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Santoshi M, Tare P, Nagaraja V. Nucleoid-associated proteins of mycobacteria come with a distinctive flavor. Mol Microbiol 2024. [PMID: 38922783 DOI: 10.1111/mmi.15287] [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: 02/16/2024] [Revised: 05/31/2024] [Accepted: 06/05/2024] [Indexed: 06/28/2024]
Abstract
In every bacterium, nucleoid-associated proteins (NAPs) play crucial roles in chromosome organization, replication, repair, gene expression, and other DNA transactions. Their central role in controlling the chromatin dynamics and transcription has been well-appreciated in several well-studied organisms. Here, we review the diversity, distribution, structure, and function of NAPs from the genus Mycobacterium. We highlight the progress made in our understanding of the effects of these proteins on various processes and in responding to environmental stimuli and stress of mycobacteria in their free-living as well as during distinctive intracellular lifestyles. We project them as potential drug targets and discuss future studies to bridge the information gap with NAPs from well-studied systems.
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Affiliation(s)
- Meghna Santoshi
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bengaluru, India
| | - Priyanka Tare
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bengaluru, India
| | - Valakunja Nagaraja
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bengaluru, India
- Jawaharlal Nehru Centre for Advanced Scientific Research, Bengaluru, India
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2
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Sunita, Singhvi N, Gupta V, Singh Y, Shukla P. Computational Approaches for the Structure-Based Identification of Novel Inhibitors Targeting Nucleoid-Associated Proteins in Mycobacterium Tuberculosis. Mol Biotechnol 2024; 66:814-823. [PMID: 36913083 DOI: 10.1007/s12033-023-00710-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Accepted: 02/24/2023] [Indexed: 03/14/2023]
Abstract
Implementation of computational tools in the identification of novel drug targets for Tuberculosis (TB) has been a promising area of research. TB has been a chronic infectious disease caused by Mycobacterium tuberculosis (Mtb) localized primarily on the lungs and it has been one of the most successful pathogen in the history of mankind. Extensively arising drug resistivity in TB has made it a global challenge and need for new drugs has become utmost important.The involvement of Nucleoid-Associated Proteins (NAPs) in maintaining the structure of the genomic material and regulating various cellular processes like transcription, DNA replication, repair and recombination makes significant, has opened a new arena to find the drugs targeting Mtb. The current study aims to identify potential inhibitors of NAPs through a computational approach. In the present work we worked on the eight NAPs of Mtb, namely, Lsr2, EspR, HupB, HNS, NapA, mIHF and NapM. The structural modelling and analysis of these NAPs were carried out. Moreover, molecular interaction were checked and binding energy was identified for 2500 FDA-approved drugs that were selected for antagonist analysis to choose novel inhibitors targeting NAPs of Mtb. Drugs including Amikacin, streptomycin, kanamycin, and isoniazid along with eight FDA-approved molecules that were found to be potential novel targets for these mycobacterial NAPs and have an impact on their functions. The potentiality of several anti-tubercular drugs as therapeutic agents identified through computational modelling and simulation unlocks a new gateway for accomplishing the goal to treat TB.
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Affiliation(s)
- Sunita
- Department of Microbiology, Maharshi Dayanand University, Rohtak, 124001, Haryana, India
- Bacterial Pathogenesis Laboratory, Department of Zoology, University of Delhi, Delhi, 110007, India
| | - Nirjara Singhvi
- Department of Zoology, Hansraj College, University of Delhi, Delhi, 110007, India
- School of Allied Sciences, Dev Bhoomi Uttarakhand University, Dehradun, Uttarakhand, 248001, India
| | - Vipin Gupta
- Ministry of Environment, Forest and Climate Change, Government of India, Dehradun, Uttarakhand, 248001, India
| | - Yogendra Singh
- Bacterial Pathogenesis Laboratory, Department of Zoology, University of Delhi, Delhi, 110007, India
| | - Pratyoosh Shukla
- Department of Microbiology, Maharshi Dayanand University, Rohtak, 124001, Haryana, India.
- Enzyme Technology and Protein Bioinformatics Laboratory, School of Biotechnology, Institute of Science, Banaras Hindu University, Varanasi, 221005, India.
