberculosis can replicate normally and can synthesize peptidoglycan in an osmoprotective medium. Comparative phosphoproteomics of PknB-producing and PknB-depleted mycobacteria identify CwlM, an essential regulator of peptidoglycan synthesis, as a major PknB substrate. Our complementation studies of a cwlM mutant of M. tuberculosis support CwlM phosphorylation as a likely molecular basis for PknB being essential for mycobacterial growth. We demonstrate that growing mycobacteria produce two forms of CwlM: a non-phosphorylated membrane-associated form and a PknB-phosphorylated cytoplasmic form. Furthermore, we show that the partner proteins for the phosphorylated and non-phosphorylated forms of CwlM are FhaA, a fork head-associated domain protein, and MurJ, a proposed lipid II flippase, respectively. From our results, we propose a model in which CwlM potentially regulates both the biosynthesis of peptidoglycan precursors and their transport across the cytoplasmic membrane.
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Affiliation(s)
- Obolbek Turapov
- Leicester Tuberculosis Research Group, Department of Infection, Immunity and Inflammation, University of Leicester, Leicester LE1 9HN, UK
| | - Francesca Forti
- Department of Biosciences, University of Milan, Milan 20133, Italy
| | - Baleegh Kadhim
- Leicester Tuberculosis Research Group, Department of Infection, Immunity and Inflammation, University of Leicester, Leicester LE1 9HN, UK; Biology Department, College of Science, University of Al-Qadisiyah, Al-Diwaniyah 58002, Iraq
| | - Daniela Ghisotti
- Department of Biosciences, University of Milan, Milan 20133, Italy
| | - Jad Sassine
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne NE2 4AX, UK
| | - Anna Straatman-Iwanowska
- Electron Microscopy Facility, Core Biotechnology Services, University of Leicester, Leicester LE1 7RH, UK
| | - Andrew R Bottrill
- Protein Nucleic Acid Laboratory, University of Leicester, Leicester LE1 7RH, UK
| | - Patrick J Moynihan
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - Russell Wallis
- Leicester Tuberculosis Research Group, Department of Infection, Immunity and Inflammation, University of Leicester, Leicester LE1 9HN, UK; The Leicester Institute of Structural and Chemical Biology, Henry Wellcome Building, University of Leicester, Lancaster Road, Leicester LE1 7HB, UK
| | - Philippe Barthe
- Centre de Biochimie Structurale, CNRS, INSERM, University of Montpellier, Montpellier 34090, France
| | - Martin Cohen-Gonsaud
- Centre de Biochimie Structurale, CNRS, INSERM, University of Montpellier, Montpellier 34090, France
| | - Paul Ajuh
- Gemini Biosciences, Liverpool Science Park, Liverpool L3 5TF, UK
| | - Waldemar Vollmer
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne NE2 4AX, UK
| | - Galina V Mukamolova
- Leicester Tuberculosis Research Group, Department of Infection, Immunity and Inflammation, University of Leicester, Leicester LE1 9HN, UK.
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13
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Biophysical Characterization of the Tandem FHA Domain Regulatory Module from the Mycobacterium tuberculosis ABC Transporter Rv1747. Structure 2018; 26:972-986.e6. [PMID: 29861345 DOI: 10.1016/j.str.2018.04.018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Revised: 04/13/2018] [Accepted: 04/27/2018] [Indexed: 11/23/2022]
Abstract
The Mycobacterium tuberculosis ATP-binding cassette transporter Rv1747 is a putative exporter of cell wall biosynthesis intermediates. Rv1747 has a cytoplasmic regulatory module consisting of two pThr-interacting Forkhead-associated (FHA) domains connected by a conformationally disordered linker with two phospho-acceptor threonines (pThr). The structures of FHA-1 and FHA-2 were determined by X-ray crystallography and nuclear magnetic resonance (NMR) spectroscopy, respectively. Relative to the canonical 11-strand β-sandwich FHA domain fold of FHA-1, FHA-2 is circularly permuted and lacking one β-strand. Nevertheless, the two share a conserved pThr-binding cleft. FHA-2 is less stable and more dynamic than FHA-1, yet binds model pThr peptides with moderately higher affinity (∼50 μM versus 500 μM equilibrium dissociation constants). Based on NMR relaxation and chemical shift perturbation measurements, when joined within a polypeptide chain, either FHA domain can bind either linker pThr to form intra- and intermolecular complexes. We hypothesize that this enables tunable phosphorylation-dependent multimerization to regulate Rv1747 transporter activity.
