1
|
EL Haddoumi G, Mansouri M, Bendani H, Bouricha EM, Kandoussi I, Belyamani L, Ibrahimi A. Facing Antitubercular Resistance: Identification of Potential Direct Inhibitors Targeting InhA Enzyme and Generation of 3D-pharmacophore Model by in silico Approach. Adv Appl Bioinform Chem 2023; 16:49-59. [PMID: 37143606 PMCID: PMC10153438 DOI: 10.2147/aabc.s394535] [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: 10/23/2022] [Accepted: 01/21/2023] [Indexed: 05/06/2023] Open
Abstract
Purpose The enoyl-acyl carrier protein reductase (InhA) is one of the important key enzymes employed in mycolic acids biosynthesis pathway and an important component of mycobacterial cell walls. This enzyme has also been identified as major target of isoniazid drug, except that isoniazid needs to be activated first by the catalase peroxidase (KatG) protein to form the isonicotinoyl-NAD (INH-NAD) adduct that inhibits the action of InhA enzyme. However, this activation becomes more difficult and unreachable with the problem of mutation-related resistance caused mainly by acquired mutations in KatG and InhA protein. Our main interest in this study is to identify direct InhA inhibitors using computer-aided drug design. Methods Computer-aided drug design was used to solve this problem by applying three different approaches including mutation impact modelling, virtual screening and 3D-pharmacophore search. Results A total of 15 mutations were collected from the literature, then a 3D model was generated for each of them and their impact was predicted. Of the 15 mutations, 10 were found to be deleterious and have a direct effect on flexibility, stability and SASA of the protein. In virtual screening, from 1,000 similar INH-NAD analogues obtained by the similarity search method, 823 compounds passed toxicity filter and drug likeness rules, which were then docked to the wild-type of InhA protein. Subsequently, 34 compounds with binding energy score better than that of INH-NAD were selected and docked against the 10 generated mutated models of InhA. Only three leads showed a lower binding affinity better than the reference. The 3D-pharmacophore model approach was used to identify the common features between those three compounds by generating a pharmacophoric map. Conclusion The result of this study may pave the way to develop more potent mutant-specific inhibitors to overcome this resistance.
Collapse
Affiliation(s)
- Ghyzlane EL Haddoumi
- Biotechnology Lab (MedBiotech), Rabat Medical and Pharmacy School, University Mohammed V, Rabat, Morocco
- Centre Mohammed VI for Research & Innovation (CM6), Rabat, Morocco
| | - Mariam Mansouri
- Biotechnology Lab (MedBiotech), Rabat Medical and Pharmacy School, University Mohammed V, Rabat, Morocco
- Centre Mohammed VI for Research & Innovation (CM6), Rabat, Morocco
| | - Houda Bendani
- Biotechnology Lab (MedBiotech), Rabat Medical and Pharmacy School, University Mohammed V, Rabat, Morocco
- Centre Mohammed VI for Research & Innovation (CM6), Rabat, Morocco
| | - El Mehdi Bouricha
- Biotechnology Lab (MedBiotech), Rabat Medical and Pharmacy School, University Mohammed V, Rabat, Morocco
- Centre Mohammed VI for Research & Innovation (CM6), Rabat, Morocco
| | - Ilham Kandoussi
- Biotechnology Lab (MedBiotech), Rabat Medical and Pharmacy School, University Mohammed V, Rabat, Morocco
- Centre Mohammed VI for Research & Innovation (CM6), Rabat, Morocco
| | - Lahcen Belyamani
- Centre Mohammed VI for Research & Innovation (CM6), Rabat, Morocco
- Mohammed VI University of Health Sciences (UM6SS), Casablanca, Morocco
- Emergency Department, Military Hospital Mohammed V, Rabat, Morocco
| | - Azeddine Ibrahimi
- Biotechnology Lab (MedBiotech), Rabat Medical and Pharmacy School, University Mohammed V, Rabat, Morocco
- Centre Mohammed VI for Research & Innovation (CM6), Rabat, Morocco
- Mohammed VI University of Health Sciences (UM6SS), Casablanca, Morocco
- Correspondence: Azeddine Ibrahimi, Mohammed VI University of Health Sciences (UM6SS), Casablanca, Morocco, Tel +212660240131, Email
| |
Collapse
|
2
|
Sun M, Ge S, Li Z. The Role of Phosphorylation and Acylation in the Regulation of Drug Resistance in Mycobacterium tuberculosis. Biomedicines 2022; 10:biomedicines10102592. [PMID: 36289854 PMCID: PMC9599588 DOI: 10.3390/biomedicines10102592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 10/12/2022] [Accepted: 10/14/2022] [Indexed: 11/16/2022] Open
Abstract
Tuberculosis is a chronic and lethal infectious disease caused by Mycobacterium tuberculosis. In previous decades, most studies in this area focused on the pathogenesis and drug targets for disease treatments. However, the emergence of drug-resistant strains has increased the difficulty of clinical trials over time. Now, more post-translational modified proteins in Mycobacterium tuberculosis have been discovered. Evidence suggests that these proteins have the ability to influence tuberculosis drug resistance. Hence, this paper systematically summarizes updated research on the impacts of protein acylation and phosphorylation on the acquisition of drug resistance in Mycobacterium tuberculosis through acylation and phosphorylation protein regulating processes. This provides us with a better understanding of the mechanism of antituberculosis drugs and may contribute to a reduction the harm that tuberculosis brings to society, as well as aiding in the discovery of new drug targets and therapeutic regimen adjustments in the future.
Collapse
Affiliation(s)
- Manluan Sun
- School of Medicine, Shanxi Datong University, Datong 037009, China
- Institute of Carbon Materials Science, Shanxi Datong University, Datong 037009, China
- Correspondence:
| | - Sai Ge
- Institute of Carbon Materials Science, Shanxi Datong University, Datong 037009, China
- Center of Academic Journal, Shanxi Datong University, Datong 037009, China
| | - Zhaoyang Li
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| |
Collapse
|
3
|
Sundararajan S, Muniyan R. Latent tuberculosis: interaction of virulence factors in Mycobacterium tuberculosis. Mol Biol Rep 2021; 48:6181-6196. [PMID: 34351540 DOI: 10.1007/s11033-021-06611-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Accepted: 07/29/2021] [Indexed: 11/28/2022]
Abstract
Tuberculosis (TB) remains a prominent health concern worldwide. Besides extensive research and vaccinations available, attempts to control the pandemic are cumbersome due to the complex physiology of Mycobacterium tuberculosis (Mtb). Alongside the emergence of drug-resistant TB, latent TB has worsened the condition. The tubercle bacilli are unusually behaved and successful with its strategies to modulate genes to evade host immune system and persist within macrophages. Under latent/unfavorable conditions, Mtb conceals itself from immune system and modulates its genes. Among many intracellular modulated genes, important are those involved in cell entry, fatty acid degradation, mycolic acid synthesis, phagosome acidification inhibition, inhibition of phagosome-lysosome complex and chaperon protein modulation. Though the study on these genes date back to early times of TB, an insight on their inter-relation within and to newly evolved genes are still required. This review focuses on the findings and discussions on these genes, possible mechanism, credibility as target for novel drugs and repurposed drugs and their interaction that enables Mtb in survival, pathogenesis, resistance and latency.
Collapse
Affiliation(s)
- Sadhana Sundararajan
- School of Biosciences and Technology, Vellore Institute of Technology, Vellore, Tamil Nadu, 632014, India
| | - Rajiniraja Muniyan
- School of Biosciences and Technology, Vellore Institute of Technology, Vellore, Tamil Nadu, 632014, India.
| |
Collapse
|
4
|
Melly GC, Stokas H, Davidson PM, Roma JS, Rhodes HL, Purdy GE. Identification of residues important for M. tuberculosis MmpL11 function reveals that function is modulated by phosphorylation in the C-terminal domain. Mol Microbiol 2021; 115:208-221. [PMID: 32985735 DOI: 10.1111/mmi.14611] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 09/03/2020] [Accepted: 09/14/2020] [Indexed: 11/26/2022]
Abstract
The Mycobacterium tuberculosis cell envelope is a critical interface between the host and pathogen and provides a protective barrier against the immune response and antibiotics. Cell envelope lipids are also mycobacterial virulence factors that influence the host immune response. The mycobacterial membrane protein large (MmpL) proteins transport cell envelope lipids and siderophores that are important for the basic physiology and pathogenesis of M. tuberculosis. We recently identified MmpL11 as a conserved transporter of mycolic acid-containing lipids including monomeromycolyl diacylglycerol (MMDAG), mycolate wax ester (MWE), and long-chain triacylglycerols (LC-TAGs). These lipids contribute to biofilm formation in M. tuberculosis and M. smegmatis, and non-replicating persistence in M. tuberculosis. In this report, we identified domains and residues that are essential for MmpL11TB lipid transporter activity. Specifically, we show that the D1 periplasmic loop and a conserved tyrosine are essential for the MmpL11 function. Intriguingly, we found that MmpL11 levels are regulated by the phosphorylation of threonine in the cytoplasmic C-terminal domain, providing the first direct evidence of the phospho-regulation of MmpL11 transporter activity in M. tuberculosis and M. smegmatis. Our results offer further insight into the function of MmpL transporters and regulation of mycobacterial cell envelope biogenesis.
Collapse
Affiliation(s)
- Geoff C Melly
- Department of Molecular Microbiology & Immunology, Oregon Health & Science University, Portland, OR, USA
| | - Haley Stokas
- Department of Molecular Microbiology & Immunology, Oregon Health & Science University, Portland, OR, USA
| | - Patrick M Davidson
- Department of Molecular Microbiology & Immunology, Oregon Health & Science University, Portland, OR, USA
| | - José Santinni Roma
- Department of Molecular Microbiology & Immunology, Oregon Health & Science University, Portland, OR, USA
| | - Heather L Rhodes
- Department of Molecular Microbiology & Immunology, Oregon Health & Science University, Portland, OR, USA
| | - Georgiana E Purdy
- Department of Molecular Microbiology & Immunology, Oregon Health & Science University, Portland, OR, USA
| |
Collapse
|
5
|
Phosphorylation on PstP Regulates Cell Wall Metabolism and Antibiotic Tolerance in Mycobacterium smegmatis. J Bacteriol 2021; 203:JB.00563-20. [PMID: 33257524 DOI: 10.1128/jb.00563-20] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Accepted: 11/18/2020] [Indexed: 12/18/2022] Open
Abstract
Mycobacterium tuberculosis and its relatives, like many bacteria, have dynamic cell walls that respond to environmental stresses. Modulation of cell wall metabolism in stress is thought to be responsible for decreased permeability and increased tolerance to antibiotics. The signaling systems that control cell wall metabolism under stress, however, are poorly understood. Here, we examine the cell wall regulatory function of a key cell wall regulator, the serine/threonine phosphatase PstP, in the model organism Mycobacterium smegmatis We show that the peptidoglycan regulator CwlM is a substrate of PstP. We find that a phosphomimetic mutation, pstP T171E, slows growth, misregulates both mycolic acid and peptidoglycan metabolism in different conditions, and interferes with antibiotic tolerance. These data suggest that phosphorylation on PstP affects its activity against various substrates and is important in the transition between growth and stasis.IMPORTANCE Regulation of cell wall assembly is essential for bacterial survival and contributes to pathogenesis and antibiotic tolerance in mycobacteria, including pathogens such as Mycobacterium tuberculosis However, little is known about how the cell wall is regulated in stress. We describe a pathway of cell wall modulation in Mycobacterium smegmatis through the only essential Ser/Thr phosphatase, PstP. We showed that phosphorylation on PstP is important in regulating peptidoglycan metabolism in the transition to stasis and mycolic acid metabolism in growth. This regulation also affects antibiotic tolerance in growth and stasis. This work helps us to better understand the phosphorylation-mediated cell wall regulation circuitry in Mycobacteria.
Collapse
|
6
|
Arora G, Bothra A, Prosser G, Arora K, Sajid A. Role of post-translational modifications in the acquisition of drug resistance in Mycobacterium tuberculosis. FEBS J 2020; 288:3375-3393. [PMID: 33021056 DOI: 10.1111/febs.15582] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2020] [Revised: 09/16/2020] [Accepted: 09/30/2020] [Indexed: 12/22/2022]
Abstract
Tuberculosis (TB) is one of the primary causes of deaths due to infectious diseases. The current TB regimen is long and complex, failing of which leads to relapse and/or the emergence of drug resistance. There is a critical need to understand the mechanisms of resistance development. With increasing drug pressure, Mycobacterium tuberculosis (Mtb) activates various pathways to counter drug-related toxicity. Signaling modules steer the evolution of Mtb to a variant that can survive, persist, adapt, and emerge as a form that is resistant to one or more drugs. Recent studies reveal that about 1/3rd of the annotated Mtb proteome is modified post-translationally, with a large number of these proteins being essential for mycobacterial survival. Post-translational modifications (PTMs) such as phosphorylation, acetylation, and pupylation play a salient role in mycobacterial virulence, pathogenesis, and metabolism. The role of many other PTMs is still emerging. Understanding the signaling pathways and PTMs may assist clinical strategies and drug development for Mtb. In this review, we explore the contribution of PTMs to mycobacterial physiology, describe the related cellular processes, and discuss how these processes are linked to drug resistance. A significant number of drug targets, InhA, RpoB, EmbR, and KatG, are modified at multiple residues via PTMs. A better understanding of drug-resistance regulons and associated PTMs will aid in developing effective drugs against TB.
