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Spivey VL, Molle V, Whalan RH, Rodgers A, Leiba J, Stach L, Walker KB, Smerdon SJ, Buxton RS. Forkhead-associated (FHA) domain containing ABC transporter Rv1747 is positively regulated by Ser/Thr phosphorylation in Mycobacterium tuberculosis. J Biol Chem 2011; 286:26198-209. [PMID: 21622570 PMCID: PMC3138270 DOI: 10.1074/jbc.m111.246132] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2011] [Revised: 05/24/2011] [Indexed: 12/22/2022] Open
Abstract
One major signaling method employed by Mycobacterium tuberculosis, the causative agent of tuberculosis, is through reversible phosphorylation of proteins mediated by protein kinases and phosphatases. This study concerns one of these enzymes, the serine/threonine protein kinase PknF, that is encoded in an operon with Rv1747, an ABC transporter that is necessary for growth of M. tuberculosis in vivo and contains two forkhead-associated (FHA) domains. FHA domains are phosphopeptide recognition motifs that specifically recognize phosphothreonine-containing epitopes. Experiments to determine how PknF regulates the function of Rv1747 demonstrated that phosphorylation occurs on two specific threonine residues, Thr-150 and Thr-208. To determine the in vivo consequences of phosphorylation, infection experiments were performed in bone marrow-derived macrophages and in mice using threonine-to-alanine mutants of Rv1747 that prevent specific phosphorylation and revealed that phosphorylation positively modulates Rv1747 function in vivo. The role of the FHA domains in this regulation was further demonstrated by isothermal titration calorimetry, using peptides containing both phosphothreonine residues. FHA-1 domain mutation resulted in attenuation in macrophages highlighting the critical role of this domain in Rv1747 function. A mutant deleted for pknF did not, however, have a growth phenotype in an infection, suggesting that other kinases can fulfill its role when it is absent. This study provides the first information on the molecular mechanism(s) regulating Rv1747 through PknF-dependent phosphorylation but also indicates that phosphorylation activates Rv1747, which may have important consequences in regulating growth of M. tuberculosis.
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Affiliation(s)
- Vicky L. Spivey
- From the Division of Mycobacterial Research, Medical Research Council National Institute for Medical Research, Mill Hill, London NW7 1AA, United Kingdom
| | - Virginie Molle
- the Laboratoire de Dynamique des Interactions Membranaires Normales et Pathologiques, Universités de Montpellier II et I, CNRS, UMR 5235, Case 107, Place Eugène Bataillon, 34095 Montpellier Cedex 05, France
| | - Rachael H. Whalan
- From the Division of Mycobacterial Research, Medical Research Council National Institute for Medical Research, Mill Hill, London NW7 1AA, United Kingdom
| | - Angela Rodgers
- the Immunology and Cellular Immunity Section, Bacteriology Division, National Institute of Biological Standards and Control (A Centre of the Health Protection Agency), Blanche Lane, South Mimms, Potters Bar, Hertfordshire EN6 3QG, United Kingdom, and
| | - Jade Leiba
- the Laboratoire de Dynamique des Interactions Membranaires Normales et Pathologiques, Universités de Montpellier II et I, CNRS, UMR 5235, Case 107, Place Eugène Bataillon, 34095 Montpellier Cedex 05, France
| | - Lasse Stach
- the Division of Molecular Structure, Medical Research Council National Institute for Medical Research, Mill Hill, London NW7 1AA, United Kingdom
| | - K. Barry Walker
- the Immunology and Cellular Immunity Section, Bacteriology Division, National Institute of Biological Standards and Control (A Centre of the Health Protection Agency), Blanche Lane, South Mimms, Potters Bar, Hertfordshire EN6 3QG, United Kingdom, and
| | - Stephen J. Smerdon
- the Division of Molecular Structure, Medical Research Council National Institute for Medical Research, Mill Hill, London NW7 1AA, United Kingdom
| | - Roger S. Buxton
- From the Division of Mycobacterial Research, Medical Research Council National Institute for Medical Research, Mill Hill, London NW7 1AA, United Kingdom
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52
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Abstract
Genomic studies have revealed the presence of Ser/Thr kinases and phosphatases in many bacterial species, although their physiological roles have largely been unclear. Here we review bacterial Ser/Thr kinases (eSTKs) that show homology in their catalytic domains to eukaryotic Ser/Thr kinases and their partner phosphatases (eSTPs) that are homologous to eukaryotic phosphatases. We first discuss insights into the enzymatic mechanism of eSTK activation derived from structural studies on both the ligand-binding and catalytic domains. We then turn our attention to the identified substrates of eSTKs and eSTPs for a number of species and to the implications of these findings for understanding their physiological roles in these organisms.