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3
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Keshavam CC, Naz S, Gupta A, Sanyal P, Kochar M, Gangwal A, Sangwan N, Kumar N, Tyagi E, Goel S, Singh NK, Sowpati DT, Khare G, Ganguli M, Raze D, Locht C, Basu-Modak S, Gupta M, Nandicoori VK, Singh Y. The heparin-binding hemagglutinin protein of Mycobacterium tuberculosis is a nucleoid-associated protein. J Biol Chem 2023; 299:105364. [PMID: 37865319 PMCID: PMC10665949 DOI: 10.1016/j.jbc.2023.105364] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Revised: 10/05/2023] [Accepted: 10/10/2023] [Indexed: 10/23/2023] Open
Abstract
Nucleoid-associated proteins (NAPs) regulate multiple cellular processes such as gene expression, virulence, and dormancy throughout bacterial species. NAPs help in the survival and adaptation of Mycobacterium tuberculosis (Mtb) within the host. Fourteen NAPs have been identified in Escherichia coli; however, only seven NAPs are documented in Mtb. Given its complex lifestyle, it is reasonable to assume that Mtb would encode for more NAPs. Using bioinformatics tools and biochemical experiments, we have identified the heparin-binding hemagglutinin (HbhA) protein of Mtb as a novel sequence-independent DNA-binding protein which has previously been characterized as an adhesion molecule required for extrapulmonary dissemination. Deleting the carboxy-terminal domain of HbhA resulted in a complete loss of its DNA-binding activity. Atomic force microscopy showed HbhA-mediated architectural modulations in the DNA, which may play a regulatory role in transcription and genome organization. Our results showed that HbhA colocalizes with the nucleoid region of Mtb. Transcriptomics analyses of a hbhA KO strain revealed that it regulates the expression of ∼36% of total and ∼29% of essential genes. Deletion of hbhA resulted in the upregulation of ∼73% of all differentially expressed genes, belonging to multiple pathways suggesting it to be a global repressor. The results show that HbhA is a nonessential NAP regulating gene expression globally and acting as a plausible transcriptional repressor.
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Affiliation(s)
| | - Saba Naz
- Department of Zoology, University of Delhi, Delhi, India; CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India
| | - Aanchal Gupta
- CSIR-Institute of Genomics and Integrative Biology, New Delhi, India
| | - Priyadarshini Sanyal
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India; Academy of Scientific and Innovative Research (AcSIR), CSIR- Centre for Cellular and Molecular Biology (CSIR-CCMB) Campus, Hyderabad, India
| | - Manisha Kochar
- Department of Zoology, University of Delhi, Delhi, India; CSIR-Institute of Genomics and Integrative Biology, New Delhi, India
| | | | - Nitika Sangwan
- Department of Zoology, University of Delhi, Delhi, India
| | - Nishant Kumar
- Department of Zoology, University of Delhi, Delhi, India
| | - Ekta Tyagi
- Department of Zoology, University of Delhi, Delhi, India
| | - Simran Goel
- Department of Zoology, University of Delhi, Delhi, India
| | | | | | - Garima Khare
- Department of Biochemistry, University of Delhi South Campus, New Delhi, India
| | - Munia Ganguli
- CSIR-Institute of Genomics and Integrative Biology, New Delhi, India
| | - Dominique Raze
- Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019 - UMR9017 - CIIL - Centre for Infection and Immunity of Lille, Lille, France
| | - Camille Locht
- Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019 - UMR9017 - CIIL - Centre for Infection and Immunity of Lille, Lille, France
| | | | - Meetu Gupta
- CSIR-Institute of Genomics and Integrative Biology, New Delhi, India.
| | - Vinay Kumar Nandicoori
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India; Academy of Scientific and Innovative Research (AcSIR), CSIR- Centre for Cellular and Molecular Biology (CSIR-CCMB) Campus, Hyderabad, India; National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, India.
| | - Yogendra Singh
- Department of Zoology, University of Delhi, Delhi, India; Delhi School of Public Health, Institution of Eminence, University of Delhi, Delhi, India.
