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Guiza Beltran D, Wan T, Zhang L. WhiB-like proteins: Diversity of structure, function and mechanism. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2024; 1871:119787. [PMID: 38879133 PMCID: PMC11365794 DOI: 10.1016/j.bbamcr.2024.119787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Revised: 05/20/2024] [Accepted: 06/11/2024] [Indexed: 06/22/2024]
Abstract
The WhiB-Like (Wbl) proteins are a large family of iron-sulfur (Fe-S) cluster-containing transcription factors exclusively found in the phylum Actinobacteria, including the notable genera like Mycobacteria, Streptomycetes and Corynebacteria. These proteins play pivotal roles in diverse biological processes, such as cell development, redox stress response and antibiotic resistance. Members of the Wbl family exhibit remarkable diversity in their sequences, structures and functions, attracting great attention since their first discovery. This review highlights the most recent breakthroughs in understanding the structural and mechanistic aspects of Wbl-dependent transcriptional regulation.
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Affiliation(s)
- Daisy Guiza Beltran
- Department of Biochemistry, University of Nebraska-Lincoln, N138 Beadle Center, 1901 Vine Street, Lincoln, NE 68588, USA
| | - Tao Wan
- Department of Biochemistry, University of Nebraska-Lincoln, N138 Beadle Center, 1901 Vine Street, Lincoln, NE 68588, USA
| | - LiMei Zhang
- Department of Biochemistry, University of Nebraska-Lincoln, N138 Beadle Center, 1901 Vine Street, Lincoln, NE 68588, USA; Redox Biology Center, University of Nebraska-Lincoln, N138 Beadle Center, 1901 Vine Street, Lincoln, NE 68588, USA; Nebraska Center for Integrated Biomolecular Communication, University of Nebraska-Lincoln, N138 Beadle Center, 1901 Vine Street, Lincoln, NE 68588, USA.
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Płocińska R, Struś K, Korycka-Machała M, Płociński P, Kuzioła M, Żaczek A, Słomka M, Dziadek J. MnoSR removal in Mycobacterium smegmatis triggers broad transcriptional response to 1,3-propanediol and glucose as sole carbon sources. Front Cell Infect Microbiol 2024; 14:1427829. [PMID: 39113823 PMCID: PMC11303327 DOI: 10.3389/fcimb.2024.1427829] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2024] [Accepted: 07/02/2024] [Indexed: 08/10/2024] Open
Abstract
Introduction The two-component signal transduction systems play an essential role in the adaptation of bacteria to changing environmental conditions. One of them is the MnoSR system involved in the regulation of methylotrophic metabolism in M. smegmatis. Methods Mycobacterium smegmatis mutant strains ΔmnoS, ΔmnoR and ΔmnoS/R lacking functional mnoS, mnoR and both genes were generated using a homologous recombination approach. MnoR recombinant protein was purified by affinity column chromatography. The present study employs molecular biology techniques: cloning strategies, global RNA sequencing, qRT-PCR, EMSA, Microscale thermophoresis, and bioinformatics analysis. Results and discussion The ∆mnoS, ∆mnoR, and ∆mnoS/R mutant strains were generated and cultured in the presence of defined carbon sources. Growth curve analysis confirmed that inactivation of the MnoSR impairs the ability of M. smegmatis cells to use alcohols such as 1,3-propanediol and ethanol but improves the bacterial growth on ethylene glycol, xylitol, and glycerol. The total RNA sequencing method was employed to understand the importance of MnoSR in the global responses of mycobacteria to limited carbon access and in carbon-rich conditions. The loss of MnoSR significantly affected carbon utilization in the case of mycobacteria cultured on glucose or 1,3-propanediol as sole carbon sources as it influenced the expression of multiple metabolic pathways. The numerous transcriptional changes could not be linked to the presence of evident MnoR DNA-binding sites within the promotor regions for the genes outside of the mno operon. This was confirmed by EMSA and microscale thermophoresis with mutated MnoR binding consensus region. Our comprehensive analysis highlights the system's vital role in metabolic adaptability, providing insights into its potential impact on the environmental survival of mycobacteria.
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Affiliation(s)
- Renata Płocińska
- Institute of Medical Biology of the Polish Academy of Sciences, Łódź, Poland
| | - Katarzyna Struś
- Institute of Medical Biology of the Polish Academy of Sciences, Łódź, Poland
| | | | - Przemysław Płociński
- Department of Immunology and Infectious Biology, Faculty of Biology and Environmental Protection, University of Łódz, Łódź, Poland
| | - Magdalena Kuzioła
- Institute of Medical Biology of the Polish Academy of Sciences, Łódź, Poland
- BioMedChem Doctoral School of the UL and Łódź Institutes of the Polish Academy of Sciences, Łódź, Poland
| | - Anna Żaczek
- Department of Microbiology, College of Medical Sciences, University of Rzeszów, Rzeszów, Poland
| | - Marcin Słomka
- Biobank Lab, Department of Molecular Biophysics, Faculty of Biology and Environmental Protection, University of Łódź, Łódź, Poland
| | - Jarosław Dziadek
- Institute of Medical Biology of the Polish Academy of Sciences, Łódź, Poland
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Liu Y, Li H, Dai D, He J, Liang Z. Gene Regulatory Mechanism of Mycobacterium Tuberculosis during Dormancy. Curr Issues Mol Biol 2024; 46:5825-5844. [PMID: 38921019 PMCID: PMC11203133 DOI: 10.3390/cimb46060348] [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: 04/10/2024] [Revised: 06/05/2024] [Accepted: 06/07/2024] [Indexed: 06/27/2024] Open
Abstract
Tuberculosis (TB), caused by Mycobacterium tuberculosis (Mtb) complex, is a zoonotic disease that remains one of the leading causes of death worldwide. Latent tuberculosis infection reactivation is a challenging obstacle to eradicating TB globally. Understanding the gene regulatory network of Mtb during dormancy is important. This review discusses up-to-date information about TB gene regulatory networks during dormancy, focusing on the regulation of lipid and energy metabolism, dormancy survival regulator (DosR), White B-like (Wbl) family, Toxin-Antitoxin (TA) systems, sigma factors, and MprAB. We outline the progress in vaccine and drug development associated with Mtb dormancy.
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Affiliation(s)
- Yiduo Liu
- College of Animal Science and Technology, Guangxi University, No. 100 University West Road, Nanning 530004, China (D.D.)
- College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Han Li
- College of Animal Science and Technology, Guangxi University, No. 100 University West Road, Nanning 530004, China (D.D.)
| | - Dejia Dai
- College of Animal Science and Technology, Guangxi University, No. 100 University West Road, Nanning 530004, China (D.D.)
| | - Jiakang He
- College of Animal Science and Technology, Guangxi University, No. 100 University West Road, Nanning 530004, China (D.D.)
| | - Zhengmin Liang
- College of Animal Science and Technology, Guangxi University, No. 100 University West Road, Nanning 530004, China (D.D.)
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Das M, Sreedharan S, Shee S, Malhotra N, Nandy M, Banerjee U, Kohli S, Rajmani RS, Chandra N, Seshasayee ASN, Laxman S, Singh A. Cysteine desulfurase (IscS)-mediated fine-tuning of bioenergetics and SUF expression prevents Mycobacterium tuberculosis hypervirulence. SCIENCE ADVANCES 2023; 9:eadh2858. [PMID: 38091389 PMCID: PMC10848736 DOI: 10.1126/sciadv.adh2858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Accepted: 11/10/2023] [Indexed: 12/18/2023]
Abstract
Iron-sulfur (Fe-S) biogenesis requires multiprotein assembly systems, SUF and ISC, in most prokaryotes. M. tuberculosis (Mtb) encodes a complete SUF system, the depletion of which was bactericidal. The ISC operon is truncated to a single gene iscS (cysteine desulfurase), whose function remains uncertain. Here, we show that MtbΔiscS is bioenergetically deficient and hypersensitive to oxidative stress, antibiotics, and hypoxia. MtbΔiscS resisted killing by nitric oxide (NO). RNA sequencing indicates that IscS is important for expressing regulons of DosR and Fe-S-containing transcription factors, WhiB3 and SufR. Unlike wild-type Mtb, MtbΔiscS could not enter a stable persistent state, continued replicating in mice, and showed hypervirulence. The suf operon was overexpressed in MtbΔiscS during infection in a NO-dependent manner. Suppressing suf expression in MtbΔiscS either by CRISPR interference or upon infection in inducible NO-deficient mice arrests hypervirulence. Together, Mtb redesigned the ISC system to "fine-tune" the expression of SUF machinery for establishing persistence without causing detrimental disease in the host.
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Affiliation(s)
- Mayashree Das
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore 560012, India
- Centre for Infectious Disease Research, Indian Institute of Science, Bangalore 560012, India
| | - Sreesa Sreedharan
- Institute for Stem Cell Science and Regenerative Medicine, Bangalore 560065, India
- School of Chemical and Biotechnology, (SASTRA)-Deemed to be University, Thanjavur 613401, India
| | - Somnath Shee
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore 560012, India
- Centre for Infectious Disease Research, Indian Institute of Science, Bangalore 560012, India
| | - Nitish Malhotra
- National Centre for Biological Sciences (NCBS), Tata Institute of Fundamental Research (TIFR), Bangalore 560065, India
| | - Meghna Nandy
- National Centre for Biological Sciences (NCBS), Tata Institute of Fundamental Research (TIFR), Bangalore 560065, India
| | - Ushashi Banerjee
- Department of Biochemistry, Indian Institute of Science, Bangalore 560012, India
| | - Sakshi Kohli
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore 560012, India
- Centre for Infectious Disease Research, Indian Institute of Science, Bangalore 560012, India
| | - Raju S. Rajmani
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560012, India
| | - Nagasuma Chandra
- Department of Biochemistry, Indian Institute of Science, Bangalore 560012, India
| | - Aswin Sai Narain Seshasayee
- National Centre for Biological Sciences (NCBS), Tata Institute of Fundamental Research (TIFR), Bangalore 560065, India
| | - Sunil Laxman
- Institute for Stem Cell Science and Regenerative Medicine, Bangalore 560065, India
| | - Amit Singh
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore 560012, India
- Centre for Infectious Disease Research, Indian Institute of Science, Bangalore 560012, India
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Limón G, Samhadaneh NM, Pironti A, Darwin KH. Aldehyde accumulation in Mycobacterium tuberculosis with defective proteasomal degradation results in copper sensitivity. mBio 2023; 14:e0036323. [PMID: 37350636 PMCID: PMC10470581 DOI: 10.1128/mbio.00363-23] [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: 02/11/2023] [Accepted: 04/17/2023] [Indexed: 06/24/2023] Open
Abstract
Mycobacterium tuberculosis is a major human pathogen and the causative agent of tuberculosis disease. M. tuberculosis is able to persist in the face of host-derived antimicrobial molecules nitric oxide (NO) and copper (Cu). However, M. tuberculosis with defective proteasome activity is highly sensitive to NO and Cu, making the proteasome an attractive target for drug development. Previous work linked NO susceptibility with the accumulation of para-hydroxybenzaldehyde (pHBA) in M. tuberculosis mutants with defective proteasomal degradation. In this study, we found that pHBA accumulation was also responsible for Cu sensitivity in these strains. We showed that exogenous addition of pHBA to wild-type M. tuberculosis cultures sensitized bacteria to Cu to a degree similar to that of a proteasomal degradation mutant. We determined that pHBA reduced the production and function of critical Cu resistance proteins of the regulated in copper repressor (RicR) regulon. Furthermore, we extended these Cu-sensitizing effects to an aldehyde that M. tuberculosis may face within the macrophage. Collectively, this study is the first to mechanistically propose how aldehydes can render M. tuberculosis susceptible to an existing host defense and could support a broader role for aldehydes in controlling M. tuberculosis infections. IMPORTANCE M. tuberculosis is a leading cause of death by a single infectious agent, causing 1.5 million deaths annually. An effective vaccine for M. tuberculosis infections is currently lacking, and prior infection does not typically provide robust immunity to subsequent infections. Nonetheless, immunocompetent humans can control M. tuberculosis infections for decades. For these reasons, a clear understanding of how mammalian immunity inhibits mycobacterial growth is warranted. In this study, we show aldehydes can increase M. tuberculosis susceptibility to copper, an established antibacterial metal used by immune cells to control M. tuberculosis and other microbes. Given that activated macrophages produce increased amounts of aldehydes during infection, we propose host-derived aldehydes may help control bacterial infections, making aldehydes a previously unappreciated antimicrobial defense.
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Affiliation(s)
- Gina Limón
- Department of Microbiology, New York University Grossman School of Medicine, New York, New York, USA
| | - Nora M. Samhadaneh
- Department of Microbiology, New York University Grossman School of Medicine, New York, New York, USA
- Antimicrobial-Resistant Pathogens Program, New York University Grossman School of Medicine, New York, New York, USA
- Microbial Computational Genomic Core Lab, New York University Grossman School of Medicine, New York, New York, USA
| | - Alejandro Pironti
- Department of Microbiology, New York University Grossman School of Medicine, New York, New York, USA
- Antimicrobial-Resistant Pathogens Program, New York University Grossman School of Medicine, New York, New York, USA
- Microbial Computational Genomic Core Lab, New York University Grossman School of Medicine, New York, New York, USA
| | - K. Heran Darwin
- Department of Microbiology, New York University Grossman School of Medicine, New York, New York, USA
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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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Li Y, Guan H, Li J, Zhang J, Wang Y, Li J, Tan H. An intricate regulation of WblA controlling production of silent tylosin analogues and abolishment of expressible nikkomycin. SCIENCE CHINA. LIFE SCIENCES 2023; 66:612-625. [PMID: 36607495 DOI: 10.1007/s11427-022-2199-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Accepted: 09/21/2022] [Indexed: 01/07/2023]
Abstract
Genome sequencing has revealed that actinomycetes possess the potential to produce many more secondary metabolites than previously thought. The existing challenge is to devise efficient methods to activate these silent biosynthetic gene clusters (BGCs). In Streptomyces ansochromogenes, disruption of wblA, a pleiotropic regulatory gene, activated the expression of cryptic tylosin analogues and abolished nikkomycin production simultaneously. Overexpressing pathway-specific regulatory genes tylR1 and tylR2 can also trigger the biosynthesis of silent tylosin analogues, in which TylR1 exerted its function via enhancing tylR2 expression. Bacterial one-hybrid system experiments unveiled that WblA directly inhibits the transcription of tylR1 and tylR2 to result in the silence of tylosin analogues BGC. Furthermore, WblA can activate the nikkomycin production through up-regulating the transcription of pleiotropic regulatory gene adpA. More interestingly, AdpA can activate sanG (an activator gene in nikkomycin BGC) but repress wblA. Our studies provide a valuable insight into the complex functions of pleiotropic regulators.
