1
|
Murarka P, Keshav A, Meena BK, Srivastava P. Functional characterization of the transcription regulator WhiB1 from Gordonia sp. IITR100. MICROBIOLOGY-SGM 2020; 166:1181-1190. [PMID: 33215983 DOI: 10.1099/mic.0.000985] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
WhiB is a transcription regulator which has been reported to be involved in the regulation of cell morphogenesis, cell division, antibiotic resistance, stress, etc., in several members of the family Actinomycetes. The present study describes functional characterization of a WhiB family protein, WhiB1 (protein ID: WP_065632651.1), from Gordonia sp. IITR100. We demonstrate that WhiB1 affects chromosome segregation and cell morphology in recombinant Escherichia coli, Gordonia sp. IITR100 as well as in Rhodococcus erythropolis. Multiple sequence alignment suggests that WhiB1 is a conserved protein among members of the family Actinomycetes. It has been reported that overexpression of WhiB1 leads to repression of the biodesulfurization operon in recombinant E. coli, Gordonia sp. IITR100 and R. erythropolis. A WhiB1-mut containing a point mutation Q116A in the DNA binding domain of WhiB1 led to partial alleviation of repression of the biodesulfurization operon. We show for the first time that the WhiB family protein WhiB1 is also involved in repression of the biodesulfurization operon by directly binding to the dsz promoter DNA.
Collapse
Affiliation(s)
- Pooja Murarka
- Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
| | - Aditi Keshav
- Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
| | - Bintu Kumar Meena
- Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
| | - Preeti Srivastava
- Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
| |
Collapse
|
2
|
Unraveling the transcriptional regulatory networks associated to mycobacterial cell wall defective form induction by glycine and lysozyme treatment. Microbiol Res 2013. [DOI: 10.1016/j.micres.2012.10.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
3
|
Lee JY, Park JS, Kim HJ, Kim Y, Lee HS. Corynebacterium glutamicum whcB, a stationary phase-specific regulatory gene. FEMS Microbiol Lett 2011; 327:103-9. [DOI: 10.1111/j.1574-6968.2011.02463.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2011] [Revised: 11/06/2011] [Accepted: 11/08/2011] [Indexed: 11/27/2022] Open
Affiliation(s)
- Joo-Young Lee
- Department of Biotechnology and Bioinformatics; Korea University; Jochiwon; Chungnam; Korea
| | - Joon-Song Park
- Department of Biotechnology and Bioinformatics; Korea University; Jochiwon; Chungnam; Korea
| | - Hyung-Joon Kim
- CJ Research Institute of Biotechnology; CJ Cheiljedang Corporation; Seoul; Korea
| | - Younhee Kim
- Department of Oriental Medicine; Semyung University; Checheon; Chungbuk; Korea
| | - Heung-Shick Lee
- Department of Biotechnology and Bioinformatics; Korea University; Jochiwon; Chungnam; Korea
| |
Collapse
|
4
|
Genes and regulatory networks involved in persistence of Mycobacterium tuberculosis. SCIENCE CHINA-LIFE SCIENCES 2011; 54:300-10. [PMID: 21267668 DOI: 10.1007/s11427-011-4134-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2010] [Accepted: 09/06/2010] [Indexed: 10/18/2022]
Abstract
The causative agent of tuberculosis, Mycobacterium tuberculosis, is one of the most successful of human pathogens. It can evade the host immune response and establish a persistent infection or enter a dormant state within the host which can be reactivated if the host becomes immuno-compromised. Both of these features are major obstacles to tuberculosis eradication. Dormancy and reactivation of M. tuberculosis are tightly coordinated dynamic processes involving numerous genes and their products. Molecular mechanisms underlying M. tuberculosis persistence may provide an opportunity for the discovery of effective drug targets for tuberculosis control. Here, we review the genes required for M. tuberculosis persistence and propose a regulatory network for the action of these genes using text mining. This should provide fresh insights into the persistence mechanisms of M. tuberculosis and suggest candidates for new drug targets and immune intervention.
