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Fu X, Wan X, Memon AA, Fan XY, Sun Q, Chen H, Yao Y, Deng Z, Ma J, Ma W. Regulatory role of Mycobacterium tuberculosis MtrA on dormancy/resuscitation revealed by a novel target gene-mining strategy. Front Microbiol 2024; 15:1415554. [PMID: 38952446 PMCID: PMC11215152 DOI: 10.3389/fmicb.2024.1415554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2024] [Accepted: 05/28/2024] [Indexed: 07/03/2024] Open
Abstract
Introduction The unique dormancy of Mycobacterium tuberculosis plays a significant role in the major clinical treatment challenge of tuberculosis, such as its long treatment cycle, antibiotic resistance, immune escape, and high latent infection rate. Methods To determine the function of MtrA, the only essential response regulator, one strategy was developed to establish its regulatory network according to high-quality genome-wide binding sites. Results and discussion The complex modulation mechanisms were implied by the strong bias distribution of MtrA binding sites in the noncoding regions, and 32.7% of the binding sites were located inside the target genes. The functions of 288 potential MtrA target genes predicted according to 294 confirmed binding sites were highly diverse, and DNA replication and damage repair, lipid metabolism, cell wall component biosynthesis, cell wall assembly, and cell division were the predominant pathways. Among the 53 pathways shared between dormancy/resuscitation and persistence, which accounted for 81.5% and 93.0% of the total number of pathways, respectively, MtrA regulatory genes were identified not only in 73.6% of their mutual pathways, but also in 75.4% of the pathways related to dormancy/resuscitation and persistence respectively. These results suggested the pivotal roles of MtrA in regulating dormancy/resuscitation and the apparent relationship between dormancy/resuscitation and persistence. Furthermore, the finding that 32.6% of the MtrA regulons were essential in vivo and/or in vitro for M. tuberculosis provided new insight into its indispensability. The findings mentioned above indicated that MtrA is a novel promising therapeutic target for tuberculosis treatment since the crucial function of MtrA may be a point of weakness for M. tuberculosis.
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Affiliation(s)
- Xiang Fu
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Xiaoyu Wan
- Department of Respiratory and Critical Care Medicine, Shanghai Pulmonary Hospital, Shanghai, China
| | - Aadil Ahmed Memon
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Xiao-Yong Fan
- Shanghai Public Health Clinical Center, Shanghai Institute of Infectious Diseases and Biosecurity, Fudan University, Shanghai, China
| | - Qiuhong Sun
- Department of Respiratory and Critical Care Medicine, Shanghai Pulmonary Hospital, Shanghai, China
| | - Haifeng Chen
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Yufeng Yao
- Department of Laboratory Medicine, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, China
| | - Zixin Deng
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Jian Ma
- Department of Respiratory and Critical Care Medicine, Shanghai Pulmonary Hospital, Shanghai, China
| | - Wei Ma
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
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Bagchi S, Sharma AK, Ghosh A, Saha S, Basu J, Kundu M. RegX3-dependent transcriptional activation of kdpDE and repression of rv0500A are linked to potassium homeostasis in Mycobacterium tuberculosis. FEBS J 2024. [PMID: 38414198 DOI: 10.1111/febs.17100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Revised: 01/18/2024] [Accepted: 02/12/2024] [Indexed: 02/29/2024]
Abstract
Ionic homeostasis is essential for the survival and replication of Mycobacterium tuberculosis within its host. Low potassium ion concentrations trigger a transition of M. tuberculosis into dormancy. Our current knowledge of the transcriptional regulation mechanisms governing genes involved in potassium homeostasis remains limited. Potassium transport is regulated by the constitutive Trk system and the inducible Kdp system in M. tuberculosis. The two-component system KdpDE (also known as KdpD/KdpE) activates expression of the kdpFABC operon, encoding the four protein subunits of the Kdp potassium uptake system (KdpFABC). We show that, under potassium deficiency, expression of the two-component system senX3/regX3 is upregulated, and bacterial survival is compromised in a regX3-inactivated mutant, ΔregX3. Electrophoretic mobility shift assays (EMSAs), promoter reporter assays and chromatin immunoprecipitation (ChIP) show that RegX3 binds to the kdpDE promoter and activates it under potassium deficiency, whereas RegX3 (K204A), a DNA binding-deficient mutant, fails to bind to the promoter. Mutation of the RegX3 binding motifs on the kdpDE promoter abrogates RegX3 binding. In addition, EMSAs and ChIP assays show that RegX3 represses Rv0500A, a repressor of kdpFABC, by binding to consensus RegX3 binding motifs on the rv0500A promoter. Our findings provide important insight into two converging pathways regulated by RegX3; one in which it activates an activator of kdpFABC, and the other in which it represses a repressor of kdpFABC, during potassium insufficiency. This culminates in increased expression of the potassium uptake system encoded by kdpFABC, enabling bacterial survival. These results further expand the growing transcriptional network in which RegX3 serves as a central node to enable bacterial survival under stress.
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Affiliation(s)
- Shreya Bagchi
- Department of Chemical Sciences, Bose Institute, Kolkata, India
| | | | - Abhirupa Ghosh
- Department of Biological Sciences, Bose Institute, Kolkata, India
| | - Sudipto Saha
- Department of Biological Sciences, Bose Institute, Kolkata, India
| | - Joyoti Basu
- Department of Chemical Sciences, Bose Institute, Kolkata, India
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Memon AA, Fu X, Fan XY, Xu L, Xiao J, Rahman MU, Yang X, Yao YF, Deng Z, Ma W. Substrate DNA Promoting Binding of Mycobacterium tuberculosis MtrA by Facilitating Dimerization and Interpretation of Affinity by Minor Groove Width. Microorganisms 2023; 11:2505. [PMID: 37894163 PMCID: PMC10609481 DOI: 10.3390/microorganisms11102505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 09/21/2023] [Accepted: 09/28/2023] [Indexed: 10/29/2023] Open
Abstract
In order to deepen the understanding of the role and regulation mechanisms of prokaryotic global transcription regulators in complex processes, including virulence, the associations between the affinity and binding sequences of Mycobacterium tuberculosis MtrA have been explored extensively. Analysis of MtrA 294 diversified 26 bp binding sequences revealed that the sequence similarity of fragments was not simply associated with affinity. The unique variation patterns of GC content and periodical and sequential fluctuation of affinity contribution curves were observed along the sequence in this study. Furthermore, docking analysis demonstrated that the structure of the dimer MtrA-DNA (high affinity) was generally consistent with other OmpR family members, while Arg 219 and Gly 220 of the wing domain interacted with the minor groove. The results of the binding box replacement experiment proved that box 2 was essential for binding, which implied the differential roles of the two boxes in the binding process. Furthermore, the results of the substitution of the nucleotide at the 20th and/or 21st positions indicated that the affinity was negatively associated with the value of minor groove width precisely at the 21st position. The dimerization of the unphosphorylated MtrA facilitated by a low-affinity DNA fragment was observed for the first time. However, the proportion of the dimer was associated with the affinity of substrate DNA, which further suggested that the affinity was actually one characteristic of the stability of dimers. Based on the finding of 17 inter-molecule hydrogen bonds identified in the interface of the MtrA dimer, including 8 symmetric complementary ones in the conserved α4-β5-α5 face, we propose that hydrogen bonds should be considered just as important as salt bridges and the hydrophobic patch in the dimerization. Our comprehensive study on a large number of binding fragments with quantitative affinity values provided new insight into the molecular mechanism of dimerization, binding specificity and affinity determination of MtrA and clues for solving the puzzle of how global transcription factors regulate a large quantity of target genes.