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Li X, Chen L, Wang Y, Guo X, He ZG. Zinc excess impairs Mycobacterium bovis growth through triggering a Zur-IdeR-iron homeostasis signal pathway. Microbiol Spectr 2023; 11:e0106923. [PMID: 37668384 PMCID: PMC10580935 DOI: 10.1128/spectrum.01069-23] [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: 03/10/2023] [Accepted: 07/15/2023] [Indexed: 09/06/2023] Open
Abstract
Zinc excess is toxic to bacteria and, thus, represents an important innate defense mechanism of host cells, especially against mycobacterial infections. However, the signaling pathway triggered by zinc excess and its relationship with iron homeostasis remain poorly understood in mycobacteria. Here, we characterize a novel Zur-IdeR-iron homeostasis signaling pathway that modulates the growth of Mycobacterium bovis under zinc toxicity. We found that the regulator Zur interacts with the iron-homeostasis regulator IdeR, enhancing the DNA-binding ability of IdeR. Excess zinc disrupts this interaction and represses ideR transcription through Zur, which promotes the expression of iron uptake genes and leads to the accumulation of intracellular iron in M. bovis. The elevated iron levels lower the bacterial survival ability under excess zinc stress. Consistently, deleting zur hinders intracellular iron accumulation of M. bovis and enhances bacterial growth under stress, while silencing ideR impairs the growth of the wild-type and zur-deleted strains under the same conditions. Interestingly, both Zur and IdeR are conserved in bacteria facing zinc toxicity. Overall, our work uncovers a novel antimicrobial signal pathway whereby zinc excess disrupts iron homeostasis, which may deepen our understanding of the crosstalk mechanism between iron and zinc homeostasis in bacteria.IMPORTANCEAs a catalytic and structural cofactor of proteins, zinc is essential for almost all living organisms. However, zinc excess is toxic and represents a vital innate immunity strategy of macrophages to combat intracellular pathogens, especially against mycobacterial pathogens such as Mycobacterium tuberculosis, the causative agent of tuberculosis. Here, we first characterize an antibacterial signaling pathway of zinc excess and its relationship with iron homeostasis in M. bovis. We found that excess zinc inhibits the transcription of ideR and its DNA-binding activity through Zur, which, in turn, promotes the expression of iron uptake genes, causes intracellular iron accumulation, and finally impairs the bacterial growth. This study reveals the existence of the Zur-IdeR-iron homeostasis pathway triggered by zinc excess in M. bovis, which will shed light on the crosstalk mechanisms between zinc and iron homeostasis in bacteria and the antimicrobial mechanisms of host-mediated zinc toxicity.
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Affiliation(s)
- Xiaohui Li
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Research Center for Microbial and Enzyme Engineering Technology, College of Life Science and Technology, Guangxi University, Nanning, Guangxi, China
| | - Liu Chen
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Yuankun Wang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Research Center for Microbial and Enzyme Engineering Technology, College of Life Science and Technology, Guangxi University, Nanning, Guangxi, China
| | - Xiao Guo
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Research Center for Microbial and Enzyme Engineering Technology, College of Life Science and Technology, Guangxi University, Nanning, Guangxi, China
| | - Zheng-Guo He
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Research Center for Microbial and Enzyme Engineering Technology, College of Life Science and Technology, Guangxi University, Nanning, Guangxi, China
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5
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Shee S, Veetil RT, Mohanraj K, Das M, Malhotra N, Bandopadhyay D, Beig H, Birua S, Niphadkar S, Nagarajan SN, Sinha VK, Thakur C, Rajmani RS, Chandra N, Laxman S, Singh M, Samal A, Seshasayee AN, Singh A. Biosensor-integrated transposon mutagenesis reveals rv0158 as a coordinator of redox homeostasis in Mycobacterium tuberculosis. eLife 2023; 12:e80218. [PMID: 37642294 PMCID: PMC10501769 DOI: 10.7554/elife.80218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Accepted: 08/25/2023] [Indexed: 08/31/2023] Open
Abstract
Mycobacterium tuberculosis (Mtb) is evolutionarily equipped to resist exogenous reactive oxygen species (ROS) but shows vulnerability to an increase in endogenous ROS (eROS). Since eROS is an unavoidable consequence of aerobic metabolism, understanding how Mtb manages eROS levels is essential yet needs to be characterized. By combining the Mrx1-roGFP2 redox biosensor with transposon mutagenesis, we identified 368 genes (redoxosome) responsible for maintaining homeostatic levels of eROS in Mtb. Integrating redoxosome with a global network of transcriptional regulators revealed a hypothetical protein (Rv0158) as a critical node managing eROS in Mtb. Disruption of rv0158 (rv0158 KO) impaired growth, redox balance, respiration, and metabolism of Mtb on glucose but not on fatty acids. Importantly, rv0158 KO exhibited enhanced growth on propionate, and the Rv0158 protein directly binds to methylmalonyl-CoA, a key intermediate in propionate catabolism. Metabolite profiling, ChIP-Seq, and gene-expression analyses indicate that Rv0158 manages metabolic neutralization of propionate toxicity by regulating the methylcitrate cycle. Disruption of rv0158 enhanced the sensitivity of Mtb to oxidative stress, nitric oxide, and anti-TB drugs. Lastly, rv0158 KO showed poor survival in macrophages and persistence defect in mice. Our results suggest that Rv0158 is a metabolic integrator for carbon metabolism and redox balance in Mtb.