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Affiliation(s)
- Yue Li
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China.
| | - Hanye Guan
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Jingjing Li
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Jihui Zhang
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Yanyan Wang
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Jine Li
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Huarong Tan
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China.
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Kingdon ADH, Meosa-John AR, Batt SM, Besra GS. Vanoxerine kills mycobacteria through membrane depolarization and efflux inhibition. Front Microbiol 2023; 14:1112491. [PMID: 36778873 PMCID: PMC9909702 DOI: 10.3389/fmicb.2023.1112491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Accepted: 01/11/2023] [Indexed: 01/27/2023] Open
Abstract
Mycobacterium tuberculosis is a deadly pathogen, currently the leading cause of death worldwide from a single infectious agent through tuberculosis infections. If the End TB 2030 strategy is to be achieved, additional drugs need to be identified and made available to supplement the current treatment regimen. In addition, drug resistance is a growing issue, leading to significantly lower treatment success rates, necessitating further drug development. Vanoxerine (GBR12909), a dopamine re-uptake inhibitor, was recently identified as having anti-mycobacterial activity during a drug repurposing screening effort. However, its effects on mycobacteria were not well characterized. Herein, we report vanoxerine as a disruptor of the membrane electric potential, inhibiting mycobacterial efflux and growth. Vanoxerine had an undetectable level of resistance, highlighting the lack of a protein target. This study suggests a mechanism of action for vanoxerine, which will allow for its continued development or use as a tool compound.
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Mishra S, Saito K. Clinically encountered growth phenotypes of tuberculosis-causing bacilli and their in vitro study: A review. Front Cell Infect Microbiol 2022; 12:1029111. [PMID: 36439231 PMCID: PMC9684195 DOI: 10.3389/fcimb.2022.1029111] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Accepted: 10/20/2022] [Indexed: 07/11/2024] Open
Abstract
The clinical manifestations of tuberculosis (TB) vary widely in severity, site of infection, and outcomes of treatment-leading to simultaneous efforts to individualize therapy safely and to search for shorter regimens that can be successfully used across the clinical spectrum. In these endeavors, clinicians and researchers alike employ mycobacterial culture in rich media. However, even within the same patient, individual bacilli among the population can exhibit substantial variability in their culturability. Bacilli in vitro also demonstrate substantial heterogeneity in replication rate and cultivation requirements, as well as susceptibility to killing by antimicrobials. Understanding parallels in clinical, ex vivo and in vitro growth phenotype diversity may be key to identifying those phenotypes responsible for treatment failure, relapse, and the reactivation of bacilli that progresses TB infection to disease. This review briefly summarizes the current role of mycobacterial culture in the care of patients with TB and the ex vivo evidence of variability in TB culturability. We then discuss current advances in in vitro models that study heterogenous subpopulations within a genetically identical bulk culture, with an emphasis on the effect of oxidative stress on bacillary cultivation requirements. The review highlights the complexity that heterogeneity in mycobacterial growth brings to the interpretation of culture in clinical settings and research. It also underscores the intricacies present in the interplay between growth phenotypes and antimicrobial susceptibility. Better understanding of population dynamics and growth requirements over time and space promises to aid both the attempts to individualize TB treatment and to find uniformly effective therapies.
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Affiliation(s)
- Saurabh Mishra
- Department of Microbiology and Immunology, Weill Cornell Medicine, New York, NY, United States
| | - Kohta Saito
- Department of Medicine, Weill Cornell Medicine, New York, NY, United States
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A Hydrazine-Hydrazone Adamantine Compound Shows Antimycobacterial Activity and Is a Probable Inhibitor of MmpL3. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27207130. [PMID: 36296721 PMCID: PMC9610904 DOI: 10.3390/molecules27207130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 10/03/2022] [Accepted: 10/13/2022] [Indexed: 11/06/2022]
Abstract
Tuberculosis remains an important cause of morbidity and mortality throughout the world. Notably, an important number of multi drug resistant cases is an increasing concern. This problem points to an urgent need for novel compounds with antimycobacterial properties and to improve existing therapies. Whole-cell-based screening for compounds with activity against Mycobacterium tuberculosis complex strains in the presence of linezolid was performed in this study. A set of 15 bioactive compounds with antimycobacterial activity in vitro were identified with a minimal inhibitory concentration of less than 2 µg/mL. Among them, compound 1 is a small molecule with a chemical structure consisting of an adamantane moiety and a hydrazide–hydrazone moiety. Whole genome sequencing of spontaneous mutants resistant to the compounds suggested compound 1 to be a new inhibitor of MmpL3. This compound binds to the same pocket as other already published MmpL3 inhibitors, without disturbing the proton motive force of M. bovis BCG and M. smegmatis. Compound 1 showed a strong activity against a panel ofclinical strains of M. tuberculosis in vitro. This compound showed no toxicity against mammalian cells and protected Galleria mellonella larvae against M. bovis BCG infection. These results suggest that compound 1 is a promising anti-TB agent with the potential to improve TB treatment in combination with standard TB therapies.
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11
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Iron–Sulfur Clusters toward Stresses: Implication for Understanding and Fighting Tuberculosis. INORGANICS 2022. [DOI: 10.3390/inorganics10100174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Tuberculosis (TB) remains the leading cause of death due to a single pathogen, accounting for 1.5 million deaths annually on the global level. Mycobacterium tuberculosis, the causative agent of TB, is persistently exposed to stresses such as reactive oxygen species (ROS), reactive nitrogen species (RNS), acidic conditions, starvation, and hypoxic conditions, all contributing toward inhibiting bacterial proliferation and survival. Iron–sulfur (Fe-S) clusters, which are among the most ancient protein prosthetic groups, are good targets for ROS and RNS, and are susceptible to Fe starvation. Mtb holds Fe-S containing proteins involved in essential biological process for Mtb. Fe-S cluster assembly is achieved via complex protein machineries. Many organisms contain several Fe-S assembly systems, while the SUF system is the only one in some pathogens such as Mtb. The essentiality of the SUF machinery and its functionality under the stress conditions encountered by Mtb underlines how it constitutes an attractive target for the development of novel anti-TB.
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12
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Beri D, Rodriguez M, Singh M, Liu Y, Rasquinha G, An X, Yazdanbakhsh K, Lobo CA. Identification and characterization of extracellular vesicles from red cells infected with Babesia divergens and Babesia microti. Front Cell Infect Microbiol 2022; 12:962944. [PMID: 36275032 PMCID: PMC9585353 DOI: 10.3389/fcimb.2022.962944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Accepted: 09/05/2022] [Indexed: 11/21/2022] Open
Abstract
Babesiosis is a zoonosis and an important blood-borne human parasitic infection that has gained attention because of its growing infection rate in humans by transfer from animal reservoirs. Babesia represents a potential threat to the blood supply because asymptomatic infections in man are common, and blood from such donors can cause severe disease in certain recipients. Extracellular vesicles (EVs) are vesicles released by cells that contain a complex mixture of proteins, lipids, glycans, and genetic information that have been shown to play important roles in disease pathogenesis and susceptibility, as well as cell–cell communication and immune responses. In this article, we report on the identification and characterization of EVs released from red blood cells (RBCs) infected by two major human Babesia species—Babesia divergens from in vitro culture and those from an in vivo B. microti mouse infection. Using nanoparticle tracking analysis, we show that there is a range of vesicle sizes from 30 to 1,000 nm, emanating from the Babesia-infected RBC. The study of these EVs in the context of hemoparasite infection is complicated by the fact that both the parasite and the host RBC make and release vesicles into the extracellular environment. However, the EV frequency is 2- to 10-fold higher in Babesia-infected RBCs than uninfected RBCs, depending on levels of parasitemia. Using parasite-specific markers, we were able to show that ~50%–60% of all EVs contained parasite-specific markers on their surface and thus may represent the specific proportion of EVs released by infected RBCs within the EV population. Western blot analysis on purified EVs from both in vivo and in vitro infections revealed several parasite proteins that were targets of the host immune response. In addition, microRNA analysis showed that infected RBC EVs have different microRNA signature from uninfected RBC EVs, indicating a potential role as disease biomarkers. Finally, EVs were internalized by other RBCs in culture, implicating a potential role for these vesicles in cellular communication. Overall, our study points to the multiple functional implications of EVs in Babesia–host interactions and support the potential that EVs have as agents in disease pathogenesis.
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Affiliation(s)
- Divya Beri
- Department of Blood-Borne Parasites, Lindsley F. Kimball Research Institute, New York Blood Center, New York, NY, United States
| | - Marilis Rodriguez
- Department of Blood-Borne Parasites, Lindsley F. Kimball Research Institute, New York Blood Center, New York, NY, United States
| | - Manpreet Singh
- Department of Blood-Borne Parasites, Lindsley F. Kimball Research Institute, New York Blood Center, New York, NY, United States
| | - Yunfeng Liu
- Department of Complement Biology, Lindsley F. Kimball Research Institute, New York Blood Center, New York, NY, United States
| | - Giselle Rasquinha
- Department of Biology, Georgetown University, Washington, DC, United States
| | - Xiuli An
- Department of Membrane Biology, Lindsley F. Kimball Research Institute, New York Blood Center, New York, NY, United States
| | - Karina Yazdanbakhsh
- Department of Complement Biology, Lindsley F. Kimball Research Institute, New York Blood Center, New York, NY, United States
| | - Cheryl A. Lobo
- Department of Blood-Borne Parasites, Lindsley F. Kimball Research Institute, New York Blood Center, New York, NY, United States
- *Correspondence: Cheryl A. Lobo,
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13
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Moxifloxacin-Mediated Killing of Mycobacterium tuberculosis Involves Respiratory Downshift, Reductive Stress, and Accumulation of Reactive Oxygen Species. Antimicrob Agents Chemother 2022; 66:e0059222. [PMID: 35975988 PMCID: PMC9487606 DOI: 10.1128/aac.00592-22] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Moxifloxacin is central to treatment of multidrug-resistant tuberculosis. Effects of moxifloxacin on the Mycobacterium tuberculosis redox state were explored to identify strategies for increasing lethality and reducing the prevalence of extensively resistant tuberculosis. A noninvasive redox biosensor and a reactive oxygen species (ROS)-sensitive dye revealed that moxifloxacin induces oxidative stress correlated with M. tuberculosis death. Moxifloxacin lethality was mitigated by supplementing bacterial cultures with an ROS scavenger (thiourea), an iron chelator (bipyridyl), and, after drug removal, an antioxidant enzyme (catalase). Lethality was also reduced by hypoxia and nutrient starvation. Moxifloxacin increased the expression of genes involved in the oxidative stress response, iron-sulfur cluster biogenesis, and DNA repair. Surprisingly, and in contrast with Escherichia coli studies, moxifloxacin decreased expression of genes involved in respiration, suppressed oxygen consumption, increased the NADH/NAD+ ratio, and increased the labile iron pool in M. tuberculosis. Lowering the NADH/NAD+ ratio in M. tuberculosis revealed that NADH-reductive stress facilitates an iron-mediated ROS surge and moxifloxacin lethality. Treatment with N-acetyl cysteine (NAC) accelerated respiration and ROS production, increased moxifloxacin lethality, and lowered the mutant prevention concentration. Moxifloxacin induced redox stress in M. tuberculosis inside macrophages, and cotreatment with NAC potentiated the antimycobacterial efficacy of moxifloxacin during nutrient starvation, inside macrophages, and in mice, where NAC restricted the emergence of resistance. Thus, NADH-reductive stress contributes to moxifloxacin-mediated killing of M. tuberculosis, and the respiration stimulator (NAC) enhances lethality and suppresses the emergence of drug resistance.
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14
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Bandyopadhyay P, Pramanick I, Biswas R, PS S, Sreedharan S, Singh S, Rajmani RS, Laxman S, Dutta S, Singh A. S-Adenosylmethionine-responsive cystathionine β-synthase modulates sulfur metabolism and redox balance in Mycobacterium tuberculosis. SCIENCE ADVANCES 2022; 8:eabo0097. [PMID: 35749503 PMCID: PMC9232105 DOI: 10.1126/sciadv.abo0097] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Accepted: 05/09/2022] [Indexed: 05/10/2023]
Abstract
Methionine and cysteine metabolisms are important for the survival and pathogenesis of Mycobacterium tuberculosis (Mtb). The transsulfuration pathway converts methionine to cysteine and represents an important link between antioxidant and methylation metabolism in diverse organisms. Using a combination of biochemistry and cryo-electron microscopy, we characterized the first enzyme of the transsulfuration pathway, cystathionine β-synthase (MtbCbs) in Mtb. We demonstrated that MtbCbs is a heme-less, pyridoxal-5'-phosphate-containing enzyme, allosterically activated by S-adenosylmethionine (SAM). The atomic model of MtbCbs in its native and SAM-bound conformations revealed a unique mode of SAM-dependent allosteric activation. Further, SAM stabilized MtbCbs by sterically occluding proteasomal degradation, which was crucial for supporting methionine and redox metabolism in Mtb. Genetic deficiency of MtbCbs reduced Mtb survival upon homocysteine overload in vitro, inside macrophages, and in mice coinfected with HIV. Thus, the MtbCbs-SAM axis constitutes an important mechanism of coordinating sulfur metabolism in Mtb.