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Affiliation(s)
- Aadil Ahmed Memon
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Xiang Fu
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Xiao-Yong Fan
- Shanghai Institute of Infectious Diseases and Biosecurity, Shanghai Public Health Clinical Center, Fudan University, Shanghai 200032, China
| | - Lingyun Xu
- Shanghai Huaxin Biotechnology Co., Ltd., Room 604, Building 1, Tongji Chuangyuan, No. 99 South Changjiang Road, Baoshan District, Shanghai 200441, China
| | - Jihua Xiao
- Shanghai Huaxin Biotechnology Co., Ltd., Room 604, Building 1, Tongji Chuangyuan, No. 99 South Changjiang Road, Baoshan District, Shanghai 200441, China
| | - Mueed Ur Rahman
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Xiaoqi Yang
- Shanghai Huaxin Biotechnology Co., Ltd., Room 604, Building 1, Tongji Chuangyuan, No. 99 South Changjiang Road, Baoshan District, Shanghai 200441, China
| | - Yu-Feng Yao
- Laboratory of Bacterial Pathogenesis, Institutes of Medical Sciences, School of Medicine, Shanghai Jiao Tong University, Shanghai 200025, China
| | - Zixin Deng
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Wei Ma
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
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Vatlin AA, Bekker OB, Shur KV, Ilyasov RA, Shatrov PA, Maslov DA, Danilenko VN. Kanamycin and Ofloxacin Activate the Intrinsic Resistance to Multiple Antibiotics in Mycobacterium smegmatis. BIOLOGY 2023; 12:biology12040506. [PMID: 37106707 PMCID: PMC10135989 DOI: 10.3390/biology12040506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 03/16/2023] [Accepted: 03/25/2023] [Indexed: 03/30/2023]
Abstract
Drug resistance (DR) in Mycobacterium tuberculosis is the main problem in fighting tuberculosis (TB). This pathogenic bacterium has several types of DR implementation: acquired and intrinsic DR. Recent studies have shown that exposure to various antibiotics activates multiple genes, including genes responsible for intrinsic DR. To date, there is evidence of the acquisition of resistance at concentrations well below the standard MICs. In this study, we aimed to investigate the mechanism of intrinsic drug cross-resistance induction by subinhibitory concentrations of antibiotics. We showed that pretreatment of M. smegmatis with low doses of antibiotics (kanamycin and ofloxacin) induced drug resistance. This effect may be caused by a change in the expression of transcriptional regulators of the mycobacterial resistome, in particular the main transcriptional regulator whiB7.
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Verma A, Ghoshal A, Dwivedi VP, Bhaskar A. Tuberculosis: The success tale of less explored dormant Mycobacterium tuberculosis. Front Cell Infect Microbiol 2022; 12:1079569. [PMID: 36619761 PMCID: PMC9813417 DOI: 10.3389/fcimb.2022.1079569] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Accepted: 12/06/2022] [Indexed: 12/24/2022] Open
Abstract
Mycobacterium tuberculosis (M.tb) is an intracellular pathogen that predominantly affects the alveolar macrophages in the respiratory tract. Upon infection, the activation of TLR2 and TLR4- mediated signaling pathways leads to lysosomal degradation of the bacteria. However, bacterium counteracts the host immune cells and utilizes them as a cellular niche for its survival. One distinctive mechanism of M.tb to limit the host stress responses such as hypoxia and nutrient starvation is induction of dormancy. As the environmental conditions become favorable, the bacteria resuscitate, resulting in a relapse of clinical symptoms. Different bacterial proteins play a critical role in maintaining the state of dormancy and resuscitation, namely, DevR (DosS), Hrp1, DATIN and RpfA-D, RipA, etc., respectively. Existing knowledge regarding the key proteins associated with dormancy and resuscitation can be employed to develop novel therapies. In this review we aim to highlight the current knowledge of bacterial progression from dormancy to resuscitation and the gaps in understanding the transition from dormant to active state. We have also focused on elucidating a few therapeutic strategies employed to prevent M.tb resuscitation.
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The Bacterial MtrAB Two-Component System Regulates the Cell Wall Homeostasis Responding to Environmental Alkaline Stress. Microbiol Spectr 2022; 10:e0231122. [PMID: 36073914 PMCID: PMC9602371 DOI: 10.1128/spectrum.02311-22] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Throughout the course of evolution, bacteria have developed signal transduction tools such as two-component systems (TCSs) to meet their demands to thrive even under the most challenging environmental conditions. One TCS called MtrAB is commonly found in Actinobacteria and is implicated in cell wall metabolism, osmoprotection, cell proliferation, antigen secretion, and biosynthesis of secondary metabolites. However, precisely how the MtrAB TCS regulates the bacterial responses to external environments remains unclear. Here, we report that the MtrAB TCS regulates the cell envelope response of alkali-tolerant bacterium Dietzia sp. strain DQ12-45-1b to extreme alkaline stimuli. We found that under alkaline conditions, an mtrAB mutant exhibited both reduced growth and abnormal morphology compared to the wild-type strain. Electrophoretic mobility shift assay analysis showed that MtrA binds the promoter of the mraZ gene critical for cell wall homeostasis, suggesting that MtrA directly controls transcription of this regulator. In conclusion, our findings demonstrate that MtrAB TCS is involved in controlling the bacterial response to alkaline stimuli by regulating the expression of the cell wall homeostasis regulator MraZ in Dietzia sp. DQ12-45-1b, providing novel details critical for a mechanistic understanding of how cell wall homeostasis is controlled. IMPORTANCE Microorganisms can be found in most extreme environments, and they have to adapt to a wide range of environmental stresses. The two-component systems (TCSs) found in bacteria detect environmental stimuli and regulate physiological pathways for survival. The MtrAB TCS conserved in Corynebacterineae is critical for maintaining the metabolism of the cell wall components that protects bacteria from diverse environmental stresses. However, how the MtrAB TCS regulates cell wall homeostasis and adaptation under stress conditions is unclear. Here, we report that the MtrAB TCS in Dietzia sp. DQ12-45-1b plays a critical role in alkaline resistance by modulating the cell wall homeostasis through the MtrAB-MraZ pathway. Thus, our work provides a novel regulatory pathway used by bacteria for adaptation and survival under extreme alkaline stresses.