Collapse
|
5
|
den Hengst CD, Buttner MJ. Redox control in actinobacteria. Biochim Biophys Acta Gen Subj 2008; 1780:1201-16. [PMID: 18252205 DOI: 10.1016/j.bbagen.2008.01.008] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2007] [Revised: 01/07/2008] [Accepted: 01/14/2008] [Indexed: 10/22/2022]
Abstract
As most actinobacteria are obligate aerobes, they have to cope with endogenously generated reactive oxygen species, and actinobacterial pathogens have to resist oxidative attack by phagocytes. Actinobacteria also have to survive long periods under low oxygen tension; for example, Mycobacterium tuberculosis can persist in the host for years under apparently hypoxic conditions in a latent, non-replicative state. Here we focus on the regulatory switches that control actinobacterial responses to peroxide stress, disulfide stress and low oxygen tension. Other unique aspects of their redox biology will be highlighted, including the use of the pseudodisaccharide mycothiol as their major low-molecular-weight thiol buffer, and the [4Fe-4S]-containing WhiB-like proteins, which play diverse, important roles in actinobacterial biology, but whose biochemical role is still controversial.
Collapse
Affiliation(s)
- Chris D den Hengst
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Colney, Norwich, NR4 7UH, UK.
| | | |
Collapse
|
6
|
Abstract
Once across the barrier of the epithelium, macrophages constitute the primary defense against microbial invasion. For most microbes, the acidic, hydrolytically competent environment of the phagolysosome is sufficient to kill them. Despite our understanding of the trafficking events that regulate phagosome maturation, our appreciation of the lumenal environment within the phagosome is only now becoming elucidated through real-time functional assays. The assays quantify pH change, phagosome/lysosome fusion, proteolysis, lipolysis, and beta-galactosidase activity. This information is particularly important for understanding pathogens that successfully parasitize the endosomal/lysosomal continuum. Mycobacterium tuberculosis infects macrophages through arresting the normal maturation process of the phagosome, retaining its vacuole at pH 6.4 with many of the characteristics of an early endosome. Current studies are focusing on the transcriptional response of the bacterium to the changing environment in the macrophage phagosome. Manipulation of these environmental cues, such as preventing the pH drop to pH 6.4 with concanamycin A, abrogates the majority of the transcriptional response in the bacterium, showing that pH is the dominant signal that the bacterium senses and responds to. These approaches represent our ongoing attempts to unravel the discourse that takes place between the pathogen and its host cell.
Collapse
Affiliation(s)
- Kyle Rohde
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
| | | | | | | |
Collapse
|
7
|
Geiman DE, Raghunand TR, Agarwal N, Bishai WR. Differential gene expression in response to exposure to antimycobacterial agents and other stress conditions among seven Mycobacterium tuberculosis whiB-like genes. Antimicrob Agents Chemother 2006; 50:2836-41. [PMID: 16870781 PMCID: PMC1538666 DOI: 10.1128/aac.00295-06] [Citation(s) in RCA: 153] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The seven Mycobacterium tuberculosis whiB-like genes encode small proteins postulated to be transcriptional regulators. A systematic real-time reverse transcription-PCR analysis following exposure to antibiotics and a variety of growth and in vitro stress conditions indicates differential, and in some cases dramatic, transcription modulations for the different M. tuberculosis whiB family members. This information together with biochemical analyses of the whiB1 to whiB7 gene products will be important for understanding the biology of this novel family of proteins in mycobacteria and related actinomycetes.