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Solution NMR Studies of Mycobacterium tuberculosis Proteins for Antibiotic Target Discovery. Molecules 2017; 22:molecules22091447. [PMID: 28858250 PMCID: PMC6151718 DOI: 10.3390/molecules22091447] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Accepted: 08/27/2017] [Indexed: 11/17/2022] Open
Abstract
Tuberculosis is an infectious disease caused by Mycobacteriumtuberculosis, which triggers severe pulmonary diseases. Recently, multidrug/extensively drug-resistant tuberculosis strains have emerged and continue to threaten global health. Because of the development of drug-resistant tuberculosis, there is an urgent need for novel antibiotics to treat these drug-resistant bacteria. In light of the clinical importance of M. tuberculosis, 2067 structures of M. tuberculsosis proteins have been determined. Among them, 52 structures have been solved and studied using solution nuclear magnetic resonance (NMR). The functional details based on structural analysis of M. tuberculosis using NMR can provide essential biochemical data for the development of novel antibiotic drugs. In this review, we introduce diverse structural and biochemical studies on M. tuberculosis proteins determined using NMR spectroscopy.
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Pensinger DA, Schaenzer AJ, Sauer JD. Do Shoot the Messenger: PASTA Kinases as Virulence Determinants and Antibiotic Targets. Trends Microbiol 2017; 26:56-69. [PMID: 28734616 DOI: 10.1016/j.tim.2017.06.010] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Revised: 06/15/2017] [Accepted: 06/27/2017] [Indexed: 01/14/2023]
Abstract
All domains of life utilize protein phosphorylation as a mechanism of signal transduction. In bacteria, protein phosphorylation was classically thought to be mediated exclusively by histidine kinases as part of two-component signaling systems. However, it is now well appreciated that eukaryotic-like serine/threonine kinases (eSTKs) control essential processes in bacteria. A subset of eSTKs are single-pass transmembrane proteins that have extracellular penicillin-binding-protein and serine/threonine kinase-associated (PASTA) domains which bind muropeptides. In a variety of important pathogens, PASTA kinases have been implicated in regulating biofilms, antibiotic resistance, and ultimately virulence. Although there are limited examples of direct regulation of virulence factors, PASTA kinases are critical for virulence due to their roles in regulating bacterial physiology in the context of stress. This review focuses on the role of PASTA kinases in virulence for a variety of important Gram-positive pathogens and concludes with a discussion of current efforts to develop kinase inhibitors as novel antimicrobials.
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Affiliation(s)
- Daniel A Pensinger
- Microbiology Doctoral Training Program, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI 53706, USA; Department of Medical Microbiology and Immunology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Adam J Schaenzer
- Department of Medical Microbiology and Immunology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI 53706, USA; Molecular and Cellular Pharmacology Doctoral Training Program, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - John-Demian Sauer
- Microbiology Doctoral Training Program, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI 53706, USA; Department of Medical Microbiology and Immunology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI 53706, USA; Molecular and Cellular Pharmacology Doctoral Training Program, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI 53706, USA.
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16
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Abstract
Reversible protein phosphorylation is the most common type of epigenetic posttranslational modification in living cells used as a major regulation mechanism of biological processes. The Mycobacterium tuberculosis genome encodes for 11 serine/threonine protein kinases that are responsible for sensing environmental signals to coordinate a cellular response to ensure the pathogen's infectivity, survival, and growth. To overcome killing mechanisms generated within the host during infection, M. tuberculosis enters a state of nonreplicating persistence that is characterized by arrested growth, limited metabolic activity, and phenotypic resistance to antimycobacterial drugs. In this article we focus our attention on the role of M. tuberculosis serine/threonine protein kinases in sensing the host environment to coordinate the bacilli's physiology, including growth, cell wall components, and central metabolism, to establish a persistent infection.
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Venkatesan A, Palaniyandi K, Sharma D, Bisht D, Narayanan S. Functional Characterization of PknI-Rv2159c Interaction in Redox Homeostasis of Mycobacterium tuberculosis. Front Microbiol 2016; 7:1654. [PMID: 27818650 PMCID: PMC5073100 DOI: 10.3389/fmicb.2016.01654] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Accepted: 10/04/2016] [Indexed: 01/02/2023] Open
Abstract
Mycobacterium tuberculosis adapts to stress conditions by responding to the signals from its external environment. M. tuberculosis genome encodes 11 eukaryotic like serine/threonine protein kinases (STPK) and their importance in regulating the physiology and virulence of the bacteria are being explored. Previous study from our lab identified the M. tuberculosis STPK, PknI interacts with two peroxidase proteins such as Rv2159c and Rv0148. In this study, we have characterized the biological function behind the PknI-Rv2159c interaction in M. tuberculosis. Point mutation of Ala-Gly-Trp motif identified that only Ala49 and Gly50 amino acids of Rv2159c are responsible for interaction and there is no phosphorylation involved in the PknI-Rv2159c interaction. Rv2159c is a member from the carboxymuconolactone decarboxylase family with peroxidase activity. Enzymatic assays with catalytic site point mutants showed that Cys84 of Rv2159c was responsible for its alkylhydroperoxidase activity. Interestingly, interaction with PknI increased its peroxidase activity by several folds. Gene knockdown of Rv2159c in M. tuberculosis showed increased sensitivity to peroxides such as cumene hydroperoxide and hydrogen peroxide. Proteomic analysis of differentially expressing Rv2159c strains by 2D gel electrophoresis and mass spectrometry revealed the differential abundance of 21 proteins. The total absence of oxidoreductase, GuaB1 suggests the essential role of Rv2159c in redox maintenance. Our findings provide new insights on signaling mechanisms of PknI in maintaining the redox homeostasis during oxidative stresses.