Collapse
Affiliation(s)
- Gunjan Arora
- Yale School of Medicine, Yale University, New Haven, CT, USA
| | - Ankur Bothra
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Gareth Prosser
- Cancer Research UK Manchester Institute, The University of Manchester, Alderley Park, UK
| | - Kriti Arora
- Proteus Digital Health, Inc., Redwood City, CA, USA
| | - Andaleeb Sajid
- Yale School of Medicine, Yale University, New Haven, CT, USA
| |
Collapse
|
7
|
Stokas H, Rhodes HL, Purdy GE. Modulation of the M. tuberculosis cell envelope between replicating and non-replicating persistent bacteria. Tuberculosis (Edinb) 2020; 125:102007. [PMID: 33035766 DOI: 10.1016/j.tube.2020.102007] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 09/24/2020] [Accepted: 10/02/2020] [Indexed: 12/18/2022]
Abstract
The success of Mycobacterium tuberculosis as a human pathogen depends on the bacterium's ability to persist in a quiescent form in oxygen and nutrient-poor host environments. In vitro studies have demonstrated that these restricting environments induce a shift from bacterial replication to non-replicating persistence (NRP). Entry into NRP involves changes in bacterial metabolism and remodeling of the cell envelope. Findings consistent with the phenotypes observed in vitro have been observed in patient and animal model samples. This review focuses on the cell envelope differences seen between replicating and NRP M. tuberculosis and summarizes the ways in which serine/threonine protein kinases (STPKs) may mediate this process.
Collapse
Affiliation(s)
- Haley Stokas
- Oregon Health & Science University, Department of Molecular Microbiology & Immunology, Portland, OR, 97239, United States
| | - Heather L Rhodes
- Oregon Health & Science University, Department of Molecular Microbiology & Immunology, Portland, OR, 97239, United States
| | - Georgiana E Purdy
- Oregon Health & Science University, Department of Molecular Microbiology & Immunology, Portland, OR, 97239, United States.
| |
Collapse
|
8
|
Le NH, Locard-Paulet M, Stella A, Tomas N, Molle V, Burlet-Schiltz O, Daffé M, Marrakchi H. The protein kinase PknB negatively regulates biosynthesis and trafficking of mycolic acids in mycobacteria. J Lipid Res 2020; 61:1180-1191. [PMID: 32487543 DOI: 10.1194/jlr.ra120000747] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 05/19/2020] [Indexed: 12/13/2022] Open
Abstract
Mycobacterium tuberculosis is the causative agent of tuberculosis and remains one of the most widespread and deadliest bacterial pathogens in the world. A distinguishing feature of mycobacteria that sets them apart from other bacteria is the unique architecture of their cell wall, characterized by various species-specific lipids, most notably mycolic acids (MAs). Therefore, targeted inhibition of enzymes involved in MA biosynthesis, transport, and assembly has been extensively explored in drug discovery. Additionally, more recent evidence suggests that many enzymes in the MA biosynthesis pathway are regulated by kinase-mediated phosphorylation, thus opening additional drug-development opportunities. However, how phosphorylation regulates MA production remains unclear. Here, we used genetic strategies combined with lipidomics and phosphoproteomics approaches to investigate the role of protein phosphorylation in Mycobacterium The results of this analysis revealed that the Ser/Thr protein kinase PknB regulates the export of MAs and promotes the remodeling of the mycobacterial cell envelope. In particular, we identified the essential MmpL3 as a substrate negatively regulated by PknB. Taken together, our findings add to the understanding of how PknB activity affects the mycobacterial MA biosynthesis pathway and reveal the essential role of protein phosphorylation/dephosphorylation in governing lipid metabolism, paving the way for novel antimycobacterial strategies.
Collapse
Affiliation(s)
- Nguyen-Hung Le
- Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Marie Locard-Paulet
- Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Alexandre Stella
- Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Nicolas Tomas
- Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Virginie Molle
- Laboratoire de Dynamique des Interactions Membranaires Normales et Pathologiques, Université de Montpellier, CNRS, UMR 5235, Montpellier, France
| | - Odile Burlet-Schiltz
- Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Mamadou Daffé
- Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Hedia Marrakchi
- Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, Toulouse, France
| |
Collapse
|
9
|
Taira J, Umei T, Inoue K, Kitamura M, Berenger F, Sacchettini JC, Sakamoto H, Aoki S. Improvement of the novel inhibitor for Mycobacterium enoyl-acyl carrier protein reductase (InhA): a structure-activity relationship study of KES4 assisted by in silico structure-based drug screening. J Antibiot (Tokyo) 2020; 73:372-381. [PMID: 32152525 DOI: 10.1038/s41429-020-0293-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Revised: 01/09/2020] [Accepted: 02/10/2020] [Indexed: 11/09/2022]
Abstract
InhA or enoyl-acyl carrier protein reductase of Mycobacterium tuberculosis (mtInhA), which controls mycobacterial cell wall construction, has been targeted in the development of antituberculosis drugs. Previously, our in silico structure-based drug screening study identified a novel class of compounds (designated KES4), which is capable of inhibiting the enzymatic activity of mtInhA, as well as mycobacterial growth. The compounds are composed of four ring structures (A-D), and the MD simulation predicted specific interactions with mtInhA of the D-ring and methylene group between the B-ring and C-ring; however, there is still room for improvement in the A-ring structure. In this study, a structure-activity relationship study of the A-ring was attempted with the assistance of in silico docking simulations. In brief, the virtual chemical library of A-ring-modified KES4 was constructed and subjected to in silico docking simulation against mtInhA using the GOLD program. Among the selected candidates, we achieved synthesis of seven compounds, and the bioactivities (effects on InhA activity and mycobacterial growth and cytotoxicity) of the synthesized molecules were evaluated. Among the compounds tested, two candidates (compounds 3d and 3f) exhibited superior properties as mtInhA-targeted anti-infectives for mycobacteria than the lead compound KES4.
Collapse
Affiliation(s)
- Junichi Taira
- Department of Bioscience and Bioinformatics, Graduate School of Computer Science and Systems Engineering, Kyushu Institute of Technology, Iizuka, 820-8502, Japan
| | - Tomohiro Umei
- Department of Bioscience and Bioinformatics, Graduate School of Computer Science and Systems Engineering, Kyushu Institute of Technology, Iizuka, 820-8502, Japan
| | - Keitaro Inoue
- Department of Bioscience and Bioinformatics, Graduate School of Computer Science and Systems Engineering, Kyushu Institute of Technology, Iizuka, 820-8502, Japan
| | - Mitsuru Kitamura
- Department of Applied Chemistry, Kyushu Institute of Technology, 1-1 Sensui-cho, Tobata, Kitakyushu, 804-8550, Japan
| | - Francois Berenger
- Department of Bioscience and Bioinformatics, Graduate School of Computer Science and Systems Engineering, Kyushu Institute of Technology, Iizuka, 820-8502, Japan
| | - James C Sacchettini
- Department of Biochemistry & Biophysics, Texas A&M University, College Station, TX, 77843-2128, USA
| | - Hiroshi Sakamoto
- Department of Bioscience and Bioinformatics, Graduate School of Computer Science and Systems Engineering, Kyushu Institute of Technology, Iizuka, 820-8502, Japan
| | - Shunsuke Aoki
- Department of Bioscience and Bioinformatics, Graduate School of Computer Science and Systems Engineering, Kyushu Institute of Technology, Iizuka, 820-8502, Japan.
| |
Collapse
|
10
|
Mori M, Sammartino JC, Costantino L, Gelain A, Meneghetti F, Villa S, Chiarelli LR. An Overview on the Potential Antimycobacterial Agents Targeting Serine/Threonine Protein Kinases from Mycobacterium tuberculosis. Curr Top Med Chem 2019; 19:646-661. [PMID: 30827246 DOI: 10.2174/1568026619666190227182701] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Revised: 09/27/2018] [Accepted: 10/09/2018] [Indexed: 01/07/2023]
Abstract
Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis (TB), still remains an urgent global health issue, mainly due to the emergence of multi-drug resistant strains. Therefore, there is a pressing need to develop novel and more efficient drugs to control the disease. In this context, targeting the pathogen virulence factors, and particularly signal mechanisms, seems to be a promising approach. An important transmembrane signaling system in Mtb is represented by receptor-type Serine/ Threonine protein kinases (STPKs). Mtb has 11 different STPKs, two of them, PknA and PknB, are essential. By contrast PknG and PknH are involved in Mtb virulence and adaptation, and are fundamental for the pathogen growth in infection models. Therefore, STPKs represent a very interesting group of pharmacological targets in M. tuberculosis. In this work, the principal inhibitors of the mycobacterial STPKs will be presented and discussed. In particular, medicinal chemistry efforts have been focused on discovering new antimycobacterial compounds, targeting three of these kinases, namely PknA, PknB and PknG. Generally, the inhibitory effect on these enzymes do not correlate with a significant antimycobacterial action in whole-cell assays. However, compounds with activity in the low micromolar range have been obtained, demonstrating that targeting Mtb STPKs could be a new promising strategy for the development of drugs to treat TB infections.
Collapse
Affiliation(s)
- Matteo Mori
- Dipartimento di Scienze Farmaceutiche, Università degli Studi di Milano, via L. Mangiagalli 25, 20133 Milano, Italy
| | - José Camilla Sammartino
- Dipartimento di Biologia e Biotecnologie "Lazzaro Spallanzani", Università degli Studi di Pavia, via Ferrata 9, 27100 Pavia, Italy
| | - Luca Costantino
- Dipartimento Scienze della Vita, Universita degli Studi di Modena e Reggio Emilia, via Campi 103, 41121 Modena, Italy
| | - Arianna Gelain
- Dipartimento di Scienze Farmaceutiche, Università degli Studi di Milano, via L. Mangiagalli 25, 20133 Milano, Italy
| | - Fiorella Meneghetti
- Dipartimento di Scienze Farmaceutiche, Università degli Studi di Milano, via L. Mangiagalli 25, 20133 Milano, Italy
| | - Stefania Villa
- Dipartimento di Scienze Farmaceutiche, Università degli Studi di Milano, via L. Mangiagalli 25, 20133 Milano, Italy
| | - Laurent Roberto Chiarelli
- Dipartimento di Biologia e Biotecnologie "Lazzaro Spallanzani", Università degli Studi di Pavia, via Ferrata 9, 27100 Pavia, Italy
| |
Collapse
|
11
|
Alsayed SSR, Beh CC, Foster NR, Payne AD, Yu Y, Gunosewoyo H. Kinase Targets for Mycolic Acid Biosynthesis in Mycobacterium tuberculosis. Curr Mol Pharmacol 2019; 12:27-49. [PMID: 30360731 DOI: 10.2174/1874467211666181025141114] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Revised: 10/11/2018] [Accepted: 10/11/2018] [Indexed: 12/12/2022]
Abstract
BACKGROUND Mycolic acids (MAs) are the characteristic, integral building blocks for the mycomembrane belonging to the insidious bacterial pathogen Mycobacterium tuberculosis (M.tb). These C60-C90 long α-alkyl-β-hydroxylated fatty acids provide protection to the tubercle bacilli against the outside threats, thus allowing its survival, virulence and resistance to the current antibacterial agents. In the post-genomic era, progress has been made towards understanding the crucial enzymatic machineries involved in the biosynthesis of MAs in M.tb. However, gaps still remain in the exact role of the phosphorylation and dephosphorylation of regulatory mechanisms within these systems. To date, a total of 11 serine-threonine protein kinases (STPKs) are found in M.tb. Most enzymes implicated in the MAs synthesis were found to be phosphorylated in vitro and/or in vivo. For instance, phosphorylation of KasA, KasB, mtFabH, InhA, MabA, and FadD32 downregulated their enzymatic activity, while phosphorylation of VirS increased its enzymatic activity. These observations suggest that the kinases and phosphatases system could play a role in M.tb adaptive responses and survival mechanisms in the human host. As the mycobacterial STPKs do not share a high sequence homology to the human's, there have been some early drug discovery efforts towards developing potent and selective inhibitors. OBJECTIVE Recent updates to the kinases and phosphatases involved in the regulation of MAs biosynthesis will be presented in this mini-review, including their known small molecule inhibitors. CONCLUSION Mycobacterial kinases and phosphatases involved in the MAs regulation may serve as a useful avenue for antitubercular therapy.