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Mahatha AC, Banerjee SK, Ghosh A, Lata S, Saha S, Basu J, Kundu M. A systems approach to decipher a role of transcription factor RegX3 in the adaptation of Mycobacterium tuberculosis to hypoxic stress. MICROBIOLOGY (READING, ENGLAND) 2022; 168. [PMID: 35980355 DOI: 10.1099/mic.0.001229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Two-component systems (TCSs) are required for the ability of Mycobacterium tuberculosis to respond to stress. The paired TCS, SenX3-RegX3 is known to respond to phosphate starvation and acid stress. The other stress conditions under which RegX3 is required for M. tuberculosis to mount an appropriate response, remain incompletely understood. Here we have employed genome-wide microarray profiling to compare gene expression in a ΔregX3 mutant with the wild-type under phosphate stress, in order to gain information on the probable RegX3 regulon. We pulled out a set of 128 hypoxia-associated genes, which could potentially be regulated by RegX3, by overlapping the gene set downregulated at least twofold in ΔregX3 with the gene set reported in the literature to be associated with the response to hypoxia. We identified potential RegX3 binding inverted repeats at the loci of 41 of these genes, in silico. We also observed that ΔregX3 was attenuated in terms of its ability to withstand hypoxia, and this was reversed upon complementation with regX3, corroborating a role of RegX3 in the response of M. tuberculosis to hypoxia. We validated the binding of RegX3 at the upstream regions of a selected set of these genes. Electrophoretic mobility shift assays (EMSAs) confirmed that RegX3 binds to the upstream regions of the hypoxia-associated genes Rv3334, whiB7, Rv0195, Rv0196 and Rv1960c. Gene expression analyses showed that the expression of these genes is regulated by RegX3 under hypoxia. We also show that the expression of whiB7, Rv3334 and Rv0195 in macrophage-grown M. tuberculosis, is dependent on RegX3. Finally, we show that attenuation of survival of ΔregX3 under hypoxia is partly reversed upon overexpression of either Rv0195 or Rv3334, suggesting that the RegX3-Rv0195 and the RegX3-Rv3334 axis are involved in the adaptation of M. tuberculosis to a hypoxic environment.
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Affiliation(s)
- Amar Chandra Mahatha
- Department of Chemistry, Bose Institute, 93/1 Acharya Prafulla Chandra Road, Kolkata 700009, India
| | - Srijon Kaushik Banerjee
- Department of Chemistry, Bose Institute, 93/1 Acharya Prafulla Chandra Road, Kolkata 700009, India.,Present address: Department of Microbiology and Molecular Genetics, School of Medicine, University of Pittsburgh, 450 Technology Drive, Pittsburgh, PA 15217, USA
| | - Abhirupa Ghosh
- Division of Bioinformatics, Bose Institute, P-1/12 C.I.T. Scheme VIIM, Kolkata 700054, India
| | - Suruchi Lata
- Department of Chemistry, Bose Institute, 93/1 Acharya Prafulla Chandra Road, Kolkata 700009, India
| | - Sudipto Saha
- Division of Bioinformatics, Bose Institute, P-1/12 C.I.T. Scheme VIIM, Kolkata 700054, India
| | - Joyoti Basu
- Department of Chemistry, Bose Institute, 93/1 Acharya Prafulla Chandra Road, Kolkata 700009, India
| | - Manikuntala Kundu
- Department of Chemistry, Bose Institute, 93/1 Acharya Prafulla Chandra Road, Kolkata 700009, India
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8
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Li S, Poulton NC, Chang JS, Azadian ZA, DeJesus MA, Ruecker N, Zimmerman MD, Eckartt KA, Bosch B, Engelhart CA, Sullivan DF, Gengenbacher M, Dartois VA, Schnappinger D, Rock JM. CRISPRi chemical genetics and comparative genomics identify genes mediating drug potency in Mycobacterium tuberculosis. Nat Microbiol 2022; 7:766-779. [PMID: 35637331 PMCID: PMC9159947 DOI: 10.1038/s41564-022-01130-y] [Citation(s) in RCA: 70] [Impact Index Per Article: 35.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Accepted: 04/21/2022] [Indexed: 12/14/2022]
Abstract
Mycobacterium tuberculosis (Mtb) infection is notoriously difficult to treat. Treatment efficacy is limited by Mtb's intrinsic drug resistance, as well as its ability to evolve acquired resistance to all antituberculars in clinical use. A deeper understanding of the bacterial pathways that influence drug efficacy could facilitate the development of more effective therapies, identify new mechanisms of acquired resistance, and reveal overlooked therapeutic opportunities. Here we developed a CRISPR interference chemical-genetics platform to titrate the expression of Mtb genes and quantify bacterial fitness in the presence of different drugs. We discovered diverse mechanisms of intrinsic drug resistance, unveiling hundreds of potential targets for synergistic drug combinations. Combining chemical genetics with comparative genomics of Mtb clinical isolates, we further identified several previously unknown mechanisms of acquired drug resistance, one of which is associated with a multidrug-resistant tuberculosis outbreak in South America. Lastly, we found that the intrinsic resistance factor whiB7 was inactivated in an entire Mtb sublineage endemic to Southeast Asia, presenting an opportunity to potentially repurpose the macrolide antibiotic clarithromycin to treat tuberculosis. This chemical-genetic map provides a rich resource to understand drug efficacy in Mtb and guide future tuberculosis drug development and treatment.