Collapse
Affiliation(s)
- Deborah E Geiman
- Department of Medicine, Division of Infectious Diseases, Johns Hopkins University School of Medicine, Baltimore, MD 21231, USA
| | | | | | | |
Collapse
|
8
|
Raghunand TR, Bishai WR. Mapping essential domains of Mycobacterium smegmatis WhmD: insights into WhiB structure and function. J Bacteriol 2006; 188:6966-76. [PMID: 16980499 PMCID: PMC1595512 DOI: 10.1128/jb.00384-06] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2006] [Accepted: 06/19/2006] [Indexed: 11/20/2022] Open
Abstract
A growing body of evidence suggests that the WhiB-like proteins exclusive to the GC-rich actinomycete genera play significant roles in pathogenesis and cell division. Each of these proteins contains four invariant cysteine residues and a conserved helix-turn-helix motif. whmD, the Mycobacterium smegmatis homologue of Streptomyces coelicolor whiB, is essential in M. smegmatis, and the conditionally complemented mutant M. smegmatis 628-53 undergoes filamentation under nonpermissive conditions. To identify residues critical to WhmD function, we developed a cotransformation-based assay to screen for alleles that complement the filamentation phenotype of M. smegmatis 628-53 following inducer withdrawal. Mycobacterium tuberculosis whiB2 and S. coelicolor whiB complemented the defect in M. smegmatis 628-53, indicating that these genes are true functional orthologues of whmD. Deletion analysis suggested that the N-terminal 67 and C-terminal 12 amino acid residues are dispensable for activity. Site-directed mutagenesis indicated that three of the four conserved cysteine residues (C90, C93, and C99) and a conserved aspartate (D71) are essential. Mutations in a predicted loop glycine (G111) and an unstructured leucine (L116) were poorly tolerated. The region essential for WhmD activity encompasses 6 of the 10 residues conserved in all seven M. tuberculosis WhiBs, as well as in most members of the WhiB family identified thus far. WhmD structure was found to be sensitive to the presence of a reducing agent, suggesting that the cysteine residues are involved in coordinating a metal ion. Iron-specific staining strongly suggested that WhmD contains a bound iron atom. With this information, we have now begun to comprehend the functional significance of the conserved sequence and structural elements in this novel family of proteins.
Collapse
Affiliation(s)
- Tirumalai R Raghunand
- Center for Tuberculosis Research, Johns Hopkins University School of Medicine, 1550 Orleans Street, Baltimore, MD 21231-1002, USA
| | | |
Collapse
|
9
|
Kim TH, Park JS, Kim HJ, Kim Y, Kim P, Lee HS. The whcE gene of Corynebacterium glutamicum is important for survival following heat and oxidative stress. Biochem Biophys Res Commun 2005; 337:757-64. [PMID: 16212936 DOI: 10.1016/j.bbrc.2005.09.115] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2005] [Accepted: 09/09/2005] [Indexed: 10/25/2022]
Abstract
In this study, we have analyzed an ORF from Corynebacterium glutamicum, which codes for a homologue of the Streptomyces coelicolor WhiB-family of proteins known to be involved in sporulation. This ORF encoded a putative protein which harbors a helix-turn-helix DNA-binding motif and a probable redox-sensing motif, and has been designated whcE. We constructed a whcE mutant strain and analyzed the strain under a variety of growth conditions. This mutant strain exhibited a prolonged lag phase and earlier death within the stationary phase, suggesting that the relevant gene may play a role in both growth adaptation and stress responses. Further analysis determined that the mutant strain was not only sensitive with regard to survival under heat stress, but was also markedly susceptible to thiol-specific oxidant diamide and redox cycling compounds, including menadione and plumbagin. The mutant strain also exhibited reductions in thioredoxin reductase activity, which indicates that the trxB gene encoding thioredoxin reductase is under the control of WhcE. Expression of whcE was stimulated during the stationary phase of cell growth and could be modulated by diamide. We also delineated the relationship between whcE and the sigH gene, which is located downstream of whcE, and has been shown to be involved in heat stress responses, via the encoding of an ECF sigma factor. In a sigH mutant strain, the whcE gene was no longer expressed, thereby suggesting that the sigmaH sigma factor is involved in whcE expression. Our results suggest that WhcE functions as a transcription factor which can activate the trxB gene, as well as other genes, possibly by sensing redox changes during the metabolic downshifting of cells from exponential growth to the stationary phase, whereas sigmaH appears to function as the sigma factor for these genes, including whcE.
