1
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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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2
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Shaban AK, Gebretsadik G, Hakamata M, Takihara H, Inouchi E, Nishiyama A, Ozeki Y, Tateishi Y, Nishiuchi Y, Yamaguchi T, Ohara N, Okuda S, Matsumoto S. Mycobacterial DNA-binding protein 1 is critical for BCG survival in stressful environments and simultaneously regulates gene expression. Sci Rep 2023; 13:14157. [PMID: 37644087 PMCID: PMC10465568 DOI: 10.1038/s41598-023-40941-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Accepted: 08/18/2023] [Indexed: 08/31/2023] Open
Abstract
Survival of the live attenuated Bacillus Calmette-Guérin (BCG) vaccine amidst harsh host environments is key for BCG effectiveness as it allows continuous immune response induction and protection against tuberculosis. Mycobacterial DNA binding protein 1 (MDP1), a nucleoid associated protein, is essential in BCG. However, there is limited knowledge on the extent of MDP1 gene regulation and how this influences BCG survival. Here, we demonstrate that MDP1 conditional knockdown (cKD) BCG grows slower than vector control in vitro, and dies faster upon exposure to antibiotics (bedaquiline) and oxidative stress (H2O2 and menadione). MDP1-cKD BCG also exhibited low infectivity and survival in THP-1 macrophages and mice indicating possible susceptibility to host mediated stress. Consequently, low in vivo survival resulted in reduced cytokine (IFN-gamma and TNF-alpha) production by splenocytes. Temporal transcriptome profiling showed more upregulated (81-240) than downregulated (5-175) genes in response to MDP1 suppression. Pathway analysis showed suppression of biosynthetic pathways that coincide with low in vitro growth. Notable was the deferential expression of genes involved in stress response (sigI), maintenance of DNA integrity (mutT1), REDOX balance (WhiB3), and host interactions (PE/PE_PGRS). Thus, this study shows MDP1's importance in BCG survival and highlights MDP1-dependent gene regulation suggesting its role in growth and stress adaptation.
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Affiliation(s)
- Amina K Shaban
- Department of Bacteriology, School of Medicine, Niigata University, Niigata, Japan.
| | - Gebremichal Gebretsadik
- Department of Bacteriology, School of Medicine, Niigata University, Niigata, Japan
- Department of Biology, Assosa University, Assosa, Ethiopia
| | - Mariko Hakamata
- Department of Bacteriology, School of Medicine, Niigata University, Niigata, Japan
- Department of Respiratory Medicine and Infectious Disease, School of Medicine, Niigata University, Niigata, Japan
| | - Hayato Takihara
- Bioinformatics Department, School of Medicine, Niigata University, Niigata, Japan
| | - Erina Inouchi
- Department of Bacteriology, School of Medicine, Niigata University, Niigata, Japan
| | - Akihito Nishiyama
- Department of Bacteriology, School of Medicine, Niigata University, Niigata, Japan
| | - Yuriko Ozeki
- Department of Bacteriology, School of Medicine, Niigata University, Niigata, Japan
| | - Yoshitaka Tateishi
- Department of Bacteriology, School of Medicine, Niigata University, Niigata, Japan
| | - Yukiko Nishiuchi
- Department of Bacteriology, School of Medicine, Niigata University, Niigata, Japan
- Toneyama Tuberculosis Research Institute, Osaka Metropolitan University, Osaka, Japan
- Center for the Planetary Health and Innovation Science (PHIS), The IDEC Institute, Hiroshima University, Hiroshima, Japan
| | - Takehiro Yamaguchi
- Department of Bacteriology, School of Medicine, Niigata University, Niigata, Japan
- Department of Pharmacology, Osaka Metropolitan University, Osaka, Japan
| | - Naoya Ohara
- Department of Oral Microbiology, Okayama University, Okayama, Japan
| | - Shujiro Okuda
- Bioinformatics Department, School of Medicine, Niigata University, Niigata, Japan
| | - Sohkichi Matsumoto
- Department of Bacteriology, School of Medicine, Niigata University, Niigata, Japan.
- Laboratory of Tuberculosis, Institute of Tropical Disease, Universitas Airlangga, Surabaya, East Java, Indonesia.
- Division of Research Aids, Hokkaido University Institute for Vaccine Research & Development, Sapporo, Japan.
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3
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Hołówka J, Łebkowski T, Feddersen H, Giacomelli G, Drużka K, Makowski Ł, Trojanowski D, Broda N, Bramkamp M, Zakrzewska-Czerwińska J. Mycobacterial IHF is a highly dynamic nucleoid-associated protein that assists HupB in organizing chromatin. Front Microbiol 2023; 14:1146406. [PMID: 36960278 PMCID: PMC10028186 DOI: 10.3389/fmicb.2023.1146406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Accepted: 02/20/2023] [Indexed: 03/09/2023] Open
Abstract
Nucleoid-associated proteins (NAPs) crucially contribute to organizing bacterial chromatin and regulating gene expression. Among the most highly expressed NAPs are the HU and integration host factor (IHF) proteins, whose functional homologues, HupB and mycobacterial integration host factor (mIHF), are found in mycobacteria. Despite their importance for the pathogenicity and/or survival of tubercle bacilli, the role of these proteins in mycobacterial chromosome organization remains unknown. Here, we used various approaches, including super-resolution microscopy, to perform a comprehensive analysis of the roles of HupB and mIHF in chromosome organization. We report that HupB is a structural agent that maintains chromosome integrity on a local scale, and that the lack of this protein alters chromosome morphology. In contrast, mIHF is a highly dynamic protein that binds DNA only transiently, exhibits susceptibility to the chromosomal DNA topology changes and whose depletion leads to the growth arrest of tubercle bacilli. Additionally, we have shown that depletion of Mycobacterium smegmatis integration host factor (msIHF) leads to chromosome shrinkage and replication inhibition.
