Mycobacterium tuberculosis WhiB4 regulates oxidative stress response to modulate survival and dissemination in vivo

Manbeena Chawla, Pankti Parikh, Alka Saxena, Mohamedhusen Munshi, Mansi Mehta, Deborah Mai, Anup K. Srivastava, K. V. Narasimhulu, Kevin Redding, Nimi Vashi, Dhiraj Kumar, Adrie J C Steyn, Amit Singh

Research output: Contribution to journalArticle

42 Citations (Scopus)

Abstract

Host-generated oxidative stress is considered one of the main mechanisms constraining Mycobacterium tuberculosis (Mtb) growth. The redox-sensing mechanisms in Mtb are not completely understood. Here we show that WhiB4 responds to oxygen (O2) and nitric oxide (NO) via its 4Fe-4S cluster and controls the oxidative stress response in Mtb. The WhiB4 mutant (MtbΔwhiB4) displayed an altered redox balance and a reduced membrane potential. Microarray analysis demonstrated that MtbΔwhiB4 overexpresses the antioxidant systems including alkyl hydroperoxidase (ahpC-ahpD) and rubredoxins (rubA-rubB). DNA binding assays showed that WhiB4 [4Fe-4S] cluster is dispensable for DNA binding. However, oxidation of the apo-WhiB4 Cys thiols induced disulphide-linked oligomerization, DNA binding and transcriptional repression, whereas reduction reversed the effect. Furthermore, WhiB4 binds DNA with a preference for GC-rich sequences. Expression analysis showed that oxidative stress repressed whiB4 and induced antioxidants in Mtb, while their hyper-induction was observed in MtbΔwhiB4. MtbΔwhiB4 showed increased resistance to oxidative stress in vitro and enhanced survival inside the macrophages. Lastly, MtbΔwhiB4 displayed hypervirulence in the lungs of guinea pigs, but showed a defect in dissemination to their spleen. These findings suggest that WhiB4 systematically calibrates the activation of oxidative stress response in Mtb to maintain redox balance, and to modulate virulence.

Original languageEnglish (US)
Pages (from-to)1148-1165
Number of pages18
JournalMolecular Microbiology
Volume85
Issue number6
DOIs
StatePublished - Sep 2012

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Mycobacterium tuberculosis
Oxidative Stress
Oxidation-Reduction
DNA
Rubredoxins
Antioxidants
GC Rich Sequence
Microarray Analysis
Sulfhydryl Compounds
Disulfides
Membrane Potentials
Virulence
Nitric Oxide
Guinea Pigs
Spleen
Macrophages
Oxygen
Lung
Growth

ASJC Scopus subject areas

  • Molecular Biology
  • Microbiology

Cite this

Mycobacterium tuberculosis WhiB4 regulates oxidative stress response to modulate survival and dissemination in vivo. / Chawla, Manbeena; Parikh, Pankti; Saxena, Alka; Munshi, Mohamedhusen; Mehta, Mansi; Mai, Deborah; Srivastava, Anup K.; Narasimhulu, K. V.; Redding, Kevin; Vashi, Nimi; Kumar, Dhiraj; Steyn, Adrie J C; Singh, Amit.

In: Molecular Microbiology, Vol. 85, No. 6, 09.2012, p. 1148-1165.

Research output: Contribution to journalArticle

Chawla, M, Parikh, P, Saxena, A, Munshi, M, Mehta, M, Mai, D, Srivastava, AK, Narasimhulu, KV, Redding, K, Vashi, N, Kumar, D, Steyn, AJC & Singh, A 2012, 'Mycobacterium tuberculosis WhiB4 regulates oxidative stress response to modulate survival and dissemination in vivo', Molecular Microbiology, vol. 85, no. 6, pp. 1148-1165. https://doi.org/10.1111/j.1365-2958.2012.08165.x
Chawla, Manbeena ; Parikh, Pankti ; Saxena, Alka ; Munshi, Mohamedhusen ; Mehta, Mansi ; Mai, Deborah ; Srivastava, Anup K. ; Narasimhulu, K. V. ; Redding, Kevin ; Vashi, Nimi ; Kumar, Dhiraj ; Steyn, Adrie J C ; Singh, Amit. / Mycobacterium tuberculosis WhiB4 regulates oxidative stress response to modulate survival and dissemination in vivo. In: Molecular Microbiology. 2012 ; Vol. 85, No. 6. pp. 1148-1165.
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