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Affiliation(s)
- Arunkumar Venkatesan
- Department of Immunology, National Institute for Research in Tuberculosis Chennai, India
| | - Kannan Palaniyandi
- Department of Immunology, National Institute for Research in Tuberculosis Chennai, India
| | - Divakar Sharma
- Department of Biochemistry, National JALMA Institute for Leprosy and other Mycobacterial Diseases Agra, India
| | - Deepa Bisht
- Department of Biochemistry, National JALMA Institute for Leprosy and other Mycobacterial Diseases Agra, India
| | - Sujatha Narayanan
- Department of Immunology, National Institute for Research in Tuberculosis Chennai, India
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18
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Barthe P, Veyron-Churlet R, de Visch A, Gilleron M, Saliou JM, Tomavo S, Nigou J, Brodin P, Cohen-Gonsaud M. Mycobacterium tuberculosis LppM Displays an Original Structure and Domain Composition Linked to a Dual Localization. Structure 2016; 24:1788-1794. [DOI: 10.1016/j.str.2016.07.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Revised: 06/02/2016] [Accepted: 07/06/2016] [Indexed: 01/24/2023]
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19
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Turapov O, Loraine J, Jenkins CH, Barthe P, McFeely D, Forti F, Ghisotti D, Hesek D, Lee M, Bottrill AR, Vollmer W, Mobashery S, Cohen-Gonsaud M, Mukamolova GV. The external PASTA domain of the essential serine/threonine protein kinase PknB regulates mycobacterial growth. Open Biol 2016; 5:150025. [PMID: 26136255 PMCID: PMC4632501 DOI: 10.1098/rsob.150025] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
PknB is an essential serine/threonine protein kinase required for mycobacterial cell division and cell-wall biosynthesis. Here we demonstrate that overexpression of the external PknB_PASTA domain in mycobacteria results in delayed regrowth, accumulation of elongated bacteria and increased sensitivity to β-lactam antibiotics. These changes are accompanied by altered production of certain enzymes involved in cell-wall biosynthesis as revealed by proteomics studies. The growth inhibition caused by overexpression of the PknB_PASTA domain is completely abolished by enhanced concentration of magnesium ions, but not muropeptides. Finally, we show that the addition of recombinant PASTA domain could prevent regrowth of Mycobacterium tuberculosis, and therefore offers an alternative opportunity to control replication of this pathogen. These results suggest that the PknB_PASTA domain is involved in regulation of peptidoglycan biosynthesis and maintenance of cell-wall architecture.
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Affiliation(s)
- Obolbek Turapov
- Department of Infection, Immunity and Inflammation, University of Leicester, Leicester LE1 9HN, UK
| | - Jessica Loraine
- Department of Infection, Immunity and Inflammation, University of Leicester, Leicester LE1 9HN, UK
| | - Christopher H Jenkins
- Department of Infection, Immunity and Inflammation, University of Leicester, Leicester LE1 9HN, UK
| | - Philippe Barthe
- Centre de Biochimie Structurale, CNRS UMR 5048, 29, rue de Navacelles, Montpellier 34090, France INSERM U1054, Université Montpellier I et II, Montpellier, France
| | - Daniel McFeely
- Department of Infection, Immunity and Inflammation, University of Leicester, Leicester LE1 9HN, UK
| | - Francesca Forti
- Dipartimento di BioScienze, Università degli Studi di Milano, Milan, Italy
| | - Daniela Ghisotti
- Dipartimento di BioScienze, Università degli Studi di Milano, Milan, Italy
| | - Dusan Hesek
- Department of Chemistry and Biochemistry, 423 Nieuwland Science Center, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Mijoon Lee
- Department of Chemistry and Biochemistry, 423 Nieuwland Science Center, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Andrew R Bottrill
- Department of Infection, Immunity and Inflammation, University of Leicester, Leicester LE1 9HN, UK
| | - Waldemar Vollmer
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne NE2 4AX, UK
| | - Shahriar Mobashery
- Department of Chemistry and Biochemistry, 423 Nieuwland Science Center, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Martin Cohen-Gonsaud
- Centre de Biochimie Structurale, CNRS UMR 5048, 29, rue de Navacelles, Montpellier 34090, France INSERM U1054, Université Montpellier I et II, Montpellier, France
| | - Galina V Mukamolova
- Department of Infection, Immunity and Inflammation, University of Leicester, Leicester LE1 9HN, UK
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20
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Abstract
The Mycobacterium tuberculosis genome encodes 11 serine/threonine protein kinases (STPKs). A similar number of two-component systems are also present, indicating that these two signal transduction mechanisms are both important in the adaptation of this bacterial pathogen to its environment. The M. tuberculosis phosphoproteome includes hundreds of Ser- and Thr-phosphorylated proteins that participate in all aspects of M. tuberculosis biology, supporting a critical role for the STPKs in regulating M. tuberculosis physiology. Nine of the STPKs are receptor type kinases, with an extracytoplasmic sensor domain and an intracellular kinase domain, indicating that these kinases transduce external signals. Two other STPKs are cytoplasmic and have regulatory domains that sense changes within the cell. Structural analysis of some of the STPKs has led to advances in our understanding of the mechanisms by which these STPKs are activated and regulated. Functional analysis has provided insights into the effects of phosphorylation on the activity of several proteins, but for most phosphoproteins the role of phosphorylation in regulating function is unknown. Major future challenges include characterizing the functional effects of phosphorylation for this large number of phosphoproteins, identifying the cognate STPKs for these phosphoproteins, and determining the signals that the STPKs sense. Ultimately, combining these STPK-regulated processes into larger, integrated regulatory networks will provide deeper insight into M. tuberculosis adaptive mechanisms that contribute to tuberculosis pathogenesis. Finally, the STPKs offer attractive targets for inhibitor development that may lead to new therapies for drug-susceptible and drug-resistant tuberculosis.