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Affiliation(s)
- Joanna Hołówka
- Department of Molecular Microbiology, University of Wrocław, Wrocław, Poland
- *Correspondence: Joanna Hołówka,
| | - Tomasz Łebkowski
- Department of Molecular Microbiology, University of Wrocław, Wrocław, Poland
| | - Helge Feddersen
- Institute for General Microbiology, Christian-Albrechts-University, Kiel, Germany
| | - Giacomo Giacomelli
- Institute for General Microbiology, Christian-Albrechts-University, Kiel, Germany
| | - Karolina Drużka
- Department of Molecular Microbiology, University of Wrocław, Wrocław, Poland
| | - Łukasz Makowski
- Department of Molecular Microbiology, University of Wrocław, Wrocław, Poland
| | - Damian Trojanowski
- Department of Molecular Microbiology, University of Wrocław, Wrocław, Poland
| | - Natalia Broda
- Department of Molecular Microbiology, University of Wrocław, Wrocław, Poland
| | - Marc Bramkamp
- Institute for General Microbiology, Christian-Albrechts-University, Kiel, Germany
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4
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Singh N, Sharma N, Singh P, Pandey M, Ilyas M, Sisodiya L, Choudhury T, Gosain TP, Singh R, Atmakuri K. HupB, a nucleoid-associated protein, is critical for survival of Mycobacterium tuberculosis under host-mediated stresses and for enhanced tolerance to key first-line antibiotics. Front Microbiol 2022; 13:937970. [PMID: 36071978 PMCID: PMC9441915 DOI: 10.3389/fmicb.2022.937970] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 07/12/2022] [Indexed: 11/30/2022] Open
Abstract
To survive and establish its niche, Mycobacterium tuberculosis (Mtb) engages in a steady battle against an array of host defenses and a barrage of antibiotics. Here, we demonstrate that Mtb employs HupB, a nucleoid-associated protein (NAP) as its key player to simultaneously battle and survive in these two stress-inducing fronts. Typically, NAPs are key to bacterial survival under a wide array of environmental or host-mediated stresses. Here, we report that for Mtb to survive under different macrophage-induced assaults including acidic pH, nutrient depletion, oxidative and nitrosative stresses, HupB presence is critical. As expected, the hupB knockout mutant is highly sensitive to these host-mediated stresses. Furthermore, Mtb aptly modulates HupB protein levels to overcome these stresses. We also report that HupB aids Mtb to gain tolerance to high levels of rifampicin (RIF) and isoniazid (INH) exposure. Loss of hupB makes Mtb highly susceptible to even short exposures to reduced amounts of RIF and INH. Overexpressing hupB in Mtb or complementing hupB in the hupB knockout mutant triggers enhanced survival of Mtb under these stresses. We also find that upon loss of hupB, Mtb significantly enhances the permeability of its cell wall by modulating the levels of several surface lipids including phthiocerol dimycocerosates (PDIMs), thus possibly influencing overall susceptibility to host-mediated stresses. Loss of hupB also downregulates efflux pump expression possibly influencing increased susceptibility to INH and RIF. Finally, we find that therapeutic targeting of HupB with SD1, a known small molecule inhibitor, significantly enhances Mtb susceptibility to INH and THP-1 macrophages and significantly reduces MIC to INH. Thus, our data strongly indicate that HupB is a highly promising therapeutic target especially for potential combinatorial shortened therapy with reduced INH and RIF doses.
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Affiliation(s)
- Niti Singh
- Infection and Immunology Group, Translational Health Science and Technology Institute, Faridabad, Haryana, India
- Manipal University, Manipal, Karnataka, India
| | - Nishant Sharma
- Infection and Immunology Group, Translational Health Science and Technology Institute, Faridabad, Haryana, India
| | - Padam Singh
- Infection and Immunology Group, Translational Health Science and Technology Institute, Faridabad, Haryana, India
| | - Manitosh Pandey
- Infection and Immunology Group, Translational Health Science and Technology Institute, Faridabad, Haryana, India
- Department of Life Sciences, ITM University, Gwalior, Madhya Pradesh, India
| | - Mohd Ilyas
- Infection and Immunology Group, Translational Health Science and Technology Institute, Faridabad, Haryana, India
- School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
| | - Lovely Sisodiya
- Infection and Immunology Group, Translational Health Science and Technology Institute, Faridabad, Haryana, India
- School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
| | - Tejaswini Choudhury
- Infection and Immunology Group, Translational Health Science and Technology Institute, Faridabad, Haryana, India
| | - Tannu Priya Gosain
- Infection and Immunology Group, Translational Health Science and Technology Institute, Faridabad, Haryana, India
- School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
| | - Ramandeep Singh
- Infection and Immunology Group, Translational Health Science and Technology Institute, Faridabad, Haryana, India
| | - Krishnamohan Atmakuri
- Infection and Immunology Group, Translational Health Science and Technology Institute, Faridabad, Haryana, India
- *Correspondence: Krishnamohan Atmakuri
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5
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Griego A, Douché T, Gianetto QG, Matondo M, Manina G. RNase E and HupB dynamics foster mycobacterial cell homeostasis and fitness. iScience 2022; 25:104233. [PMID: 35521527 PMCID: PMC9062218 DOI: 10.1016/j.isci.2022.104233] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 01/12/2022] [Accepted: 04/07/2022] [Indexed: 12/26/2022] Open
Abstract
RNA turnover is a primary source of gene expression variation, in turn promoting cellular adaptation. Mycobacteria leverage reversible mRNA stabilization to endure hostile conditions. Although RNase E is essential for RNA turnover in several species, its role in mycobacterial single-cell physiology and functional phenotypic diversification remains unexplored. Here, by integrating live-single-cell and quantitative-mass-spectrometry approaches, we show that RNase E forms dynamic foci, which are associated with cellular homeostasis and fate, and we discover a versatile molecular interactome. We show a likely interaction between RNase E and the nucleoid-associated protein HupB, which is particularly pronounced during drug treatment and infection, where phenotypic diversity increases. Disruption of RNase E expression affects HupB levels, impairing Mycobacterium tuberculosis growth homeostasis during treatment, intracellular replication, and host spread. Our work lays the foundation for targeting the RNase E and its partner HupB, aiming to undermine M. tuberculosis cellular balance, diversification capacity, and persistence. Single mycobacterial cells exhibit phenotypic variation in RNase E expression RNase E is implicated in the maintenance of mycobacterial cell growth homeostasis RNase E and HupB show a functional interplay in single mycobacterial cells RNase E-HupB disruption impairs Mycobacterium tuberculosis fate under drug and in macrophages
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6
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Peraman R, Meka G, Chilamakuru NB, Kutagulla VK, Malla S, Ashby CR, Tiwari AK, Yiragamreddy PR. Novel stilbene scaffolds efficiently target Mycobacterium tuberculosis nucleoid-associated protein, HU. NEW J CHEM 2021. [DOI: 10.1039/d0nj05947a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Novel scaffolds of stilbene were identified as inhibitors of Mycobacterium tuberculosis by targeting the nucleoid-associated protein, HU, using molecular docking.