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Affiliation(s)
- Shuqi Li
- Laboratory of Host-Pathogen Biology, The Rockefeller University, New York, NY, USA
| | - Nicholas C Poulton
- Laboratory of Host-Pathogen Biology, The Rockefeller University, New York, NY, USA
| | - Jesseon S Chang
- Laboratory of Host-Pathogen Biology, The Rockefeller University, New York, NY, USA
| | - Zachary A Azadian
- Laboratory of Host-Pathogen Biology, The Rockefeller University, New York, NY, USA
| | - Michael A DeJesus
- Laboratory of Host-Pathogen Biology, The Rockefeller University, New York, NY, USA
| | - Nadine Ruecker
- Department of Microbiology and Immunology, Weill Cornell Medicine, New York, NY, USA
| | - Matthew D Zimmerman
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, NJ, USA
| | - Kathryn A Eckartt
- Laboratory of Host-Pathogen Biology, The Rockefeller University, New York, NY, USA
| | - Barbara Bosch
- Laboratory of Host-Pathogen Biology, The Rockefeller University, New York, NY, USA
| | - Curtis A Engelhart
- Department of Microbiology and Immunology, Weill Cornell Medicine, New York, NY, USA
| | - Daniel F Sullivan
- Department of Microbiology and Immunology, Weill Cornell Medicine, New York, NY, USA
| | - Martin Gengenbacher
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, NJ, USA
- Hackensack Meridian School of Medicine, Hackensack Meridian Health, Nutley, NJ, USA
| | - Véronique A Dartois
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, NJ, USA
- Hackensack Meridian School of Medicine, Hackensack Meridian Health, Nutley, NJ, USA
| | - Dirk Schnappinger
- Department of Microbiology and Immunology, Weill Cornell Medicine, New York, NY, USA
| | - Jeremy M Rock
- Laboratory of Host-Pathogen Biology, The Rockefeller University, New York, NY, USA.
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Lata S, Mahatha AC, Mal S, Gupta UD, Kundu M, Basu J. Unravelling novel roles of the Mycobacterium tuberculosis transcription factor Rv0081 in regulation of the nucleoid-associated proteins Lsr2 and EspR, cholesterol utilization and subversion of lysosomal trafficking in macrophages. Mol Microbiol 2022; 117:1104-1120. [PMID: 35304930 DOI: 10.1111/mmi.14895] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 03/14/2022] [Accepted: 03/15/2022] [Indexed: 11/30/2022]
Abstract
The transcriptional network of Mycobacterium tuberculosis is designed to enable the organism to withstand host-associated stresses and to exploit the host milieu for its own survival and multiplication. Rv0081 (MT0088) is a transcriptional regulator whose interplay with other gene regulatory proteins and role in enabling M. tuberculosis to thrive within its host is incompletely understood. M. tuberculosis utilizes cholesterol within the granuloma. We show that deletion of Rv0081 compromises the ability of M. tuberculosis to utilize cholesterol as sole carbon source, to subvert lysosomal trafficking, and to form granulomas in vitro. Rv0081 downregulates expression of the nucleoid associated repressor Lsr2, leading to increased expression of the cholesterol catabolism-linked gene kshA and genes of the cholesterol importing operon, accounting for the requirement of Rv0081 in cholesterol utilization. Further, Rv0081 activates EspR which is required for secretion of ESX-1 substrates, which in turn are involved in subversion of lysosomal traffickingof M. tuberculosisand granuloma expansion. These results provide new insight into the role of Rv0081 under conditions which resemble the environment encountered by M. tuberculosis within its host. Rv0081 emergesas a central regulator of genes linked to various pathways which are crucial for the survival of the bacterium in vivo.
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Affiliation(s)
- Suruchi Lata
- Department of Chemistry, Bose Institute, 93/1 Acharya Prafulla Chandra Road, Kolkata, 700009, India
| | - Amar Chandra Mahatha
- Department of Chemistry, Bose Institute, 93/1 Acharya Prafulla Chandra Road, Kolkata, 700009, India
| | - Soumya Mal
- Department of Chemistry, Bose Institute, 93/1 Acharya Prafulla Chandra Road, Kolkata, 700009, India
| | - Umesh D Gupta
- National JALMA Institute for Leprosy and Other Mycobacterial Diseases, Tajganj, Agra 282004, India
| | - Manikuntala Kundu
- Department of Chemistry, Bose Institute, 93/1 Acharya Prafulla Chandra Road, Kolkata, 700009, India
| | - Joyoti Basu
- Department of Chemistry, Bose Institute, 93/1 Acharya Prafulla Chandra Road, Kolkata, 700009, India
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Waturuocha UW, P. J. A, Singh KK, Malhotra V, Krishna MS, Saini DK. A high-frequency single nucleotide polymorphism in the MtrB sensor kinase in clinical strains of Mycobacterium tuberculosis alters its biochemical and physiological properties. PLoS One 2021; 16:e0256664. [PMID: 34529706 PMCID: PMC8445491 DOI: 10.1371/journal.pone.0256664] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Accepted: 08/11/2021] [Indexed: 11/19/2022] Open
Abstract
The DNA polymorphisms found in clinical strains of Mycobacterium tuberculosis drive altered physiology, virulence, and pathogenesis in them. Although the lineages of these clinical strains can be traced back to common ancestor/s, there exists a plethora of difference between them, compared to those that have evolved in the laboratory. We identify a mutation present in ~80% of clinical strains, which maps in the HATPase domain of the sensor kinase MtrB and alters kinase and phosphatase activities, and affects its physiological role. The changes conferred by the mutation were probed by in-vitro biochemical assays which revealed changes in signaling properties of the sensor kinase. These changes also affect bacterial cell division rates, size and membrane properties. The study highlights the impact of DNA polymorphisms on the pathophysiology of clinical strains and provides insights into underlying mechanisms that drive signal transduction in pathogenic bacteria.
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Affiliation(s)
- Uchenna Watson Waturuocha
- Department of Studies in Zoology, Manasagangotri, University of Mysore, Mysore, India
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bangalore, India
| | - Athira P. J.
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bangalore, India
| | - Krishna Kumar Singh
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bangalore, India
| | - Vandana Malhotra
- Department of Biochemistry, Sri Venkateswara College, University of Delhi, Delhi, India
| | - M. S. Krishna
- Department of Studies in Zoology, Manasagangotri, University of Mysore, Mysore, India
| | - Deepak Kumar Saini
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bangalore, India
- Center for Biosystems Science and Engineering, Indian Institute of Science, Bangalore, India
- * E-mail:
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Abstract
Nε-lysine acetylation is an important, dynamic regulatory posttranslational modification (PTM) that is common in bacteria. Protein acetylomes have been characterized for more than 30 different species, and it is known that acetylation plays important regulatory roles in many essential biological processes. The levels of acetylation are enzymatically controlled by the opposing actions of lysine acetyltransferases and deacetylases. In bacteria, a second mechanism of acetylation exists and occurs via an enzyme-independent manner using the secondary metabolite acetyl-phosphate. Nonenzymatic acetylation accounts for global low levels of acetylation. Recently, studies concerning the role of protein acetylation in bacterial virulence have begun. Acetylated virulence factors have been identified and further characterized. The roles of the enzymes that acetylate and deacetylate proteins in the establishment of infection and biofilm formation have also been investigated. In this review, we discuss the acetylomes of human bacterial pathogens. We highlight examples of known acetylated virulence proteins and examine how they affect survival in the host. Finally, we discuss how acetylation might influence host-pathogen interactions and look at the contribution of acetylation to antimicrobial resistance.