Collapse
Affiliation(s)
- Shahinda S R Alsayed
- School of Pharmacy and Biomedical Sciences, Faculty of Health Sciences, Curtin University, Perth, WA 6102, Australia
| | - Chau C Beh
- Western Australia School of Mines: Minerals, Energy and Chemical Engineering, Curtin University, Bentley 6102 WA, Australia.,David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02142, United States
| | - Neil R Foster
- Western Australia School of Mines: Minerals, Energy and Chemical Engineering, Curtin University, Bentley 6102 WA, Australia
| | - Alan D Payne
- School of Molecular and Life Sciences, Curtin University, Perth, WA 6102, Australia
| | - Yu Yu
- School of Pharmacy and Biomedical Sciences, Faculty of Health Sciences, Curtin University, Perth, WA 6102, Australia
| | - Hendra Gunosewoyo
- School of Pharmacy and Biomedical Sciences, Faculty of Health Sciences, Curtin University, Perth, WA 6102, Australia
| |
Collapse
|
12
|
Kaur P, Rausch M, Malakar B, Watson U, Damle NP, Chawla Y, Srinivasan S, Sharma K, Schneider T, Jhingan GD, Saini D, Mohanty D, Grein F, Nandicoori VK. LipidII interaction with specific residues of Mycobacterium tuberculosis PknB extracytoplasmic domain governs its optimal activation. Nat Commun 2019; 10:1231. [PMID: 30874556 PMCID: PMC6428115 DOI: 10.1038/s41467-019-09223-9] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Accepted: 02/28/2019] [Indexed: 02/08/2023] Open
Abstract
The Mycobacterium tuberculosis kinase PknB is essential for growth and survival of the pathogen in vitro and in vivo. Here we report the results of our efforts to elucidate the mechanism of regulation of PknB activity. The specific residues in the PknB extracytoplasmic domain that are essential for ligand interaction and survival of the bacterium are identified. The extracytoplasmic domain interacts with mDAP-containing LipidII, and this is abolished upon mutation of the ligand-interacting residues. Abrogation of ligand-binding or sequestration of the ligand leads to aberrant localization of PknB. Contrary to the prevailing hypothesis, abrogation of ligand-binding is linked to activation loop hyperphosphorylation, and indiscriminate hyperphosphorylation of PknB substrates as well as other proteins, ultimately causing loss of homeostasis and cell death. We propose that the ligand-kinase interaction directs the appropriate localization of the kinase, coupled to stringently controlled activation of PknB, and consequently the downstream processes thereof. The Mycobacterium tuberculosis kinase PknB regulates essential cell functions via interactions with muropeptides. Here the authors identify interaction sites in the extracytoplasmic PASTA domain and show that abrogation of ligand binding leads to a hyper-activated kinase, causing loss of homeostasis and cell death.
Collapse
Affiliation(s)
- Prabhjot Kaur
- National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Marvin Rausch
- Institute for Pharmaceutical Microbiology, University Hospital Bonn, University of Bonn, Bonn, 53105, Germany.,German Center for Infection Research (DZIF), Partner Site Bonn-Cologne, Bonn, 53105, Germany
| | - Basanti Malakar
- National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Uchenna Watson
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bengaluru, 560012, India
| | - Nikhil P Damle
- National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, 110067, India.,BIOSS, Center for Biological Signaling Studies, University of Freiburg, Freiburg, 79104, Germany
| | - Yogesh Chawla
- National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, 110067, India.,Department of Microbiology and Immunology, Weill Cornell Medical College, New York, 10065, NY, USA
| | - Sandhya Srinivasan
- Vproteomics, Valerian Chem Private Limited, Green Park Main, New Delhi, 110016, India
| | - Kanika Sharma
- Vproteomics, Valerian Chem Private Limited, Green Park Main, New Delhi, 110016, India
| | - Tanja Schneider
- Institute for Pharmaceutical Microbiology, University Hospital Bonn, University of Bonn, Bonn, 53105, Germany.,German Center for Infection Research (DZIF), Partner Site Bonn-Cologne, Bonn, 53105, Germany
| | - Gagan Deep Jhingan
- Vproteomics, Valerian Chem Private Limited, Green Park Main, New Delhi, 110016, India
| | - Deepak Saini
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bengaluru, 560012, India
| | - Debasisa Mohanty
- National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Fabian Grein
- Institute for Pharmaceutical Microbiology, University Hospital Bonn, University of Bonn, Bonn, 53105, Germany.,German Center for Infection Research (DZIF), Partner Site Bonn-Cologne, Bonn, 53105, Germany
| | | |
Collapse
|
13
|
Multisystem Analysis of Mycobacterium tuberculosis Reveals Kinase-Dependent Remodeling of the Pathogen-Environment Interface. mBio 2018; 9:mBio.02333-17. [PMID: 29511081 PMCID: PMC5845002 DOI: 10.1128/mbio.02333-17] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Tuberculosis is the leading killer among infectious diseases worldwide. Increasing multidrug resistance has prompted new approaches for tuberculosis drug development, including targeted inhibition of virulence determinants and of signaling cascades that control many downstream pathways. We used a multisystem approach to determine the effects of a potent small-molecule inhibitor of the essential Mycobacterium tuberculosis Ser/Thr protein kinases PknA and PknB. We observed differential levels of phosphorylation of many proteins and extensive changes in levels of gene expression, protein abundance, cell wall lipids, and intracellular metabolites. The patterns of these changes indicate regulation by PknA and PknB of several pathways required for cell growth, including ATP synthesis, DNA synthesis, and translation. These data also highlight effects on pathways for remodeling of the mycobacterial cell envelope via control of peptidoglycan turnover, lipid content, a SigE-mediated envelope stress response, transmembrane transport systems, and protein secretion systems. Integrated analysis of phosphoproteins, transcripts, proteins, and lipids identified an unexpected pathway whereby threonine phosphorylation of the essential response regulator MtrA decreases its DNA binding activity. Inhibition of this phosphorylation is linked to decreased expression of genes for peptidoglycan turnover, and of genes for mycolyl transferases, with concomitant changes in mycolates and glycolipids in the cell envelope. These findings reveal novel roles for PknA and PknB in regulating multiple essential cell functions and confirm that these kinases are potentially valuable targets for new antituberculosis drugs. In addition, the data from these linked multisystems provide a valuable resource for future targeted investigations into the pathways regulated by these kinases in the M. tuberculosis cell. Tuberculosis is the leading killer among infectious diseases worldwide. Increasing drug resistance threatens efforts to control this epidemic; thus, new antitubercular drugs are urgently needed. We performed an integrated, multisystem analysis of Mycobacterium tuberculosis responses to inhibition of its two essential serine/threonine protein kinases. These kinases allow the bacterium to adapt to its environment by phosphorylating cellular proteins in response to extracellular signals. We identified differentially phosphorylated proteins, downstream changes in levels of specific mRNA and protein abundance, and alterations in the metabolite and lipid content of the cell. These results include changes previously linked to growth arrest and also reveal new roles for these kinases in regulating essential processes, including growth, stress responses, transport of proteins and other molecules, and the structure of the mycobacterial cell envelope. Our multisystem data identify PknA and PknB as promising targets for drug development and provide a valuable resource for future investigation of their functions.
Collapse
|
14
|
Madacki J, Laval F, Grzegorzewicz A, Lemassu A, Záhorszká M, Arand M, McNeil M, Daffé M, Jackson M, Lanéelle MA, Korduláková J. Impact of the epoxide hydrolase EphD on the metabolism of mycolic acids in mycobacteria. J Biol Chem 2018; 293:5172-5184. [PMID: 29472294 DOI: 10.1074/jbc.ra117.000246] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Revised: 02/16/2018] [Indexed: 01/09/2023] Open
Abstract
Mycolic acids are the hallmark of the cell envelope in mycobacteria, which include the important human pathogens Mycobacterium tuberculosis and Mycobacterium leprae Mycolic acids are very long C60-C90 α-alkyl β-hydroxy fatty acids having a variety of functional groups on their hydrocarbon chain that define several mycolate types. Mycobacteria also produce an unusually large number of putative epoxide hydrolases, but the physiological functions of these enzymes are still unclear. Here, we report that the mycobacterial epoxide hydrolase EphD is involved in mycolic acid metabolism. We found that orthologs of EphD from M. tuberculosis and M. smegmatis are functional epoxide hydrolases, cleaving a lipophilic substrate, 9,10-cis-epoxystearic acid, in vitro and forming a vicinal diol. The results of EphD overproduction in M. smegmatis and M. bovis BCG Δhma strains producing epoxymycolic acids indicated that EphD is involved in the metabolism of these forms of mycolates in both fast- and slow-growing mycobacteria. Moreover, using MALDI-TOF-MS and 1H NMR spectroscopy of mycolic acids and lipids isolated from EphD-overproducing M. smegmatis, we identified new oxygenated mycolic acid species that accumulated during epoxymycolate depletion. Disruption of the ephD gene in M. tuberculosis specifically impaired the synthesis of ketomycolates and caused accumulation of their precursor, hydroxymycolate, indicating either direct or indirect involvement of EphD in ketomycolate biosynthesis. Our results clearly indicate that EphD plays a role in metabolism of oxygenated mycolic acids in mycobacteria.
Collapse
Affiliation(s)
- Jan Madacki
- From the Department of Biochemistry, Faculty of Natural Sciences, Comenius University, 842 15 Bratislava, Slovakia
| | - Françoise Laval
- the Tuberculosis & Infection Biology Department, Institut de Pharmacologie et de Biologie Structurale, CNRS, 31077 Toulouse, France
| | - Anna Grzegorzewicz
- the Mycobacteria Research Laboratories, Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, Colorado 80523-1682, and
| | - Anne Lemassu
- the Tuberculosis & Infection Biology Department, Institut de Pharmacologie et de Biologie Structurale, CNRS, 31077 Toulouse, France
| | - Monika Záhorszká
- From the Department of Biochemistry, Faculty of Natural Sciences, Comenius University, 842 15 Bratislava, Slovakia
| | - Michael Arand
- the Institute of Pharmacology and Toxicology, University of Zürich, CH-8057 Zürich, Switzerland
| | - Michael McNeil
- the Mycobacteria Research Laboratories, Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, Colorado 80523-1682, and
| | - Mamadou Daffé
- the Tuberculosis & Infection Biology Department, Institut de Pharmacologie et de Biologie Structurale, CNRS, 31077 Toulouse, France
| | - Mary Jackson
- the Mycobacteria Research Laboratories, Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, Colorado 80523-1682, and
| | - Marie-Antoinette Lanéelle
- the Tuberculosis & Infection Biology Department, Institut de Pharmacologie et de Biologie Structurale, CNRS, 31077 Toulouse, France
| | - Jana Korduláková
- From the Department of Biochemistry, Faculty of Natural Sciences, Comenius University, 842 15 Bratislava, Slovakia,
| |
Collapse
|
15
|
An overview on crystal structures of InhA protein: Apo-form, in complex with its natural ligands and inhibitors. Eur J Med Chem 2018; 146:318-343. [PMID: 29407960 DOI: 10.1016/j.ejmech.2018.01.047] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 01/02/2018] [Accepted: 01/15/2018] [Indexed: 11/23/2022]
Abstract
The enoyl-ACP reductase InhA from the mycobacterial fatty acid biosynthesis pathway has become a target of interest for the development of new anti-tubercular drugs. This protein has been identified as essential for the survival of Mycobacterium tuberculosis, the causative agent of tuberculosis, and as the main target of two pro-drugs: isoniazid, the frontline anti-tubercular drug, and ethionamide, a second-line medicine. Since most cases of resistance to isoniazid and ethionamide result from mutations in the mycobacterial activating enzyme (KatG for isoniazid and EthA for ethionamide), research of direct InhA inhibitors, avoiding the activation step, has emerged as a promising strategy for combating tuberculosis. Thereby, InhA is drawing much attention and its three-dimensional structure has been particularly studied. A better understanding of key sites of interactions responsible for InhA inhibition arises thus as an essential tool for the rational design of new potent inhibitors. In this paper, we propose an overview of the 80 available crystal structures of wild-type and mutant InhA, in its apo form, in complex with its cofactor, with an analogue of its natural ligands (C16 fatty acid and/or NADH) or with inhibitors. We will first discuss structural and mechanistic aspects in order to highlight key features of the protein before delivering thorough inventory of structures of InhA in the presence of synthetic ligands to underline the key interactions implicated in high affinity inhibition.