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Affiliation(s)
- Ramalingam Peraman
- Medicinal chemistry Division
- Raghavendra Institute of Pharmaceutical Education and Research (RIPER)-Autonomous
- Anantapur (AP)
- India
| | - Geethavani Meka
- Medicinal chemistry Division
- Raghavendra Institute of Pharmaceutical Education and Research (RIPER)-Autonomous
- Anantapur (AP)
- India
| | - Naresh Babu Chilamakuru
- Medicinal chemistry Division
- Raghavendra Institute of Pharmaceutical Education and Research (RIPER)-Autonomous
- Anantapur (AP)
- India
| | - Vinay Kumar Kutagulla
- Medicinal chemistry Division
- Raghavendra Institute of Pharmaceutical Education and Research (RIPER)-Autonomous
- Anantapur (AP)
- India
| | - Saloni Malla
- Department of Pharmacology & Experimental Therapeutics
- College of Pharmacy & Pharmaceutical Sciences
- The University of Toledo
- Toledo
- USA
| | - Charles R. Ashby
- Department of Pharmaceutical Sciences
- St. John's University
- Queens
- USA
| | - Amit K. Tiwari
- Department of Pharmacology & Experimental Therapeutics
- College of Pharmacy & Pharmaceutical Sciences
- The University of Toledo
- Toledo
- USA
| | - Padmanabha Reddy Yiragamreddy
- Medicinal chemistry Division
- Raghavendra Institute of Pharmaceutical Education and Research (RIPER)-Autonomous
- Anantapur (AP)
- India
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7
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Salina EG, Grigorov A, Skvortsova Y, Majorov K, Bychenko O, Ostrik A, Logunova N, Ignatov D, Kaprelyants A, Apt A, Azhikina T. MTS1338, A Small Mycobacterium tuberculosis RNA, Regulates Transcriptional Shifts Consistent With Bacterial Adaptation for Entering Into Dormancy and Survival Within Host Macrophages. Front Cell Infect Microbiol 2019; 9:405. [PMID: 31850238 PMCID: PMC6901956 DOI: 10.3389/fcimb.2019.00405] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Accepted: 11/12/2019] [Indexed: 11/13/2022] Open
Abstract
Small non-coding RNAs play a significant role in bacterial adaptation to changing environmental conditions. We investigated the dynamics of expression of MTS1338, a small non-coding RNA of Mycobacterium tuberculosis, in the mouse model in vivo, regulation of its expression in the infected macrophages, and the consequences of its overexpression in bacterial cultures. Here we demonstrate that MTS1338 significantly contributes to host-pathogen interactions. Activation of the host immune system triggered NO-inducible up-regulation of MTS1338 in macrophage-engulfed mycobacteria. Constitutive overexpression of MTS1338 in cultured mycobacteria improved their survival in vitro under low pH conditions. MTS1338 up-regulation launched a spectrum of shifts in the transcriptome profile similar to those reported for M. tuberculosis adaptation to hostile intra-macrophage environment. Using the RNA-seq approach, we demonstrate that gene expression changes accompanying MTS1338 overexpression indicate reduction in translational activity and bacterial growth. These changes indicate mycobacteria entering the dormant state. Taken together, our results suggest a direct involvement of this sRNA in the interplay between mycobacteria and the host immune system during infectious process.
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Affiliation(s)
- Elena G. Salina
- Laboratory of Biochemistry of Stresses in Microorganisms, Bach Institute of Biochemistry, Research Center of Biotechnology, Moscow, Russia
| | - Artem Grigorov
- Laboratory of Regulatory Transcriptomics, Department of Genomics and Postgenomic Technologies, Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Moscow, Russia
| | - Yulia Skvortsova
- Laboratory of Regulatory Transcriptomics, Department of Genomics and Postgenomic Technologies, Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Moscow, Russia
| | - Konstantin Majorov
- Laboratory for Immunogenetics, Department of Immunology, Central Institute for Tuberculosis, Moscow, Russia
| | - Oksana Bychenko
- Laboratory of Regulatory Transcriptomics, Department of Genomics and Postgenomic Technologies, Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Moscow, Russia
| | - Albina Ostrik
- Laboratory of Biochemistry of Stresses in Microorganisms, Bach Institute of Biochemistry, Research Center of Biotechnology, Moscow, Russia
| | - Nadezhda Logunova
- Laboratory for Immunogenetics, Department of Immunology, Central Institute for Tuberculosis, Moscow, Russia
| | - Dmitriy Ignatov
- Laboratory of Regulatory Transcriptomics, Department of Genomics and Postgenomic Technologies, Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Moscow, Russia
| | - Arseny Kaprelyants
- Laboratory of Biochemistry of Stresses in Microorganisms, Bach Institute of Biochemistry, Research Center of Biotechnology, Moscow, Russia
| | - Alexander Apt
- Laboratory for Immunogenetics, Department of Immunology, Central Institute for Tuberculosis, Moscow, Russia
| | - Tatyana Azhikina
- Laboratory of Regulatory Transcriptomics, Department of Genomics and Postgenomic Technologies, Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Moscow, Russia
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8
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Kalra P, Mishra SK, Kaur S, Kumar A, Prasad HK, Sharma TK, Tyagi JS. G-Quadruplex-Forming DNA Aptamers Inhibit the DNA-Binding Function of HupB and Mycobacterium tuberculosis Entry into Host Cells. MOLECULAR THERAPY. NUCLEIC ACIDS 2018; 13:99-109. [PMID: 30245472 PMCID: PMC6148841 DOI: 10.1016/j.omtn.2018.08.011] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/09/2018] [Revised: 08/16/2018] [Accepted: 08/16/2018] [Indexed: 01/26/2023]
Abstract
The entry and survival of Mycobacterium tuberculosis (Mtb) within host cells is orchestrated partly by an essential histone-like protein HupB (Rv2986c). Despite being an essential drug target, the lack of structural information has impeded the development of inhibitors targeting the indispensable and multifunctional C-terminal domain (CTD) of HupB. To bypass the requirement for structural information in the classical drug discovery route, we generated a panel of DNA aptamers against HupB protein through systemic evolution of ligands by exponential (SELEX) enrichment. Two G-quadruplex-forming high-affinity aptamers (HupB-4T and HupB-13T) were identified, each of which bound two distinct sites on full-length HupB, with an estimated KD of ∼1.72 μM and ∼0.17 μM, respectively, for the high-affinity sites. While HupB-4T robustly inhibited DNA-binding activity of HupB in vitro, both the aptamers recognized surface-located HupB and significantly blocked Mtb entry into THP-1 monocytic cells (p < 0.0001). In summary, DNA aptamers generated in this study block DNA-binding activity of HupB, inhibit virulent Mtb infection in host cells, and demonstrate aptamers to be inhibitors of HupB functions. This study also illustrates the utility of SELEX in developing inhibitors against essential targets for whom structural information is not available.