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Affiliation(s)
- Parijat Bandyopadhyay
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, Karnataka 560012, India
- Centre for Infectious Disease Research, Indian Institute of Science, Bangalore, Karnataka 560012, India
| | - Ishika Pramanick
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, Karnataka 560012, India
| | - Rupam Biswas
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, Karnataka 560012, India
| | - Sabarinath PS
- Institute for Stem Cell Science and Regenerative Medicine, Bangalore, Karnataka 560065, India
| | - Sreesa Sreedharan
- Institute for Stem Cell Science and Regenerative Medicine, Bangalore, Karnataka 560065, India
| | - Shalini Singh
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, Karnataka 560012, India
- Centre for Infectious Disease Research, Indian Institute of Science, Bangalore, Karnataka 560012, India
| | - Raju S. Rajmani
- Centre for Infectious Disease Research, Indian Institute of Science, Bangalore, Karnataka 560012, India
| | - Sunil Laxman
- Institute for Stem Cell Science and Regenerative Medicine, Bangalore, Karnataka 560065, India
| | - Somnath Dutta
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, Karnataka 560012, India
| | - Amit Singh
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, Karnataka 560012, India
- Centre for Infectious Disease Research, Indian Institute of Science, Bangalore, Karnataka 560012, India
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15
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Role of a Putative Alkylhydroperoxidase Rv2159c in the Oxidative Stress Response and Virulence of Mycobacterium tuberculosis. Pathogens 2022; 11:pathogens11060684. [PMID: 35745538 PMCID: PMC9227533 DOI: 10.3390/pathogens11060684] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Revised: 05/26/2022] [Accepted: 05/31/2022] [Indexed: 02/04/2023] Open
Abstract
Mycobacterium tuberculosis, which causes tuberculosis, is one of the leading infectious agents worldwide with a high rate of mortality. Following aerosol inhalation, M. tuberculosis primarily infects the alveolar macrophages, which results in a host immune response that gradually activates various antimicrobial mechanisms, including the production of reactive oxygen species (ROS), within the phagocytes to neutralize the bacteria. OxyR is the master regulator of oxidative stress response in several bacterial species. However, due to the absence of a functional oxyR locus in M. tuberculosis, the peroxidase stress is controlled by alkylhydroperoxidases. M. tuberculosis expresses alkylhydroperoxide reductase to counteract the toxic effects of ROS. In the current study, we report the functional characterization of an orthologue of alkylhydroperoxidase family member, Rv2159c, a conserved protein with putative peroxidase activity, during stress response and virulence of M. tuberculosis. We generated a gene knockout mutant of M. tuberculosis Rv2159c (MtbΔ2159) by specialized transduction. The MtbΔ2159 was sensitive to oxidative stress and exposure to toxic transition metals. In a human monocyte (THP-1) cell infection model, MtbΔ2159 showed reduced uptake and intracellular survival and increased expression of pro-inflammatory molecules, including IL-1β, IP-10, and MIP-1α, compared to the wild type M. tuberculosis and Rv2159c-complemented MtbΔ2159 strains. Similarly, in a guinea pig model of pulmonary infection, MtbΔ2159 displayed growth attenuation in the lungs, compared to the wild type M. tuberculosis and Rv2159c-complemented MtbΔ2159 strains. Our study suggests that Rv2159c has a significant role in maintaining the cellular homeostasis during stress and virulence of M. tuberculosis.
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16
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Tripathi A, Anand K, Das M, O'Niel RA, P S S, Thakur C, R L RR, Rajmani RS, Chandra N, Laxman S, Singh A. Mycobacterium tuberculosis requires SufT for Fe-S cluster maturation, metabolism, and survival in vivo. PLoS Pathog 2022; 18:e1010475. [PMID: 35427399 PMCID: PMC9045647 DOI: 10.1371/journal.ppat.1010475] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2021] [Revised: 04/27/2022] [Accepted: 03/25/2022] [Indexed: 11/18/2022] Open
Abstract
Iron-sulfur (Fe-S) cluster proteins carry out essential cellular functions in diverse organisms, including the human pathogen Mycobacterium tuberculosis (Mtb). The mechanisms underlying Fe-S cluster biogenesis are poorly defined in Mtb. Here, we show that Mtb SufT (Rv1466), a DUF59 domain-containing essential protein, is required for the Fe-S cluster maturation. Mtb SufT homodimerizes and interacts with Fe-S cluster biogenesis proteins; SufS and SufU. SufT also interacts with the 4Fe-4S cluster containing proteins; aconitase and SufR. Importantly, a hyperactive cysteine in the DUF59 domain mediates interaction of SufT with SufS, SufU, aconitase, and SufR. We efficiently repressed the expression of SufT to generate a SufT knock-down strain in Mtb (SufT-KD) using CRISPR interference. Depleting SufT reduces aconitase's enzymatic activity under standard growth conditions and in response to oxidative stress and iron limitation. The SufT-KD strain exhibited defective growth and an altered pool of tricarboxylic acid cycle intermediates, amino acids, and sulfur metabolites. Using Seahorse Extracellular Flux analyzer, we demonstrated that SufT depletion diminishes glycolytic rate and oxidative phosphorylation in Mtb. The SufT-KD strain showed defective survival upon exposure to oxidative stress and nitric oxide. Lastly, SufT depletion reduced the survival of Mtb in macrophages and attenuated the ability of Mtb to persist in mice. Altogether, SufT assists in Fe-S cluster maturation and couples this process to bioenergetics of Mtb for survival under low and high demand for Fe-S clusters.
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Affiliation(s)
- Ashutosh Tripathi
- Centre for Infectious Disease Research (CIDR), Department of Microbiology and Cell Biology, Indian Institute of Science (IISc), Bengaluru, India
| | - Kushi Anand
- Centre for Infectious Disease Research (CIDR), Department of Microbiology and Cell Biology, Indian Institute of Science (IISc), Bengaluru, India
| | - Mayashree Das
- Centre for Infectious Disease Research (CIDR), Department of Microbiology and Cell Biology, Indian Institute of Science (IISc), Bengaluru, India
| | - Ruchika Annie O'Niel
- Institute for Stem Cell Science and Regenerative Medicine (inStem), Bangalore, India
| | - Sabarinath P S
- Institute for Stem Cell Science and Regenerative Medicine (inStem), Bangalore, India
| | - Chandrani Thakur
- Department of Biochemistry, Indian Institute of Science, Bangalore, India
| | - Raghunatha Reddy R L
- Regional Horticultural Research and Extension Centre (RHREK), GKVK, Bengaluru, India
| | - Raju S Rajmani
- Centre for Infectious Disease Research (CIDR), Department of Microbiology and Cell Biology, Indian Institute of Science (IISc), Bengaluru, India
| | - Nagasuma Chandra
- Department of Biochemistry, Indian Institute of Science, Bangalore, India
| | - Sunil Laxman
- Institute for Stem Cell Science and Regenerative Medicine (inStem), Bangalore, India
| | - Amit Singh
- Centre for Infectious Disease Research (CIDR), Department of Microbiology and Cell Biology, Indian Institute of Science (IISc), Bengaluru, India
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17
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WhiB4 Is Required for the Reactivation of Persistent Infection of Mycobacterium marinum in Zebrafish. Microbiol Spectr 2022; 10:e0044321. [PMID: 35266819 PMCID: PMC9045381 DOI: 10.1128/spectrum.00443-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Granulomas are the pathological hallmark of tuberculosis (TB). In individuals with latent TB infection, Mycobacterium tuberculosis cells reside within granulomas in a nonreplicating dormant state, and a portion of them will develop active TB. Little is known on the bacterial mechanisms/factors involved in this process. In this study, we found that WhiB4, an oxygen sensor and a transcription factor, plays a critical role in disease progression and reactivation of Mycobacterium marinum (M. marinum) infection in zebrafish. We show that the whiB4::Tn mutant of M. marinum caused persistent infection in adult zebrafish, which is characterized by the lower but stable bacterial loads, constant number of nonnecrotized granulomas in fewer organs, and reduced inflammation compared to those of zebrafish infected with the wild-type bacteria or the complemented strain. The mutant bacteria in zebrafish were also less responsive to antibiotic treatments. Moreover, the whiB4::Tn mutant was defective in resuscitation from hypoxia-induced dormancy and the DosR regulon was dysregulated in the mutant. Taken together, our results suggest that WhiB4 is a major driver of reactivation from persistent infection. IMPORTANCE About one-quarter of the world’s population has latent TB infection, and 5 to 10% of those individuals will fall ill with TB. Our finding suggests that WhiB4 is an attractive target for the development of novel therapeutics, which may help to prevent the reactivation of latent infection, thereby reducing the incidences of active TB.
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18
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Exploratory Growth in Streptomyces venezuelae Involves a Unique Transcriptional Program, Enhanced Oxidative Stress Response, and Profound Acceleration in Response to Glycerol. J Bacteriol 2022; 204:e0062321. [PMID: 35254103 DOI: 10.1128/jb.00623-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Exploration is a recently discovered mode of growth and behavior exhibited by some Streptomyces species that is distinct from their classical sporulating life cycle. While much has been uncovered regarding initiating environmental conditions and phenotypic outcomes of exploratory growth, how this process is coordinated at a genetic level remains unclear. We used RNA sequencing to survey global changes in the transcriptional profile of exploring cultures over time in the model organism Streptomyces venezuelae. Transcriptomic analyses revealed widespread changes in gene expression impacting diverse cellular functions. Investigations into differentially expressed regulatory elements revealed specific groups of regulatory factors to be impacted, including the expression of several extracytoplasmic function (ECF) sigma factors, second messenger signaling pathways, and members of the whiB-like (wbl) family of transcription factors. Dramatic changes were observed among primary metabolic pathways, especially among respiration-associated genes and the oxidative stress response; enzyme assays confirmed that exploring cultures exhibit an enhanced oxidative stress response compared with classically growing cultures. Changes in the expression of the glycerol catabolic genes in S. venezuelae led to the discovery that glycerol supplementation of the growth medium promotes a dramatic acceleration of exploration. This effect appears to be unique to glycerol as an alternative carbon source, and this response is broadly conserved across other exploration-competent species. IMPORTANCE Exploration represents an alternative growth strategy for Streptomyces bacteria and is initiated in response to other microbes or specific environmental conditions. Here, we show that entry into exploration involves comprehensive transcriptional reprogramming, with an emphasis on changes in primary metabolism and regulatory/signaling functions. Intriguingly, a number of transcription factor classes were downregulated upon entry into exploration. In contrast, respiration-associated genes were strongly induced, and this was accompanied by an enhanced oxidative stress response. Notably, our transcriptional analyses suggested that glycerol may play a role in exploration, and we found that glycerol supplementation dramatically enhanced the exploration response in many streptomycetes. This work sheds new light on the regulatory and metabolic cues that influence a fascinating new microbial behavior.
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19
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Dow A, Burger A, Marcantonio E, Prisic S. Multi-Omics Profiling Specifies Involvement of Alternative Ribosomal Proteins in Response to Zinc Limitation in Mycobacterium smegmatis. Front Microbiol 2022; 13:811774. [PMID: 35222334 PMCID: PMC8866557 DOI: 10.3389/fmicb.2022.811774] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 01/04/2022] [Indexed: 12/13/2022] Open
Abstract
Zinc ion (Zn2+) is an essential micronutrient and a potent antioxidant. However, Zn2+ is often limited in the environment. Upon Zn2+ limitation, Mycolicibacterium (basonym: Mycobacterium) smegmatis (Msm) undergoes a morphogenesis, which relies on alternative ribosomal proteins (AltRPs); i.e., Zn2+-independent paralogues of Zn2+-dependent ribosomal proteins. However, the underlying physiological changes triggered by Zn2+ limitation and how AltRPs contribute to these changes were not known. In this study, we expand the knowledge of mechanisms utilized by Msm to endure Zn2+ limitation, by comparing the transcriptomes and proteomes of Zn2+-limited and Zn2+-replete Msm. We further compare, corroborate and contrast our results to those reported for the pathogenic mycobacterium, M. tuberculosis, which highlighted conservation of the upregulated oxidative stress response when Zn2+ is limited in both mycobacteria. By comparing the multi-omics analysis of a knockout mutant lacking AltRPs (ΔaltRP) to the Msm wild type strain, we specify the involvement of AltRPs in the response to Zn2+ limitation. Our results show that AltRP expression in Msm does not affect the conserved oxidative stress response during Zn2+ limitation observed in mycobacteria, but AltRPs do significantly impact expression patterns of numerous genes that may be involved in morphogenesis or other adaptive responses. We conclude that AltRPs are not only important as functional replacements for their Zn2+-dependent paralogues; they are also involved in the transcriptomic response to the Zn2+-limited environment.