Collapse
|
16
|
Dual phosphorylation in response regulator protein PrrA is crucial for intracellular survival of mycobacteria consequent upon transcriptional activation. Biochem J 2017; 474:4119-4136. [PMID: 29101285 DOI: 10.1042/bcj20170596] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 11/02/2017] [Accepted: 11/03/2017] [Indexed: 01/05/2023]
Abstract
The remarkable ability of Mycobacterium tuberculosis (Mtb) to survive inside human macrophages is attributed to the presence of a complex sensory and regulatory network. PrrA is a DNA-binding regulatory protein, belonging to an essential two-component system (TCS), PrrA/B, which is required for early phase intracellular replication of Mtb. Despite its importance, the mechanism of PrrA/B-mediated signaling is not well understood. In the present study, we demonstrate that the binding of PrrA on the promoter DNA and its consequent activation is cumulatively controlled via dual phosphorylation of the protein. We have further characterized the role of terminal phospho-acceptor domain in the physical interaction of PrrA with its cognate kinase PrrB. The genetic deletion of prrA/B in Mycobacterium smegmatis was possible only in the presence of ectopic copies of the genes, suggesting the essentiality of this TCS in fast-growing mycobacterial strains as well. The overexpression of phospho-mimetic mutant (T6D) altered the growth of M. smegmatis in an in vitro culture and affected the replication of Mycobacterium bovis BCG in mouse peritoneal macrophages. Interestingly, the Thr6 site was found to be conserved in Mtb complex, whereas it was altered in some fast-growing mycobacterial strains, indicating that this unique phosphorylation might be predominant in employing the regulatory circuit in M. bovis BCG and presumably also in Mtb complex.
Collapse
|
17
|
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.
Collapse
|
18
|
Abstract
Acid-fast (AF) staining, also known as Ziehl-Neelsen stain microscopic detection, developed over a century ago, is even today the most widely used diagnostic method for tuberculosis. Herein we present a short historical review of the evolution of AF staining methods and discuss Koch's paradox, in which non-AF tubercle bacilli can be detected in tuberculosis patients or in experimentally infected animals. The conversion of Mycobacterium tuberculosis from an actively growing, AF-positive form to a nonreplicating, AF-negative form during the course of infection is now well documented. The mechanisms of loss of acid-fastness are not fully understood but involve important metabolic processes, such as the accumulation of triacylglycerol-containing intracellular inclusions and changes in the composition and spatial architecture of the cell wall. Although the precise component(s) responsible for the AF staining method remains largely unknown, analysis of a series of genetically defined M. tuberculosis mutants, which are attenuated in mice, pointed to the primary role of mycolic acids and other cell wall-associated (glyco)lipids as molecular markers responsible for the AF property of mycobacteria. Further studies are now required to better describe the cell wall reorganization that occurs during dormancy and to develop new staining procedures that are not affected by such cell wall alterations and that are capable of detecting AF-negative cells.
Collapse
|
19
|
Disruption of key NADH-binding pocket residues of the Mycobacterium tuberculosis InhA affects DD-CoA binding ability. Sci Rep 2017; 7:4714. [PMID: 28680153 PMCID: PMC5498604 DOI: 10.1038/s41598-017-05042-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Accepted: 05/24/2017] [Indexed: 12/03/2022] Open
Abstract
Tuberculosis (TB) is a global health problem that affects over 10 million people. There is an urgent need to develop novel antimicrobial therapies to combat TB. To achieve this, a thorough understanding of key validated drug targets is required. The enoyl reductase InhA, responsible for synthesis of essential mycolic acids in the mycobacterial cell wall, is the target for the frontline anti-TB drug isoniazid. To better understand the activity of this protein a series of mutants, targeted to the NADH co-factor binding pocket were created. Residues P193 and W222 comprise a series of hydrophobic residues surrounding the cofactor binding site and mutation of both residues negatively affect InhA function. Construction of an M155A mutant of InhA results in increased affinity for NADH and DD-CoA turnover but with a reduction in Vmax for DD-CoA, impairing overall activity. This suggests that NADH-binding geometry of InhA likely permits long-range interactions between residues in the NADH-binding pocket to facilitate substrate turnover in the DD-CoA binding region of the protein. Understanding the precise details of substrate binding and turnover in InhA and how this may affect protein-protein interactions may facilitate the development of improved inhibitors enabling the development of novel anti-TB drugs.
Collapse
|
20
|
Recent advancements in the development of anti-tuberculosis drugs. Bioorg Med Chem Lett 2016; 27:370-386. [PMID: 28017531 DOI: 10.1016/j.bmcl.2016.11.084] [Citation(s) in RCA: 80] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Revised: 11/16/2016] [Accepted: 11/27/2016] [Indexed: 01/09/2023]
Abstract
Modern chemotherapy has significantly improved patient outcomes against drug-sensitive tuberculosis. However, the rapid emergence of drug-resistant tuberculosis, together with the bacterium's ability to persist and remain latent present a major public health challenge. To overcome this problem, research into novel anti-tuberculosis targets and drug candidates is thus of paramount importance. This review article provides an overview of tuberculosis highlighting the recent advances and tools that are employed in the field of anti-tuberculosis drug discovery. The predominant focus is on anti-tuberculosis agents that are currently in the pipeline, i.e. clinical trials.
Collapse
|
21
|
Le NH, Molle V, Eynard N, Miras M, Stella A, Bardou F, Galandrin S, Guillet V, André-Leroux G, Bellinzoni M, Alzari P, Mourey L, Burlet-Schiltz O, Daffé M, Marrakchi H. Ser/Thr Phosphorylation Regulates the Fatty Acyl-AMP Ligase Activity of FadD32, an Essential Enzyme in Mycolic Acid Biosynthesis. J Biol Chem 2016; 291:22793-22805. [PMID: 27590338 DOI: 10.1074/jbc.m116.748053] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Revised: 08/31/2016] [Indexed: 12/21/2022] Open
Abstract
Mycolic acids are essential components of the mycobacterial cell envelope, and their biosynthetic pathway is a well known source of antituberculous drug targets. Among the promising new targets in the pathway, FadD32 is an essential enzyme required for the activation of the long meromycolic chain of mycolic acids and is essential for mycobacterial growth. Following the in-depth biochemical, biophysical, and structural characterization of FadD32, we investigated its putative regulation via post-translational modifications. Comparison of the fatty acyl-AMP ligase activity between phosphorylated and dephosphorylated FadD32 isoforms showed that the native protein is phosphorylated by serine/threonine protein kinases and that this phosphorylation induced a significant loss of activity. Mass spectrometry analysis of the native protein confirmed the post-translational modifications and identified Thr-552 as the phosphosite. Phosphoablative and phosphomimetic FadD32 mutant proteins confirmed both the position and the importance of the modification and its correlation with the negative regulation of FadD32 activity. Investigation of the mycolic acid condensation reaction catalyzed by Pks13, involving FadD32 as a partner, showed that FadD32 phosphorylation also impacts the condensation activity. Altogether, our results bring to light FadD32 phosphorylation by serine/threonine protein kinases and its correlation with the enzyme-negative regulation, thus shedding a new horizon on the mycolic acid biosynthesis modulation and possible inhibition strategies for this promising drug target.
Collapse
Affiliation(s)
- Nguyen-Hung Le
- From the Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS
| | - Virginie Molle
- the Laboratoire de Dynamique des Interactions Membranaires Normales et Pathologiques, Université de Montpellier, CNRS UMR 5235, Place Eugène Bataillon, 34095 Montpellier Cedex 05, and
| | - Nathalie Eynard
- From the Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS
| | - Mathieu Miras
- From the Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS
| | - Alexandre Stella
- From the Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS
| | - Fabienne Bardou
- From the Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS
| | - Ségolène Galandrin
- From the Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS
| | - Valérie Guillet
- From the Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS
| | - Gwenaëlle André-Leroux
- the Institut Pasteur, Unité de Microbiologie Structurale, 25 Rue du Docteur Roux, 75724 Paris Cedex 15, France
| | - Marco Bellinzoni
- the Institut Pasteur, Unité de Microbiologie Structurale, 25 Rue du Docteur Roux, 75724 Paris Cedex 15, France
| | - Pedro Alzari
- the Institut Pasteur, Unité de Microbiologie Structurale, 25 Rue du Docteur Roux, 75724 Paris Cedex 15, France
| | - Lionel Mourey
- From the Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS
| | - Odile Burlet-Schiltz
- From the Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS
| | - Mamadou Daffé
- From the Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS,
| | - Hedia Marrakchi
- From the Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS,
| |
Collapse
|
22
|
Quémard A. New Insights into the Mycolate-Containing Compound Biosynthesis and Transport in Mycobacteria. Trends Microbiol 2016; 24:725-738. [DOI: 10.1016/j.tim.2016.04.009] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Revised: 04/14/2016] [Accepted: 04/29/2016] [Indexed: 12/15/2022]
|
23
|
Stk1-mediated phosphorylation stimulates the DNA-binding properties of the Staphylococcus aureus SpoVG transcriptional factor. Biochem Biophys Res Commun 2016; 473:1223-1228. [DOI: 10.1016/j.bbrc.2016.04.044] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Accepted: 04/10/2016] [Indexed: 11/17/2022]
|
24
|
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.
Collapse
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
| |
Collapse
|
25
|
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.
Collapse
|
26
|
Manjunatha UH, S Rao SP, Kondreddi RR, Noble CG, Camacho LR, Tan BH, Ng SH, Ng PS, Ma NL, Lakshminarayana SB, Herve M, Barnes SW, Yu W, Kuhen K, Blasco F, Beer D, Walker JR, Tonge PJ, Glynne R, Smith PW, Diagana TT. Direct inhibitors of InhA are active against Mycobacterium tuberculosis. Sci Transl Med 2015; 7:269ra3. [PMID: 25568071 DOI: 10.1126/scitranslmed.3010597] [Citation(s) in RCA: 87] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
New chemotherapeutic agents are urgently required to combat the global spread of multidrug-resistant tuberculosis (MDR-TB). The mycobacterial enoyl reductase InhA is one of the few clinically validated targets in tuberculosis drug discovery. We report the identification of a new class of direct InhA inhibitors, the 4-hydroxy-2-pyridones, using phenotypic high-throughput whole-cell screening. This class of orally active compounds showed potent bactericidal activity against common isoniazid-resistant TB clinical isolates. Biophysical studies revealed that 4-hydroxy-2-pyridones bound specifically to InhA in an NADH (reduced form of nicotinamide adenine dinucleotide)-dependent manner and blocked the enoyl substrate-binding pocket. The lead compound NITD-916 directly blocked InhA in a dose-dependent manner and showed in vivo efficacy in acute and established mouse models of Mycobacterium tuberculosis infection. Collectively, our structural and biochemical data open up new avenues for rational structure-guided optimization of the 4-hydroxy-2-pyridone class of compounds for the treatment of MDR-TB.
Collapse
Affiliation(s)
- Ujjini H Manjunatha
- Novartis Institute for Tropical Diseases, 138670 Singapore, Singapore. Yong Loo Lin School of Medicine, National University of Singapore, 119228 Singapore, Singapore.
| | - Srinivasa P S Rao
- Novartis Institute for Tropical Diseases, 138670 Singapore, Singapore
| | | | - Christian G Noble
- Novartis Institute for Tropical Diseases, 138670 Singapore, Singapore
| | - Luis R Camacho
- Novartis Institute for Tropical Diseases, 138670 Singapore, Singapore
| | - Bee H Tan
- Novartis Institute for Tropical Diseases, 138670 Singapore, Singapore
| | - Seow H Ng
- Novartis Institute for Tropical Diseases, 138670 Singapore, Singapore
| | - Pearly Shuyi Ng
- Novartis Institute for Tropical Diseases, 138670 Singapore, Singapore
| | - Ng L Ma
- Novartis Institute for Tropical Diseases, 138670 Singapore, Singapore
| | | | - Maxime Herve
- Novartis Institute for Tropical Diseases, 138670 Singapore, Singapore
| | - Susan W Barnes
- Genomics Institute of the Novartis Research Foundation, San Diego, CA 92121, USA
| | - Weixuan Yu
- Institute of Chemical Biology & Drug Discovery, Stony Brook University, Stony Brook, NY 11794-3400, USA
| | - Kelli Kuhen
- Genomics Institute of the Novartis Research Foundation, San Diego, CA 92121, USA
| | - Francesca Blasco
- Novartis Institute for Tropical Diseases, 138670 Singapore, Singapore
| | - David Beer
- Novartis Institute for Tropical Diseases, 138670 Singapore, Singapore
| | - John R Walker
- Genomics Institute of the Novartis Research Foundation, San Diego, CA 92121, USA
| | - Peter J Tonge
- Institute of Chemical Biology & Drug Discovery, Stony Brook University, Stony Brook, NY 11794-3400, USA
| | - Richard Glynne
- Genomics Institute of the Novartis Research Foundation, San Diego, CA 92121, USA
| | - Paul W Smith
- Novartis Institute for Tropical Diseases, 138670 Singapore, Singapore
| | - Thierry T Diagana
- Novartis Institute for Tropical Diseases, 138670 Singapore, Singapore. Yong Loo Lin School of Medicine, National University of Singapore, 119228 Singapore, Singapore.