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Affiliation(s)
- Priya Kalra
- Department of Biotechnology, All India Institute of Medical Sciences, New Delhi, Delhi 110029, India
| | - Subodh Kumar Mishra
- Discipline of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Simrol, Madhya Pradesh 453552, India
| | - Surinder Kaur
- Department of Biotechnology, All India Institute of Medical Sciences, New Delhi, Delhi 110029, India
| | - Amit Kumar
- Discipline of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Simrol, Madhya Pradesh 453552, India
| | | | - Tarun Kumar Sharma
- Centre for Biodesign and Diagnostics, Translational Health Science and Technology Institute, Faridabad, Haryana 121001, India.
| | - Jaya Sivaswami Tyagi
- Department of Biotechnology, All India Institute of Medical Sciences, New Delhi, Delhi 110029, India; Centre for Biodesign and Diagnostics, Translational Health Science and Technology Institute, Faridabad, Haryana 121001, India.
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9
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C-terminal intrinsically disordered region-dependent organization of the mycobacterial genome by a histone-like protein. Sci Rep 2018; 8:8197. [PMID: 29844400 PMCID: PMC5974015 DOI: 10.1038/s41598-018-26463-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Accepted: 05/11/2018] [Indexed: 11/23/2022] Open
Abstract
The architecture of the genome influences the functions of DNA from bacteria to eukaryotes. Intrinsically disordered regions (IDR) of eukaryotic histones have pivotal roles in various processes of gene expression. IDR is rare in bacteria, but interestingly, mycobacteria produce a unique histone-like protein, MDP1 that contains a long C-terminal IDR. Here we analyzed the role of IDR in MDP1 function. By employing Mycobacterium smegmatis that inducibly expresses MDP1 or its IDR-deficient mutant, we observed that MDP1 induces IDR-dependent DNA compaction. MDP1-IDR is also responsible for the induction of growth arrest and tolerance to isoniazid, a front line tuberculosis drug that kills growing but not growth-retardated mycobacteria. We demonstrated that MDP1-deficiency and conditional knock out of MDP1 cause spreading of the M. smegmatis genome in the stationary phase. This study thus demonstrates for the first time a C-terminal region-dependent organization of the genome architecture by MDP1, implying the significance of IDR in the function of bacterial histone-like protein.
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10
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The Origin of Chromosomal Replication Is Asymmetrically Positioned on the Mycobacterial Nucleoid, and the Timing of Its Firing Depends on HupB. J Bacteriol 2018. [PMID: 29531181 DOI: 10.1128/jb.00044-18] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
The bacterial chromosome undergoes dynamic changes in response to ongoing cellular processes and adaptation to environmental conditions. Among the many proteins involved in maintaining this dynamism, the most abundant is the nucleoid-associated protein (NAP) HU. In mycobacteria, the HU homolog, HupB, possesses an additional C-terminal domain that resembles that of eukaryotic histones H1/H5. Recently, we demonstrated that the highly abundant HupB protein occupies the entirety of the Mycobacterium smegmatis chromosome and that the HupB-binding sites exhibit a bias from the origin (oriC) to the terminus (ter). In this study, we used HupB fused with enhanced green fluorescent protein (EGFP) to perform the first analysis of chromosome dynamics and to track the oriC and replication machinery directly on the chromosome during the mycobacterial cell cycle. We show that the chromosome is located in an off-center position that reflects the unequal division and growth of mycobacterial cells. Moreover, unlike the situation in E. coli, the sister oriC regions of M. smegmatis move asymmetrically along the mycobacterial nucleoid. Interestingly, in this slow-growing organism, the initiation of the next round of replication precedes the physical separation of sister chromosomes. Finally, we show that HupB is involved in the precise timing of replication initiation.IMPORTANCE Although our view of mycobacterial nucleoid organization has evolved considerably over time, we still know little about the dynamics of the mycobacterial nucleoid during the cell cycle. HupB is a highly abundant mycobacterial nucleoid-associated protein (NAP) with an indispensable histone-like tail. It was previously suggested as a potential target for antibiotic therapy against tuberculosis. Here, we fused HupB with enhanced green fluorescent protein (EGFP) to study the dynamics of the mycobacterial chromosome in real time and to monitor the replication process directly on the chromosome. Our results reveal that, unlike the situation in Escherichia coli, the nucleoid of an apically growing mycobacterium is positioned asymmetrically within the cell throughout the cell cycle. We show that HupB is involved in controlling the timing of replication initiation. Since tuberculosis remains a serious health problem, studies concerning mycobacterial cell biology are of great importance.