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Singh KK, Athira PJ, Bhardwaj N, Singh DP, Watson U, Saini DK. Acetylation of Response Regulator Protein MtrA in M. tuberculosis Regulates Its Repressor Activity. Front Microbiol 2021; 11:516315. [PMID: 33519719 PMCID: PMC7843721 DOI: 10.3389/fmicb.2020.516315] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Accepted: 12/17/2020] [Indexed: 11/13/2022] Open
Abstract
MtrA is an essential response regulator (RR) protein in M. tuberculosis, and its activity is modulated after phosphorylation from its sensor kinase MtrB. Interestingly, many regulatory effects of MtrA have been reported to be independent of its phosphorylation, thereby suggesting alternate mechanisms of regulation of the MtrAB two-component system in M. tuberculosis. Here, we show that RR MtrA undergoes non-enzymatic acetylation through acetyl phosphate, modulating its activities independent of its phosphorylation status. Acetylated MtrA shows increased phosphorylation and enhanced interaction with SK MtrB assessed by phosphotransfer assays and FRET analysis. We also observed that acetylated MtrA loses its DNA-binding ability on gene targets that are otherwise enhanced by phosphorylation. More interestingly, acetylation is the dominant post-translational modification, overriding the effect of phosphorylation. Evaluation of the impact of MtrA and its lysine mutant overexpression on the growth of H37Ra bacteria under different conditions along with the infection studies on alveolar epithelial cells further strengthens the importance of acetylated MtrA protein in regulating the growth of M. tuberculosis. Overall, we show that both acetylation and phosphorylation regulate the activities of RR MtrA on different target genomic regions. We propose here that, although phosphorylation-dependent binding of MtrA drives its repressor activity on oriC and rpf, acetylation of MtrA turns this off and facilitates division in mycobacteria. Our findings, thus, reveal a more complex regulatory role of RR proteins in which multiple post-translational modifications regulate the activities at the levels of interaction with SK and the target gene expression.
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Affiliation(s)
- Krishna Kumar Singh
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bengaluru, India
| | - P J Athira
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bengaluru, India
| | - Neerupma Bhardwaj
- Molecular Biophysics Unit, Indian Institute of Science, Bengaluru, India
| | - Devendra Pratap Singh
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bengaluru, India
| | - Uchenna Watson
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bengaluru, India.,Department of Studies in Zoology, University of Mysore, Mysore, India
| | - Deepak Kumar Saini
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bengaluru, India.,Centre for Biosystems Science and Engineering, Indian Institute of Science, Bengaluru, India
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Mahatha AC, Mal S, Majumder D, Saha S, Ghosh A, Basu J, Kundu M. RegX3 Activates whiB3 Under Acid Stress and Subverts Lysosomal Trafficking of Mycobacterium tuberculosis in a WhiB3-Dependent Manner. Front Microbiol 2020; 11:572433. [PMID: 33042081 PMCID: PMC7525159 DOI: 10.3389/fmicb.2020.572433] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2020] [Accepted: 08/10/2020] [Indexed: 11/17/2022] Open
Abstract
Two-component systems (TCSs) are central to the ability of Mycobacterium tuberculosis to respond to stress. One such paired TCS is SenX3-RegX3, which responds to phosphate starvation. Here we show that RegX3 is required for M. tuberculosis to withstand low pH, one of the challenges encountered by the bacterium in the host environment, and that RegX3 activates the cytosolic redox sensor WhiB3 to launch an appropriate response to acid stress. We show that the whiB3 promoter of M. tuberculosis harbors a RegX3 binding motif. Electrophoretic mobility shift assays (EMSAs) show that phosphorylated RegX3 (RegX3-P) (but not its unphosphorylated counterpart) binds to this motif, whereas a DNA binding mutant, RegX3 (K204A) fails to do so. Mutation of the putative RegX3 binding motif on the whiB3 promoter, abrogates the binding of RegX3-P. The significance of this binding is established by demonstrating that the expression of whiB3 is significantly attenuated under phosphate starvation or under acid stress in the regX3-inactivated mutant, ΔregX3. Green fluorescent protein (GFP)-based reporter assays further confirm the requirement of RegX3 for the activation of the whiB3 promoter. The compromised survival of ΔregX3 under acid stress and its increased trafficking to the lysosomal compartment are reversed upon complementation with either regX3 or whiB3, suggesting that RegX3 exerts its effects in a WhiB3-dependent manner. Finally, using an in vitro granuloma model, we show that granuloma formation is compromised in the absence of regX3, but restored upon complementation with either regX3 or whiB3. Our findings provide insight into an important role of RegX3 in the network that regulates the survival of M. tuberculosis under acid stress similar to that encountered in its intracellular niche. Our results argue strongly in favor of a role of the RegX3-WhiB3 axis in establishment of M. tuberculosis infection.
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Affiliation(s)
| | - Soumya Mal
- Department of Chemistry, Bose Institute, Kolkata, India
| | | | - Sudipto Saha
- Division of Bioinformatics, Bose Institute, Kolkata, India
| | - Abhirupa Ghosh
- Division of Bioinformatics, Bose Institute, Kolkata, India
| | - Joyoti Basu
- Department of Chemistry, Bose Institute, Kolkata, India
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14
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Impact on Multiple Antibiotic Pathways Reveals MtrA as a Master Regulator of Antibiotic Production in Streptomyces spp. and Potentially in Other Actinobacteria. Appl Environ Microbiol 2020; 86:AEM.01201-20. [PMID: 32801172 DOI: 10.1128/aem.01201-20] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 08/03/2020] [Indexed: 12/12/2022] Open
Abstract
Regulation of antibiotic production by Streptomyces is complex. We report that the response regulator MtrA is a master regulator for antibiotic production in Streptomyces Deletion of MtrA altered production of actinorhodin, undecylprodigiosin, calcium-dependent antibiotic, and the yellow-pigmented type I polyketide and resulted in altered expression of the corresponding gene clusters in S. coelicolor Integrated in vitro and in vivo analyses identified MtrA binding sites upstream of cdaR, actII-orf4, and redZ and between cpkA and cpkD MtrA disruption also led to marked changes in chloramphenicol and jadomycin production and in transcription of their biosynthetic gene clusters (cml and jad, respectively) in S. venezuelae, and MtrA sites were identified within cml and jad MtrA also recognized predicted sites within the avermectin and oligomycin pathways in S. avermitilis and in the validamycin gene cluster of S. hygroscopicus The regulator GlnR competed for several MtrA sites and impacted production of some antibiotics, but its effects were generally less dramatic than those of MtrA. Additional potential MtrA sites were identified in a range of other antibiotic biosynthetic gene clusters in Streptomyces species and other actinobacteria. Overall, our study suggests a universal role for MtrA in antibiotic production in Streptomyces and potentially other actinobacteria.IMPORTANCE In natural environments, the ability to produce antibiotics helps the producing host to compete with surrounding microbes. In Streptomyces, increasing evidence suggests that the regulation of antibiotic production is complex, involving multiple regulatory factors. The regulatory factor MtrA is known to have additional roles beyond controlling development, and using bioassays, transcriptional studies, and DNA-binding assays, our study identified MtrA recognition sequences within multiple antibiotic pathways and indicated that MtrA directly controls the production of multiple antibiotics. Our analyses further suggest that this role of MtrA is evolutionarily conserved in Streptomyces species, as well as in other actinobacterial species, and also suggest that MtrA is a major regulatory factor in antibiotic production and in the survival of actinobacteria in nature.