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Affiliation(s)
- Allexa Dow
- School of Life Sciences, University of Hawai‘i at Mānoa, Honolulu, HI, United States
| | - Andrew Burger
- School of Ocean and Earth Science and Technology, University of Hawai‘i at Mānoa, Honolulu, HI, United States
| | - Endrei Marcantonio
- School of Life Sciences, University of Hawai‘i at Mānoa, Honolulu, HI, United States
| | - Sladjana Prisic
- School of Life Sciences, University of Hawai‘i at Mānoa, Honolulu, HI, United States
- *Correspondence: Sladjana Prisic,
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20
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Liu N, Chen B, Zhao X, Wen J, Qi G. Cations and surfactin serving as signal molecules trigger quorum sensing in Bacillus amyloliquefaciens. J Basic Microbiol 2021; 62:35-47. [PMID: 34825384 DOI: 10.1002/jobm.202100315] [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: 07/02/2021] [Revised: 10/31/2021] [Accepted: 11/06/2021] [Indexed: 11/06/2022]
Abstract
Microorganisms including Bacillus can produce signal molecules such as surfactin, resulting in the variation of membrane potential to trigger quorum sensing such as biofilm formation and sporulation in response to the environment stresses. However, biosynthesis of surfactin requires multiple resources such as huge enzyme complex, amino acids, fatty acids, and energy. Insufficient resources in the natural soil environment restrain biosynthesis of surfactin. When surfactin is inadequate, cations in soil might serve as substitutes to regulate quorum sensing. Our results showed that both surfactin and cations could lead to the variation of membrane potential, thus providing signals to trigger the quorum sensing such as growth, biofilm formation, and sporulation in Bacillus amyloliquefaciens. Neither KinC nor Abh was essential for surfactin or cations to trigger quorum sensing. The cation signaling pathway is only partially dependent on Spo0A, but the surfactin signaling pathway is fully dependent on this global regulator. Compared to surfactin, cations are less effective in promoting biofilm formation, but more effective to trigger sporulation in B. amyloliquefaciens. This study reveals a pathway through which cations regulate the quorum sensing in B. amyloliquefaciens in the case of insufficient surfactin in environment.
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Affiliation(s)
- Na Liu
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Bing Chen
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Xiuyun Zhao
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Jiahong Wen
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Gaofu Qi
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
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21
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Sarkar S, Dey U, Khohliwe TB, Yella VR, Kumar A. Analysis of nucleoid-associated protein-binding regions reveals DNA structural features influencing genome organization in Mycobacterium tuberculosis. FEBS Lett 2021; 595:2504-2521. [PMID: 34387867 DOI: 10.1002/1873-3468.14178] [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: 06/11/2021] [Revised: 08/01/2021] [Accepted: 08/11/2021] [Indexed: 11/10/2022]
Abstract
Nucleoid-associated proteins (NAPs) maintain bacterial nucleoid configuration through their architectural properties of DNA bending, wrapping, and bridging. However, the contribution of DNA structural alterations to DNA-NAP recognition at the genomic scale remains unresolved. Present work dissects the DNA sequence, shape and altered structural preferences at a genomic scale for six NAPs in Mycobacterium tuberculosis. Results suggest narrower minor groove width (MGW) and higher DNA rigidity are marked for the binding sites of EspR and Lsr2, while mIHF, MtHU and NapM have heterogeneous DNA structural predilections. In contrast, WhiB4-DNA-binding sites were characterized by wider MGW, highly deformable and less curved DNA. This work provides systematic insight into NAP-mediated genome organization as a function of DNA structural features.
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Affiliation(s)
- Sharmilee Sarkar
- Department of Molecular Biology and Biotechnology, Tezpur University, India
| | - Upalabdha Dey
- Department of Molecular Biology and Biotechnology, Tezpur University, India
| | | | - Venkata Rajesh Yella
- Department of Biotechnology, Koneru Lakshmaiah Education Foundation, Guntur, India
| | - Aditya Kumar
- Department of Molecular Biology and Biotechnology, Tezpur University, India
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22
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Wan T, Horová M, Beltran DG, Li S, Wong HX, Zhang LM. Structural insights into the functional divergence of WhiB-like proteins in Mycobacterium tuberculosis. Mol Cell 2021; 81:2887-2900.e5. [PMID: 34171298 DOI: 10.1016/j.molcel.2021.06.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 04/12/2021] [Accepted: 05/31/2021] [Indexed: 12/12/2022]
Abstract
WhiB7 represents a distinct subclass of transcription factors in the WhiB-Like (Wbl) family, a unique group of iron-sulfur (4Fe-4S] cluster-containing proteins exclusive to the phylum of Actinobacteria. In Mycobacterium tuberculosis (Mtb), WhiB7 interacts with domain 4 of the primary sigma factor (σA4) in the RNA polymerase holoenzyme and activates genes involved in multiple drug resistance and redox homeostasis. Here, we report crystal structures of the WhiB7:σA4 complex alone and bound to its target promoter DNA at 1.55-Å and 2.6-Å resolution, respectively. These structures show how WhiB7 regulates gene expression by interacting with both σA4 and the AT-rich sequence upstream of the -35 promoter DNA via its C-terminal DNA-binding motif, the AT-hook. By combining comparative structural analysis of the two high-resolution σA4-bound Wbl structures with molecular and biochemical approaches, we identify the structural basis of the functional divergence between the two distinct subclasses of Wbl proteins in Mtb.
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Affiliation(s)
- Tao Wan
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE 68588, USA
| | - Magdaléna Horová
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE 68588, USA
| | - Daisy Guiza Beltran
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE 68588, USA
| | - Shanren Li
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE 68588, USA
| | - Huey-Xian Wong
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE 68588, USA
| | - Li-Mei Zhang
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE 68588, USA; Redox Biology Center, University of Nebraska-Lincoln, Lincoln, NE 68588, USA; Nebraska Center for Integrated Biomolecular Communication, University of Nebraska-Lincoln, Lincoln, NE 68588, USA.
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23
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Collateral Sensitivity to β-Lactam Drugs in Drug-Resistant Tuberculosis Is Driven by the Transcriptional Wiring of BlaI Operon Genes. mSphere 2021; 6:e0024521. [PMID: 34047652 PMCID: PMC8265638 DOI: 10.1128/msphere.00245-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The evolution of resistance to one antimicrobial can result in enhanced sensitivity to another, known as "collateral sensitivity." This underexplored phenomenon opens new therapeutic possibilities for patients infected with pathogens unresponsive to classical treatments. Intrinsic resistance to β-lactams in Mycobacterium tuberculosis (the causative agent of tuberculosis) has traditionally curtailed the use of these low-cost and easy-to-administer drugs for tuberculosis treatment. Recently, β-lactam sensitivity has been reported in strains resistant to classical tuberculosis therapy, resurging the interest in β-lactams for tuberculosis. However, a lack of understanding of the molecular underpinnings of this sensitivity has delayed exploration in the clinic. We performed gene expression and network analyses and in silico knockout simulations of genes associated with β-lactam sensitivity and genes associated with resistance to classical tuberculosis drugs to investigate regulatory interactions and identify key gene mediators. We found activation of the key inhibitor of β-lactam resistance, blaI, following classical drug treatment as well as transcriptional links between genes associated with β-lactam sensitivity and those associated with resistance to classical treatment, suggesting that regulatory links might explain collateral sensitivity to β-lactams. Our results support M. tuberculosis β-lactam sensitivity as a collateral consequence of the evolution of resistance to classical tuberculosis drugs, mediated through changes to transcriptional regulation. These findings support continued exploration of β-lactams for the treatment of patients infected with tuberculosis strains resistant to classical therapies. IMPORTANCE Tuberculosis remains a significant cause of global mortality, with strains resistant to classical drug treatment considered a major health concern by the World Health Organization. Challenging treatment regimens and difficulty accessing drugs in low-income communities have led to a high prevalence of strains resistant to multiple drugs, making the development of alternative therapies a priority. Although Mycobacterium tuberculosis is naturally resistant to β-lactam drugs, previous studies have shown sensitivity in strains resistant to classical drug treatment, but we currently lack understanding of the molecular underpinnings behind this phenomenon. We found that genes involved in β-lactam susceptibility are activated after classical drug treatment resulting from tight regulatory links with genes involved in drug resistance. Our study supports the hypothesis that β-lactam susceptibility observed in drug-resistant strains results from the underlying regulatory network of M. tuberculosis, supporting further exploration of the use of β-lactams for tuberculosis treatment.
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Khan MZ, Singha B, Ali MF, Taunk K, Rapole S, Gourinath S, Nandicoori VK. Redox homeostasis in Mycobacterium tuberculosis is modulated by a novel actinomycete-specific transcription factor. EMBO J 2021; 40:e106111. [PMID: 34018220 PMCID: PMC8280819 DOI: 10.15252/embj.2020106111] [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] [Received: 07/01/2020] [Revised: 04/17/2021] [Accepted: 04/20/2021] [Indexed: 11/09/2022] Open
Abstract
Mycobacterium tuberculosis (Mtb) has evolved diverse cellular processes in response to the multiple stresses it encounters within the infected host. We explored available TnSeq datasets to identify transcription factors (TFs) that are essential for Mtb survival inside the host. The analysis identified a single TF, Rv1332 (AosR), conserved across actinomycetes with a so‐far uncharacterized function. AosR mitigates phagocyte‐derived oxidative and nitrosative stress, thus promoting mycobacterial growth in the murine lungs and spleen. Oxidative stress induces formation of a single intrasubunit disulphide bond in AosR, which in turn facilitates AosR interaction with an extracytoplasmic‐function sigma factor, SigH. This leads to the specific upregulation of the CysM‐dependent non‐canonical cysteine biosynthesis pathway through an auxiliary intragenic stress‐responsive promoter, an axis critical in detoxifying host‐derived oxidative and nitrosative radicals. Failure to upregulate AosR‐dependent cysteine biosynthesis during the redox stress causes differential expression of 6% of Mtb genes. Our study shows that the AosR‐SigH pathway is critical for detoxifying host‐derived oxidative and nitrosative radicals to enhance Mtb survival in the hostile intracellular environment.
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Dow A, Sule P, O’Donnell TJ, Burger A, Mattila JT, Antonio B, Vergara K, Marcantonio E, Adams LG, James N, Williams PG, Cirillo JD, Prisic S. Zinc limitation triggers anticipatory adaptations in Mycobacterium tuberculosis. PLoS Pathog 2021; 17:e1009570. [PMID: 33989345 PMCID: PMC8121289 DOI: 10.1371/journal.ppat.1009570] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Accepted: 04/19/2021] [Indexed: 01/06/2023] Open
Abstract
Mycobacterium tuberculosis (Mtb) has complex and dynamic interactions with the human host, and subpopulations of Mtb that emerge during infection can influence disease outcomes. This study implicates zinc ion (Zn2+) availability as a likely driver of bacterial phenotypic heterogeneity in vivo. Zn2+ sequestration is part of "nutritional immunity", where the immune system limits micronutrients to control pathogen growth, but this defense mechanism seems to be ineffective in controlling Mtb infection. Nonetheless, Zn2+-limitation is an environmental cue sensed by Mtb, as calprotectin triggers the zinc uptake regulator (Zur) regulon response in vitro and co-localizes with Zn2+-limited Mtb in vivo. Prolonged Zn2+ limitation leads to numerous physiological changes in vitro, including differential expression of certain antigens, alterations in lipid metabolism and distinct cell surface morphology. Furthermore, Mtb enduring limited Zn2+ employ defensive measures to fight oxidative stress, by increasing expression of proteins involved in DNA repair and antioxidant activity, including well described virulence factors KatG and AhpC, along with altered utilization of redox cofactors. Here, we propose a model in which prolonged Zn2+ limitation defines a population of Mtb with anticipatory adaptations against impending immune attack, based on the evidence that Zn2+-limited Mtb are more resistant to oxidative stress and exhibit increased survival and induce more severe pulmonary granulomas in mice. Considering that extracellular Mtb may transit through the Zn2+-limited caseum before infecting naïve immune cells or upon host-to-host transmission, the resulting phenotypic heterogeneity driven by varied Zn2+ availability likely plays a key role during early interactions with host cells.
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Affiliation(s)
- Allexa Dow
- School of Life Sciences, University of Hawaiʻi at Mānoa, Honolulu, Hawaii, United States of America
| | - Preeti Sule
- Microbial Pathogenesis and Immunology, Texas A&M University Health, Bryan, Texas, United States of America
| | - Timothy J. O’Donnell
- Department of Chemistry, University of Hawaiʻi at Mānoa, Honolulu, Hawaii, United States of America
| | - Andrew Burger
- School of Ocean and Earth Science and Technology, University of Hawaiʻi at Mānoa, Honolulu, Hawaii, United States of America
| | - Joshua T. Mattila
- Department of Infectious Diseases and Microbiology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Brandi Antonio
- School of Life Sciences, University of Hawaiʻi at Mānoa, Honolulu, Hawaii, United States of America
| | - Kevin Vergara
- School of Life Sciences, University of Hawaiʻi at Mānoa, Honolulu, Hawaii, United States of America
| | - Endrei Marcantonio
- School of Life Sciences, University of Hawaiʻi at Mānoa, Honolulu, Hawaii, United States of America
| | - L. Garry Adams
- Department of Veterinary Pathobiology, Texas A&M University, College Station, Texas, United States of America
| | - Nicholas James
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, Honolulu, Hawaii, United States of America
| | - Philip G. Williams
- Department of Chemistry, University of Hawaiʻi at Mānoa, Honolulu, Hawaii, United States of America
| | - Jeffrey D. Cirillo
- Microbial Pathogenesis and Immunology, Texas A&M University Health, Bryan, Texas, United States of America
| | - Sladjana Prisic
- School of Life Sciences, University of Hawaiʻi at Mānoa, Honolulu, Hawaii, United States of America
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Zhai Q, Lin C, Duan B, Liu J, Zhang L, Xia B. 1H, 13C, and 15N resonance assignments of reduced apo-WhiB4 from Mycobacterium tuberculosis. BIOMOLECULAR NMR ASSIGNMENTS 2021; 15:99-101. [PMID: 33389547 DOI: 10.1007/s12104-020-09989-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Accepted: 11/20/2020] [Indexed: 06/12/2023]
Abstract
The WhiB4 protein, a member of WhiB-like proteins, plays an important role in the survival and pathology of Mycobacterium tuberculosis (Mtb). As a transcription factor, WhiB4 regulates the expression of genes involved in maintaining redox homeostasis, central metabolism, and respiration. Furthermore, WhiB4 leads to the condensation of mycobacterial nucleoids and is capable of binding to DNA. WhiB4 contains four cysteine residues and exists in multiple forms under different redox environments, including a dimeric holo form with iron-sulfur cluster, multimeric disulfide-linked oxidized apo forms and monomeric reduced apo form. Here, we report the 1H, 13C, 15N chemical shifts of WhiB4 protein in its reduced apo state, providing a basis for the determination of its solution structure.