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Abstract
In bacteria, chromosomal DNA must be efficiently compacted to fit inside the small cell compartment while remaining available for the proteins involved in replication, segregation, and transcription. Among the nucleoid-associated proteins (NAPs) responsible for maintaining this highly organized and yet dynamic chromosome structure, the HU protein is one of the most conserved and highly abundant. HupB, a homologue of HU, was recently identified in mycobacteria. This intriguing mycobacterial NAP is composed of two domains: an N-terminal domain that resembles bacterial HU, and a long and distinctive C-terminal domain that contains several PAKK/KAAK motifs, which are characteristic of the H1/H5 family of eukaryotic histones. In this study, we analyzed the in vivo binding of HupB on the chromosome scale. By using PALM (photoactivated localization microscopy) and ChIP-Seq (chromatin immunoprecipitation followed by deep sequencing), we observed that the C-terminal domain is indispensable for the association of HupB with the nucleoid. Strikingly, the in vivo binding of HupB displayed a bias from the origin (oriC) to the terminus (ter) of the mycobacterial chromosome (numbers of binding sites decreased toward ter). We hypothesized that this binding mode reflects a role for HupB in organizing newly replicated oriC regions. Thus, HupB may be involved in coordinating replication with chromosome segregation.IMPORTANCE We currently know little about the organization of the mycobacterial chromosome and its dynamics during the cell cycle. Among the mycobacterial nucleoid-associated proteins (NAPs) responsible for chromosome organization and dynamics, HupB is one of the most intriguing. It contains a long and distinctive C-terminal domain that harbors several PAKK/KAAK motifs, which are characteristic of the eukaryotic histone H1/H5 proteins. The HupB protein is also known to be crucial for the survival of tubercle bacilli during infection. Here, we provide in vivo experimental evidence showing that the C-terminal domain of HupB is crucial for its DNA binding. Our results suggest that HupB may be involved in organizing newly replicated regions and could help coordinate chromosome replication with segregation. Given that tuberculosis (TB) remains a serious worldwide health problem (10.4 million new TB cases were diagnosed in 2015, according to WHO) and new multidrug-resistant Mycobacterium tuberculosis strains are continually emerging, further studies of the biological function of HupB are needed to determine if this protein could be a prospect for novel antimicrobial drug development.
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Roy A, Dutta A, Roy D, Ganguly P, Ghosh R, Kar RK, Bhunia A, Mukhopadhyay J, Chaudhuri S. Deciphering the role of the AT-rich interaction domain and the HMG-box domain of ARID-HMG proteins of Arabidopsis thaliana. PLANT MOLECULAR BIOLOGY 2016; 92:371-88. [PMID: 27503561 DOI: 10.1007/s11103-016-0519-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Accepted: 07/28/2016] [Indexed: 05/22/2023]
Abstract
ARID-HMG DNA-binding proteins represent a novel group of HMG-box containing protein family where the AT-rich interaction domain (ARID) is fused with the HMG-box domain in a single polypeptide chain. ARID-HMG proteins are highly plant specific with homologs found both in flowering plants as well as in moss such as Physcomitrella. The expression of these proteins is ubiquitous in plant tissues and primarily localises in the cell nucleus. HMGB proteins are involved in several nuclear processes, but the role of ARID-HMG proteins in plants remains poorly explored. Here, we performed DNA-protein interaction studies with Arabidopsis ARID-HMG protein HMGB11 (At1g55650) to understand the functionality of this protein and its individual domains. DNA binding assays revealed that AtHMGB11 can bind double-stranded DNA with a weaker affinity (Kd = 475 ± 17.9 nM) compared to Arabidopsis HMGB1 protein (Kd = 39.8 ± 2.68 nM). AtHMGB11 also prefers AT-rich DNA as a substrate and shows structural bias for supercoiled DNA. Molecular docking of the DNA-AtHMGB11 complex indicated that the protein interacts with the DNA major groove, mainly through its ARID domain and the junction region connecting the ARID and the HMG-box domain. Also, predicted by the docking model, mutation of Lys(85) from the ARID domain and Arg(199) & Lys(202) from the junction region affects the DNA binding affinity of AtHMGB11. In addition, AtHMGB11 and its truncated form containing the HMG-box domain can not only promote DNA mini-circle formation but are also capable of inducing negative supercoils into relaxed plasmid DNA suggesting the involvement of this protein in several nuclear events. Overall, the study signifies that both the ARID and the HMG-box domain contribute to the optimal functioning of ARID-HMG protein in vivo.
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Affiliation(s)
- Adrita Roy
- Division of Plant Biology, Bose Institute, Kolkata, 700054, India
| | - Arkajyoti Dutta
- Department of Chemistry, Bose Institute, Kolkata, 700054, India
| | - Dipan Roy
- Division of Plant Biology, Bose Institute, Kolkata, 700054, India
| | - Payel Ganguly
- Division of Plant Biology, Bose Institute, Kolkata, 700054, India
| | - Ritesh Ghosh
- School of Biotechnology, Yeungnam University, Gyeongsan, 712-749, South Korea
| | - Rajiv K Kar
- Department of Biophysics, Bose Institute, Kolkata, 700054, India
| | - Anirban Bhunia
- Department of Biophysics, Bose Institute, Kolkata, 700054, India
| | | | - Shubho Chaudhuri
- Division of Plant Biology, Bose Institute, Kolkata, 700054, India.