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15
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Rajeev L, Luning EG, Zane GM, Juba TR, Kazakov AE, Novichkov PS, Wall JD, Mukhopadhyay A. LurR is a regulator of the central lactate oxidation pathway in sulfate-reducing Desulfovibrio species. PLoS One 2019; 14:e0214960. [PMID: 30964892 PMCID: PMC6456213 DOI: 10.1371/journal.pone.0214960] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Accepted: 03/22/2019] [Indexed: 11/18/2022] Open
Abstract
The central carbon/lactate utilization pathway in the model sulfate-reducing bacterium, Desulfovibrio vulgaris Hildenborough, is encoded by the highly conserved operon DVU3025-3033. Our earlier in vitro genome-wide study had suggested a network of four two-component system regulators that target this large operon; however, how these four regulators control this operon was not known. Here, we probe the regulation of the lactate utilization operon with mutant strains and DNA-protein binding assays. We show that the LurR response regulator is required for optimal growth and complete lactate utilization, and that it activates the DVU3025-3033 lactate oxidation operon as well as DVU2451, a lactate permease gene, in the presence of lactate. We show by electrophoretic mobility shift assays that LurR binds to three sites in the upstream region of DVU3025, the first gene of the operon. NrfR, a response regulator that is activated under nitrite stress, and LurR share similar binding site motifs and bind the same sites upstream of DVU3025. The DVU3025 promoter also has a binding site motif (Pho box) that is bound by PhoB, a two-component response regulator activated under phosphate limitation. The lactate utilization operon, the regulator LurR, and LurR binding sites are conserved across the order Desulfovibrionales whereas possible modulation of the lactate utilization genes by additional regulators such as NrfR and PhoB appears to be limited to D. vulgaris.
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Affiliation(s)
- Lara Rajeev
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America
| | - Eric G. Luning
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America
| | - Grant M. Zane
- Department of Biochemistry, University of Missouri, Columbia, Missouri, United States of America
| | - Thomas R. Juba
- Department of Biochemistry, University of Missouri, Columbia, Missouri, United States of America
| | - Alexey E. Kazakov
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America
| | - Pavel S. Novichkov
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America
| | - Judy D. Wall
- Department of Biochemistry, University of Missouri, Columbia, Missouri, United States of America
| | - Aindrila Mukhopadhyay
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America
- * E-mail:
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16
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Schwenk S, Moores A, Nobeli I, McHugh TD, Arnvig KB. Cell-wall synthesis and ribosome maturation are co-regulated by an RNA switch in Mycobacterium tuberculosis. Nucleic Acids Res 2018; 46:5837-5849. [PMID: 29618088 PMCID: PMC6009663 DOI: 10.1093/nar/gky226] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Revised: 03/11/2018] [Accepted: 03/15/2018] [Indexed: 01/16/2023] Open
Abstract
The success of Mycobacterium tuberculosis relies on the ability to switch between active growth and non-replicating persistence, associated with latent TB infection. Resuscitation promoting factors (Rpfs) are essential for the transition between these states. Rpf expression is tightly regulated as these enzymes are able to degrade the cell wall, and hence potentially lethal to the bacterium itself. We have identified a regulatory element in the 5' untranslated region (UTR) of rpfB. We demonstrate that this element is a transcriptionally regulated RNA switch/riboswitch candidate, which appears to be restricted to pathogenic mycobacteria, suggesting a role in virulence. We have used translation start site mapping to re-annotate the RpfB start codon and identified and validated a ribosome binding site that is likely to be targeted by an rpfB antisense RNA. Finally, we show that rpfB is co-transcribed with ksgA and ispE downstream. ksgA encodes a universally conserved methyltransferase involved in ribosome maturation and ispE encodes an essential kinase involved in cell wall synthesis. This arrangement implies co-regulation of resuscitation, cell wall synthesis and ribosome maturation via the RNA switch.
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Affiliation(s)
- Stefan Schwenk
- Institute for Structural and Molecular Biology, University College London, London WC1E 6BT, UK
| | - Alexandra Moores
- Institute for Structural and Molecular Biology, University College London, London WC1E 6BT, UK
| | - Irene Nobeli
- Institute for Structural and Molecular Biology, Birkbeck, London WC1E 7HX, UK
| | - Timothy D McHugh
- Centre for Clinical Microbiology, Royal Free Campus, University College London, London NW3 2QG, UK
| | - Kristine B Arnvig
- Institute for Structural and Molecular Biology, University College London, London WC1E 6BT, UK
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17
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Kundu M. The role of two-component systems in the physiology of Mycobacterium tuberculosis. IUBMB Life 2018; 70:710-717. [PMID: 29885211 DOI: 10.1002/iub.1872] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Accepted: 04/22/2018] [Indexed: 12/14/2022]
Abstract
Tuberculosis is a global health problem, with a third of the world's population infected with the bacillus, Mycobacterium tuberculosis. The problem is exacerbated by the emergence of multidrug resistant and extensively drug resistant strains. The search for new drug targets is therefore a priority for researchers in the field. The two-component systems (TCSs) are central to the ability of the bacterium to sense and to respond appropriately to its environment. Here we summarize current knowledge on the paired TCSs of M. tuberculosis. We discuss what is currently understood regarding the signals to which each of the sensor kinases responds, and the regulons of each of the cognate response regulators. We also discuss what is known regarding attempts to inhibit the TCSs by small molecules and project their potential as pharmacological targets for the development of novel antimycobacterial agents. © 2018 IUBMB Life, 70(8):710-717, 2018.