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53
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Chakraborti PK, Matange N, Nandicoori VK, Singh Y, Tyagi JS, Visweswariah SS. Signalling mechanisms in Mycobacteria. Tuberculosis (Edinb) 2011; 91:432-40. [PMID: 21570916 DOI: 10.1016/j.tube.2011.04.005] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2010] [Revised: 03/28/2011] [Accepted: 04/10/2011] [Indexed: 11/18/2022]
Abstract
The importance of inter- and intracellular signal transduction in all forms of life cannot be underestimated. A large number of genes dedicated to cellular signalling are found in almost all sequenced genomes, and Mycobacteria are no exception. What appears to be interesting in Mycobacteria is that well characterized signalling mechanisms used by bacteria, such as the histidine-aspartate phosphorelay seen in two-component systems, are found alongside signalling components that closely mimic those seen in higher eukaryotes. This review will describe the important contribution made by researchers in India towards the identification and characterization of proteins involved in two-component signalling, protein phosphorylation and cyclic nucleotide metabolism.
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Lougheed KE, Osborne SA, Saxty B, Whalley D, Chapman T, Bouloc N, Chugh J, Nott TJ, Patel D, Spivey VL, Kettleborough CA, Bryans JS, Taylor DL, Smerdon SJ, Buxton RS. Effective inhibitors of the essential kinase PknB and their potential as anti-mycobacterial agents. Tuberculosis (Edinb) 2011; 91:277-86. [PMID: 21482481 PMCID: PMC3158675 DOI: 10.1016/j.tube.2011.03.005] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2010] [Revised: 03/03/2011] [Accepted: 03/15/2011] [Indexed: 01/18/2023]
Abstract
PknB is an essential serine/threonine kinase of Mycobacterium tuberculosis with possible roles in a number of signalling pathways involved in cell division and metabolism. We screened a library of >50,000 compounds for inhibitors of the in vitro phosphorylation of GarA (Rv1827) by PknB and identified a number of inhibitors. A program of synthetic medicinal chemistry was subsequently conducted around one class of inhibitors and was successful in generating ATP competitive inhibitors with potency in the nanomolar range. Compounds in this class showed cross-reactivity with the related M. tuberculosis kinase, PknF, but not with PknG in an in vitro autophosphorylation assay. These synthesised inhibitors were able to prevent the growth of M. tuberculosis in an Alamar blue assay and in an intracellular model of infection, but only in the micromolar range. We attempted to determine if cell wall permeability was an explanation for the discrepancy between the potent in vitro compared with relatively poor in vivo activity, but found no evidence that the activity of the inhibitors could be improved by weakening the cell wall. Despite a number of drug discovery efforts attempting to develop inhibitors against PknB, it is yet to be reported that any such inhibitors prevent mycobacterial growth at submicromolar concentrations.