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21
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Manuse S, Fleurie A, Zucchini L, Lesterlin C, Grangeasse C. Role of eukaryotic-like serine/threonine kinases in bacterial cell division and morphogenesis. FEMS Microbiol Rev 2015; 40:41-56. [DOI: 10.1093/femsre/fuv041] [Citation(s) in RCA: 89] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/27/2015] [Indexed: 11/14/2022] Open
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22
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Wang XM, Soetaert K, Peirs P, Kalai M, Fontaine V, Dehaye JP, Lefèvre P. Biochemical analysis of the NAD+-dependent malate dehydrogenase, a substrate of several serine/threonine protein kinases of Mycobacterium tuberculosis. PLoS One 2015; 10:e0123327. [PMID: 25860441 PMCID: PMC4393303 DOI: 10.1371/journal.pone.0123327] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Accepted: 03/02/2015] [Indexed: 12/21/2022] Open
Abstract
PknD is one of the eleven eukaryotic-like serine/threonine protein kinases (STPKs) of Mycobacterium tuberculosis (Mtb). In vitro phosphorylation assays with the active recombinant PknD showed that the intracellular protein NAD+-dependent malate dehydrogenase (MDH) is a substrate of this kinase. MDH, an energy-supplying enzyme, catalyzes the interconversion of malate and oxaloacetate and plays crucial roles in several metabolic pathways including the citric acid cycle. The phosphorylation site was identified on threonine residues and the phosphorylation inhibited the MDH activity. In vitro, the recombinant MDH could also be phosphorylated by at least five other STPKs, PknA, PknE, PknH, PknJ, and PknG. Immunoprecipitation analysis revealed that MDH was hyperphosphorylated in the bacteria at the beginning of the stationary and under oxygen-limited conditions by STPKs other than PknD. On the contrary, when PknD-deficient mutant mycobacteria were grown in a phosphate-depleted medium, MDH was not detectably phosphorylated. These results suggest that although the MDH is a substrate of several mycobacterial STPKs, the activity of these kinases can depend on the environment, as we identified PknD as a key element in the MDH phosphorylation assay under phosphate-poor conditions.
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Affiliation(s)
- Xiao Ming Wang
- Scientific Institute of Public Health, Direction of Communicable and Infectious Diseases, Rue Engeland 642, 1180 Brussels, Belgium
| | - Karine Soetaert
- Scientific Institute of Public Health, Direction of Communicable and Infectious Diseases, Rue Engeland 642, 1180 Brussels, Belgium
| | - Priska Peirs
- Scientific Institute of Public Health, Direction of Communicable and Infectious Diseases, Rue Engeland 642, 1180 Brussels, Belgium
| | - Michaël Kalai
- Scientific Institute of Public Health, Direction of Communicable and Infectious Diseases, Rue Engeland 642, 1180 Brussels, Belgium
| | - Véronique Fontaine
- Unité de Microbiologie Pharmaceutique et Hygiène, Faculty of Pharmacy, Université Libre de Bruxelles, Boulevard du Triomphe, CP205/2, 1050 Brussels, Belgium
| | - Jean Paul Dehaye
- Unité de Microbiologie Pharmaceutique et Hygiène, Faculty of Pharmacy, Université Libre de Bruxelles, Boulevard du Triomphe, CP205/2, 1050 Brussels, Belgium
| | - Philippe Lefèvre
- Unité de Microbiologie Pharmaceutique et Hygiène, Faculty of Pharmacy, Université Libre de Bruxelles, Boulevard du Triomphe, CP205/2, 1050 Brussels, Belgium
- * E-mail:
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23
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Baer CE, Iavarone AT, Alber T, Sassetti CM. Biochemical and spatial coincidence in the provisional Ser/Thr protein kinase interaction network of Mycobacterium tuberculosis. J Biol Chem 2015; 289:20422-33. [PMID: 24928517 DOI: 10.1074/jbc.m114.559054] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Many Gram-positive bacteria coordinate cellular processes by signaling through Ser/Thr protein kinases (STPKs), but the architecture of these phosphosignaling cascades is unknown. To investigate the network structure of a prokaryotic STPK system, we comprehensively explored the pattern of signal transduction in the Mycobacterium tuberculosis Ser/Thr kinome. Autophosphorylation is the dominant mode of STPK activation, but the 11 M. tuberculosis STPKs also show a specific pattern of efficient cross-phosphorylation in vitro. The biochemical specificity intrinsic to each kinase domain was used to map the provisional signaling network, revealing a three-layer architecture that includes master regulators, signal transducers, and terminal substrates. Fluorescence microscopy revealed that the STPKs are specifically localized in the cell. Master STPKs are concentrated at the same subcellular sites as their substrates, providing additional support for the biochemically defined network. Together, these studies imply a branched functional architecture of the M. tuberculosis Ser/Thr kinome that could enable horizontal signal spreading. This systems-level approach provides a biochemical and spatial framework for understanding Ser/Thr phospho-signaling in M. tuberculosis, which differs fundamentally from previously defined linear histidine kinase cascades.