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Affiliation(s)
- Somnath Shee
- Department of Microbiology and Cell Biology, Indian Institute of Science BangaloreBangaloreIndia
- Centre for Infectious Disease Research, Indian Institute of Science BangaloreKarnatakaIndia
| | | | - Karthikeyan Mohanraj
- The Institute of Mathematical Sciences, A CI of Homi Bhabha National InstituteChennaiIndia
| | - Mayashree Das
- Department of Microbiology and Cell Biology, Indian Institute of Science BangaloreBangaloreIndia
- Centre for Infectious Disease Research, Indian Institute of Science BangaloreKarnatakaIndia
| | | | | | - Hussain Beig
- Department of Microbiology and Cell Biology, Indian Institute of Science BangaloreBangaloreIndia
- Centre for Infectious Disease Research, Indian Institute of Science BangaloreKarnatakaIndia
| | - Shalini Birua
- Department of Microbiology and Cell Biology, Indian Institute of Science BangaloreBangaloreIndia
- Centre for Infectious Disease Research, Indian Institute of Science BangaloreKarnatakaIndia
| | - Shreyas Niphadkar
- Institute for Stem Cell Science and Regenerative MedicineBangaloreIndia
| | - Sathya Narayanan Nagarajan
- Department of Microbiology and Cell Biology, Indian Institute of Science BangaloreBangaloreIndia
- Centre for Infectious Disease Research, Indian Institute of Science BangaloreKarnatakaIndia
| | - Vikrant Kumar Sinha
- Molecular Biophysics Unit, Indian Institute of Science BangaloreBangaloreIndia
| | - Chandrani Thakur
- Department of Biochemistry, Indian Institute of Science BangaloreBangaloreIndia
| | - Raju S Rajmani
- Centre for Infectious Disease Research, Indian Institute of Science BangaloreKarnatakaIndia
| | - Nagasuma Chandra
- Department of Biochemistry, Indian Institute of Science BangaloreBangaloreIndia
| | - Sunil Laxman
- Institute for Stem Cell Science and Regenerative MedicineBangaloreIndia
| | - Mahavir Singh
- Molecular Biophysics Unit, Indian Institute of Science BangaloreBangaloreIndia
| | - Areejit Samal
- The Institute of Mathematical Sciences, A CI of Homi Bhabha National InstituteChennaiIndia
| | | | - Amit Singh
- Department of Microbiology and Cell Biology, Indian Institute of Science BangaloreBangaloreIndia
- Centre for Infectious Disease Research, Indian Institute of Science BangaloreKarnatakaIndia
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6
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Bo H, Moure UAE, Yang Y, Pan J, Li L, Wang M, Ke X, Cui H. Mycobacterium tuberculosis-macrophage interaction: Molecular updates. Front Cell Infect Microbiol 2023; 13:1062963. [PMID: 36936766 PMCID: PMC10020944 DOI: 10.3389/fcimb.2023.1062963] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Accepted: 02/13/2023] [Indexed: 03/06/2023] Open
Abstract
Mycobacterium tuberculosis (Mtb), the causative agent of Tuberculosis (TB), remains a pathogen of great interest on a global scale. This airborne pathogen affects the lungs, where it interacts with macrophages. Acidic pH, oxidative and nitrosative stressors, and food restrictions make the macrophage's internal milieu unfriendly to foreign bodies. Mtb subverts the host immune system and causes infection due to its genetic arsenal and secreted effector proteins. In vivo and in vitro research have examined Mtb-host macrophage interaction. This interaction is a crucial stage in Mtb infection because lung macrophages are the first immune cells Mtb encounters in the host. This review summarizes Mtb effectors that interact with macrophages. It also examines how macrophages control and eliminate Mtb and how Mtb manipulates macrophage defense mechanisms for its own survival. Understanding these mechanisms is crucial for TB prevention, diagnosis, and treatment.