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Affiliation(s)
- Qiran Zhai
- Beijing Nuclear Magnetic Resonance Center, College of Chemistry and Molecular Engineering, School of Life Sciences, Peking University, Beijing, China
| | - Chen Lin
- State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Science, Fudan University, Shanghai, China
| | - Bo Duan
- Beijing Nuclear Magnetic Resonance Center, College of Chemistry and Molecular Engineering, School of Life Sciences, Peking University, Beijing, China
| | - Jun Liu
- State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Science, Fudan University, Shanghai, China
| | - Lu Zhang
- State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Science, Fudan University, Shanghai, China
| | - Bin Xia
- Beijing Nuclear Magnetic Resonance Center, College of Chemistry and Molecular Engineering, School of Life Sciences, Peking University, Beijing, China.
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Alhadlaq MA, Green J, Kudhair BK. Analysis of Kytococcus sedentarius Strain Isolated from a Dehumidifier Operating in a University Lecture Theatre: Systems for Aerobic Respiration, Resisting Osmotic Stress, and Sensing Nitric Oxide. Microb Physiol 2021; 31:135-145. [PMID: 33730718 DOI: 10.1159/000512751] [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: 06/17/2020] [Accepted: 10/28/2020] [Indexed: 11/19/2022]
Abstract
A strain of Kytococcus sedentarius was isolated from a dehumidifier operating in a university lecture theatre. Genome analysis and phenotypic characterisation showed that this strain, K. sedentarius MBB13, was a moderately halotolerant aerobe with a branched aerobic electron transport chain and genes that could contribute to erythromycin resistance. The major compatible solute was glycine betaine, with ectoine and proline being deployed at higher osmolarities. Actinobacteria possess multiple WhiB-like (Wbl) regulatory proteins, and K. sedentarius MBB13 has four (WhiB1, WhiB2, WhiB3, and WhiB7). Wbls are iron-sulfur proteins that regulate gene expression through interactions with RNA polymerase sigma factors and/or other regulatory proteins. Bacterial two-hybrid analyses suggested that WhiB1 and WhiB2, but not WhiB3 and WhiB7, interact with the C-terminal domain of the major sigma factor, σA; no interaction was detected between any of the Wbl proteins and the only alternative sigma factors, σB, σH, or σJ. The interaction between σA and WhiB1 or WhiB2 was disrupted in a heterologous system under growth conditions that produce nitric oxide and the iron-sulfur clusters of the isolated WhiB1 and WhiB2 proteins reacted with nitric oxide. Thus, K. sedentarius strain exhibits the major phenotypic characteristics of the type strain and a comprehensive examination of the interactions between its four Wbl proteins and four sigma factors suggested that the Wbl proteins all operate through interaction with σA.
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Affiliation(s)
- Meshari Ahmed Alhadlaq
- Molecular Biology and Biotechnology, University of Sheffield, Sheffield, United Kingdom, .,Research and Laboratories Sector, Saudi Food and Drug Authority, Riyadh, Saudi Arabia,
| | - Jeffrey Green
- Molecular Biology and Biotechnology, University of Sheffield, Sheffield, United Kingdom
| | - Bassam K Kudhair
- Department of Laboratory Investigations, Faculty of Science, University of Kufa, Najaf, Iraq
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28
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Mapping Gene-by-Gene Single-Nucleotide Variation in 8,535 Mycobacterium tuberculosis Genomes: a Resource To Support Potential Vaccine and Drug Development. mSphere 2021; 6:6/2/e01224-20. [PMID: 33692198 PMCID: PMC8546714 DOI: 10.1128/msphere.01224-20] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Tuberculosis (TB) is responsible for millions of deaths annually. More effective vaccines and new antituberculous drugs are essential to control the disease. Numerous genomic studies have advanced our knowledge about M. tuberculosis drug resistance, population structure, and transmission patterns. At the same time, reverse vaccinology and drug discovery pipelines have identified potential immunogenic vaccine candidates or drug targets. However, a better understanding of the sequence variation of all the M. tuberculosis genes on a large scale could aid in the identification of new vaccine and drug targets. Achieving this was the focus of the current study. Genome sequence data were obtained from online public sources covering seven M. tuberculosis lineages. A total of 8,535 genome sequences were mapped against M. tuberculosis H37Rv reference genome, in order to identify single nucleotide polymorphisms (SNPs). The results of the initial mapping were further processed, and a frequency distribution of nucleotide variants within genes was identified and further analyzed. The majority of genomic positions in the M. tuberculosis H37Rv genome were conserved. Genes with the highest level of conservation were often associated with stress responses and maintenance of redox balance. Conversely, genes with high levels of nucleotide variation were often associated with drug resistance. We have provided a high-resolution analysis of the single-nucleotide variation of all M. tuberculosis genes across seven lineages as a resource to support future drug and vaccine development. We have identified a number of highly conserved genes, important in M. tuberculosis biology, that could potentially be used as targets for novel vaccine candidates and antituberculous medications. IMPORTANCE Tuberculosis is an infectious disease caused by the bacterium Mycobacterium tuberculosis. In the first half of the 20th century, the discovery of the Mycobacterium bovis BCG vaccine and antituberculous drugs heralded a new era in the control of TB. However, combating TB has proven challenging, especially with the emergence of HIV and drug resistance. A major hindrance in TB control is the lack of an effective vaccine, as the efficacy of BCG is geographically variable and provides little protection against pulmonary disease in high-risk groups. Our research is significant because it provides a resource to support future drug and vaccine development. We have achieved this by developing a better understanding of the nucleotide variation of all of the M. tuberculosis genes on a large scale and by identifying highly conserved genes that could potentially be used as targets for novel vaccine candidates and antituberculous medications.
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Nah HJ, Park J, Choi S, Kim ES. WblA, a global regulator of antibiotic biosynthesis in Streptomyces. J Ind Microbiol Biotechnol 2021; 48:6127318. [PMID: 33928363 PMCID: PMC9113171 DOI: 10.1093/jimb/kuab007] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 12/10/2020] [Indexed: 12/14/2022]
Abstract
Streptomyces species are soil-dwelling bacteria that produce vast numbers of pharmaceutically valuable secondary metabolites (SMs), such as antibiotics, immunosuppressants, antiviral, and anticancer drugs. On the other hand, the biosynthesis of most SMs remains very low due to tightly controlled regulatory networks. Both global and pathway-specific regulators are involved in the regulation of a specific SM biosynthesis in various Streptomyces species. Over the past few decades, many of these regulators have been identified and new ones are still being discovered. Among them, a global regulator of SM biosynthesis named WblA was identified in several Streptomyces species. The identification and understanding of the WblAs have greatly contributed to increasing the productivity of several Streptomyces SMs. This review summarizes the characteristics and applications on WblAs reported to date, which were found in various Streptomyces species and other actinobacteria.
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Affiliation(s)
- Hee-Ju Nah
- Department of Biological Engineering, Inha University, Incheon 22212, Republic of Korea
| | - Jihee Park
- Department of Biological Engineering, Inha University, Incheon 22212, Republic of Korea
| | - Sisun Choi
- Department of Biological Engineering, Inha University, Incheon 22212, Republic of Korea
| | - Eung-Soo Kim
- Department of Biological Engineering, Inha University, Incheon 22212, Republic of Korea
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Mishra R, Kohli S, Malhotra N, Bandyopadhyay P, Mehta M, Munshi M, Adiga V, Ahuja VK, Shandil RK, Rajmani RS, Seshasayee ASN, Singh A. Targeting redox heterogeneity to counteract drug tolerance in replicating Mycobacterium tuberculosis. Sci Transl Med 2020; 11:11/518/eaaw6635. [PMID: 31723039 DOI: 10.1126/scitranslmed.aaw6635] [Citation(s) in RCA: 63] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Revised: 06/26/2019] [Accepted: 10/25/2019] [Indexed: 12/23/2022]
Abstract
The capacity of Mycobacterium tuberculosis (Mtb) to tolerate multiple antibiotics represents a major problem in tuberculosis (TB) management. Heterogeneity in Mtb populations is one of the factors that drives antibiotic tolerance during infection. However, the mechanisms underpinning this variation in bacterial population remain poorly understood. Here, we show that phagosomal acidification alters the redox physiology of Mtb to generate a population of replicating bacteria that display drug tolerance during infection. RNA sequencing of this redox-altered population revealed the involvement of iron-sulfur (Fe-S) cluster biogenesis, hydrogen sulfide (H2S) gas, and drug efflux pumps in antibiotic tolerance. The fraction of the pH- and redox-dependent tolerant population increased when Mtb infected macrophages with actively replicating HIV-1, suggesting that redox heterogeneity could contribute to high rates of TB therapy failure during HIV-TB coinfection. Pharmacological inhibition of phagosomal acidification by the antimalarial drug chloroquine (CQ) eradicated drug-tolerant Mtb, ameliorated lung pathology, and reduced postchemotherapeutic relapse in in vivo models. The pharmacological profile of CQ (C max and AUClast) exhibited no major drug-drug interaction when coadministered with first line anti-TB drugs in mice. Our data establish a link between phagosomal pH, redox metabolism, and drug tolerance in replicating Mtb and suggest repositioning of CQ to shorten TB therapy and achieve a relapse-free cure.
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Affiliation(s)
- Richa Mishra
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore 560012, India.,Centre for Infectious Disease Research, Indian Institute of Science, Bangalore 560012, India
| | - Sakshi Kohli
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore 560012, India.,Centre for Infectious Disease Research, Indian Institute of Science, Bangalore 560012, India
| | - Nitish Malhotra
- National Centre for Biological Sciences (NCBS), Tata Institute of Fundamental Research (TIFR), Bangalore 560065, India
| | - Parijat Bandyopadhyay
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore 560012, India.,Centre for Infectious Disease Research, Indian Institute of Science, Bangalore 560012, India
| | - Mansi Mehta
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore 560012, India.,Centre for Infectious Disease Research, Indian Institute of Science, Bangalore 560012, India
| | - MohamedHusen Munshi
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore 560012, India.,Centre for Infectious Disease Research, Indian Institute of Science, Bangalore 560012, India
| | - Vasista Adiga
- Centre for Infectious Disease Research, Indian Institute of Science, Bangalore 560012, India
| | | | - Radha K Shandil
- Foundation for Neglected Disease Research, Bangalore 560065, India
| | - Raju S Rajmani
- Centre for Infectious Disease Research, Indian Institute of Science, Bangalore 560012, India
| | - Aswin Sai Narain Seshasayee
- National Centre for Biological Sciences (NCBS), Tata Institute of Fundamental Research (TIFR), Bangalore 560065, India
| | - Amit Singh
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore 560012, India.
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Maione V, Grifagni D, Torricella F, Cantini F, Banci L. CIAO3 protein forms a stable ternary complex with two key players of the human cytosolic iron–sulfur cluster assembly machinery. J Biol Inorg Chem 2020; 25:501-508. [DOI: 10.1007/s00775-020-01778-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Accepted: 03/16/2020] [Indexed: 11/24/2022]
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Jiang J, Lin C, Zhang J, Wang Y, Shen L, Yang K, Xiao W, Li Y, Zhang L, Liu J. Transcriptome Changes of Mycobacterium marinum in the Process of Resuscitation From Hypoxia-Induced Dormancy. Front Genet 2020; 10:1359. [PMID: 32117415 PMCID: PMC7025489 DOI: 10.3389/fgene.2019.01359] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Accepted: 12/11/2019] [Indexed: 12/22/2022] Open
Abstract
Nearly one-third of the world's population is latently infected with Mycobacterium tuberculosis (M. tb), which represents a huge disease reservoir for reactivation and a major obstacle for effective control of tuberculosis. During latent infection, M. tb is thought to enter nonreplicative dormant states by virtue of its response to hypoxia and nutrient-deprived conditions. Knowledge of the genetic programs used to facilitate entry into and exit from the nonreplicative dormant states remains incomplete. In this study, we examined the transcriptional changes of Mycobacterium marinum (M. marinum), a pathogenic mycobacterial species closely related to M. tb, at different stages of resuscitation from hypoxia-induced dormancy. RNA-seq analyses were performed on M. marinum cultures recovered at multiple time points after resuscitation. Differentially expressed genes (DEGs) at each time period were identified and analyzed. Co-expression networks of transcription factors and DEGs in each period were constructed. In addition, we performed a weighted gene co-expression network analysis (WGCNA) on all genes and obtained 12 distinct gene modules. Collectively, these data provided valuable insight into the transcriptome changes of M. marinum upon resuscitation as well as gene module function of the bacteria during active metabolism and growth.