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24
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Fortuin S, Tomazella GG, Nagaraj N, Sampson SL, Gey van Pittius NC, Soares NC, Wiker HG, de Souza GA, Warren RM. Phosphoproteomics analysis of a clinical Mycobacterium tuberculosis Beijing isolate: expanding the mycobacterial phosphoproteome catalog. Front Microbiol 2015; 6:6. [PMID: 25713560 PMCID: PMC4322841 DOI: 10.3389/fmicb.2015.00006] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Accepted: 01/04/2015] [Indexed: 11/29/2022] Open
Abstract
Reversible protein phosphorylation, regulated by protein kinases and phosphatases, mediates a switch between protein activity and cellular pathways that contribute to a large number of cellular processes. The Mycobacterium tuberculosis genome encodes 11 Serine/Threonine kinases (STPKs) which show close homology to eukaryotic kinases. This study aimed to elucidate the phosphoproteomic landscape of a clinical isolate of M. tuberculosis. We performed a high throughput mass spectrometric analysis of proteins extracted from an early-logarithmic phase culture. Whole cell lysate proteins were processed using the filter-aided sample preparation method, followed by phosphopeptide enrichment of tryptic peptides by strong cation exchange (SCX) and Titanium dioxide (TiO2) chromatography. The MaxQuant quantitative proteomics software package was used for protein identification. Our analysis identified 414 serine/threonine/tyrosine phosphorylated sites, with a distribution of S/T/Y sites; 38% on serine, 59% on threonine and 3% on tyrosine; present on 303 unique peptides mapping to 214 M. tuberculosis proteins. Only 45 of the S/T/Y phosphorylated proteins identified in our study had been previously described in the laboratory strain H37Rv, confirming previous reports. The remaining 169 phosphorylated proteins were newly identified in this clinical M. tuberculosis Beijing strain. We identified 5 novel tyrosine phosphorylated proteins. These findings not only expand upon our current understanding of the protein phosphorylation network in clinical M. tuberculosis but the data set also further extends and complements previous knowledge regarding phosphorylated peptides and phosphorylation sites in M. tuberculosis.
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Affiliation(s)
- Suereta Fortuin
- Division of Molecular Biology and Human Genetics, Faculty Medicine and Health Sciences, DST/NRF Centre of Excellence for Biomedical Tuberculosis Research, SAMRC Centre for Tuberculosis Research, Stellenbosch University Cape Town, South Africa
| | - Gisele G Tomazella
- The Gade Research Group for Infection and Immunity, Department of Clinical Science, University of Bergen Bergen, Norway
| | | | - Samantha L Sampson
- Division of Molecular Biology and Human Genetics, Faculty Medicine and Health Sciences, DST/NRF Centre of Excellence for Biomedical Tuberculosis Research, SAMRC Centre for Tuberculosis Research, Stellenbosch University Cape Town, South Africa
| | - Nicolaas C Gey van Pittius
- Division of Molecular Biology and Human Genetics, Faculty Medicine and Health Sciences, DST/NRF Centre of Excellence for Biomedical Tuberculosis Research, SAMRC Centre for Tuberculosis Research, Stellenbosch University Cape Town, South Africa
| | - Nelson C Soares
- Faculty of Health Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town Cape Town, South Africa
| | - Harald G Wiker
- The Gade Research Group for Infection and Immunity, Department of Clinical Science, University of Bergen Bergen, Norway
| | - Gustavo A de Souza
- Norway Proteomics Core Facility, Department of Immunology, Oslo University Oslo, Norway
| | - Robin M Warren
- Division of Molecular Biology and Human Genetics, Faculty Medicine and Health Sciences, DST/NRF Centre of Excellence for Biomedical Tuberculosis Research, SAMRC Centre for Tuberculosis Research, Stellenbosch University Cape Town, South Africa
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25
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Identification of Ser/Thr kinase and forkhead associated domains in Mycobacterium ulcerans: characterization of novel association between protein kinase Q and MupFHA. PLoS Negl Trop Dis 2014; 8:e3315. [PMID: 25412098 PMCID: PMC4238996 DOI: 10.1371/journal.pntd.0003315] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Accepted: 10/04/2014] [Indexed: 11/24/2022] Open
Abstract