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Affiliation(s)
- Kathryn E.A. Lougheed
- Division of Mycobacterial Research, MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London, NW7 1AA, United Kingdom
| | - Simon A. Osborne
- Centre for Therapeutics Discovery, MRC Technology, 1-3 Burtonhole Lane, Mill Hill, London, NW7 1AD, United Kingdom
| | - Barbara Saxty
- Centre for Therapeutics Discovery, MRC Technology, 1-3 Burtonhole Lane, Mill Hill, London, NW7 1AD, United Kingdom
| | - David Whalley
- Centre for Therapeutics Discovery, MRC Technology, 1-3 Burtonhole Lane, Mill Hill, London, NW7 1AD, United Kingdom
| | - Tim Chapman
- Centre for Therapeutics Discovery, MRC Technology, 1-3 Burtonhole Lane, Mill Hill, London, NW7 1AD, United Kingdom
| | - Nathalie Bouloc
- Centre for Therapeutics Discovery, MRC Technology, 1-3 Burtonhole Lane, Mill Hill, London, NW7 1AD, United Kingdom
| | - Jasveen Chugh
- Centre for Therapeutics Discovery, MRC Technology, 1-3 Burtonhole Lane, Mill Hill, London, NW7 1AD, United Kingdom
| | - Timothy J. Nott
- Division of Molecular Structure, MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London, NW7 1AA, United Kingdom
| | - Dony Patel
- Division of Molecular Structure, MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London, NW7 1AA, United Kingdom
| | - Vicky L. Spivey
- Division of Mycobacterial Research, MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London, NW7 1AA, United Kingdom
| | - Catherine A. Kettleborough
- Centre for Therapeutics Discovery, MRC Technology, 1-3 Burtonhole Lane, Mill Hill, London, NW7 1AD, United Kingdom
| | - Justin S. Bryans
- Centre for Therapeutics Discovery, MRC Technology, 1-3 Burtonhole Lane, Mill Hill, London, NW7 1AD, United Kingdom
| | - Debra L. Taylor
- Centre for Therapeutics Discovery, MRC Technology, 1-3 Burtonhole Lane, Mill Hill, London, NW7 1AD, United Kingdom
| | - Stephen J. Smerdon
- Division of Molecular Structure, MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London, NW7 1AA, United Kingdom
| | - Roger S. Buxton
- Division of Mycobacterial Research, MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London, NW7 1AA, United Kingdom
- Corresponding author. Tel.: +44 20 8816 2225; fax: +44 20 8906 4477.
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Gago G, Diacovich L, Arabolaza A, Tsai SC, Gramajo H. Fatty acid biosynthesis in actinomycetes. FEMS Microbiol Rev 2011; 35:475-97. [PMID: 21204864 DOI: 10.1111/j.1574-6976.2010.00259.x] [Citation(s) in RCA: 116] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
All organisms that produce fatty acids do so via a repeated cycle of reactions. In mammals and other animals, these reactions are catalyzed by a type I fatty acid synthase (FAS), a large multifunctional protein to which the growing chain is covalently attached. In contrast, most bacteria (and plants) contain a type II system in which each reaction is catalyzed by a discrete protein. The pathway of fatty acid biosynthesis in Escherichia coli is well established and has provided a foundation for elucidating the type II FAS pathways in other bacteria (White et al., 2005). However, fatty acid biosynthesis is more diverse in the phylum Actinobacteria: Mycobacterium, possess both FAS systems while Streptomyces species have only the multienzyme FAS II system and Corynebacterium species exclusively FAS I. In this review, we present an overview of the genome organization, biochemical properties and physiological relevance of the two FAS systems in the three genera of actinomycetes mentioned above. We also address in detail the biochemical and structural properties of the acyl-CoA carboxylases (ACCases) that catalyzes the first committed step of fatty acid synthesis in actinomycetes, and discuss the molecular bases of their substrate specificity and the structure-based identification of new ACCase inhibitors with antimycobacterial properties.
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Affiliation(s)
- Gabriela Gago
- Microbiology Division, IBR (Instituto de Biología Molecular y Celular de Rosario), Consejo Nacional de Investigaciones Científicas y Técnicas, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
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Molle V, Gulten G, Vilchèze C, Veyron-Churlet R, Zanella-Cléon I, Sacchettini JC, Jacobs Jr WR, Kremer L. Phosphorylation of InhA inhibits mycolic acid biosynthesis and growth of Mycobacterium tuberculosis. Mol Microbiol 2010; 78:1591-605. [DOI: 10.1111/j.1365-2958.2010.07446.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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57
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Molle V, Leiba J, Zanella-Cléon I, Becchi M, Kremer L. An improved method to unravel phosphoacceptors in Ser/Thr protein kinase-phosphorylated substrates. Proteomics 2010; 10:3910-5. [DOI: 10.1002/pmic.201000316] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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58
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The Staphylococcus aureus autoinducer-2 synthase LuxS is regulated by Ser/Thr phosphorylation. J Bacteriol 2010; 192:6295-301. [PMID: 20870760 DOI: 10.1128/jb.00853-10] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The Staphylococcus aureus autoinducer-2 (AI-2) producer protein LuxS is phosphorylated by the Ser/Thr kinase Stk1 at a unique position, Thr14. The enzymatic activity of the phosphorylated isoform of LuxS was abrogated compared to that of nonphosphorylated LuxS, thus providing the first evidence of an AI-2-producing enzyme regulated by phosphorylation and demonstrating that S. aureus possesses an original and specific system for controlling AI-2 synthesis.