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Affiliation(s)
- Jun Jiang
- State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Science, Fudan University, Shanghai, China
| | - Chen Lin
- State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Science, Fudan University, Shanghai, China
| | - Junli Zhang
- State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Science, Fudan University, Shanghai, China
| | - Yuchen Wang
- State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Science, Fudan University, Shanghai, China
| | - Lifang Shen
- State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Science, Fudan University, Shanghai, China
| | - Kunpeng Yang
- State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Science, Fudan University, Shanghai, China
| | - Wenxuan Xiao
- State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Science, Fudan University, Shanghai, China
| | - Yao Li
- State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Science, Fudan University, Shanghai, China
| | - Lu Zhang
- State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Science, Fudan University, Shanghai, China.,State Key Laboratory of Genetic Engineering, MOE Engineering Research Center of Gene Technology, School of Life Science, Fudan University, Shanghai, China
| | - Jun Liu
- State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Science, Fudan University, Shanghai, China.,Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
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Abstract
Mycofactocin (MFT) belongs to the class of ribosomally synthesized and posttranslationally modified peptides conserved in many Actinobacteria Mycobacterium tuberculosis assimilates cholesterol during chronic infection, and its in vitro growth in the presence of cholesterol requires most of the MFT biosynthesis genes (mftA, mftB, mftC, mftD, mftE, and mftF), although the reasons for this requirement remain unclear. To identify the function of MFT, we characterized MFT biosynthesis mutants constructed in Mycobacterium smegmatis, M. marinum, and M. tuberculosis We found that the growth deficit of mft deletion mutants in medium containing cholesterol-a phenotypic basis for gene essentiality prediction-depends on ethanol, a solvent used to solubilize cholesterol. Furthermore, functionality of MFT was strictly required for growth of free-living mycobacteria in ethanol and other primary alcohols. Among other genes encoding predicted MFT-associated dehydrogenases, MSMEG_6242 was indispensable for M. smegmatis ethanol assimilation, suggesting that it is a candidate catalytic interactor with MFT. Despite being a poor growth substrate, ethanol treatment resulted in a reductive cellular state with NADH accumulation in M. tuberculosis During ethanol treatment, mftC mutant expressed the transcriptional signatures that are characteristic of respirational dysfunction and a redox-imbalanced cellular state. Counterintuitively, there were no differences in cellular bioenergetics and redox parameters in mftC mutant cells treated with ethanol. Therefore, further understanding of the function of MFT in ethanol metabolism is required to identify the cause of growth retardation of MFT mutants in cholesterol. Nevertheless, our results establish the physiological role of MFT and also provide new insights into the specific functions of MFT homologs in other actinobacterial systems.IMPORTANCE Tuberculosis is caused by Mycobacterium tuberculosis, and the increasing emergence of multidrug-resistant strains renders current treatment options ineffective. Although new antimycobacterial drugs are urgently required, their successful development often relies on complete understanding of the metabolic pathways-e.g., cholesterol assimilation-that are critical for persistence and for pathogenesis of M. tuberculosis In this regard, mycofactocin (MFT) function appears to be important because its biosynthesis genes are predicted to be essential for M. tuberculosis in vitro growth in cholesterol. In determining the metabolic basis of this genetic requirement, our results unexpectedly revealed the essential function of MFT in ethanol metabolism. The metabolic dysfunction thereof was found to affect the mycobacterial growth in cholesterol which is solubilized by ethanol. This knowledge is fundamental in recognizing the bona fide function of MFT, which likely resembles the pyrroloquinoline quinone-dependent ethanol oxidation in acetic acid bacteria exploited for industrial production of vinegar.
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Briffotaux J, Liu S, Gicquel B. Genome-Wide Transcriptional Responses of Mycobacterium to Antibiotics. Front Microbiol 2019; 10:249. [PMID: 30842759 PMCID: PMC6391361 DOI: 10.3389/fmicb.2019.00249] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Accepted: 01/30/2019] [Indexed: 11/13/2022] Open
Abstract
Antibiotics can stimulate or depress gene expression in bacteria. The analysis of transcriptional responses of Mycobacterium to antimycobacterial compounds has improved our understanding of the mode of action of various drug classes and the efficacy and effect of such compounds on the global metabolism of Mycobacterium. This approach can provide new insights for known antibiotics, for example those currently used for tuberculosis treatment, as well as help to identify the mode of action and predict the targets of new compounds identified by whole-cell screening assays. In addition, changes in gene expression profiles after antimycobacterial treatment can provide information about the adaptive ability of bacteria to escape the effects of antibiotics and allow monitoring of the physiology of the bacteria during treatment. Genome-wide expression profiling also makes it possible to pinpoint genes differentially expressed between drug sensitive Mycobacterium and multidrug-resistant clinical isolates. Finally, genes involved in adaptive responses and drug tolerance could become new targets for improving the efficacy of existing antibiotics.
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Affiliation(s)
- Julien Briffotaux
- Department of Tuberculosis Control and Prevention, Shenzhen Nanshan Center for Chronic Disease Control, Shenzhen, China.,Emerging Bacterial Pathogens Unit, CAS Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, China
| | - Shengyuan Liu
- Department of Tuberculosis Control and Prevention, Shenzhen Nanshan Center for Chronic Disease Control, Shenzhen, China
| | - Brigitte Gicquel
- Department of Tuberculosis Control and Prevention, Shenzhen Nanshan Center for Chronic Disease Control, Shenzhen, China.,Emerging Bacterial Pathogens Unit, CAS Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, China.,Mycobacterial Genetics Unit, Institut Pasteur, Paris, France
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35
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Mehta M, Singh A. Mycobacterium tuberculosis WhiB3 maintains redox homeostasis and survival in response to reactive oxygen and nitrogen species. Free Radic Biol Med 2019; 131:50-58. [PMID: 30500421 PMCID: PMC6635127 DOI: 10.1016/j.freeradbiomed.2018.11.032] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2018] [Revised: 10/30/2018] [Accepted: 11/26/2018] [Indexed: 12/20/2022]
Abstract
Mycobacterium tuberculosis (Mtb) survives under oxidatively and nitosatively hostile niches inside host phagocytes. In other bacteria, adaptation to these stresses is dependent upon the redox sensitive two component systems (e.g., ArcAB) and transcription factors (e.g., FNR/SoxR). However, these factors are absent in Mtb. Therefore, it is not completely understood how Mtb maintains survival and redox balance in response to reactive oxygen species (ROS) and reactive nitrogen species (RNS). Here, we present evidences that a 4Fe-4S-cofactor containing redox-sensitive transcription factor (WhiB3) is exploited by Mtb to adapt under ROS and RNS stress. We show that MtbΔwhiB3 is acutely sensitive to oxidants and to nitrosative agents. Using a genetic biosensor of cytoplasmic redox state (Mrx1-roGFP2) of Mtb, we show that WhiB3 facilitates recovery from ROS (cumene hydroperoxide and hydrogen peroxide) and RNS (acidified nitrite and peroxynitrite). Also, MtbΔwhiB3 displayed reduced survival inside RAW 264.7 macrophages. Consistent with the role of WhiB3 in modulating host-pathogen interaction, we discovered that WhiB3 coordinates the formation of early human granulomas during interaction of Mtb with human peripheral blood mononuclear cells (PBMCs). Altogether, our study provides empirical proof that WhiB3 is required to mitigate redox stress induced by ROS and RNS, which may be important to activate host/bacterial pathways required for the granuloma development and maintenance.
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Affiliation(s)
- Mansi Mehta
- Microbiology and Cell Biology, Centre for Infectious Disease Research (CIDR), Indian Institute of Science (IISc), CV Raman Av, Bangalore 12, India
| | - Amit Singh
- Microbiology and Cell Biology, Centre for Infectious Disease Research (CIDR), Indian Institute of Science (IISc), CV Raman Av, Bangalore 12, India.
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Shur KV, Bekker OB, Zaichikova MV, Maslov DA, Akimova NI, Zakharevich NV, Chekalina MS, Danilenko VN. Genetic Aspects of Drug Resistance and Virulence in Mycobacterium tuberculosis. RUSS J GENET+ 2018. [DOI: 10.1134/s1022795418120141] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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Duan W, Li X, Ge Y, Yu Z, Li P, Li J, Qin L, Xie J. Mycobacterium tuberculosis Rv1473 is a novel macrolides ABC Efflux Pump regulated by WhiB7. Future Microbiol 2018; 14:47-59. [PMID: 30539658 DOI: 10.2217/fmb-2018-0207] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
AIM To characterize a novel macrolide ATP binding cassette efflux pump encoding gene Rv1473 which might be involved in antibiotic resistance. METHODS Mycobacterium smegmatis was used as a surrogate model for pathogenic mycobacteria, drug susceptibility assays and ethidium bromide accumulation assay were harnessed to verify drug resistance. The real-time quantitative PCR was used to evaluate the transcription levels of WhiB7 and Ms3140 upon exposure to macrolides. RESULTS Rv1473 contributes to macrolides resistance via efflux mechanisms, and was positively regulated by the transcription factor WhiB7 upon macrolides exposure. CONCLUSION Rv1473 is a novel ATP binding cassette efflux pump involved in mycobacterium intrinsic antibiotics resistance via efflux mechanism. This finding will facilitate novel antibiotic discovery and the treatment of pathogen, especially for nontuberculous mycobacteria.
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Affiliation(s)
- Wei Duan
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment & Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, School of Life Sciences, Southwest University, Beibei, Chongqing 400715, PR China
| | - Xue Li
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment & Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, School of Life Sciences, Southwest University, Beibei, Chongqing 400715, PR China
| | - Yan Ge
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment & Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, School of Life Sciences, Southwest University, Beibei, Chongqing 400715, PR China
| | - Zhaoxiao Yu
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment & Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, School of Life Sciences, Southwest University, Beibei, Chongqing 400715, PR China
| | - Ping Li
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment & Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, School of Life Sciences, Southwest University, Beibei, Chongqing 400715, PR China
| | - Jiang Li
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment & Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, School of Life Sciences, Southwest University, Beibei, Chongqing 400715, PR China
| | - Lianhua Qin
- Shanghai Key Laboratory of Tuberculosis, Shanghai Pulmonary Hospital, Tongji University School of Medicine, 507 Zhengmin Road, Shanghai 200433, PR China
| | - Jianping Xie
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment & Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, School of Life Sciences, Southwest University, Beibei, Chongqing 400715, PR China
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Bush MJ. The actinobacterial WhiB-like (Wbl) family of transcription factors. Mol Microbiol 2018; 110:663-676. [PMID: 30179278 PMCID: PMC6282962 DOI: 10.1111/mmi.14117] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Revised: 08/29/2018] [Accepted: 08/30/2018] [Indexed: 02/06/2023]
Abstract
The WhiB‐like (Wbl) family of proteins are exclusively found in Actinobacteria. Wbls have been shown to play key roles in virulence and antibiotic resistance in Mycobacteria and Corynebacteria, reflecting their importance during infection by the human pathogens Mycobacterium tuberculosis, Mycobacterium leprae and Corynebacterium diphtheriae. In the antibiotic‐producing Streptomyces, several Wbls have important roles in the regulation of morphological differentiation, including WhiB, a protein that controls the initiation of sporulation septation and the founding member of the Wbl family. In recent years, genome sequencing has revealed the prevalence of Wbl paralogues in species throughout the Actinobacteria. Wbl proteins are small (generally ~80–140 residues) and each contains four invariant cysteine residues that bind an O2‐ and NO‐sensitive [4Fe–4S] cluster, raising the question as to how they can maintain distinct cellular functions within a given species. Despite their discovery over 25 years ago, the Wbl protein family has largely remained enigmatic. Here I summarise recent research in Mycobacteria, Corynebacteria and Streptomyces that sheds light on the biochemical function of Wbls as transcription factors and as potential sensors of O2 and NO. I suggest that Wbl evolution has created diversity in protein–protein interactions, [4Fe–4S] cluster‐sensitivity and the ability to bind DNA.
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Affiliation(s)
- Matthew J Bush
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
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Maione V, Cantini F, Severi M, Banci L. Investigating the role of the human CIA2A-CIAO1 complex in the maturation of aconitase. Biochim Biophys Acta Gen Subj 2018; 1862:1980-1987. [DOI: 10.1016/j.bbagen.2018.05.019] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Revised: 05/15/2018] [Accepted: 05/24/2018] [Indexed: 02/08/2023]
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Chawla M, Mishra S, Anand K, Parikh P, Mehta M, Vij M, Verma T, Singh P, Jakkala K, Verma HN, AjitKumar P, Ganguli M, Narain Seshasayee AS, Singh A. Redox-dependent condensation of the mycobacterial nucleoid by WhiB4. Redox Biol 2018; 19:116-133. [PMID: 30149290 PMCID: PMC6111044 DOI: 10.1016/j.redox.2018.08.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Revised: 08/02/2018] [Accepted: 08/11/2018] [Indexed: 12/22/2022] Open
Abstract
Oxidative stress response in bacteria is mediated through coordination between the regulators of oxidant-remediation systems (e.g. OxyR, SoxR) and nucleoid condensation (e.g. Dps, Fis). However, these genetic factors are either absent or rendered non-functional in the human pathogen Mycobacterium tuberculosis (Mtb). Therefore, how Mtb organizes genome architecture and regulates gene expression to counterbalance oxidative imbalance is unknown. Here, we report that an intracellular redox-sensor, WhiB4, dynamically links genome condensation and oxidative stress response in Mtb. Disruption of WhiB4 affects the expression of genes involved in maintaining redox homeostasis, central metabolism, and respiration under oxidative stress. Notably, disulfide-linked oligomerization of WhiB4 in response to oxidative stress activates the protein’s ability to condense DNA. Further, overexpression of WhiB4 led to hypercondensation of nucleoids, redox imbalance and increased susceptibility to oxidative stress, whereas WhiB4 disruption reversed this effect. In accordance with the findings in vitro, ChIP-Seq data demonstrated non-specific binding of WhiB4 to GC-rich regions of the Mtb genome. Lastly, data indicate that WhiB4 deletion affected the expression of ~ 30% of genes preferentially bound by the protein, suggesting both direct and indirect effects on gene expression. We propose that WhiB4 structurally couples Mtb’s response to oxidative stress with genome organization and transcription. Genome condensation is involved in the management of oxidative stress in bacteria. A relation between the genome condensation and oxidative stress is unclear in Mtb. A redox sensor WhiB4 calibrates genome-condensation and antioxidants in Mtb. Over-expression of WhiB4 hyper-condensed genome and induced killing by oxidants. WhiB4 deficiency delayed genome condensation and promoted oxidative stress survival.