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Bouthier de la Tour C, Blanchard L, Dulermo R, Ludanyi M, Devigne A, Armengaud J, Sommer S, de Groot A. The abundant and essential HU proteins in Deinococcus deserti and Deinococcus radiodurans are translated from leaderless mRNA. MICROBIOLOGY-SGM 2015; 161:2410-22. [PMID: 26385459 DOI: 10.1099/mic.0.000186] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
HU proteins have an important architectural role in nucleoid organization in bacteria. Compared with HU of many bacteria, HU proteins from Deinococcus species possess an N-terminal lysine-rich extension similar to the eukaryotic histone H1 C-terminal domain involved in DNA compaction. The single HU gene in Deinococcus radiodurans, encoding DrHU, is required for nucleoid compaction and cell viability. Deinococcus deserti contains three expressed HU genes, encoding DdHU1, DdHU2 and DdHU3. Here, we show that either DdHU1 or DdHU2 is essential in D. deserti. DdHU1 and DdHU2, but not DdHU3, can substitute for DrHU in D. radiodurans, indicating that DdHU3 may have a non-essential function different from DdHU1, DdHU2 and DrHU. Interestingly, the highly abundant DrHU and DdHU1 proteins, and also the less expressed DdHU2, are translated in Deinococcus from leaderless mRNAs, which lack a 5'-untranslated region and, hence, the Shine-Dalgarno sequence. Unexpectedly, cloning the DrHU or DdHU1 gene under control of a strong promoter in an expression plasmid, which results in leadered transcripts, strongly reduced the DrHU and DdHU1 protein level in D. radiodurans compared with that obtained from the natural leaderless gene. We also show that the start codon position for DrHU and DdHU1 should be reannotated, resulting in proteins that are 15 and 4 aa residues shorter than initially reported. The expression level and start codon correction were crucial for functional characterization of HU in Deinococcus.
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Affiliation(s)
- Claire Bouthier de la Tour
- 1Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris Sud, Bâtiment 409, F-91405 Orsay, France
| | - Laurence Blanchard
- 2CEA, DSV, IBEB, Lab Bioenerget Cellulaire, F-13108 Saint-Paul-lez-Durance, France 3CNRS, UMR 7265 Biol Veget & Microbiol Environ, F-13108 Saint-Paul-lez-Durance, France 4Aix-Marseille Université, F-13108 Saint-Paul-lez-Durance, France
| | - Rémi Dulermo
- 1Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris Sud, Bâtiment 409, F-91405 Orsay, France 3CNRS, UMR 7265 Biol Veget & Microbiol Environ, F-13108 Saint-Paul-lez-Durance, France 4Aix-Marseille Université, F-13108 Saint-Paul-lez-Durance, France 5CEA, DSV, IBEB, Lab Ecol Microb Rhizosphere & Environ Extrem, F-13108 Saint-Paul-lez-Durance, France
| | - Monika Ludanyi
- 2CEA, DSV, IBEB, Lab Bioenerget Cellulaire, F-13108 Saint-Paul-lez-Durance, France 3CNRS, UMR 7265 Biol Veget & Microbiol Environ, F-13108 Saint-Paul-lez-Durance, France 4Aix-Marseille Université, F-13108 Saint-Paul-lez-Durance, France
| | - Alice Devigne
- 1Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris Sud, Bâtiment 409, F-91405 Orsay, France
| | - Jean Armengaud
- 6CEA-Marcoule, DSV/IBITEC-S/SPI/Li2D, Laboratory 'Innovative technologies for Detection and Diagnostic', BP 17171, F-30207 Bagnols-sur-Cèze, France
| | - Suzanne Sommer
- 1Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris Sud, Bâtiment 409, F-91405 Orsay, France
| | - Arjan de Groot
- 3CNRS, UMR 7265 Biol Veget & Microbiol Environ, F-13108 Saint-Paul-lez-Durance, France 2CEA, DSV, IBEB, Lab Bioenerget Cellulaire, F-13108 Saint-Paul-lez-Durance, France 4Aix-Marseille Université, F-13108 Saint-Paul-lez-Durance, France
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Pandey SD, Choudhury M, Sritharan M. Transcriptional regulation of Mycobacterium tuberculosis hupB gene expression. MICROBIOLOGY-SGM 2014; 160:1637-1647. [PMID: 24858079 DOI: 10.1099/mic.0.079640-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The influence of iron levels on the transcription of the hupB gene in Mycobacterium tuberculosis is the focus of this study. Studies in our laboratory showed HupB to be co-expressed with the two siderophores in low-iron organisms. Mycobactin biosynthesis is repressed by the IdeR-Fe(2+) complex that binds the IdeR box in the mbtB promoter. Recently, we demonstrated the positive regulatory effect of HupB on mycobactin biosynthesis by demonstrating its binding to a 10 bp HupB box in the mbtB promoter. Earlier, we observed that HupB, expressed maximally in low-iron media (0.02 µg Fe ml(-1); 0.36 µM Fe) was still detectable at 8 µg Fe ml(-1) (144 µM Fe) when the siderophores were absent and complete repression was seen only at 12 µg Fe ml(-1) (216 µM Fe). In this study, we observed elevated levels of hupB transcripts in iron-limited organisms. IdeR, and not FurA, functioned as the iron regulator, by binding to two IdeR boxes in the hupB promoter. Interestingly, the 10 bp HupB box, first reported in the mbtB promoter, was identified in the hupB promoter. Using DNA footprinting and electrophoretic mobility shift assays, we demonstrated the functionality of the HupB box and the two IdeR boxes. The high hupB transcript levels expressed by the organism and the in vitro protein-DNA interaction studies led us to hypothesize the sequence of events occurring in response to changes in the intracellular iron concentration, emphasizing the roles played by IdeR and HupB in iron homeostasis.
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Affiliation(s)
- Satya Deo Pandey
- Department of Animal Sciences, School of Life Sciences, University of Hyderabad, Prof. C.R. Rao Road, Gachibowli, Hyderabad 500046, India
| | - Mitali Choudhury
- Department of Animal Sciences, School of Life Sciences, University of Hyderabad, Prof. C.R. Rao Road, Gachibowli, Hyderabad 500046, India
| | - Manjula Sritharan
- Department of Animal Sciences, School of Life Sciences, University of Hyderabad, Prof. C.R. Rao Road, Gachibowli, Hyderabad 500046, India
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HupB, a nucleoid-associated protein of Mycobacterium tuberculosis, is modified by serine/threonine protein kinases in vivo. J Bacteriol 2014; 196:2646-57. [PMID: 24816602 DOI: 10.1128/jb.01625-14] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
HU, a widely conserved bacterial histone-like protein, regulates many genes, including those involved in stress response and virulence. Whereas ample data are available on HU-DNA communication, the knowledge on how HU perceives a signal and transmit it to DNA remains limited. In this study, we identify HupB, the HU homolog of the human pathogen Mycobacterium tuberculosis, as a component of serine/threonine protein kinase (STPK) signaling. HupB is extracted in its native state from the exponentially growing cells of M. tuberculosis H37Ra and is shown to be phosphorylated on both serine and threonine residues. The STPKs capable of modifying HupB are determined in vitro and the residues modified by the STPKs are identified for both in vivo and the in vitro proteins through mass spectrometry. Of the identified phosphosites, Thr(65) and Thr(74) in the DNA-embracing β-strand of the N-terminal domain of HupB (N-HupB) are shown to be crucial for its interaction with DNA. In addition, Arg(55) is also identified as an important residue for N-HupB-DNA interaction. N-HupB is shown to have a diminished interaction with DNA after phosphorylation. Furthermore, hupB is shown to be maximally expressed during the stationary phase in M. tuberculosis H37Ra, while HupB kinases were found to be constitutively expressed (PknE and PknF) or most abundant during the exponential phase (PknB). In conclusion, HupB, a DNA-binding protein, with an ability to modulate chromatin structure is proposed to work in a growth-phase-dependent manner through its phosphorylation carried out by the mycobacterial STPKs.