| |
Collapse
|
27
|
Touchette MH, Bommineni GR, Delle Bovi RJ, Gadbery JE, Nicora CD, Shukla AK, Kyle JE, Metz TO, Martin DW, Sampson NS, Miller WT, Tonge PJ, Seeliger JC. Diacyltransferase Activity and Chain Length Specificity of Mycobacterium tuberculosis PapA5 in the Synthesis of Alkyl β-Diol Lipids. Biochemistry 2015; 54:5457-68. [PMID: 26271001 DOI: 10.1021/acs.biochem.5b00455] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Although they are classified as Gram-positive bacteria, Corynebacterineae possess an asymmetric outer membrane that imparts structural and thereby physiological similarity to more distantly related Gram-negative bacteria. Like lipopolysaccharide in Gram-negative bacteria, lipids in the outer membrane of Corynebacterineae have been associated with the virulence of pathogenic species such as Mycobacterium tuberculosis (Mtb). For example, Mtb strains that lack long, branched-chain alkyl esters known as dimycocerosates (DIMs) are significantly attenuated in model infections. The resultant interest in the biosynthetic pathway of these unusual virulence factors has led to the elucidation of many of the steps leading to the final esterification of the alkyl β-diol, phthiocerol, with branched-chain fatty acids known as mycocerosates. PapA5 is an acyltransferase implicated in these final reactions. Here, we show that PapA5 is indeed the terminal enzyme in DIM biosynthesis by demonstrating its dual esterification activity and chain-length preference using synthetic alkyl β-diol substrate analogues. By applying these analogues to a series of PapA5 mutants, we also revise a model for the substrate binding within PapA5. Finally, we demonstrate that the Mtb Ser/Thr kinases PknB and PknE modify PapA5 on three overlapping Thr residues and that a fourth Thr is unique to PknE phosphorylation. These results clarify the DIM biosynthetic pathway and indicate post-translational modifications that warrant further elucidation for their roles in the regulation of DIM biosynthesis.
Collapse
Affiliation(s)
| | | | | | | | - Carrie D Nicora
- Biological Sciences Division, Pacific Northwest National Laboratory , Richland, Washington 99352, United States
| | - Anil K Shukla
- Biological Sciences Division, Pacific Northwest National Laboratory , Richland, Washington 99352, United States
| | - Jennifer E Kyle
- Biological Sciences Division, Pacific Northwest National Laboratory , Richland, Washington 99352, United States
| | - Thomas O Metz
- Biological Sciences Division, Pacific Northwest National Laboratory , Richland, Washington 99352, United States
| | | | | | | | | | | |
Collapse
|
28
|
Richard-Greenblatt M, Bach H, Adamson J, Peña-Diaz S, Li W, Steyn AJC, Av-Gay Y. Regulation of Ergothioneine Biosynthesis and Its Effect on Mycobacterium tuberculosis Growth and Infectivity. J Biol Chem 2015; 290:23064-76. [PMID: 26229105 DOI: 10.1074/jbc.m115.648642] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Indexed: 11/06/2022] Open
Abstract
Ergothioneine (EGT) is synthesized in mycobacteria, but limited knowledge exists regarding its synthesis, physiological role, and regulation. We have identified Rv3701c from Mycobacterium tuberculosis to encode for EgtD, a required histidine methyltransferase that catalyzes first biosynthesis step in EGT biosynthesis. EgtD was found to be phosphorylated by the serine/threonine protein kinase PknD. PknD phosphorylates EgtD both in vitro and in a cell-based system on Thr(213). The phosphomimetic (T213E) but not the phosphoablative (T213A) mutant of EgtD failed to restore EGT synthesis in a ΔegtD mutant. The findings together with observed elevated levels of EGT in a pknD transposon mutant during in vitro growth suggests that EgtD phosphorylation by PknD negatively regulates EGT biosynthesis. We further showed that EGT is required in a nutrient-starved model of persistence and is needed for long term infection of murine macrophages.
Collapse
Affiliation(s)
| | - Horacio Bach
- From the Division of Infectious Diseases, Department of Medicine and
| | - John Adamson
- Kwazulu-Natal Research Institute for Tuberculosis and HIV, Durban, South Africa 4001
| | - Sandra Peña-Diaz
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, British Columbia V6H 3Z6, Canada
| | - Wu Li
- Institute of Modern Biopharmaceuticals, School of Life Sciences, Southwest University, Chongqing 400715, China, and
| | - Adrie J C Steyn
- Kwazulu-Natal Research Institute for Tuberculosis and HIV, Durban, South Africa 4001, Department of Microbiology and Centers for AIDS Research and Free Radical Biology, University of Alabama, Birmingham, Alabama 35233
| | - Yossef Av-Gay
- From the Division of Infectious Diseases, Department of Medicine and
| |
Collapse
|
29
|
Nataraj V, Varela C, Javid A, Singh A, Besra GS, Bhatt A. Mycolic acids: deciphering and targeting the Achilles' heel of the tubercle bacillus. Mol Microbiol 2015; 98:7-16. [PMID: 26135034 PMCID: PMC4949712 DOI: 10.1111/mmi.13101] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/18/2015] [Indexed: 12/31/2022]
Abstract
Mycolic acids are unique long chain fatty acids found in the lipid-rich cell walls of mycobacteria including the tubercle bacillus Mycobacterium tuberculosis. Essential for viability and virulence, enzymes involved in the biosynthesis of mycolic acids represent novel targets for drug development. This is particularly relevant to the impact on global health given the rise of multidrug resistant and extensively drug resistant strains of M. tuberculosis. In this review, we discuss recent advances in our understanding of how mycolic acid are synthesised, especially the potential role of specialised fatty acid synthase complexes. Also, we examine the role of a recently reported mycolic acid transporter MmpL3 with reference to several reports of the targeting of this transporter by diverse compounds with anti-M. tuberculosis activity. Additionally, we consider recent findings that place mycolic acid biosynthesis in the context of the cell biology of the bacterium, viz its localisation and co-ordination with the bacterial cytoskeleton, and its role beyond maintaining cell envelope integrity.
Collapse
Affiliation(s)
- Vijayashankar Nataraj
- School of Biosciences and Institute of Microbiology and Infection, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Cristian Varela
- School of Biosciences and Institute of Microbiology and Infection, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Asma Javid
- School of Biosciences and Institute of Microbiology and Infection, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Albel Singh
- School of Biosciences and Institute of Microbiology and Infection, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Gurdyal S Besra
- School of Biosciences and Institute of Microbiology and Infection, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Apoorva Bhatt
- School of Biosciences and Institute of Microbiology and Infection, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| |
Collapse
|
30
|
Ferreira LG, Dos Santos RN, Oliva G, Andricopulo AD. Molecular docking and structure-based drug design strategies. Molecules 2015; 20:13384-421. [PMID: 26205061 PMCID: PMC6332083 DOI: 10.3390/molecules200713384] [Citation(s) in RCA: 938] [Impact Index Per Article: 104.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Revised: 07/14/2015] [Accepted: 07/20/2015] [Indexed: 02/07/2023] Open
Abstract
Pharmaceutical research has successfully incorporated a wealth of molecular modeling methods, within a variety of drug discovery programs, to study complex biological and chemical systems. The integration of computational and experimental strategies has been of great value in the identification and development of novel promising compounds. Broadly used in modern drug design, molecular docking methods explore the ligand conformations adopted within the binding sites of macromolecular targets. This approach also estimates the ligand-receptor binding free energy by evaluating critical phenomena involved in the intermolecular recognition process. Today, as a variety of docking algorithms are available, an understanding of the advantages and limitations of each method is of fundamental importance in the development of effective strategies and the generation of relevant results. The purpose of this review is to examine current molecular docking strategies used in drug discovery and medicinal chemistry, exploring the advances in the field and the role played by the integration of structure- and ligand-based methods.
Collapse
Affiliation(s)
- Leonardo G Ferreira
- Laboratório de Química Medicinal e Computacional, Centro de Pesquisa e Inovação em Biodiversidade e Fármacos, Instituto de Física de São Carlos, Universidade de São Paulo, Av. João Dagnone 1100, São Carlos-SP 13563-120, Brazil.
| | - Ricardo N Dos Santos
- Laboratório de Química Medicinal e Computacional, Centro de Pesquisa e Inovação em Biodiversidade e Fármacos, Instituto de Física de São Carlos, Universidade de São Paulo, Av. João Dagnone 1100, São Carlos-SP 13563-120, Brazil.
| | - Glaucius Oliva
- Laboratório de Química Medicinal e Computacional, Centro de Pesquisa e Inovação em Biodiversidade e Fármacos, Instituto de Física de São Carlos, Universidade de São Paulo, Av. João Dagnone 1100, São Carlos-SP 13563-120, Brazil.
| | - Adriano D Andricopulo
- Laboratório de Química Medicinal e Computacional, Centro de Pesquisa e Inovação em Biodiversidade e Fármacos, Instituto de Física de São Carlos, Universidade de São Paulo, Av. João Dagnone 1100, São Carlos-SP 13563-120, Brazil.
| |
Collapse
|
31
|
Pompeo F, Foulquier E, Serrano B, Grangeasse C, Galinier A. Phosphorylation of the cell division protein GpsB regulates PrkC kinase activity through a negative feedback loop in Bacillus subtilis. Mol Microbiol 2015; 97:139-50. [PMID: 25845974 DOI: 10.1111/mmi.13015] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/31/2015] [Indexed: 01/12/2023]
Abstract
Although many membrane Ser/Thr-kinases with PASTA motifs have been shown to control bacterial cell division and morphogenesis, inactivation of the Ser/Thr-kinase PrkC does not impact Bacillus subtilis cell division. In this study, we show that PrkC localizes at the division septum. In addition, three proteins involved in cell division/elongation, GpsB, DivIVA and EzrA are required for stimulating PrkC activity in vivo. We show that GpsB interacts with the catalytic subunit of PrkC that, in turn, phosphorylates GpsB. These observations are not made with DivIVA and EzrA. Consistent with the phosphorylated residue previously detected for GpsB in a high-throughput phosphoproteomic analysis of B. subtilis, we show that threonine 75 is the single PrkC-mediated phosphorylation site in GpsB. Importantly, the substitution of this threonine by a phospho-mimetic residue induces a loss of PrkC kinase activity in vivo and a reduced growth under high salt conditions as observed for gpsB and prkC null mutants. Conversely, substitution of threonine 75 by a phospho-ablative residue does not induce such growth and PrkC kinase activity defects. Altogether, these data show that proteins of the divisome control PrkC activity and thereby phosphorylation of PrkC substrates through a negative feedback loop in B. subtilis.
Collapse
Affiliation(s)
- Frédérique Pompeo
- Laboratoire de Chimie Bactérienne, UMR 7283, IMM, CNRS, Aix-Marseille Université, 31 Chemin Joseph Aiguier, Marseille, 13009, France
| | - Elodie Foulquier
- Laboratoire de Chimie Bactérienne, UMR 7283, IMM, CNRS, Aix-Marseille Université, 31 Chemin Joseph Aiguier, Marseille, 13009, France
| | - Bastien Serrano
- Laboratoire de Chimie Bactérienne, UMR 7283, IMM, CNRS, Aix-Marseille Université, 31 Chemin Joseph Aiguier, Marseille, 13009, France
| | - Christophe Grangeasse
- Bases Moléculaires et Structurales des Systèmes Infectieux, IBCP, CNRS, UMR, Université Lyon 1, Lyon, 5086, France
| | - Anne Galinier
- Laboratoire de Chimie Bactérienne, UMR 7283, IMM, CNRS, Aix-Marseille Université, 31 Chemin Joseph Aiguier, Marseille, 13009, France
| |
Collapse
|
32
|
Crystal structure of the enoyl-ACP reductase of Mycobacterium tuberculosis (InhA) in the apo-form and in complex with the active metabolite of isoniazid pre-formed by a biomimetic approach. J Struct Biol 2015; 190:328-37. [PMID: 25891098 DOI: 10.1016/j.jsb.2015.04.008] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Revised: 04/09/2015] [Accepted: 04/10/2015] [Indexed: 11/21/2022]
Abstract
InhA is an enoyl-ACP reductase of Mycobacterium tuberculosis implicated in the biosynthesis of mycolic acids, essential constituents of the mycobacterial cell wall. To date, this enzyme is considered as a promising target for the discovery of novel antitubercular drugs. In this work, we describe the first crystal structure of the apo form of the wild-type InhA at 1.80Å resolution as well as the crystal structure of InhA in complex with the synthetic metabolite of the antitubercular drug isoniazid refined to 1.40Å. This metabolite, synthesized in the absence of InhA, is able to displace and replace the cofactor NADH in the enzyme active site. This work provides a unique opportunity to enlighten the structural adaptation of apo-InhA to the binding of the NADH cofactor or of the isoniazid adduct. In addition, a differential scanning fluorimetry study of InhA, in the apo-form as well as in the presence of NAD(+), NADH and INH-NADH was performed showing that binding of the INH-NADH adduct had a strong stabilizing effect.