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Affiliation(s)
- Manbeena Chawla
- Department of Microbiology and Cell Biology, Centre for Infectious Disease Research, Indian Institute of Science, Bangalore 560012, India
| | - Saurabh Mishra
- Department of Microbiology and Cell Biology, Centre for Infectious Disease Research, Indian Institute of Science, Bangalore 560012, India
| | - Kushi Anand
- Department of Microbiology and Cell Biology, Centre for Infectious Disease Research, Indian Institute of Science, Bangalore 560012, India
| | - Pankti Parikh
- Department of Microbiology and Cell Biology, Centre for Infectious Disease Research, Indian Institute of Science, Bangalore 560012, India
| | - Mansi Mehta
- Department of Microbiology and Cell Biology, Centre for Infectious Disease Research, Indian Institute of Science, Bangalore 560012, India
| | - Manika Vij
- Department of Structural Biology, CSIR-Institute of Genomics and Integrative Biology, South Campus, Mathura Road, New Delhi 110020, India; Academy of Scientific and Innovative Research (AcSIR), Anusandhan Bhawan, 2 Rafi Marg, New Delhi 110001, India
| | - Taru Verma
- Department of Microbiology and Cell Biology, Centre for Infectious Disease Research, Indian Institute of Science, Bangalore 560012, India; Centre for BioSystems Science and Engineering (BSSE), Indian Institute of Science, Bangalore 560012, India
| | - Parul Singh
- National Centre for Biological Science, Bangalore 560065, India; SASTRA University, Thanjavur 613401, Tamil Nadu, India
| | - Kishor Jakkala
- Department of Microbiology and Cell Biology, Centre for Infectious Disease Research, Indian Institute of Science, Bangalore 560012, India
| | - H N Verma
- Jaipur National University, Jagatpura, Jaipur 302017, India
| | - Parthasarathi AjitKumar
- Department of Microbiology and Cell Biology, Centre for Infectious Disease Research, Indian Institute of Science, Bangalore 560012, India
| | - Munia Ganguli
- Department of Structural Biology, CSIR-Institute of Genomics and Integrative Biology, South Campus, Mathura Road, New Delhi 110020, India; Academy of Scientific and Innovative Research (AcSIR), Anusandhan Bhawan, 2 Rafi Marg, New Delhi 110001, India
| | | | - Amit Singh
- Department of Microbiology and Cell Biology, Centre for Infectious Disease Research, Indian Institute of Science, Bangalore 560012, India.
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Pacl HT, Reddy VP, Saini V, Chinta KC, Steyn AJC. Host-pathogen redox dynamics modulate Mycobacterium tuberculosis pathogenesis. Pathog Dis 2018; 76:4972762. [PMID: 29873719 PMCID: PMC5989597 DOI: 10.1093/femspd/fty036] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Accepted: 04/13/2018] [Indexed: 12/18/2022] Open
Abstract
Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis, encounters variable and hostile environments within the host. A major component of these hostile conditions is reductive and oxidative stresses induced by factors modified by the host immune response, such as oxygen tension, NO or CO gases, reactive oxygen and nitrogen intermediates, the availability of different carbon sources and changes in pH. It is therefore essential for Mtb to continuously monitor and appropriately respond to the microenvironment. To this end, Mtb has developed various redox-sensitive systems capable of monitoring its intracellular redox environment and coordinating a response essential for virulence. Various aspects of Mtb physiology are regulated by these systems, including drug susceptibility, secretion systems, energy metabolism and dormancy. While great progress has been made in understanding the mechanisms and pathways that govern the response of Mtb to the host's redox environment, many questions in this area remain unanswered. The answers to these questions are promising avenues for addressing the tuberculosis crisis.
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Affiliation(s)
- Hayden T Pacl
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama 35205, USA
| | - Vineel P Reddy
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama 35205, USA
| | - Vikram Saini
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama 35205, USA
| | - Krishna C Chinta
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama 35205, USA
| | - Adrie J C Steyn
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama 35205, USA
- Centers for AIDS Research and Free Radical Biology, University of Alabama at Birmingham, Birmingham, Alabama 35205, USA
- Africa Health Research Institute, K-RITH Tower Building, Durban 4001, South Africa
- School of Laboratory Medicine and Medical Sciences, Nelson R. Mandela School of Medicine, University of KwaZulu-Natal, Durban 4001, South Africa
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Roles of Alanine Dehydrogenase and Induction of Its Gene in Mycobacterium smegmatis under Respiration-Inhibitory Conditions. J Bacteriol 2018; 200:JB.00152-18. [PMID: 29712875 DOI: 10.1128/jb.00152-18] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Accepted: 04/25/2018] [Indexed: 01/08/2023] Open
Abstract
Here we demonstrated that the inhibition of electron flux through the respiratory electron transport chain (ETC) by either the disruption of the gene for the major terminal oxidase (aa3 cytochrome c oxidase) or treatment with KCN resulted in the induction of ald encoding alanine dehydrogenase in Mycobacterium smegmatis A decrease in functionality of the ETC shifts the redox state of the NADH/NAD+ pool toward a more reduced state, which in turn leads to an increase in cellular levels of alanine by Ald catalyzing the conversion of pyruvate to alanine with the concomitant oxidation of NADH to NAD+ The induction of ald expression under respiration-inhibitory conditions in M. smegmatis is mediated by the alanine-responsive AldR transcriptional regulator. The growth defect of M. smegmatis by respiration inhibition was exacerbated by inactivation of the ald gene, suggesting that Ald is beneficial to M. smegmatis in its adaptation and survival under respiration-inhibitory conditions by maintaining NADH/NAD+ homeostasis. The low susceptibility of M. smegmatis to bcc1 complex inhibitors appears to be, at least in part, attributable to the high expression level of the bd quinol oxidase in M. smegmatis when the bcc1-aa3 branch of the ETC is inactivated.IMPORTANCE We demonstrated that the functionality of the respiratory electron transport chain is inversely related to the expression level of the ald gene encoding alanine dehydrogenase in Mycobacterium smegmatis Furthermore, the importance of Ald in NADH/NAD+ homeostasis during the adaptation of M. smegmatis to severe respiration-inhibitory conditions was demonstrated in this study. On the basis of these results, we propose that combinatory regimens including both an Ald-specific inhibitor and respiration-inhibitory antitubercular drugs such as Q203 and bedaquiline are likely to enable a more efficient therapy for tuberculosis.
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Ranaivomanana P, Raberahona M, Rabarioelina S, Borella Y, Machado A, Randria MJDD, Rakotoarivelo RA, Rasolofo V, Rakotosamimanana N. Cytokine Biomarkers Associated with Human Extra-Pulmonary Tuberculosis Clinical Strains and Symptoms. Front Microbiol 2018. [PMID: 29515555 PMCID: PMC5826350 DOI: 10.3389/fmicb.2018.00275] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Background: The primary site of infection for Mycobacterium tuberculosis (Mtb) is the alveolar macrophages. However, Mtb can disseminate into other organs and causes extrapulmonary tuberculosis (EPTB). The diagnosis of EPTB is challenging due to relatively inaccessible infectious sites that may be paucibacillary and with clinical symptoms varying by site that are similar to those seen in other diseases. Hence, we sought to identify the expression patterns of a variety of cytokines that may be specific to EPTB from in vitro infections and in the plasma of TB patients. Methods: To define those cytokine secretions associated with EPTB, human THP-1 derived macrophages were first infected with Mtb clinical isolates from pulmonary and EPTB. Infected macrophages supernatants were harvested at different time points and cytokines known to play key roles in TB immune responses including TNF-α, IL-6, IL-10, IFN-γ, and VEGF-A were measured by ELISA. Those cytokines that were in vitro associated to EPTB were also measured in the plasma from patients with PTB, EPTB, non-EPTB-confirmed-like symptoms and healthy controls. Results: While all of the studied cytokine secretions varied after in vitro infection, higher levels of TNF-α and VEGF secretions were observed in vitro in the infected macrophages respectively in the PTB and EPTB infecting clinical isolates. Similar trends were observed from the plasma of patients where patients with PTB showed significantly higher level of TNF-α compared to EPTB and healthy control groups. The patients with EPTB showed higher plasma level of VEGF compared to those patients with the non-EPTB (p < 0.01) and to healthy controls group (p < 0.0001). Using Receiver Operating Curves (ROC), we showed that TNF-α and VEGF concentrations could distinguish EPTB from non-confirmed EPTB with high sensitivity and specificity. Conclusion: Pulmonary and extrapulmonary Mtb clinical isolates showed different cytokine induction pattern in human macrophages that is also found in the plasma level of the EPTB patients. Further investigations are needed to define cytokine secretions that can lead to the definition of bio-signatures to differentiate EPTB from other pathologies with confusing symptoms that hampered the diagnosis of TB.
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Affiliation(s)
- Paulo Ranaivomanana
- Unité des Mycobactéries, Institut Pasteur de Madagascar, Antananarivo, Madagascar
| | - Mihaja Raberahona
- Infectious Diseases, Joseph Raseta Befelatanana University Hospital, Antananarivo, Madagascar
| | - Sedera Rabarioelina
- Unité des Mycobactéries, Institut Pasteur de Madagascar, Antananarivo, Madagascar
| | - Ysé Borella
- Unité des Mycobactéries, Institut Pasteur de Madagascar, Antananarivo, Madagascar
| | - Alice Machado
- Unité des Mycobactéries, Institut Pasteur de Madagascar, Antananarivo, Madagascar
| | - Mamy J De Dieu Randria
- Infectious Diseases, Joseph Raseta Befelatanana University Hospital, Antananarivo, Madagascar
| | - Rivo A Rakotoarivelo
- Infectious Diseases, Joseph Raseta Befelatanana University Hospital, Antananarivo, Madagascar.,Faculté de Médecine, University of Fianarantsoa, Fianarantsoa, Madagascar
| | - Voahangy Rasolofo
- Unité des Mycobactéries, Institut Pasteur de Madagascar, Antananarivo, Madagascar
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Zondervan NA, van Dam JCJ, Schaap PJ, Martins Dos Santos VAP, Suarez-Diez M. Regulation of Three Virulence Strategies of Mycobacterium tuberculosis: A Success Story. Int J Mol Sci 2018; 19:E347. [PMID: 29364195 PMCID: PMC5855569 DOI: 10.3390/ijms19020347] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Revised: 01/19/2018] [Accepted: 01/21/2018] [Indexed: 12/28/2022] Open
Abstract
Tuberculosis remains one of the deadliest diseases. Emergence of drug-resistant and multidrug-resistant M. tuberculosis strains makes treating tuberculosis increasingly challenging. In order to develop novel intervention strategies, detailed understanding of the molecular mechanisms behind the success of this pathogen is required. Here, we review recent literature to provide a systems level overview of the molecular and cellular components involved in divalent metal homeostasis and their role in regulating the three main virulence strategies of M. tuberculosis: immune modulation, dormancy and phagosomal rupture. We provide a visual and modular overview of these components and their regulation. Our analysis identified a single regulatory cascade for these three virulence strategies that respond to limited availability of divalent metals in the phagosome.
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Affiliation(s)
- Niels A Zondervan
- Laboratory of Systems and Synthetic Biology, Wageningen University & Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands.
| | - Jesse C J van Dam
- Laboratory of Systems and Synthetic Biology, Wageningen University & Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands.
| | - Peter J Schaap
- Laboratory of Systems and Synthetic Biology, Wageningen University & Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands.
| | - Vitor A P Martins Dos Santos
- Laboratory of Systems and Synthetic Biology, Wageningen University & Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands.
- LifeGlimmer GmbH, Markelstrasse 38, 12163 Berlin, Germany.
| | - Maria Suarez-Diez
- Laboratory of Systems and Synthetic Biology, Wageningen University & Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands.
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Kumar A, Alam A, Tripathi D, Rani M, Khatoon H, Pandey S, Ehtesham NZ, Hasnain SE. Protein adaptations in extremophiles: An insight into extremophilic connection of mycobacterial proteome. Semin Cell Dev Biol 2018; 84:147-157. [PMID: 29331642 DOI: 10.1016/j.semcdb.2018.01.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2017] [Revised: 09/01/2017] [Accepted: 01/09/2018] [Indexed: 02/02/2023]
Abstract
The biological paradox about how extremophiles persist at extreme ecological conditions throws a fascinating picture of the enormous potential of a single cell to adapt to homeostatic conditions in order to propagate. Unicellular organisms face challenges from both environmental factors and the ecological niche provided by the host tissue. Although the existence of extremophiles and their physiological properties were known for a long time, availability of whole genome sequence has catapulted the study on mechanisms of adaptation and the underlying principles that have enabled these unique organisms to withstand evolutionary and environmental pressures. Comparative genomics has shown that extremophiles possess the unique set of genes and proteins that empower them with biochemical machinery necessary to thrive in extreme environments. The presence of these proteins safeguards the cell against a wide array of extreme conditions such as temperature, pressure, radiations, chemicals, drugs etc. An insight into these adaptive mechanisms in extremophiles may help us to devise strategies to alter the genes and proteins that may have therapeutic potential and commercial value. Here we present an overview of the various adaptations in extremophiles. We also try to explain how mycobacterium channelizes its proteome to survive in stress conditions posed by host immune system.