Background Mycobacterium ulcerans, the causative agent of Buruli ulcer in humans, is unique among the members of Mycobacterium genus due to the presence of the virulence determinant megaplasmid pMUM001. This plasmid encodes multiple virulence-associated genes, including mup011, which is an uncharacterized Ser/Thr protein kinase (STPK) PknQ. Methodology/Principal Findings In this study, we have characterized PknQ and explored its interaction with MupFHA (Mup018c), a FHA domain containing protein also encoded by pMUM001. MupFHA was found to interact with PknQ and suppress its autophosphorylation. Subsequent protein-protein docking and molecular dynamic simulation analyses showed that this interaction involves the FHA domain of MupFHA and PknQ activation loop residues Ser170 and Thr174. FHA domains are known to recognize phosphothreonine residues, and therefore, MupFHA may be acting as one of the few unusual FHA-domain having overlapping specificity. Additionally, we elucidated the PknQ-dependent regulation of MupDivIVA (Mup012c), which is a DivIVA domain containing protein encoded by pMUM001. MupDivIVA interacts with MupFHA and this interaction may also involve phospho-threonine/serine residues of MupDivIVA. Conclusions/Significance Together, these results describe novel signaling mechanisms in M. ulcerans and show a three-way regulation of PknQ, MupFHA, and MupDivIVA. FHA domains have been considered to be only pThr specific and our results indicate a novel mechanism of pSer as well as pThr interaction exhibited by MupFHA. These results signify the need of further re-evaluating the FHA domain –pThr/pSer interaction model. MupFHA may serve as the ideal candidate for structural studies on this unique class of modular enzymes. Mycobacterium ulcerans is a slow growing pathogen, which is prevalent in many tropical and sub-tropical countries. M. ulcerans possesses unique signaling pathways with only 13 STPK containing genes. This is strikingly different from its closest homolog Mycobacterium marinum and surprisingly closer to the human pathogen, Mycobacterium tuberculosis. PknQ, MupFHA and MupDivIVA are regulatory proteins encoded by the virulence determining plasmid pMUM001 of M. ulcerans. In addition to characterizing the STPK, we focused on deciphering the basis of interaction between the three partner proteins leading to the identification of critical residues. Present study describes the newly identified phosphoserine-based interactions, which is unique amongst the FHA-domain containing proteins. We confirmed our results using structural analysis via specific mutants and their interaction profiles. Importantly, these data highlight the significance of FHA domains and their role in understanding cellular signaling. This work will encourage further studies to elucidate role of M. ulcerans signaling systems. It will also raise questions like how less studied tropical bacterial pathogens acquire eukaryotic-like Ser/Thr protein kinase and exhibit unusual mechanisms to interact with its partner domains.
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26
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Sherman DR, Grundner C. Agents of change - concepts in Mycobacterium tuberculosis Ser/Thr/Tyr phosphosignalling. Mol Microbiol 2014; 94:231-41. [PMID: 25099260 DOI: 10.1111/mmi.12747] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/03/2014] [Indexed: 11/26/2022]
Abstract
The flow of information from the outside to the inside of bacterial cells is largely directed by protein kinases. In addition to histidine/aspartate phosphorelays of two-component response regulators, recent work in Mycobacterium tuberculosis (Mtb) reinforces the idea that phosphorylation on serine (Ser), threonine (Thr) and tyrosine (Tyr) is central to bacterial physiology and pathogenesis, and that the corresponding phosphosystems are highly similar to those in eukaryotes. In this way, eukaryotes are a useful guide to understanding Ser/Thr/Tyr phosphorylation (O-phosphorylation) in prokaryotes such as Mtb. However, as novel functions and components of bacterial O-phosphorylation are identified, distinct differences between pro- and eukaryotic phosphosignalling systems become apparent. The emerging picture of O-phosphorylation in Mtb is complicated, goes beyond the eukaryotic paradigms, and shows the limitations of viewing bacterial phosphosignalling within the confines of the 'eukaryotic-like' model. Here, we summarize recent findings about Ser/Thr and the recently discovered Tyr phosphorylation pathways in Mtb, highlight the similarities and differences between eukaryotic and prokaryotic O-phosphorylation, and pose additional questions about signalling components, pathway organization, and ultimately, the cellular roles of O-phosphorylation in Mtb physiology and pathogenesis.