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18
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Uhía I, Krishnan N, Robertson BD. Characterising resuscitation promoting factor fluorescent-fusions in mycobacteria. BMC Microbiol 2018; 18:30. [PMID: 29649975 PMCID: PMC5898023 DOI: 10.1186/s12866-018-1165-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Accepted: 03/15/2018] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Resuscitation promoting factor proteins (Rpfs) are peptidoglycan glycosidases capable of resuscitating dormant mycobacteria, and have been found to play a role in the pathogenesis of tuberculosis. However, the specific roles and localisation of each of the 5 Rpfs in Mycobacterium tuberculosis remain mostly unknown. In this work our aim was to construct fluorescent fusions of M. tuberculosis Rpf proteins as tools to investigate their function. RESULTS We found that Rpf-fusions to the fluorescent protein mCherry are functional and able to promote cell growth under different conditions. However, fusions to Enhanced Green Fluorescent Protein (EGFP) were non-functional in the assays used and none were secreted into the extracellular medium, which suggests Rpfs may be secreted via the Sec pathway. No specific cellular localization was observed for either set of fusions using time-lapse video microscopy. CONCLUSIONS We present the validation and testing of five M. tuberculosis Rpfs fused to mCherry, which are functional in resuscitation assays, but do not show any specific cellular localisation under the conditions tested. Our results suggest that Rpfs are likely to be secreted via the Sec pathway. We propose that such mCherry fusions will be useful tools for the further study of Rpf localisation, individual expression, and function.
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Affiliation(s)
- Iria Uhía
- MRC Centre for Molecular Bacteriology and Infection, Department of Medicine, Imperial College London, London, SW7 2AZ UK
| | - Nitya Krishnan
- MRC Centre for Molecular Bacteriology and Infection, Department of Medicine, Imperial College London, London, SW7 2AZ UK
| | - Brian D. Robertson
- MRC Centre for Molecular Bacteriology and Infection, Department of Medicine, Imperial College London, London, SW7 2AZ UK
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19
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Takada H, Yoshikawa H. Essentiality and function of WalK/WalR two-component system: the past, present, and future of research. Biosci Biotechnol Biochem 2018. [PMID: 29514560 DOI: 10.1080/09168451.2018.1444466] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The WalK/WalR two-component system (TCS), originally identified in Bacillus subtilis, is very highly conserved in gram-positive bacteria, including several important pathogens. The WalK/WalR TCS appears to be involved in the growth of most bacterial species encoding it. Previous studies have indicated conserved functions of this system, defining this signal transduction pathway as a crucial regulatory system for cell wall metabolism. Because of such effects on essential functions, this system is considered a potential target for anti-infective therapeutics. In this review, we discuss the role of WalK/WalR TCS in different bacterial cells, focusing on the function of the genes in its regulon as well as the variations in walRK operon structure, its auxiliary proteins, and the composition of its regulon. We also discuss recent experimental data addressing its essential function and the potential type of signal being sensed by B. subtilis. This review also focuses on the potential future research.
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Affiliation(s)
- Hiraku Takada
- Department of Life Science and Research Center for Life Science, College of Science, Rikkyo University, Tokyo, Japan.,Department of Bioscience, Tokyo University of Agriculture, Tokyo, Japan
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20
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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.
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21
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Chatterjee A, Sharma AK, Mahatha AC, Banerjee SK, Kumar M, Saha S, Basu J, Kundu M. Global mapping of MtrA-binding sites links MtrA to regulation of its targets in Mycobacterium tuberculosis. MICROBIOLOGY-SGM 2017; 164:99-110. [PMID: 29182512 DOI: 10.1099/mic.0.000585] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Mycobacterium tuberculosis employs two-component systems (TCSs) for survival within its host. The TCS MtrAB is conserved among mycobacteria. The response regulator MtrA is essential in M. tuberculosis. The genome-wide chromatin immunoprecipitation (ChIP) sequencing performed in this study suggested that MtrA binds upstream of at least 45 genes of M. tuberculosis, including those involved in cell wall remodelling, stress responses, persistence and regulation of transcription. It binds to the promoter regions and regulates the peptidoglycan hydrolases rpfA and rpfC, which are required for resuscitation from dormancy. It also regulates the expression of whiB4, a critical regulator of the oxidative stress response, and relF, one-half of the toxin-antitoxin locus relFG. We have identified a new consensus 9 bp loose motif for MtrA binding. Mutational changes in the consensus sequence greatly reduced the binding of MtrA to its newly identified targets. Importantly, we observed that overexpression of a gain-of-function mutant, MtrAY102C, enhanced expression of the aforesaid genes in M. tuberculosis isolated from macrophages, whereas expression of each of these targets was lower in M. tuberculosis overexpressing a phosphorylation-defective mutant, MtrAD56N. This result suggests that phosphorylated MtrA (MtrA-P) is required for the expression of its targets in macrophages. Our data have uncovered new MtrA targets that suggest that MtrA is required for a transcriptional response that likely enables M. tuberculosis to persist within its host and emerge out of dormancy when the conditions are favourable.
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Affiliation(s)
- Ayan Chatterjee
- Department of Chemistry, Bose Institute, 93/1 Acharya Prafulla Chandra Road, Kolkata-700009, India
| | - Arun Kumar Sharma
- Department of Chemistry, Bose Institute, 93/1 Acharya Prafulla Chandra Road, Kolkata-700009, India
| | - Amar Chandra Mahatha
- Department of Chemistry, Bose Institute, 93/1 Acharya Prafulla Chandra Road, Kolkata-700009, India
| | - Srijon Kaushik Banerjee
- Department of Chemistry, Bose Institute, 93/1 Acharya Prafulla Chandra Road, Kolkata-700009, India
| | - Manish Kumar
- Department of Chemistry, Bose Institute, 93/1 Acharya Prafulla Chandra Road, Kolkata-700009, India
| | - Sudipto Saha
- Bioinformatics Centre, Bose Institute (Centenary Building), P 1/12, C. I. T. Road, Scheme-VIIM, Kolkata-700054, India
| | - Joyoti Basu
- Department of Chemistry, Bose Institute, 93/1 Acharya Prafulla Chandra Road, Kolkata-700009, India
| | - Manikuntala Kundu
- Department of Chemistry, Bose Institute, 93/1 Acharya Prafulla Chandra Road, Kolkata-700009, India
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22
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Zhang P, Wu L, Zhu Y, Liu M, Wang Y, Cao G, Chen XL, Tao M, Pang X. Deletion of MtrA Inhibits Cellular Development of Streptomyces coelicolor and Alters Expression of Developmental Regulatory Genes. Front Microbiol 2017; 8:2013. [PMID: 29085353 PMCID: PMC5650626 DOI: 10.3389/fmicb.2017.02013] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2017] [Accepted: 09/29/2017] [Indexed: 11/18/2022] Open
Abstract
The developmental life cycle of Streptomyces species includes aerial hyphae formation and spore maturation, two distinct developmental processes that are controlled, respectively, by two families of developmental regulatory genes, bld and whi. In this study, we show that the response regulator MtrA (SCO3013) is critical for normal development of aerial hyphae in S. coelicolor and related species. ΔmtrA, a deletion mutant of the response regulator gene mtrA, exhibited the bald phenotype typical of bld mutants defective in aerial mycelium formation, with formation either much delayed or absent depending on the culture medium. Transcriptional analysis indicated that MtrA activates multiple genes involved in formation of aerial mycelium, including chp, rdl, and ram genes, as well as developmental regulatory genes of the bld and whi families. However, the major regulatory gene bldD showed enhanced expression in ΔmtrA, suggesting it is repressed by MtrA. electrophoretic mobility shift assays indicated that MtrA binds upstream of several genes with altered expression in ΔmtrA, including bldD and whiI, and sequences similar to the consensus binding sequence for MtrA of another actinomycete, Mycobacterium tuberculosis, were found in the bound sites. A loosely conserved recognition sequence containing two short, direct repeats was identified for MtrA of S. coelicolor and was validated using mutational analysis. MtrA homologs are widely distributed among Streptomyces species, and as with S. coelicolor, deletion of the mtrA homologs sve_2757 from S. venezuelae and sli_3357 from S. lividans resulted in conditional bald morphology. Our study suggests a critical and conserved role for MtrA in Streptomyces development.