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Affiliation(s)
- Ashutosh Kumar
- Molecular Infection and Functional Biology Lab, Kusuma School of Biological Sciences, Indian Institute of Technology-Delhi, New Delhi, India
| | - Anwar Alam
- Molecular Infection and Functional Biology Lab, Kusuma School of Biological Sciences, Indian Institute of Technology-Delhi, New Delhi, India
| | - Deeksha Tripathi
- Department of Microbiology, Central University of Rajasthan, Bandar Sindri, Ajmer, Rajasthan, India
| | - Mamta Rani
- Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology-Delhi, New Delhi, India
| | - Hafeeza Khatoon
- Molecular Infection and Functional Biology Lab, Kusuma School of Biological Sciences, Indian Institute of Technology-Delhi, New Delhi, India
| | - Saurabh Pandey
- National Institute of Pathology, Safdarjang Hospital Campus, New Delhi, India
| | - Nasreen Z Ehtesham
- National Institute of Pathology, Safdarjang Hospital Campus, New Delhi, India
| | - Seyed E Hasnain
- Molecular Infection and Functional Biology Lab, Kusuma School of Biological Sciences, Indian Institute of Technology-Delhi, New Delhi, India; JH-Institute of Molecular Medicine, Hamdard Nagar, New Delhi, India; Dr Reddy's Institute of Life Sciences, University of Hyderabad Campus, Hyderabad, India.
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Cardenal-Muñoz E, Barisch C, Lefrançois LH, López-Jiménez AT, Soldati T. When Dicty Met Myco, a (Not So) Romantic Story about One Amoeba and Its Intracellular Pathogen. Front Cell Infect Microbiol 2018; 7:529. [PMID: 29376033 PMCID: PMC5767268 DOI: 10.3389/fcimb.2017.00529] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Accepted: 12/18/2017] [Indexed: 01/06/2023] Open
Abstract
In recent years, Dictyostelium discoideum has become an important model organism to study the cell biology of professional phagocytes. This amoeba not only shares many molecular features with mammalian macrophages, but most of its fundamental signal transduction pathways are conserved in humans. The broad range of existing genetic and biochemical tools, together with its suitability for cell culture and live microscopy, make D. discoideum an ideal and versatile laboratory organism. In this review, we focus on the use of D. discoideum as a phagocyte model for the study of mycobacterial infections, in particular Mycobacterium marinum. We look in detail at the intracellular cycle of M. marinum, from its uptake by D. discoideum to its active or passive egress into the extracellular medium. In addition, we describe the molecular mechanisms that both the mycobacterial invader and the amoeboid host have developed to fight against each other, and compare and contrast with those developed by mammalian phagocytes. Finally, we introduce the methods and specific tools that have been used so far to monitor the D. discoideum-M. marinum interaction.
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Affiliation(s)
- Elena Cardenal-Muñoz
- Department of Biochemistry, Sciences II, Faculty of Sciences, University of Geneva, Geneva, Switzerland
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Chatterjee A, Sharma AK, Mahatha AC, Banerjee SK, Kumar M, Saha S, Basu J, Kundu M. Global mapping of MtrA-binding sites links MtrA to regulation of its targets in Mycobacterium tuberculosis. MICROBIOLOGY-SGM 2017; 164:99-110. [PMID: 29182512 DOI: 10.1099/mic.0.000585] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Mycobacterium tuberculosis employs two-component systems (TCSs) for survival within its host. The TCS MtrAB is conserved among mycobacteria. The response regulator MtrA is essential in M. tuberculosis. The genome-wide chromatin immunoprecipitation (ChIP) sequencing performed in this study suggested that MtrA binds upstream of at least 45 genes of M. tuberculosis, including those involved in cell wall remodelling, stress responses, persistence and regulation of transcription. It binds to the promoter regions and regulates the peptidoglycan hydrolases rpfA and rpfC, which are required for resuscitation from dormancy. It also regulates the expression of whiB4, a critical regulator of the oxidative stress response, and relF, one-half of the toxin-antitoxin locus relFG. We have identified a new consensus 9 bp loose motif for MtrA binding. Mutational changes in the consensus sequence greatly reduced the binding of MtrA to its newly identified targets. Importantly, we observed that overexpression of a gain-of-function mutant, MtrAY102C, enhanced expression of the aforesaid genes in M. tuberculosis isolated from macrophages, whereas expression of each of these targets was lower in M. tuberculosis overexpressing a phosphorylation-defective mutant, MtrAD56N. This result suggests that phosphorylated MtrA (MtrA-P) is required for the expression of its targets in macrophages. Our data have uncovered new MtrA targets that suggest that MtrA is required for a transcriptional response that likely enables M. tuberculosis to persist within its host and emerge out of dormancy when the conditions are favourable.
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Affiliation(s)
- Ayan Chatterjee
- Department of Chemistry, Bose Institute, 93/1 Acharya Prafulla Chandra Road, Kolkata-700009, India
| | - Arun Kumar Sharma
- Department of Chemistry, Bose Institute, 93/1 Acharya Prafulla Chandra Road, Kolkata-700009, India
| | - Amar Chandra Mahatha
- Department of Chemistry, Bose Institute, 93/1 Acharya Prafulla Chandra Road, Kolkata-700009, India
| | - Srijon Kaushik Banerjee
- Department of Chemistry, Bose Institute, 93/1 Acharya Prafulla Chandra Road, Kolkata-700009, India
| | - Manish Kumar
- Department of Chemistry, Bose Institute, 93/1 Acharya Prafulla Chandra Road, Kolkata-700009, India
| | - Sudipto Saha
- Bioinformatics Centre, Bose Institute (Centenary Building), P 1/12, C. I. T. Road, Scheme-VIIM, Kolkata-700054, India
| | - Joyoti Basu
- Department of Chemistry, Bose Institute, 93/1 Acharya Prafulla Chandra Road, Kolkata-700009, India
| | - Manikuntala Kundu
- Department of Chemistry, Bose Institute, 93/1 Acharya Prafulla Chandra Road, Kolkata-700009, India
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48
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Vijay S, Vinh DN, Hai HT, Ha VTN, Dung VTM, Dinh TD, Nhung HN, Tram TTB, Aldridge BB, Hanh NT, Thu DDA, Phu NH, Thwaites GE, Thuong NTT. Influence of Stress and Antibiotic Resistance on Cell-Length Distribution in Mycobacterium tuberculosis Clinical Isolates. Front Microbiol 2017; 8:2296. [PMID: 29209302 PMCID: PMC5702322 DOI: 10.3389/fmicb.2017.02296] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Accepted: 11/07/2017] [Indexed: 11/25/2022] Open
Abstract
Mycobacterial cellular variations in growth and division increase heterogeneity in cell length, possibly contributing to cell-to-cell variation in host and antibiotic stress tolerance. This may be one of the factors influencing Mycobacterium tuberculosis persistence to antibiotics. Tuberculosis (TB) is a major public health problem in developing countries, antibiotic persistence, and emergence of antibiotic resistance further complicates this problem. We wanted to investigate the factors influencing cell-length distribution in clinical M. tuberculosis strains. In parallel we examined M. tuberculosis cell-length distribution in a large set of clinical strains (n = 158) from ex vivo sputum samples, in vitro macrophage models, and in vitro cultures. Our aim was to understand the influence of clinically relevant factors such as host stresses, M. tuberculosis lineages, antibiotic resistance, antibiotic concentrations, and disease severity on the cell size distribution in clinical M. tuberculosis strains. Increased cell size and cell-to-cell variation in cell length were associated with bacteria in sputum and infected macrophages rather than liquid culture. Multidrug-resistant (MDR) strains displayed increased cell length heterogeneity compared to sensitive strains in infected macrophages and also during growth under rifampicin (RIF) treatment. Importantly, increased cell length was also associated with pulmonary TB disease severity. Supporting these findings, individual host stresses, such as oxidative stress and iron deficiency, increased cell-length heterogeneity of M. tuberculosis strains. In addition we also observed synergism between host stress and RIF treatment in increasing cell length in MDR-TB strains. This study has identified some clinical factors contributing to cell-length heterogeneity in clinical M. tuberculosis strains. The role of these cellular adaptations to host and antibiotic tolerance needs further investigation.
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Affiliation(s)
- Srinivasan Vijay
- Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Dao N Vinh
- Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Hoang T Hai
- Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Vu T N Ha
- Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Vu T M Dung
- Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Tran D Dinh
- Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Hoang N Nhung
- Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Trinh T B Tram
- Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Bree B Aldridge
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA, United States.,Department of Biomedical Engineering, Tufts University School of Engineering, Medford, MA, United States
| | - Nguyen T Hanh
- Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Do D A Thu
- Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Nguyen H Phu
- Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | - Guy E Thwaites
- Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Nguyen T T Thuong
- Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
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49
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WhiB4 Regulates the PE/PPE Gene Family and is Essential for Virulence of Mycobacterium marinum. Sci Rep 2017; 7:3007. [PMID: 28592799 PMCID: PMC5462746 DOI: 10.1038/s41598-017-03020-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Accepted: 04/18/2017] [Indexed: 11/18/2022] Open
Abstract
During the course of infection, pathogenic mycobacteria including Mycobacterium tuberculosis (M. tb) encounter host environments of variable oxygen tension, ranging from the hypoxic center of granulomas to the most oxygenated region in the lung cavities. Mycobacterial responses to changes of oxygen tension are critically related to infection outcomes, such as latency and reactivation. WhiB4 is an iron-sulfur containing transcription factor that is highly sensitive to oxygen exposure. In this study, we found that WhiB4 of Mycobacterium marinum (M. marinum), a pathogenic mycobacterial species that is closely related to M. tb, is required for its virulence. M. marinum ΔwhiB4 exhibited defective intracellular replication in macrophages and diminished virulence in zebrafish. Histology analysis revealed that the host had successfully controlled ΔwhiB4 bacteria, forming well-organized granulomas. RNA-seq analysis identified a large number of pe/ppe genes that were regulated by WhiB4, which provides an explanation for the essential role of WhiB4 in M. marinum virulence. Several antioxidant enzymes were also upregulated in ΔwhiB4, supporting its role in modulation of oxidative stress response. Taken together, we have provided new insight into and proposed a model to explain the physiological role of WhiB4.
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50
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Mishra S, Shukla P, Bhaskar A, Anand K, Baloni P, Jha RK, Mohan A, Rajmani RS, Nagaraja V, Chandra N, Singh A. Efficacy of β-lactam/β-lactamase inhibitor combination is linked to WhiB4-mediated changes in redox physiology of Mycobacterium tuberculosis. eLife 2017; 6:e25624. [PMID: 28548640 PMCID: PMC5473688 DOI: 10.7554/elife.25624] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Accepted: 05/24/2017] [Indexed: 12/15/2022] Open
Abstract
Mycobacterium tuberculosis (Mtb) expresses a broad-spectrum β-lactamase (BlaC) that mediates resistance to one of the highly effective antibacterials, β-lactams. Nonetheless, β-lactams showed mycobactericidal activity in combination with β-lactamase inhibitor, clavulanate (Clav). However, the mechanistic aspects of how Mtb responds to β-lactams such as Amoxicillin in combination with Clav (referred as Augmentin [AG]) are not clear. Here, we identified cytoplasmic redox potential and intracellular redox sensor, WhiB4, as key determinants of mycobacterial resistance against AG. Using computer-based, biochemical, redox-biosensor, and genetic strategies, we uncovered a functional linkage between specific determinants of β-lactam resistance (e.g. β-lactamase) and redox potential in Mtb. We also describe the role of WhiB4 in coordinating the activity of β-lactamase in a redox-dependent manner to tolerate AG. Disruption of WhiB4 enhances AG tolerance, whereas overexpression potentiates AG activity against drug-resistant Mtb. Our findings suggest that AG can be exploited to diminish drug-resistance in Mtb through redox-based interventions.
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Affiliation(s)
- Saurabh Mishra
- Microbiology and Cell Biology, Centre for Infectious Disease Research, Indian Institute of Science, Bangalore, India
| | - Prashant Shukla
- Microbiology and Cell Biology, Centre for Infectious Disease Research, Indian Institute of Science, Bangalore, India
- International Centre for Genetic Engineering and Biotechnology, New Delhi, India
| | | | - Kushi Anand
- Microbiology and Cell Biology, Centre for Infectious Disease Research, Indian Institute of Science, Bangalore, India
| | - Priyanka Baloni
- Department of Biochemistry, Indian Institute of Science, Bangalore, India
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, India
| | - Rajiv Kumar Jha
- Microbiology and Cell Biology, Centre for Infectious Disease Research, Indian Institute of Science, Bangalore, India
| | - Abhilash Mohan
- Department of Biochemistry, Indian Institute of Science, Bangalore, India
| | - Raju S Rajmani
- Microbiology and Cell Biology, Centre for Infectious Disease Research, Indian Institute of Science, Bangalore, India
| | - Valakunja Nagaraja
- Microbiology and Cell Biology, Centre for Infectious Disease Research, Indian Institute of Science, Bangalore, India
- Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore, India
| | - Nagasuma Chandra
- Department of Biochemistry, Indian Institute of Science, Bangalore, India
| | - Amit Singh
- Microbiology and Cell Biology, Centre for Infectious Disease Research, Indian Institute of Science, Bangalore, India
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