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59
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Khan S, Nagarajan SN, Parikh A, Samantaray S, Singh A, Kumar D, Roy RP, Bhatt A, Nandicoori VK. Phosphorylation of enoyl-acyl carrier protein reductase InhA impacts mycobacterial growth and survival. J Biol Chem 2010; 285:37860-71. [PMID: 20864541 DOI: 10.1074/jbc.m110.143131] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
InhA, the primary target for the first line anti-tuberculosis drug isoniazid, is a key enzyme of the fatty-acid synthase II system involved in mycolic acid biosynthesis in Mycobacterium tuberculosis. In this study, we show that InhA is a substrate for mycobacterial serine/threonine protein kinases. Using a novel approach to validate phosphorylation of a substrate by multiple kinases in a surrogate host (Escherichia coli), we have demonstrated efficient phosphorylation of InhA by PknA, PknB, and PknH, and to a lower extent by PknF. Additionally, the sites targeted by PknA/PknB have been identified and shown to be predominantly located at the C terminus of InhA. Results demonstrate in vivo phosphorylation of InhA in mycobacteria and validate Thr-266 as one of the key sites of phosphorylation. Significantly, our studies reveal that the phosphorylation of InhA by kinases modulates its biochemical activity, with phosphorylation resulting in decreased enzymatic activity. Co-expression of kinase and InhA alters the growth dynamics of Mycobacterium smegmatis, suggesting that InhA phosphorylation in vivo is an important event in regulating its activity. An InhA-T266E mutant, which mimics constitutive phosphorylation, is unable to rescue an M. smegmatis conditional inhA gene replacement mutant, emphasizing the critical role of Thr-266 in mediating post-translational regulation of InhA activity. The involvement of various serine/threonine kinases in modulating the activity of a number of enzymes of the mycolic acid synthesis pathway, including InhA, accentuates the intricacies of mycobacterial signaling networks in parallel with the changing environment.
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Affiliation(s)
- Shazia Khan
- National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi 110067 India
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60
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Fiuza M, Letek M, Leiba J, Villadangos AF, Vaquera J, Zanella-Cléon I, Mateos LM, Molle V, Gil JA. Phosphorylation of a novel cytoskeletal protein (RsmP) regulates rod-shaped morphology in Corynebacterium glutamicum. J Biol Chem 2010; 285:29387-97. [PMID: 20622015 DOI: 10.1074/jbc.m110.154427] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Corynebacteria grow by wall extension at the cell poles, with DivIVA being an essential protein orchestrating cell elongation and morphogenesis. DivIVA is considered a scaffolding protein able to recruit other proteins and enzymes involved in polar peptidoglycan biosynthesis. Partial depletion of DivIVA induced overexpression of cg3264, a previously uncharacterized gene that encodes a novel coiled coil-rich protein specific for corynebacteria and a few other actinomycetes. By partial depletion and overexpression of Cg3264, we demonstrated that this protein is an essential cytoskeletal element needed for maintenance of the rod-shaped morphology of Corynebacterium glutamicum, and it was therefore renamed RsmP (rod-shaped morphology protein). RsmP forms long polymers in vitro in the absence of any cofactors, thus resembling eukaryotic intermediate filaments. We also investigated whether RsmP could be regulated post-translationally by phosphorylation, like eukaryotic intermediate filaments. RsmP was phosphorylated in vitro by the PknA protein kinase and to a lesser extent by PknL. A mass spectrometric analysis indicated that phosphorylation exclusively occurred on a serine (Ser-6) and two threonine (Thr-168 and Thr-211) residues. We confirmed that mutagenesis to alanine (phosphoablative protein) totally abolished PknA-dependent phosphorylation of RsmP. Interestingly, when the three residues were converted to aspartic acid, the phosphomimetic protein accumulated at the cell poles instead of making filaments along the cell, as observed for the native or phosphoablative RsmP proteins, indicating that phosphorylation of RsmP is necessary for directing cell growth at the cell poles.
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Affiliation(s)
- Maria Fiuza
- Departamento de Biología Molecular, Area de Microbiología, Facultad de Biología, Universidad de León, León 24071, Spain
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