Collapse
|
33
|
Abstract
ABSTRACT
Mycolic acids are major and specific long-chain fatty acids that represent essential components of the
Mycobacterium tuberculosis
cell envelope. They play a crucial role in the cell wall architecture and impermeability, hence the natural resistance of mycobacteria to most antibiotics, and represent key factors in mycobacterial virulence. Biosynthesis of mycolic acid precursors requires two types of fatty acid synthases (FASs), the eukaryotic-like multifunctional enzyme FAS I and the acyl carrier protein (ACP)–dependent FAS II systems, which consists of a series of discrete mono-functional proteins, each catalyzing one reaction in the pathway. Unlike FAS II synthases of other bacteria, the mycobacterial FAS II is incapable of
de novo
fatty acid synthesis from acetyl-coenzyme A, but instead elongates medium-chain-length fatty acids previously synthesized by FAS I, leading to meromycolic acids. In addition, mycolic acid subspecies with defined biological properties can be distinguished according to the chemical modifications decorating the meromycolate. Nearly all the genetic components involved in both elongation and functionalization of the meromycolic acid have been identified and are generally clustered in distinct transcriptional units. A large body of information has been generated on the enzymology of the mycolic acid biosynthetic pathway and on their genetic and biochemical/structural characterization as targets of several antitubercular drugs. This chapter is a comprehensive overview of mycolic acid structure, function, and biosynthesis. Special emphasis is given to recent work addressing the regulation of mycolic acid biosynthesis, adding new insights to our understanding of how pathogenic mycobacteria adapt their cell wall composition in response to environmental changes.
Collapse
|
34
|
Foulquier E, Pompeo F, Freton C, Cordier B, Grangeasse C, Galinier A. PrkC-mediated phosphorylation of overexpressed YvcK protein regulates PBP1 protein localization in Bacillus subtilis mreB mutant cells. J Biol Chem 2014; 289:23662-9. [PMID: 25012659 DOI: 10.1074/jbc.m114.562496] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The YvcK protein has been shown to be necessary for growth under gluconeogenic conditions in Bacillus subtilis. Amazingly, its overproduction rescues growth and morphology defects of the actin-like protein MreB deletion mutant by restoration of PBP1 localization. In this work, we observed that YvcK was phosphorylated at Thr-304 by the protein kinase PrkC and that phosphorylated YvcK was dephosphorylated by the cognate phosphatase PrpC. We show that neither substitution of this threonine with a constitutively phosphorylated mimicking glutamic acid residue or a phosphorylation-dead mimicking alanine residue nor deletion of prkC or prpC altered the ability of B. subtilis to grow under gluconeogenic conditions. However, we observed that a prpC mutant and a yvcK mutant were more sensitive to bacitracin compared with the WT strain. In addition, the bacitracin sensitivity of strains in which YvcK Thr-304 was replaced with either an alanine or a glutamic acid residue was also affected. We also analyzed rescue of the mreB mutant strain by overproduction of YvcK in which the phosphorylation site was substituted. We show that YvcK T304A overproduction did not rescue the mreB mutant aberrant morphology due to PBP1 mislocalization. The same observation was made in an mreB prkC double mutant overproducing YvcK. Altogether, these data show that YvcK may have two distinct functions: 1) in carbon source utilization independent of its phosphorylation level and 2) in cell wall biosynthesis and morphogenesis through its phosphorylation state.
Collapse
Affiliation(s)
- Elodie Foulquier
- From the Laboratoire de Chimie Bactérienne, UMR 7283, Institut de Microbiologie de la Méditerranée, CNRS, Aix-Marseille Université, 13009 Marseille and
| | - Frédérique Pompeo
- From the Laboratoire de Chimie Bactérienne, UMR 7283, Institut de Microbiologie de la Méditerranée, CNRS, Aix-Marseille Université, 13009 Marseille and
| | - Céline Freton
- From the Laboratoire de Chimie Bactérienne, UMR 7283, Institut de Microbiologie de la Méditerranée, CNRS, Aix-Marseille Université, 13009 Marseille and the Bases Moléculaires et Structurales des Systèmes Infectieux, UMR 5086, CNRS, Université de Lyon, 69367 Lyon Cedex 07, France
| | - Baptiste Cordier
- From the Laboratoire de Chimie Bactérienne, UMR 7283, Institut de Microbiologie de la Méditerranée, CNRS, Aix-Marseille Université, 13009 Marseille and
| | - Christophe Grangeasse
- the Bases Moléculaires et Structurales des Systèmes Infectieux, UMR 5086, CNRS, Université de Lyon, 69367 Lyon Cedex 07, France
| | - Anne Galinier
- From the Laboratoire de Chimie Bactérienne, UMR 7283, Institut de Microbiologie de la Méditerranée, CNRS, Aix-Marseille Université, 13009 Marseille and
| |
Collapse
|
35
|
Abstract
Mycobacterium tuberculosis, which is the aetiological agent of tuberculosis, owes much of its success as a pathogen to its unique cell wall and unusual mechanism of growth, which facilitate its adaptation to the human host and could have a role in clinical latency. Asymmetric growth and division increase population heterogeneity, which may promote antibiotic tolerance and the fitness of single cells. In this Review, we describe the unusual mechanisms of mycobacterial growth, cell wall biogenesis and division, and discuss how these processes might affect the survival of M. tuberculosis in vivo and contribute to the persistence of infection.
Collapse
|
36
|
Mycobacterium tuberculosis proteins involved in mycolic acid synthesis and transport localize dynamically to the old growing pole and septum. PLoS One 2014; 9:e97148. [PMID: 24817274 PMCID: PMC4016276 DOI: 10.1371/journal.pone.0097148] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Accepted: 04/15/2014] [Indexed: 11/19/2022] Open
Abstract
Understanding the mechanism that controls space-time coordination of elongation and division of Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis (TB), is critical for fighting the tubercle bacillus. Most of the numerous enzymes involved in the synthesis of Mycolic acid - Arabinogalactan-Peptidoglycan complex (MAPc) in the cell wall are essential in vivo. Using a dynamic approach, we localized Mtb enzymes belonging to the fatty acid synthase-II (FAS-II) complexes and involved in mycolic acid (MA) biosynthesis in a mycobacterial model of Mtb: M. smegmatis. Results also showed that the MA transporter MmpL3 was present in the mycobacterial envelope and was specifically and dynamically accumulated at the poles and septa during bacterial growth. This localization was due to its C-terminal domain. Moreover, the FAS-II enzymes were co-localized at the poles and septum with Wag31, the protein responsible for the polar localization of mycobacterial peptidoglycan biosynthesis. The dynamic localization of FAS-II and of the MA transporter with Wag31, at the old-growing poles and at the septum suggests that the main components of the mycomembrane may potentially be synthesized at these precise foci. This finding highlights a major difference between mycobacteria and other rod-shaped bacteria studied to date. Based on the already known polar activities of envelope biosynthesis in mycobacteria, we propose the existence of complex polar machinery devoted to the biogenesis of the entire envelope. As a result, the mycobacterial pole would represent the Achilles' heel of the bacillus at all its growing stages.
Collapse
|
37
|
Vilchèze C, Molle V, Carrère-Kremer S, Leiba J, Mourey L, Shenai S, Baronian G, Tufariello J, Hartman T, Veyron-Churlet R, Trivelli X, Tiwari S, Weinrick B, Alland D, Guérardel Y, Jacobs WR, Kremer L. Phosphorylation of KasB regulates virulence and acid-fastness in Mycobacterium tuberculosis. PLoS Pathog 2014; 10:e1004115. [PMID: 24809459 PMCID: PMC4014462 DOI: 10.1371/journal.ppat.1004115] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Accepted: 03/28/2014] [Indexed: 11/18/2022] Open
Abstract
Mycobacterium tuberculosis bacilli display two signature features: acid-fast staining and the capacity to induce long-term latent infections in humans. However, the mechanisms governing these two important processes remain largely unknown. Ser/Thr phosphorylation has recently emerged as an important regulatory mechanism allowing mycobacteria to adapt their cell wall structure/composition in response to their environment. Herein, we evaluated whether phosphorylation of KasB, a crucial mycolic acid biosynthetic enzyme, could modulate acid-fast staining and virulence. Tandem mass spectrometry and site-directed mutagenesis revealed that phosphorylation of KasB occurred at Thr334 and Thr336 both in vitro and in mycobacteria. Isogenic strains of M. tuberculosis with either a deletion of the kasB gene or a kasB_T334D/T336D allele, mimicking constitutive phosphorylation of KasB, were constructed by specialized linkage transduction. Biochemical and structural analyses comparing these mutants to the parental strain revealed that both mutant strains had mycolic acids that were shortened by 4–6 carbon atoms and lacked trans-cyclopropanation. Together, these results suggested that in M. tuberculosis, phosphorylation profoundly decreases the condensing activity of KasB. Structural/modeling analyses reveal that Thr334 and Thr336 are located in the vicinity of the catalytic triad, which indicates that phosphorylation of these amino acids would result in loss of enzyme activity. Importantly, the kasB_T334D/T336D phosphomimetic and deletion alleles, in contrast to the kasB_T334A/T336A phosphoablative allele, completely lost acid-fast staining. Moreover, assessing the virulence of these strains indicated that the KasB phosphomimetic mutant was attenuated in both immunodeficient and immunocompetent mice following aerosol infection. This attenuation was characterized by the absence of lung pathology. Overall, these results highlight for the first time the role of Ser/Thr kinase-dependent KasB phosphorylation in regulating the later stages of mycolic acid elongation, with important consequences in terms of acid-fast staining and pathogenicity. Acid-fast staining has been used since 1882 as the hallmark diagnostic test for detecting Mycobacterium tuberculosis, the causative agent of tuberculosis. It has been attributed to the presence of a waxy cell envelope, and primarily to its key components, mycolic acids. Here, we report a new mechanism of regulation in which phosphorylation of KasB, involved in the completion of full-length mycolic acids, leads to shortened mycolic acids and loss of acid-fast staining. Moreover, a M. tuberculosis mutant strain mimicking constitutive phosphorylation of KasB is severely attenuated for growth in both immunocompetent and immunosuppressed mice and fails to cause mortality and pathophysiological symptoms. These results emphasize the critical role of kinase-dependent phosphorylation in the pathogenesis of M. tuberculosis by controlling the mycolic acid chain length. Our study demonstrates the importance of a regulatory mechanism governing acid-fastness and virulence of M. tuberculosis.
Collapse
Affiliation(s)
- Catherine Vilchèze
- Howard Hughes Medical Institute, Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York, New York, United States of America
| | - Virginie Molle
- Laboratoire de Dynamique des Interactions Membranaires Normales et Pathologiques, Universités de Montpellier II et I, CNRS; UMR 5235, Montpellier, France
| | - Séverine Carrère-Kremer
- Laboratoire de Dynamique des Interactions Membranaires Normales et Pathologiques, Universités de Montpellier II et I, CNRS; UMR 5235, Montpellier, France
| | - Jade Leiba
- Laboratoire de Dynamique des Interactions Membranaires Normales et Pathologiques, Universités de Montpellier II et I, CNRS; UMR 5235, Montpellier, France
| | - Lionel Mourey
- Institut de Pharmacologie et de Biologie Structurale, CNRS, Toulouse, France; The Université de Toulouse, Université Paul Sabatier, IPBS, Toulouse, France
| | - Shubhada Shenai
- Division of Infectious Diseases, Department of Medicine, and the Ruy V. Lourenco Center for the Study of Emerging and Reemerging Pathogens, New Jersey Medical School, Rutgers Biomedical and Health Sciences, Newark, New Jersey, United States of America
| | - Grégory Baronian
- Laboratoire de Dynamique des Interactions Membranaires Normales et Pathologiques, Universités de Montpellier II et I, CNRS; UMR 5235, Montpellier, France
| | - Joann Tufariello
- Howard Hughes Medical Institute, Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York, New York, United States of America
| | - Travis Hartman
- Howard Hughes Medical Institute, Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York, New York, United States of America
| | - Romain Veyron-Churlet
- Laboratoire de Dynamique des Interactions Membranaires Normales et Pathologiques, Universités de Montpellier II et I, CNRS; UMR 5235, Montpellier, France
| | - Xavier Trivelli
- Université Lille 1, Unité de Glycobiologie Structurale et Fonctionnelle, UGSF, Villeneuve d'Ascq, France; CNRS, UMR 8576, Villeneuve d'Ascq, France
| | - Sangeeta Tiwari
- Howard Hughes Medical Institute, Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York, New York, United States of America
| | - Brian Weinrick
- Howard Hughes Medical Institute, Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York, New York, United States of America
| | - David Alland
- Division of Infectious Diseases, Department of Medicine, and the Ruy V. Lourenco Center for the Study of Emerging and Reemerging Pathogens, New Jersey Medical School, Rutgers Biomedical and Health Sciences, Newark, New Jersey, United States of America
| | - Yann Guérardel
- Université Lille 1, Unité de Glycobiologie Structurale et Fonctionnelle, UGSF, Villeneuve d'Ascq, France; CNRS, UMR 8576, Villeneuve d'Ascq, France
| | - William R Jacobs
- Howard Hughes Medical Institute, Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York, New York, United States of America
| | - Laurent Kremer
- Laboratoire de Dynamique des Interactions Membranaires Normales et Pathologiques, Universités de Montpellier II et I, CNRS; UMR 5235, Montpellier, France; INSERM, DIMNP, Montpellier, France
| |
Collapse
|
38
|
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.