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Integration host factor of Mycobacterium tuberculosis, mIHF, compacts DNA by a bending mechanism. PLoS One 2013; 8:e69985. [PMID: 23922883 PMCID: PMC3724605 DOI: 10.1371/journal.pone.0069985] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2013] [Accepted: 06/14/2013] [Indexed: 12/03/2022] Open
Abstract
The bacterial chromosomal DNA is folded into a compact structure called as ‘nucleoid’ so that the bacterial genome can be accommodated inside the cell. The shape and size of the nucleoid are determined by several factors including DNA supercoiling, macromolecular crowding and nucleoid associated proteins (NAPs). NAPs bind to different sites of the genome in sequence specific or non-sequence specific manner and play an important role in DNA compaction as well as regulation. Until recently, few NAPs have been discovered in mycobacteria owing to poor sequence similarities with other histone-like proteins of eubacteria. Several putative NAPs have now been identified in Mycobacteria on the basis of enriched basic residues or histone-like “PAKK” motifs. Here, we investigate mycobacterial Integration Host Factor (mIHF) for its architectural roles as a NAP using atomic force microscopy and DNA compaction experiments. We demonstrate that mIHF binds DNA in a non-sequence specific manner and compacts it by a DNA bending mechanism. AFM experiments also indicate a dual architectural role for mIHF in DNA compaction as well as relaxation. These results suggest a convergent evolution in the mechanism of E. coli and mycobacterial IHF in DNA compaction.
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Bradshaw E, Saalbach G, McArthur M. Proteomic survey of the Streptomyces coelicolor nucleoid. J Proteomics 2013; 83:37-46. [PMID: 23523638 PMCID: PMC3784963 DOI: 10.1016/j.jprot.2013.02.033] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2012] [Revised: 02/17/2013] [Accepted: 02/28/2013] [Indexed: 11/29/2022]
Abstract
Nucleoid-associated proteins (NAPs) are small, highly abundant transcriptional regulators with low sequence specificity which are involved in multiple DNA-related processes including gene expression, DNA protection, recombination/repair and nucleoid structuring. Through these functions they are able to regulate important phenotypic properties including virulence, secondary metabolism and stress resistance. However the set of NAPs known within the Actinobacteria is small and incomplete. The missing proteins are likely to be key regulators of virulence in pathogens such as Mycobacterium tuberculosis and also of development and secondary metabolism in industrially-important species such as Streptomyces. Here, we use label-free LC–MS/MS to systematically search for novel NAPs in isolated nucleoids of the model actinomycete Streptomyces coelicolor. Based on the criteria of high abundance (emPAI score) and predicted DNA-binding ability (DNAbinder score) we identified a set of 24 proteins with a high predicted likelihood of being NAPs. The approach was deemed successful as the set included known major NAPs HupA, HupS, sIHF and Lsr2 as well as the global transcriptional regulators BldD and CRP and the pleiotropic response regulator AfsQ1. It also included a number of proteins whose functions are not yet known from recognisable classes of transcription factor (SCO2140, SCO4493, SCO1839, SCO1210, SCO5405, SCO4229, SCO3198) or from uncharacterised protein families (SCO5783, SCO5592, SCO3793, SCO6482) which comprise a valuable set of candidates for further study. Biological significance In this paper we establish a robust protocol for preparing S. coelicolor nucleoids for mass spectrometric analysis and develop a workflow for identifying novel nucleoid-associated proteins (NAPs) by combining LC–MS/MS with a bioinformatical analysis. The nucleoid-associated proteins of many species are known to be key regulators of virulence, stress tolerance and global patterns of gene expression. Identifying the “missing” nucleoid proteins of S. coelicolor is likely to have important implications for manipulating the production of secondary metabolites such as antibiotics. Candidate NAPs were identified. Several of these are highly conserved in clinically important species such as Mycobacterium and in many commercially important species such as Salinispora and Micromonospora which represent a vital source of novel drugs such as antibiotics, antifungals and anticancer agents. Streptomyces coelicolor was grown in liquid culture to late vegetative phase. Whole nucleoids were isolated by sucrose gradient sedimentation. Proteins attached to the nucleoids were identified by label-free LC–MS/MS. A list of high-abundance DNA-binding proteins was generated, representing likely NAPs.
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Beckmann JF, Markowski TW, Witthuhn BA, Fallon AM. Detection of the Wolbachia-encoded DNA binding protein, HU beta, in mosquito gonads. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2013; 43:272-279. [PMID: 23287400 PMCID: PMC3578164 DOI: 10.1016/j.ibmb.2012.12.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2012] [Revised: 12/14/2012] [Accepted: 12/18/2012] [Indexed: 05/31/2023]
Abstract
Wolbachia are obligate intracellular bacteria that cause cytoplasmic incompatibility in mosquitoes. In an incompatible cross, eggs of uninfected females fail to hatch when fertilized by sperm from infected males. We used polyacrylamide gel electrophoresis and tandem mass spectrometry to identify Wolbachia proteins in infected mosquito gonads. These included surface proteins with masses of 25 and 18 kDa and the DNA binding protein, HU beta. Using reverse transcriptase polymerase chain reaction, we showed that the HU gene is transcribed in Wolbachia-infected Culex pipiens and Aedes albopictus mosquitoes. We sequenced HU genes from four Wolbachia strains and compared deduced protein sequences with additional homologs from the databases. Among the Rickettsiales, Wolbachia HU has distinct N- and C-terminal basic/acidic amino acid motifs as well as a pair of conserved, cysteine residues.