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Affiliation(s)
- Peipei Zhang
- The State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Jinan, China
| | - Lili Wu
- The State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Jinan, China
| | - Yanping Zhu
- The State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Jinan, China
| | - Meng Liu
- The State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Jinan, China
| | - Yemin Wang
- The State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai, China
| | - Guangxiang Cao
- Shandong Medicinal Biotechnology Center, Shandong Academy of Medical Sciences, Jinan, China
| | - Xiu-Lan Chen
- The State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Jinan, China
| | - Meifeng Tao
- The State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai, China
| | - Xiuhua Pang
- The State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Jinan, China
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23
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Banerjee SK, Kumar M, Alokam R, Sharma AK, Chatterjee A, Kumar R, Sahu SK, Jana K, Singh R, Yogeeswari P, Sriram D, Basu J, Kundu M. Targeting multiple response regulators of Mycobacterium tuberculosis augments the host immune response to infection. Sci Rep 2016; 6:25851. [PMID: 27181265 PMCID: PMC4867592 DOI: 10.1038/srep25851] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Accepted: 04/25/2016] [Indexed: 11/06/2022] Open
Abstract
The genome of M. tuberculosis (Mtb) encodes eleven paired two component systems (TCSs) consisting of a sensor kinase (SK) and a response regulator (RR). The SKs sense environmental signals triggering RR-dependent gene expression pathways that enable the bacterium to adapt in the host milieu. We demonstrate that a conserved motif present in the C-terminal domain regulates the DNA binding functions of the OmpR family of Mtb RRs. Molecular docking studies against this motif helped to identify two molecules with a thiazolidine scaffold capable of targeting multiple RRs, and modulating their regulons to attenuate bacterial replication in macrophages. The changes in the bacterial transcriptome extended to an altered immune response with increased autophagy and NO production, leading to compromised survival of Mtb in macrophages. Our findings underscore the promise of targeting multiple RRs as a novel yet unexplored approach for development of new anti-mycobacterial agents particularly against drug-resistant Mtb.
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Affiliation(s)
- Srijon Kaushik Banerjee
- Department of Chemistry, Bose Institute, 93/1 Acharya Prafulla Chandra Road, Kolkata 700009, India
| | - Manish Kumar
- Department of Chemistry, Bose Institute, 93/1 Acharya Prafulla Chandra Road, Kolkata 700009, India
| | - Reshma Alokam
- Department of Pharmacy, Birla Institute of Technology &Science-Pilani, Hyderabad Campus, Jawahar Nagar, Hyderabad 500078, India
| | - Arun Kumar Sharma
- Department of Chemistry, Bose Institute, 93/1 Acharya Prafulla Chandra Road, Kolkata 700009, India
| | - Ayan Chatterjee
- Department of Chemistry, Bose Institute, 93/1 Acharya Prafulla Chandra Road, Kolkata 700009, India
| | - Ranjeet Kumar
- Department of Chemistry, Bose Institute, 93/1 Acharya Prafulla Chandra Road, Kolkata 700009, India
| | - Sanjaya Kumar Sahu
- Department of Chemistry, Bose Institute, 93/1 Acharya Prafulla Chandra Road, Kolkata 700009, India
| | - Kuladip Jana
- Division of Molecular Medicine, Bose Institute, P-1/12 CIT Scheme VII M, Kolkata 700054, India
| | - Ramandeep Singh
- Vaccine and Infectious Disease Research Centre, Translational Health Science and Technology Institute, NCR-Biotech Science Cluster, 3rd Milestone, Faridabad Gurgaon Expressway. Faridabad-121001, India
| | - Perumal Yogeeswari
- Department of Pharmacy, Birla Institute of Technology &Science-Pilani, Hyderabad Campus, Jawahar Nagar, Hyderabad 500078, India
| | - Dharmarajan Sriram
- Department of Pharmacy, Birla Institute of Technology &Science-Pilani, Hyderabad Campus, Jawahar Nagar, Hyderabad 500078, India
| | - Joyoti Basu
- Department of Chemistry, Bose Institute, 93/1 Acharya Prafulla Chandra Road, Kolkata 700009, India
| | - Manikuntala Kundu
- Department of Chemistry, Bose Institute, 93/1 Acharya Prafulla Chandra Road, Kolkata 700009, India
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Mycobacterium tuberculosis Transcription Machinery: Ready To Respond to Host Attacks. J Bacteriol 2016; 198:1360-73. [PMID: 26883824 DOI: 10.1128/jb.00935-15] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Regulating responses to stress is critical for all bacteria, whether they are environmental, commensal, or pathogenic species. For pathogenic bacteria, successful colonization and survival in the host are dependent on adaptation to diverse conditions imposed by the host tissue architecture and the immune response. Once the bacterium senses a hostile environment, it must enact a change in physiology that contributes to the organism's survival strategy. Inappropriate responses have consequences; hence, the execution of the appropriate response is essential for survival of the bacterium in its niche. Stress responses are most often regulated at the level of gene expression and, more specifically, transcription. This minireview focuses on mechanisms of regulating transcription initiation that are required by Mycobacterium tuberculosis to respond to the arsenal of defenses imposed by the host during infection. In particular, we highlight how certain features of M. tuberculosis physiology allow this pathogen to respond swiftly and effectively to host defenses. By enacting highly integrated and coordinated gene expression changes in response to stress,M. tuberculosis is prepared for battle against the host defense and able to persist within the human population.
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