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Affiliation(s)
- David R Sherman
- Seattle Biomedical Research Institute, Seattle, WA, 98109, USA; Department of Global Health, University of Washington, Seattle, WA, 98195, USA
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27
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Mycobacterium tuberculosis supports protein tyrosine phosphorylation. Proc Natl Acad Sci U S A 2014; 111:9265-70. [PMID: 24927537 DOI: 10.1073/pnas.1323894111] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Reversible protein phosphorylation determines growth and adaptive decisions in Mycobacterium tuberculosis (Mtb). At least 11 two-component systems and 11 Ser/Thr protein kinases (STPKs) mediate phosphorylation on Asp, His, Ser, and Thr. In contrast, protein phosphorylation on Tyr has not been described previously in Mtb. Here, using a combination of phospho-enrichment and highly sensitive mass spectrometry, we show extensive protein Tyr phosphorylation of diverse Mtb proteins, including STPKs. Several STPKs function as dual-specificity kinases that phosphorylate Tyr in cis and in trans, suggesting that dual-specificity kinases have a major role in bacterial phospho-signaling. Mutation of a phosphotyrosine site of the essential STPK PknB reduces its activity in vitro and in live Mtb, indicating that Tyr phosphorylation has a functional role in bacterial growth. These data identify a previously unrecognized phosphorylation system in a human pathogen that claims ∼ 1.4 million lives every year.
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Chawla Y, Upadhyay S, Khan S, Nagarajan SN, Forti F, Nandicoori VK. Protein kinase B (PknB) of Mycobacterium tuberculosis is essential for growth of the pathogen in vitro as well as for survival within the host. J Biol Chem 2014; 289:13858-75. [PMID: 24706757 DOI: 10.1074/jbc.m114.563536] [Citation(s) in RCA: 86] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The Mycobacterium tuberculosis protein kinase B (PknB) comprises an intracellular kinase domain, connected through a transmembrane domain to an extracellular region that contains four PASTA domains. The present study describes the comprehensive analysis of different domains of PknB in the context of viability in avirulent and virulent mycobacteria. We find stringent regulation of PknB expression necessary for cell survival, with depletion or overexpression of PknB leading to cell death. Although PknB-mediated kinase activity is essential for cell survival, active kinase lacking the transmembrane or extracellular domain fails to complement conditional mutants not expressing PknB. By creating chimeric kinases, we find that the intracellular kinase domain has unique functions in the virulent strain, which cannot be substituted by other kinases. Interestingly, we find that although the presence of the C-terminal PASTA domain is dispensable in the avirulent M. smegmatis, all four PASTA domains are essential in M. tuberculosis. The differential behavior of PknB vis-à-vis the number of essential PASTA domains and the specificity of kinase domain functions suggest that PknB-mediated growth and signaling events differ in virulent compared with avirulent mycobacteria. Mouse infection studies performed to determine the role of PknB in mediating pathogen survival in the host demonstrate that PknB is not only critical for growth of the pathogen in vitro but is also essential for the survival of the pathogen in the host.
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Affiliation(s)
- Yogesh Chawla
- From the National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi 110067, India and
| | - Sandeep Upadhyay
- From the National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi 110067, India and
| | - Shazia Khan
- From the National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi 110067, India and
| | | | - Francesca Forti
- the Dipartimento di Scienze Biomolecolari e Biotecnologie, Università degli Studi di Milano, Via Celoria 26, 20133 Milano, Italy
| | - Vinay Kumar Nandicoori
- From the National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi 110067, India and
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Kerns PW, Ackhart DF, Basaraba RJ, Leid JG, Shirtliff ME. Mycobacterium tuberculosis pellicles express unique proteins recognized by the host humoral response. Pathog Dis 2014; 70:347-58. [PMID: 24453174 DOI: 10.1111/2049-632x.12142] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2013] [Revised: 01/10/2014] [Accepted: 01/13/2014] [Indexed: 01/02/2023] Open
Abstract
Mycobacterium tuberculosis (MTB) causes both acute and chronic infections in humans characterized by tolerance to antibiotics and reactivation to cause secondary tuberculosis. These characteristics have led to renewed interest in the in vitro pellicle, or biofilm mode of growth, where bacteria grow to produce a thick aggregate at the air-liquid interface and exhibit increased phenotypic resistance to antibiotics. We infected guinea pigs with the virulent H37Rv strain of MTB for 60 days at which point we collected blood. To identify antigenic proteins, membrane protein extracts of MTB H37Ra pellicles and shaken cultures grown for 3, 5, or 7 weeks were probed with the infected animals' sera after the proteins were separated by two-dimensional gel electrophoresis (2DGE). Antigenic proteins were then identified using MALDI-TOF/TOF mass spectrometry peptide mass fingerprinting. Antigenic pellicle proteins were compared across the three timepoints to identify those that were produced consistently during pellicle growth. They were also compared to those membrane proteins identified from harvested shaken cultures to determine pellicle-specific vs. universally expressed proteins. Using this technique, we identified 44 distinct antigenic proteins, nine of which were pellicle-specific. The sequence of antigenic pellicle-specific proteins was checked for sequence conservation across 15 sequenced MTB clinical isolates, three other members of the MTB complex, as well as M. avium and M. smegmatis. The antigenic pellicle-specific protein Rv0097 was found to have very high sequence conservation within the MTB complex but not with related mycobacteria, while FabG4 was highly conserved in all mycobacteria analyzed. These conserved pellicle-specific proteins represent targets for the development of future diagnostic tests and vaccines.