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Affiliation(s)
- Haotian Bo
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Ulrich Aymard Ekomi Moure
- The Ninth People's Hospital of Chongqing, Affiliated Hospital of Southwest University, Chongqing, China
- Cancer Center, Medical Research Institute, Southwest University, Chongqing, China
| | - Yuanmiao Yang
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Jun Pan
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Li Li
- Cancer Center, Medical Research Institute, Southwest University, Chongqing, China
| | - Miao Wang
- Cancer Center, Medical Research Institute, Southwest University, Chongqing, China
| | - Xiaoxue Ke
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
- Cancer Center, Medical Research Institute, Southwest University, Chongqing, China
- *Correspondence: Hongjuan Cui, ; Xiaoxue Ke,
| | - Hongjuan Cui
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
- Cancer Center, Medical Research Institute, Southwest University, Chongqing, China
- Jinfeng Laboratory, Chongqing, China
- *Correspondence: Hongjuan Cui, ; Xiaoxue Ke,
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7
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Xu P, Tang J, He ZG. Induction of Endoplasmic Reticulum Stress by CdhM Mediates Apoptosis of Macrophage During Mycobacterium tuberculosis Infection. Front Cell Infect Microbiol 2022; 12:877265. [PMID: 35444960 PMCID: PMC9013901 DOI: 10.3389/fcimb.2022.877265] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 03/08/2022] [Indexed: 11/26/2022] Open
Abstract
The normal operation of the endoplasmic reticulum (ER) is critical for cells and organisms. However, ER stress, caused by imbalanced protein folding, occurs frequently, which perturbs the function of the ER and even results in cell apoptosis eventually. Many insults can induce ER stress; pathogen infection is one of them. Most of the genes involved in ER stress have been reported to be upregulated in Mycobacterium tuberculosis (Mtb) granulomas of humans and mice, implicating that infection with Mtb can induce ER stress. However, little is known about the molecular mechanism of Mtb induction of ER stress. Here, we reveal that Mycobacterium protein CDP-diglyceride hydrolase of Mycobacteriumn (CdhM) could target the ER and cause abnormal ER morphology and cell death. RNA-seq analysis suggests that most of the ER stress-involved genes were modulated by CdhM. Further assessed by biochemical experiments, the transcription and protein levels of ER stress markers BiP and CHOP, as well as the levels of XBP1 splicing and eIF2α phosphorylation, were significantly increased by CdhM, confirming that CdhM could induce ER stress alone or during infection. A single conserved amino acid mutant of CdhM, including L44A, G96A, H150A, and W175A, was incapable of inducing ER stress, which indicates that induction of ER stress by CdhM is specific and functional. Furthermore, CdhM-induced ER stress could also promote apoptosis of macrophages during Mtb infection. Overexpression of CdhM conferred a significant benefit for Mtb replication by releasing Mtb into extracellular during infection of macrophage in vitro, as presented in CFU assays. Overall, our study identified a novel Mtb effector protein CdhM which may promote Mtb dissemination and proliferation by induction of ER stress and apoptosis and provided new insight into the physiological significance of induction of ER stress in tuberculosis (TB) granulomas.