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Affiliation(s)
- John F Beckmann
- Department of Entomology, University of Minnesota, St. Paul, MN 55108, USA.
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The role of the mycobacterial DNA-binding protein 1 (MDP1) from Mycobacterium bovis BCG in host cell interaction. BMC Microbiol 2012; 12:165. [PMID: 22863261 PMCID: PMC3438132 DOI: 10.1186/1471-2180-12-165] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2012] [Accepted: 07/27/2012] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Mycobacterium tuberculosis differs from most pathogens in its ability to multiply inside monocytes and to persist during long periods of time within granuloma in a status of latency. A class of proteins called mycobacterial histone-like proteins has been associated with regulation of replication and latency, but their precise role in the infection process has yet to be uncovered. Our study aimed at defining the impact of the histone-like protein MDP1 from M. bovis BCG (mycobacterial DNA-binding protein 1, corresponding to Rv2986c from M. tuberculosis) on early steps of infection. RESULTS Previously, a BCG (Bacillus Calmette Guérin) strain had been generated by antisense-technique exhibiting reduced MDP1 expression. This strain was now used to analyse the impact of reduced amount of MDP1 on the interaction with human blood monocytes, macrophage lines and PBMC (peripheral blood mononuclear cells). MDP1 was revealed to be required for growth at acidic pH and for intracellular replication in human blood monocytes. Down-regulation of MDP1 resulted in reduced secretion of the cytokine IL-1β by infected human PBMC. In addition, a reduction of MDP1 expression had a major impact on the formation of fused multi-nucleated macrophages. In monocyte preparations from human blood as well as in human and mouse macrophage cell lines, both the percentage of multi-nucleated cells and the number of nuclei per cell were much enhanced when the monocytes were infected with BCG expressing less MDP1. CONCLUSION MDP1 from M. bovis BCG affects the growth at acidic pH and the intracellular replication in human monocytes. It furthermore affects cytokine secretion by host cells, and the formation of fused multi-nucleated macrophages. Our results suggest an important role of MDP1 in persistent infection.
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Sharadamma N, Khan K, Kumar S, Patil KN, Hasnain SE, Muniyappa K. Synergy between the N-terminal and C-terminal domains of Mycobacterium tuberculosis HupB is essential for high-affinity binding, DNA supercoiling and inhibition of RecA-promoted strand exchange. FEBS J 2011; 278:3447-62. [PMID: 21787377 DOI: 10.1111/j.1742-4658.2011.08267.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The occurrence of DNA architectural proteins containing two functional domains derived from two different architectural proteins is an interesting emerging research theme in the field of nucleoid structure and function. Mycobacterium tuberculosis HupB, unlike Escherichia coli HU, is a two-domain protein that, in the N-terminal region, shows broad sequence homology with bacterial HU. The long C-terminal extension, on the other hand, contains seven PAKK/KAAK motifs, which are characteristic of the histone H1/H5 family of proteins. In this article, we describe several aspects of HupB function, in comparison with its truncated derivatives lacking either the C-terminus or N-terminus. We found that HupB binds a variety of DNA repair and replication intermediates with K(d) values in the nanomolar range. By contrast, the N-terminal fragment of M. tuberculosis HupB (HupB(MtbN)) showed diminished DNA-binding activity, with K(d) values in the micromolar range, and the C-terminal domain was completely devoid of DNA-binding activity. Unlike HupB(MtbN) , HupB was able to constrain DNA in negative supercoils and introduce negative superhelical turns into relaxed DNA. Similarly, HupB exerted a robust inhibitory effect on DNA strand exchange promoted by cognate and noncognate RecA proteins, whereas HupB(MtbN), even at a 50-fold molar excess, had no inhibitory effect. Considered together, these results suggest that synergy between the N-terminal and C-terminal domains of HupB is essential for its DNA-binding ability, and to modulate the topological features of DNA, which has implications for processes such as DNA compaction, gene regulation, homologous recombination, and DNA repair.
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Affiliation(s)
- N Sharadamma
- Department of Biochemistry, Indian Institute of Science, Bangalore, India
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Yee B, Sagulenko E, Fuerst JA. Making heads or tails of the HU proteins in the planctomycete Gemmata obscuriglobus. MICROBIOLOGY-SGM 2011; 157:2012-2021. [PMID: 21511768 DOI: 10.1099/mic.0.047605-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Gemmata obscuriglobus has a highly condensed nucleoid which is implicated in its resistance to radiation. However, the mechanisms by which such compaction is achieved, and the proteins responsible, are still unknown. Here we have examined the genome of G. obscuriglobus for the presence of proteins homologous to those that have been associated with nucleoid condensation. We found two different proteins homologous to the bacterial nucleoid-associated protein HU, one with an N-terminal and one with a C-terminal extension relative to the amino acid sequence of the HU found in Escherichia coli. Sequence analysis revealed that one of these HU homologues represents a novel type with a high number of prolines in its C-terminal extension, whereas the other one has motifs similar to the N terminus of the HU homologue from the radio-resistant bacterium Deinococcus radiodurans. The occurrence of two such HU homologue proteins with these two different terminal extensions in one organism appears to be unique among the Bacteria.
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Affiliation(s)
- Benjamin Yee
- The University of Queensland, School of Chemistry and Molecular Biosciences, St Lucia, Queensland 4072, Australia
| | - Evgeny Sagulenko
- The University of Queensland, School of Chemistry and Molecular Biosciences, St Lucia, Queensland 4072, Australia
| | - John A Fuerst
- The University of Queensland, School of Chemistry and Molecular Biosciences, St Lucia, Queensland 4072, Australia
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