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Affiliation(s)
- Patrick W Kerns
- Graduate Program in Molecular Microbiology and Immunology, University of Maryland, Baltimore, Baltimore, MD, USA
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Cousin C, Derouiche A, Shi L, Pagot Y, Poncet S, Mijakovic I. Protein-serine/threonine/tyrosine kinases in bacterial signaling and regulation. FEMS Microbiol Lett 2013; 346:11-9. [PMID: 23731382 DOI: 10.1111/1574-6968.12189] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2013] [Revised: 05/30/2013] [Accepted: 05/30/2013] [Indexed: 01/05/2023] Open
Abstract
In this review, we address some recent developments in the field of bacterial protein phosphorylation, focusing specifically on serine/threonine and tyrosine kinases. We present an overview of recent studies outlining the scope of physiological processes that are regulated by phosphorylation, ranging from cell cycle, growth, cell morphology, to metabolism, developmental phenomena, and virulence. Specific emphasis is placed on Mycobacterium tuberculosis as a showcase organism for serine/threonine kinases, and Bacillus subtilis to illustrate the importance of protein phosphorylation in developmental processes. We argue that bacterial serine/threonine and tyrosine kinases have a distinctive feature of phosphorylating multiple substrates and might thus represent integration nodes in the signaling network. Some open questions regarding the evolutionary benefits of relaxed substrate selectivity of these kinases are treated, as well as the notion of nonfunctional 'background' phosphorylation of cellular proteins. We also argue that phosphorylation events for which an immediate regulatory effect is not clearly established should not be dismissed as unimportant, as they may have a role in cross-talk with other post-translational modifications. Finally, recently developed methods for studying protein phosphorylation networks in bacteria are briefly discussed.
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Gee CL, Papavinasasundaram KG, Blair SR, Baer CE, Falick AM, King DS, Griffin JE, Venghatakrishnan H, Zukauskas A, Wei JR, Dhiman RK, Crick DC, Rubin EJ, Sassetti CM, Alber T. A phosphorylated pseudokinase complex controls cell wall synthesis in mycobacteria. Sci Signal 2012; 5:ra7. [PMID: 22275220 DOI: 10.1126/scisignal.2002525] [Citation(s) in RCA: 118] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Prokaryotic cell wall biosynthesis is coordinated with cell growth and division, but the mechanisms regulating this dynamic process remain obscure. Here, we describe a phosphorylation-dependent regulatory complex that controls peptidoglycan (PG) biosynthesis in Mycobacterium tuberculosis. We found that PknB, a PG-responsive Ser-Thr protein kinase (STPK), initiates complex assembly by phosphorylating a kinase-like domain in the essential PG biosynthetic protein, MviN. This domain was structurally diverged from active kinases and did not mediate phosphotransfer. Threonine phosphorylation of the pseudokinase domain recruited the FhaA protein through its forkhead-associated (FHA) domain. The crystal structure of this phosphorylated pseudokinase-FHA domain complex revealed the basis of FHA domain recognition, which included unexpected contacts distal to the phosphorylated threonine. Conditional degradation of these proteins in mycobacteria demonstrated that MviN was essential for growth and PG biosynthesis and that FhaA regulated these processes at the cell poles and septum. Controlling this spatially localized PG regulatory complex is only one of several cellular roles ascribed to PknB, suggesting that the capacity to coordinate signaling across multiple processes is an important feature conserved between eukaryotic and prokaryotic STPK networks.
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Affiliation(s)
- Christine L Gee
- Department of Molecular and Cell Biology, QB3 Institute, University of California, Berkeley, Berkeley, CA 94720-3220, USA
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32
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Abstract
Mycobacterium tuberculosis, the causative agent of tuberculosis, has a complex cellular envelope that comprises both the cytoplasmic membrane and the outer cell wall. Despite advances in elucidating the structural and biochemical composition of these features, the processes that ensure cell wall homeostasis remain poorly understood. New findings implicate the essential mycobacterial serine-threonine protein kinase (STPK), PknB, in regulating the formation of a regulatory complex that includes the integral membrane protein MviN, which is required for peptidoglycan biosynthesis, and a forkhead-associated (FHA) domain protein, FhaA. A model has emerged in which a peptidoglycan-derived muropeptide signal triggers the PknB-mediated phosphorylation of the MviN pseudokinase domain, which in turn recruits the FHA-containing regulatory protein to inhibit peptidoglycan biosynthesis at the cell poles and septum. In establishing PknB as central regulator of this pathway, the model reinforces the major role of this STPK network in the orchestration of fundamental mycobacterial processes, and, with the identification of MviN as having a catalytically inactive and highly divergent kinase homology domain, the model establishes a pseudokinase as a key player in cell wall metabolism.
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Affiliation(s)
- Digby F Warner
- MRC/NHLS/UCT Molecular Mycobacteriology Research Unit and DST/NRF Centre of Excellence for Biomedical Tuberculosis Research, Institute of Infectious Disease and Molecular Medicine, and Department of Clinical Laboratory Sciences, Faculty of Health Sciences, University of Cape Town, Private Bag X3, Rondebosch 7701, Cape Town, South Africa.
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