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Affiliation(s)
- Peng Xu
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Jing Tang
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Zheng-Guo He
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Science and Technology, Guangxi University, Nanning, China
- *Correspondence: Zheng-Guo He,
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Lsr2 and Its Novel Paralogue Mediate the Adjustment of Mycobacterium smegmatis to Unfavorable Environmental Conditions. mSphere 2021; 6:6/3/e00290-21. [PMID: 33980681 PMCID: PMC8125055 DOI: 10.1128/msphere.00290-21] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Nucleoid-associated proteins (NAPs) are the most abundant proteins involved in bacterial chromosome organization and global transcription regulation. The mycobacterial NAP family includes many diverse proteins; some are unique to actinobacteria, and many are crucial for survival under stress (e.g., HupB and Lsr2) and/or optimal growth conditions (e.g., mycobacterial integration host factor [mIHF]). Lsr2 is a nucleoid-associated protein (NAP) that has been found strictly in actinobacteria, including mycobacteria. It is a functional homolog of histone-like nucleoid-structuring protein (H-NS); it acts as a DNA-bridging protein that plays a role in chromosomal organization and transcriptional regulation. To date, the studies on Lsr2 have focused mainly on Mycobacterium tuberculosis. In this study, we analyze the role of Lsr2 as a transcription factor in Mycobacterium smegmatis, a saprophytic bacterium whose natural habitat (soil and water) substantially differs from those of the obligatory mycobacterial pathogens. Our chromatin immunoprecipitation-sequencing (ChIP-seq) data revealed that Lsr2 binds preferentially to AT-rich regions of the M. smegmatis chromosome. We found that Lsr2 acts mainly as a repressor, controlling gene expression either directly by binding promoter regions or indirectly through DNA loop formation and DNA coating. One of the Lsr2-repressed genes encodes polyketide synthase (MSMEG_4727), which is involved in the synthesis of lipooligosaccharides (LOSs). An M. smegmatis strain deprived of Lsr2 produces more LOSs, which is mirrored by changes in the smoothness of cells and their susceptibilities to antibiotics. Unlike M. tuberculosis, M. smegmatis additionally encodes a paralogue of Lsr2, MSMEG_1060, which is a novel member of the mycobacterial NAP family. The Lsr2 and MSMEG_1060 proteins exhibit different DNA binding specificities and chromosomal localizations. Our results suggest that these proteins help M. smegmatis cells cope with stress conditions, including hypoxia and exposure to antibiotics. Thus, the present work provides novel insight into the role of Lsr2 paralogues in the ability of a saprophytic mycobacterial species to adjust to environmental changes. IMPORTANCE Nucleoid-associated proteins (NAPs) are the most abundant proteins involved in bacterial chromosome organization and global transcription regulation. The mycobacterial NAP family includes many diverse proteins; some are unique to actinobacteria, and many are crucial for survival under stress (e.g., HupB and Lsr2) and/or optimal growth conditions (e.g., mycobacterial integration host factor [mIHF]). Here, we present a comprehensive study concerning two functional homologues of mycobacterial H-NS: Lsr2 and its paralogue from M. smegmatis, MSMEG_1060. We found that Lsr2 plays a role in transcriptional regulation, mainly by repressing gene expression via DNA loop formation and/or DNA-coating mechanisms. Intriguingly, the number of Lsr2-mediated genes was found to increase under hypoxia. Compared to Lsr2, MSMEG_1060 exhibits a different DNA binding specificity and chromosomal localization. Since tuberculosis remains a serious worldwide health problem, studies on stress response-mediating agents, such as Lsr2, may contribute to the development of novel antituberculosis drugs.
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9
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Sheikhpour M, Abolfathi H, Karimipoor M, Movafagh A, Shahsavani M. The Common miRNAs between Tuberculosis and Non-Small Cell Lung Cancer: A Critical Review. TANAFFOS 2021; 20:197-208. [PMID: 35382078 PMCID: PMC8978040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Accepted: 05/05/2021] [Indexed: 06/14/2023]
Abstract
Tuberculosis (TB) and non-small cell lung cancer (NSCLC) are two major contributors to mortality and morbidity worldwide. In this regard, TB and NSCLC have similar symptoms, and TB has symptoms that are identical to malignancy; therefore, sometimes it is mistakenly diagnosed as lung cancer. Moreover, patients with active pulmonary TB are at a higher risk of dying due to lung cancer. In addition, several signaling pathways involved in TB and NSCLC have been identified. Also, the miRNAs are biological molecules shown to play essential roles in the above-mentioned diseases through targeting the signaling pathways' genes. Most of the pathways affected by miRNAs are immune responses such as autophagy and apoptosis in TB and NSCLC, respectively. Several studies have separately investigated the expression of miRNAs profile in patients with NSCLC and infectious TB. In this critical review, we attempted to gather common miRNAs between TB and NSCLC and to explain the involved-pathways, which are affected by miRNAs in both TB and NSCLC. Results of this critical review show that the expressions of miR-155, miR-146a, miR-125b, miR-30a, miR-29a, and miR-Let7 have significantly changed in TB and NSCLC. The data suggest that miRNAs expression may provide a new method for screening or differential diagnosis of NSCLC and TB.
