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Exopolyphosphatases PPX1 and PPX2 from Mycobacterium tuberculosis regulate dormancy response and pathogenesis

Tiwari, P and Gosain, TP and Chugh, S and Singh, M and Sankhe, GD and Arora, G and Kidwai, S and Agarwal, S and Saini, DK and Singh, R (2022) Exopolyphosphatases PPX1 and PPX2 from Mycobacterium tuberculosis regulate dormancy response and pathogenesis. In: Microbial Pathogenesis, 173 .

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Official URL: https://doi.org/10.1016/j.micpath.2022.105885


Stress adaptation and virulence of various bacterial pathogens require stringent response pathways involving guanosine pentaphosphate and inorganic polyphosphate (PolyP). In M. tuberculosis, intracellular PolyP levels are maintained by the activities of polyphosphate kinase (PPK-1, PPK-2) and exopolyphosphatases (PPX-1, PPX-2). We demonstrate that these exopolyphosphatases cumulatively contribute to biofilm formation and survival of M. tuberculosis in nutrient limiting, low oxygen growth conditions and in macrophages. Characterization of single (Δppx2) and double knock out strain (dkppx) of M. tuberculosis demonstrated that these exopolyphosphatases are essential for establishing infection in guinea pigs and mice. Transcriptional profiling revealed that relative to the parental strain the expression of genes belonging to DosR regulon were significantly reduced in mid-log phase cultures of dkppx strain. We also show that PolyP inhibited the autophosphorylation activities associated with DosT and DosS sensor kinases. Host RNA-seq analysis revealed that transcripts involved in various antimicrobial pathways such as apoptosis, autophagy, macrophage activation, calcium signalling, innate and T-cell response were differentially expressed in lung tissues of dkppx strain infected mice. Taken together, we demonstrate that enzymes involved in PolyP homeostasis play a critical role in physiology and virulence of M. tuberculosis. These enzymes are attractive targets for developing novel interventions that might be active against drug-sensitive and drug-resistant M. tuberculosis.

Item Type: Journal Article
Publication: Microbial Pathogenesis
Publisher: Academic Press
Additional Information: The copyright for this article belongs to Academic Press.
Keywords: Dormancy associated genes; Exopolyphosphatases; Inorganic polyphosphate homeostasis; Mycobacterium tuberculosis; Virulence
Department/Centre: Division of Biological Sciences > Molecular Reproduction, Development & Genetics
Division of Interdisciplinary Sciences > Centre for Biosystems Science and Engineering
Date Deposited: 09 Jan 2023 06:47
Last Modified: 09 Jan 2023 06:47
URI: https://eprints.iisc.ac.in/id/eprint/78899

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