Collapse
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
| |
Collapse
|
39
|
Canova MJ, Baronian G, Brelle S, Cohen-Gonsaud M, Bischoff M, Molle V. A novel mode of regulation of the Staphylococcus aureus Vancomycin-resistance-associated response regulator VraR mediated by Stk1 protein phosphorylation. Biochem Biophys Res Commun 2014; 447:165-71. [PMID: 24704444 DOI: 10.1016/j.bbrc.2014.03.128] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Accepted: 03/25/2014] [Indexed: 12/23/2022]
Abstract
The Staphylococcus aureus Vancomycin-resistance-associated response regulator VraR is known as an important response regulator, member of the VraTSR three-component signal transduction system that modulates the expression of the cell wall stress stimulon in response to a number of different cell wall active antibiotics. Given its crucial role in regulating gene expression in response to antibiotic challenges, VraR must be tightly regulated. We report here for the first time in S. aureus convergence of two major signal transduction systems, serine/threonine protein kinase and two (three)-component systems. We demonstrate that VraR can be phosphorylated by the staphylococcal Ser/Thr protein kinase Stk1 and that phosphorylation negatively affects its DNA-binding properties. Mass spectrometric analyses and site-directed mutagenesis identified Thr106, Thr119, Thr175 and Thr178 as phosphoacceptors. A S. aureus ΔvraR mutant expressing a VraR derivative that mimics constitutive phosphorylation, VraR_Asp, still exhibited markedly decreased antibiotic resistance against different cell wall active antibiotics, when compared to the wild-type, suggesting that VraR phosphorylation may represent a novel and presumably more general mechanism of regulation of the two (three)-component systems in staphylococci.
Collapse
Affiliation(s)
- Marc J Canova
- Laboratoire de Dynamique des Interactions Membranaires Normales et Pathologiques, Université de Montpellier II, CNRS UMR 5235, Place Eugène Bataillon, 34095 Montpellier Cedex 05, France
| | - Grégory Baronian
- Laboratoire de Dynamique des Interactions Membranaires Normales et Pathologiques, Université de Montpellier II, CNRS UMR 5235, Place Eugène Bataillon, 34095 Montpellier Cedex 05, France
| | - Solène Brelle
- Laboratoire de Dynamique des Interactions Membranaires Normales et Pathologiques, Université de Montpellier II, CNRS UMR 5235, Place Eugène Bataillon, 34095 Montpellier Cedex 05, France
| | - Martin Cohen-Gonsaud
- Centre de Biochimie Structurale, CNRS UMR 5048, INSERM U554, Université Montpellier I et II, Montpellier, France
| | - Markus Bischoff
- Institute of Medical Microbiology and Hygiene, University of Saarland Hospital, Homburg, Germany
| | - Virginie Molle
- Laboratoire de Dynamique des Interactions Membranaires Normales et Pathologiques, Université de Montpellier II, CNRS UMR 5235, Place Eugène Bataillon, 34095 Montpellier Cedex 05, France.
| |
Collapse
|
40
|
Leiba J, Syson K, Baronian G, Zanella-Cléon I, Kalscheuer R, Kremer L, Bornemann S, Molle V. Mycobacterium tuberculosis maltosyltransferase GlgE, a genetically validated antituberculosis target, is negatively regulated by Ser/Thr phosphorylation. J Biol Chem 2013; 288:16546-16556. [PMID: 23609448 DOI: 10.1074/jbc.m112.398503] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
GlgE is a maltosyltransferase involved in the biosynthesis of α-glucans that has been genetically validated as a potential therapeutic target against Mycobacterium tuberculosis. Despite also making α-glucan, the GlgC/GlgA glycogen pathway is distinct and allosterically regulated. We have used a combination of genetics and biochemistry to establish how the GlgE pathway is regulated. M. tuberculosis GlgE was phosphorylated specifically by the Ser/Thr protein kinase PknB in vitro on one serine and six threonine residues. Furthermore, GlgE was phosphorylated in vivo when expressed in Mycobacterium bovis bacillus Calmette-Guérin (BCG) but not when all seven phosphorylation sites were replaced by Ala residues. The GlgE orthologues from Mycobacterium smegmatis and Streptomyces coelicolor were phosphorylated by the corresponding PknB orthologues in vitro, implying that the phosphorylation of GlgE is widespread among actinomycetes. PknB-dependent phosphorylation of GlgE led to a 2 orders of magnitude reduction in catalytic efficiency in vitro. The activities of phosphoablative and phosphomimetic GlgE derivatives, where each phosphorylation site was substituted with either Ala or Asp residues, respectively, correlated with negative phosphoregulation. Complementation studies of a M. smegmatis glgE mutant strain with these GlgE derivatives, together with both classical and chemical forward genetics, were consistent with flux through the GlgE pathway being correlated with GlgE activity. We conclude that the GlgE pathway appears to be negatively regulated in actinomycetes through the phosphorylation of GlgE by PknB, a mechanism distinct from that known in the classical glycogen pathway. Thus, these findings open new opportunities to target the GlgE pathway therapeutically.
Collapse
Affiliation(s)
- Jade Leiba
- 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
| | - Karl Syson
- Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom
| | - Grégory Baronian
- 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
| | - Isabelle Zanella-Cléon
- Institut de Biologie et Chimie des Protéines (IBCP UMR 5086), CNRS, Université Lyon1, IFR128 BioSciences, Lyon Gerland, 7 passage du Vercors, 69367 Lyon Cedex 07, France
| | - Rainer Kalscheuer
- Institute for Medical Microbiology and Hospital Hygiene, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Laurent Kremer
- 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; INSERM, Place Eugène Bataillon, 34095 Montpellier Cedex 05, France
| | - Stephen Bornemann
- Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom.
| | - Virginie Molle
- 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.
| |
Collapse
|
41
|
Kinjo T, Koseki Y, Kobayashi M, Yamada A, Morita K, Yamaguchi K, Tsurusawa R, Gulten G, Komatsu H, Sakamoto H, Sacchettini JC, Kitamura M, Aoki S. Identification of Compounds with Potential Antibacterial Activity against Mycobacterium through Structure-Based Drug Screening. J Chem Inf Model 2013; 53:1200-12. [DOI: 10.1021/ci300571n] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Tomohiro Kinjo
- Department
of Bioscience and Bioinformatics, Graduate School of
Computer Science and Systems Engineering, Kyushu Institute of Technology, 680-4 Kawazu, Iizuka-shi, Fukuoka 820-8502,
Japan
| | - Yuji Koseki
- Department
of Bioscience and Bioinformatics, Graduate School of
Computer Science and Systems Engineering, Kyushu Institute of Technology, 680-4 Kawazu, Iizuka-shi, Fukuoka 820-8502,
Japan
| | - Maiko Kobayashi
- Department
of Bioscience and Bioinformatics, Graduate School of
Computer Science and Systems Engineering, Kyushu Institute of Technology, 680-4 Kawazu, Iizuka-shi, Fukuoka 820-8502,
Japan
| | - Atsumi Yamada
- Department
of Bioscience and Bioinformatics, Graduate School of
Computer Science and Systems Engineering, Kyushu Institute of Technology, 680-4 Kawazu, Iizuka-shi, Fukuoka 820-8502,
Japan
| | - Koji Morita
- Department
of Bioscience and Bioinformatics, Graduate School of
Computer Science and Systems Engineering, Kyushu Institute of Technology, 680-4 Kawazu, Iizuka-shi, Fukuoka 820-8502,
Japan
| | - Kento Yamaguchi
- Department
of Bioscience and Bioinformatics, Graduate School of
Computer Science and Systems Engineering, Kyushu Institute of Technology, 680-4 Kawazu, Iizuka-shi, Fukuoka 820-8502,
Japan
| | - Ryoya Tsurusawa
- Department
of Bioscience and Bioinformatics, Graduate School of
Computer Science and Systems Engineering, Kyushu Institute of Technology, 680-4 Kawazu, Iizuka-shi, Fukuoka 820-8502,
Japan
| | - Gulcin Gulten
- Department of Biochemistry & Biophysics, Texas A&M University, College Station, Texas 77843-2128, United States
| | - Hideyuki Komatsu
- Department
of Bioscience and Bioinformatics, Graduate School of
Computer Science and Systems Engineering, Kyushu Institute of Technology, 680-4 Kawazu, Iizuka-shi, Fukuoka 820-8502,
Japan
| | - Hiroshi Sakamoto
- Department
of Bioscience and Bioinformatics, Graduate School of
Computer Science and Systems Engineering, Kyushu Institute of Technology, 680-4 Kawazu, Iizuka-shi, Fukuoka 820-8502,
Japan
| | - James C. Sacchettini
- Department of Biochemistry & Biophysics, Texas A&M University, College Station, Texas 77843-2128, United States
| | - Mitsuru Kitamura
- Department
of Applied Chemistry, Kyushu Institute of Technology, 1-1 Sensui-cho, Tobata, Kitakyushu 804-8550,
Japan
| | - Shunsuke Aoki
- Department
of Bioscience and Bioinformatics, Graduate School of
Computer Science and Systems Engineering, Kyushu Institute of Technology, 680-4 Kawazu, Iizuka-shi, Fukuoka 820-8502,
Japan
- Biomedical Informatics
Research
and Development Center (BMIRC), Kyushu Institute of Technology, 680-4 Kawazu, Iizuka-shi, Fukuoka 820-8502, Japan
| |
Collapse
|
42
|
Corrales RM, Leiba J, Cohen-Gonsaud M, Molle V, Kremer L. Mycobacterium tuberculosis S-adenosyl-l-homocysteine hydrolase is negatively regulated by Ser/Thr phosphorylation. Biochem Biophys Res Commun 2012. [PMID: 23178568 DOI: 10.1016/j.bbrc.2012.11.038] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
S-Adenosylhomocysteine hydrolase (SahH) is known as an ubiquitous player in methylation-based process that maintains the intracellular S-adenosylhomocysteine (SAH) and S-adenosylmethionine (SAM) equilibrium. Given its crucial role in central metabolism in both eukaryotes and prokaryotes, it is assumed that SahH must be regulated, albeit little is known regarding molecular mechanisms governing its activity. We report here that SahH from Mycobacterium tuberculosis can be phosphorylated by mycobacterial Ser/Thr protein kinases and that phosphorylation negatively affects its enzymatic activity. Mass spectrometric analyses and site-directed mutagenesis identified Thr2 and Thr221 as the two phosphoacceptors. SahH_T2D, SahH_T221D and SahH_T2D/T221D, designed to mimic constitutive phosphorylation, exhibited markedly decreased activity compared to the wild-type enzyme. Both residues are fully conserved in other mycobacterial SahH orthologues, suggesting that SahH phosphorylation on Thr2 and Thr221 may represent a novel and presumably more general mechanism of regulation of the SAH/SAM balance in mycobacteria.