Collapse
Affiliation(s)
- Tae-Hyun Kim
- Graduate School of Biotechnology, Korea University, Anam-Dong, Sungbuk-Ku, Seoul 136-701, Republic of Korea
| | | | | | | | | | | |
Collapse
|
10
|
Steyn AJC, Collins DM, Hondalus MK, Jacobs WR, Kawakami RP, Bloom BR. Mycobacterium tuberculosis WhiB3 interacts with RpoV to affect host survival but is dispensable for in vivo growth. Proc Natl Acad Sci U S A 2002; 99:3147-52. [PMID: 11880648 PMCID: PMC122487 DOI: 10.1073/pnas.052705399] [Citation(s) in RCA: 200] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Previous work established that the principal sigma factor (RpoV) of virulent Mycobacterium bovis, a member of the Mycobacterium tuberculosis complex, restores virulence to an attenuated strain containing a point mutation (Arg-515-->His) in the 4.2 domain of RpoV. We used the 4.2 domain of RpoV as bait in a yeast two-hybrid screen of an M. tuberculosis H37Rv library and identified a putative transcription factor, WhiB3, which selectively interacts with the 4.2 domain of RpoV in virulent strains but not with the mutated (Arg-515-->His) allele. Infection of mice and guinea pigs with a M. tuberculosis H37Rv whiB3 deletion mutant strain showed that whiB3 is not necessary for in vivo bacterial replication in either animal model. In contrast, an M. bovis whiB3 deletion mutant was completely attenuated for growth in guinea pigs. However, we found that immunocompetent mice infected with the M. tuberculosis H37Rv whiB3 mutant strain had significantly longer mean survival times as compared with mice challenged with wild-type M. tuberculosis. Remarkably, the bacterial organ burdens of both mutant and wild-type infected mice were identical during the acute and persistent phases of infection. Our results imply that M. tuberculosis replication per se is not a sufficient condition for virulence in vivo. They also indicate a different role for M. bovis and M. tuberculosis whiB3 genes in pathogenesis generated in different animal models. We propose that M. tuberculosis WhiB3 functions as a transcription factor regulating genes that influence the immune response of the host.
Collapse
Affiliation(s)
- Adrie J C Steyn
- Harvard School of Public Health, Department of Immunology and Infectious Disease, Boston, MA 02115, USA
| | | | | | | | | | | |
Collapse
|
11
|
Soliveri JA, Gomez J, Bishai WR, Chater KF. Multiple paralogous genes related to the Streptomyces coelicolor developmental regulatory gene whiB are present in Streptomyces and other actinomycetes. MICROBIOLOGY (READING, ENGLAND) 2000; 146 ( Pt 2):333-343. [PMID: 10708372 DOI: 10.1099/00221287-146-2-333] [Citation(s) in RCA: 128] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The whiB sporulation gene of Streptomyces coelicolor was shown [Davis, N. K. & Chater, K. F. (1992). Mol Gen Genet 232, 351-358] to encode a small, cysteine-rich putative transcription factor unlike any that had been described previously. The large database of DNA sequences of mycobacteria (like Streptomyces, members of the Actinomycetales) has revealed a family of genes encoding proteins related to WhiB. Mycobacterium tuberculosis contains at least six such genes (whiB homologues in mycobacteria: whmA-F) and a likely seventh, whmG. Using conserved features of Whm proteins, a PCR-based approach led to the discovery that S. coelicolor A3(2) contains several similar genes. Cloning and sequencing of these whiB-like (wbI) genes revealed likely orthologues of four of the whm genes of M. tuberculosis. In all, S. coelicolor contains at least five wbI genes in addition to whiB itself. All five were shown by RT-PCR to be transcribed. A Southern blotting survey using each wbI gene as a probe showed that nearly all of a series of representatives of ten actinomycete genera (including morphologically simple organisms) contain close homologues of several wbI genes, suggesting that the ancient progenitor of all these organisms already contained a family of such genes, which have not been found in any other organisms.
Collapse
Affiliation(s)
- J A Soliveri
- John Innes Centre, Norwich Research Park, Colney, Norwich NR4 7UH, UK1
| | - J Gomez
- Dept of Molecular Microbiology and Centre for Tuberculosis Research, Johns Hopkins School of Hygiene and Public Health, 615 N Wolfe Street, Baltimore, MD 21205, USA2
| | - W R Bishai
- Dept of Molecular Microbiology and Centre for Tuberculosis Research, Johns Hopkins School of Hygiene and Public Health, 615 N Wolfe Street, Baltimore, MD 21205, USA2
| | - K F Chater
- John Innes Centre, Norwich Research Park, Colney, Norwich NR4 7UH, UK1
| |
Collapse
|