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Affiliation(s)
- Mojgan Sheikhpour
- Department of Mycobacteriology and Pulmonary Research, Pasteur Institute of Iran, Tehran, Iran
- Microbiology Research Center, Pasteur Institute of Iran, Tehran, Iran
| | - Hanie Abolfathi
- Department of Mycobacteriology and Pulmonary Research, Pasteur Institute of Iran, Tehran, Iran
| | - Morteza Karimipoor
- Department of Molecular Medicine, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran
| | - Abolfazl Movafagh
- Department of Medical Genetics, Cancer Research Center, Shohada Hospital, School of Medicine, Shahid Beheshti University of Medical Science, Tehran, Iran
| | - Mahbubeh Shahsavani
- Department of Genetics & Biotechnology, School of Biological Science, Varamin-Pishva Branch, Islamic Azad University, Varamin, Iran
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10
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Parbhoo T, Sampson SL, Mouton JM. Recent Developments in the Application of Flow Cytometry to Advance our Understanding of Mycobacterium tuberculosis Physiology and Pathogenesis. Cytometry A 2020; 97:683-693. [PMID: 32437069 PMCID: PMC7496436 DOI: 10.1002/cyto.a.24030] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 04/18/2020] [Accepted: 04/21/2020] [Indexed: 12/16/2022]
Abstract
The ability of the bacterial pathogen Mycobacterium tuberculosis to adapt and survive within human cells to disseminate to other individuals and cause active disease is poorly understood. Research supports that as M. tuberculosis adapts to stressors encountered in the host, it exhibits variable physiological and metabolic states that are time and niche-dependent. Challenges associated with effective treatment and eradication of tuberculosis (TB) are in part attributed to our lack of understanding of these different mycobacterial phenotypes. This is mainly due to a lack of suitable tools to effectively identify/detect heterogeneous bacterial populations, which may include small, difficult-to-culture subpopulations. Importantly, flow cytometry allows rapid and affordable multiparametric measurements of physical and chemical characteristics of single cells, without the need to preculture cells. Here, we summarize current knowledge of flow cytometry applications that have advanced our understanding of the physiology of M. tuberculosis during TB disease. Specifically, we review how host-associated stressors influence bacterial characteristics such as metabolic activity, membrane potential, redox status and the mycobacterial cell wall. Further, we highlight that flow cytometry offers unprecedented opportunities for insight into bacterial population heterogeneity, which is increasingly appreciated as an important determinant of disease outcome. © 2020 The Authors. Cytometry Part A published by Wiley Periodicals, Inc. on behalf of International Society for Advancement of Cytometry.
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Affiliation(s)
- Trisha Parbhoo
- NRF‐DST Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health SciencesStellenbosch UniversityCape TownSouth Africa
| | - Samantha L. Sampson
- NRF‐DST Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health SciencesStellenbosch UniversityCape TownSouth Africa
| | - Jacoba M. Mouton
- NRF‐DST Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health SciencesStellenbosch UniversityCape TownSouth Africa
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Hołówka J, Zakrzewska-Czerwińska J. Nucleoid Associated Proteins: The Small Organizers That Help to Cope With Stress. Front Microbiol 2020; 11:590. [PMID: 32373086 PMCID: PMC7177045 DOI: 10.3389/fmicb.2020.00590] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2020] [Accepted: 03/18/2020] [Indexed: 12/11/2022] Open
Abstract
The bacterial chromosome must be efficiently compacted to fit inside the small and crowded cell while remaining accessible for the protein complexes involved in replication, transcription, and DNA repair. The dynamic organization of the nucleoid is a consequence of both intracellular factors (i.e., simultaneously occurring cell processes) and extracellular factors (e.g., environmental conditions, stress agents). Recent studies have revealed that the bacterial chromosome undergoes profound topological changes under stress. Among the many DNA-binding proteins that shape the bacterial chromosome structure in response to various signals, NAPs (nucleoid associated proteins) are the most abundant. These small, basic proteins bind DNA with low specificity and can influence chromosome organization under changing environmental conditions (i.e., by coating the chromosome in response to stress) or regulate the transcription of specific genes (e.g., those involved in virulence).
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Affiliation(s)
- Joanna Hołówka
- Department of Molecular Microbiology, Faculty of Biotechnology, University of Wrocław, Wrocław, Poland
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