Collapse
Affiliation(s)
- Rosa Milagros Corrales
- Laboratoire de Dynamique des Interactions Membranaires Normales et Pathologiques, Université Montpellier 2, CNRS, UMR 5235, case 107, Place Eugène Bataillon, 34095 Montpellier Cedex 05, France
| | | | | | | | | |
Collapse
|
43
|
Leiba J, Hartmann T, Cluzel ME, Cohen-Gonsaud M, Delolme F, Bischoff M, Molle V. A novel mode of regulation of the Staphylococcus aureus catabolite control protein A (CcpA) mediated by Stk1 protein phosphorylation. J Biol Chem 2012; 287:43607-19. [PMID: 23132867 DOI: 10.1074/jbc.m112.418913] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The Staphylococcus aureus serine/threonine protein kinase Stk1 (also known as PknB) affects different key pathways such as cell wall metabolism, antibiotic susceptibility, and regulation of virulence. Here we report that the catabolite control protein A (CcpA), a highly conserved regulator of carbon catabolite repression and virulence in a number of gram-positive pathogens, was efficiently phosphorylated in vitro and in vivo by Stk1 in S. aureus, whereas the CcpA homologues of Bacillus subtilis and Bacillus anthracis were not affected by the Stk1 orthologue PrkC. Mass spectrometry and mutational analyses identified Thr-18 and Thr-33 as the phosphoacceptors; both are located in the DNA binding domain of this protein. Electrophoretic mobility shift assays demonstrated that the CcpA DNA binding activity was completely abrogated for the phosphorylated CcpA. The physiological relevance of CcpA phosphorylation was assessed by generating CcpA phosphoablative (T18A/T33A) or phosphomimetic (T18D/T33D) mutants. In contrast to the wild-type and phosphoablative ccpA alleles, introduction of the phosphomimetic ccpA allele in a ΔccpA mutant failed to restore the parental biofilm formation profile and the transcription of citZ and hla to levels seen with the wild type. The strong up regulation of ccpA transcripts and CcpA level in the ccpA mutant trans-complemented with the phosphomimetic CcpA variant suggest furthermore that CcpA acts as a negative regulator of its own expression. Together, these findings demonstrate that Stk1-driven phosphorylation of CcpA inhibits its DNA binding activity toward its regulon in S. aureus, representing a novel regulatory mechanism of CcpA activity in addition to the well known regulation via HprKP/Hpr in this clinically important pathogen.
Collapse
Affiliation(s)
- Jade Leiba
- Laboratoire de Dynamique des Interactions Membranaires Normales et Pathologiques, Université de Montpellier II, CNRS UMR 5235, Place Eugène Bataillon, 34095 Montpellier Cedex 05, France
| | | | | | | | | | | | | |
Collapse
|
44
|
Hartkoorn RC, Sala C, Neres J, Pojer F, Magnet S, Mukherjee R, Uplekar S, Boy-Röttger S, Altmann KH, Cole ST. Towards a new tuberculosis drug: pyridomycin - nature's isoniazid. EMBO Mol Med 2012; 4:1032-42. [PMID: 22987724 PMCID: PMC3491834 DOI: 10.1002/emmm.201201689] [Citation(s) in RCA: 133] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2012] [Revised: 07/26/2012] [Accepted: 07/30/2012] [Indexed: 01/27/2023] Open
Abstract
Tuberculosis, a global threat to public health, is becoming untreatable due to widespread drug resistance to frontline drugs such as the InhA-inhibitor isoniazid. Historically, by inhibiting highly vulnerable targets, natural products have been an important source of antibiotics including potent anti-tuberculosis agents. Here, we describe pyridomycin, a compound produced by Dactylosporangium fulvum with specific cidal activity against mycobacteria. By selecting pyridomycin-resistant mutants of Mycobacterium tuberculosis, whole-genome sequencing and genetic validation, we identified the NADH-dependent enoyl- (Acyl-Carrier-Protein) reductase InhA as the principal target and demonstrate that pyridomycin inhibits mycolic acid synthesis in M. tuberculosis. Furthermore, biochemical and structural studies show that pyridomycin inhibits InhA directly as a competitive inhibitor of the NADH-binding site, thereby identifying a new, druggable pocket in InhA. Importantly, the most frequently encountered isoniazid-resistant clinical isolates remain fully susceptible to pyridomycin, thus opening new avenues for drug development.
Collapse
Affiliation(s)
- Ruben C Hartkoorn
- Ecole Polytechnique Fédérale de Lausanne, Global Health Institute, Lausanne, Switzerland
| | | | | | | | | | | | | | | | | | | |
Collapse
|
45
|
Corrales RM, Molle V, Leiba J, Mourey L, de Chastellier C, Kremer L. Phosphorylation of mycobacterial PcaA inhibits mycolic acid cyclopropanation: consequences for intracellular survival and for phagosome maturation block. J Biol Chem 2012; 287:26187-99. [PMID: 22621931 DOI: 10.1074/jbc.m112.373209] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Pathogenic mycobacteria survive within macrophages by residing in phagosomes, which they prevent from maturing and fusing with lysosomes. Although several bacterial components were seen to modulate phagosome processing, the molecular regulatory mechanisms taking part in this process remain elusive. We investigated whether the phagosome maturation block (PMB) could be modulated by signaling through Ser/Thr phosphorylation. Here, we demonstrated that mycolic acid cyclopropane synthase PcaA, but not MmaA2, was phosphorylated by mycobacterial Ser/Thr kinases at Thr-168 and Thr-183 both in vitro and in mycobacteria. Phosphorylation of PcaA was associated with a significant decrease in the methyltransferase activity, in agreement with the strategic structural localization of these two phosphoacceptors. Using a BCG ΔpcaA mutant, we showed that PcaA was required for intracellular survival and prevention of phagosome maturation in human monocyte-derived macrophages. The physiological relevance of PcaA phosphorylation was further assessed by generating PcaA phosphoablative (T168A/T183A) or phosphomimetic (T168D/T183D) mutants. In contrast to the wild-type and phosphoablative pcaA alleles, introduction of the phosphomimetic pcaA allele in the ΔpcaA mutant failed to restore the parental mycolic acid profile and cording morphotype. Importantly, the PcaA phosphomimetic strain, as the ΔpcaA mutant, exhibited reduced survival in human macrophages and was unable to prevent phagosome maturation. Our results add new insight into the importance of mycolic acid cyclopropane rings in the PMB and provide the first evidence of a Ser/Thr kinase-dependent mechanism for modulating mycolic acid composition and PMB.
Collapse
Affiliation(s)
- Rosa Milagros Corrales
- 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
| | | | | | | | | | | |
Collapse
|
46
|
Warrier T, Tropis M, Werngren J, Diehl A, Gengenbacher M, Schlegel B, Schade M, Oschkinat H, Daffe M, Hoffner S, Eddine AN, Kaufmann SHE. Antigen 85C inhibition restricts Mycobacterium tuberculosis growth through disruption of cord factor biosynthesis. Antimicrob Agents Chemother 2012; 56:1735-43. [PMID: 22290959 PMCID: PMC3318338 DOI: 10.1128/aac.05742-11] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2011] [Accepted: 01/04/2012] [Indexed: 11/20/2022] Open
Abstract
The antigen 85 (Ag85) protein family, consisting of Ag85A, -B, and -C, is vital for Mycobacterium tuberculosis due to its role in cell envelope biogenesis. The mycoloyl transferase activity of these proteins generates trehalose dimycolate (TDM), an envelope lipid essential for M. tuberculosis virulence, and cell wall arabinogalactan-linked mycolic acids. Inhibition of these enzymes through substrate analogs hinders growth of mycobacteria, but a link to mycolic acid synthesis has not been established. In this study, we characterized a novel inhibitor of Ag85C, 2-amino-6-propyl-4,5,6,7-tetrahydro-1-benzothiophene-3-carbonitrile (I3-AG85). I3-AG85 was isolated from a panel of four inhibitors that exhibited structure- and dose-dependent inhibition of M. tuberculosis division in broth culture. I3-AG85 also inhibited M. tuberculosis survival in infected primary macrophages. Importantly, it displayed an identical MIC against the drug-susceptible H37Rv reference strain and a panel of extensively drug-resistant/multidrug-resistant M. tuberculosis strains. Nuclear magnetic resonance analysis indicated binding of I3-AG85 to Ag85C, similar to its binding to the artificial substrate octylthioglucoside. Quantification of mycolic acid-linked lipids of the M. tuberculosis envelope showed a specific blockade of TDM synthesis. This was accompanied by accumulation of trehalose monomycolate, while the overall mycolic acid abundance remained unchanged. Inhibition of Ag85C activity also disrupted the integrity of the M. tuberculosis envelope. I3-AG85 inhibited the division of and reduced TDM synthesis in an M. tuberculosis strain deficient in Ag85C. Our results indicate that Ag85 proteins are promising targets for novel antimycobacterial drug design.
Collapse
Affiliation(s)
- Thulasi Warrier
- Department of Immunology, Max Planck Institute for Infection Biology, Berlin, Germany
| | - Marielle Tropis
- Institute of Pharmacology and Structural Biology, CNRS, and University of Toulouse (Toulouse III), Toulouse, France
| | - Jim Werngren
- Swedish Institute for Communicable Disease Control, Solna, Sweden
| | - Anne Diehl
- NMR Group, Leibniz Institut für Molekulare Pharmakologie, Berlin, Germany
| | - Martin Gengenbacher
- Department of Immunology, Max Planck Institute for Infection Biology, Berlin, Germany
| | - Brigitte Schlegel
- NMR Group, Leibniz Institut für Molekulare Pharmakologie, Berlin, Germany
| | - Markus Schade
- AstraZeneca Ltd., DECS Biophysics, Macclesfield, United Kingdom
| | - Hartmut Oschkinat
- NMR Group, Leibniz Institut für Molekulare Pharmakologie, Berlin, Germany
| | - Mamadou Daffe
- Institute of Pharmacology and Structural Biology, CNRS, and University of Toulouse (Toulouse III), Toulouse, France
| | - Sven Hoffner
- Swedish Institute for Communicable Disease Control, Solna, Sweden
| | - Ali Nasser Eddine
- Department of Immunology, Max Planck Institute for Infection Biology, Berlin, Germany
| | - Stefan H. E. Kaufmann
- Department of Immunology, Max Planck Institute for Infection Biology, Berlin, Germany
| |
Collapse
|
47
|
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.
Collapse
Affiliation(s)
- Christine L Gee
- Department of Molecular and Cell Biology, QB3 Institute, University of California, Berkeley, Berkeley, CA 94720-3220, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
48
|
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.
Collapse
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.
| | | |
Collapse
|
49
|
AccD6, a key carboxyltransferase essential for mycolic acid synthesis in Mycobacterium tuberculosis, is dispensable in a nonpathogenic strain. J Bacteriol 2011; 193:6960-72. [PMID: 21984794 DOI: 10.1128/jb.05638-11] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Acetyl coenzyme A carboxylase (ACC) is a key enzyme providing a substrate for mycolic acid biosynthesis. Although in vitro studies have demonstrated that the protein encoded by accD6 (Rv2247) may be a functional carboxyltransferase subunit of ACC in Mycobacterium tuberculosis, the in vivo function and regulation of accD6 in slow- and fast-growing mycobacteria remain elusive. Here, directed mutagenesis demonstrated that although accD6 is essential for M. tuberculosis, it can be deleted in Mycobacterium smegmatis without affecting its cell envelope integrity. Moreover, we showed that although it is part of the type II fatty acid synthase operon, the accD6 gene of M. tuberculosis, but not that of M. smegmatis, possesses its own additional promoter (P(acc)). The expression level of accD6(Mtb) placed only under the control of P(acc) is 10-fold lower than that in wild-type M. tuberculosis but is sufficient to sustain cell viability. Importantly, this limited expression level affects growth, mycolic acid content, and cell morphology. These results provide the first in vivo evidence for AccD6 as a key player in the mycolate biosynthesis of M. tuberculosis, implicating AccD6 as the essential ACC subunit in pathogenic mycobacteria and an excellent target for new antitubercular compounds. Our findings also highlight important differences in the mechanism of acetyl carboxylation between pathogenic and nonpathogenic mycobacterial species.
Collapse
|
50
|
Slama N, Leiba J, Eynard N, Daffé M, Kremer L, Quémard A, Molle V. Negative regulation by Ser/Thr phosphorylation of HadAB and HadBC dehydratases from Mycobacterium tuberculosis type II fatty acid synthase system. Biochem Biophys Res Commun 2011; 412:401-6. [PMID: 21819969 DOI: 10.1016/j.bbrc.2011.07.051] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2011] [Accepted: 07/13/2011] [Indexed: 11/30/2022]
Abstract
The type II fatty acid synthase system of mycobacteria is involved in the biosynthesis of major and essential lipids, mycolic acids, key-factors of Mycobacterium tuberculosis pathogenicity. One reason of the remarkable survival ability of M. tuberculosis in infected hosts is partly related to the presence of cell wall-associated mycolic acids. Despite their importance, the mechanisms that modulate synthesis of these lipids in response to environmental changes are unknown. We demonstrate here that HadAB and HadBC dehydratases of this system are phosphorylated by Ser/Thr protein kinases, which negatively affects their enzymatic activity. The phosphorylation of HadAB/BC is growth phase-dependent, suggesting that it represents a mechanism by which mycobacteria might tightly control mycolic acid biosynthesis under non-replicating condition.
Collapse
Affiliation(s)
- Nawel Slama
- CNRS, IPBS (Institut de Pharmacologie et de Biologie Structurale), Département Mécanismes Moléculaires des Infections Mycobactériennes, 205 Route de Narbonne, F-31077 Toulouse, France
| | | | | | | | | | | | | |
Collapse
|