Hypersensitivity of hypoxia grown Mycobacterium smegmatis to DNA damaging agents: Implications of the DNA repair deficiencies in attenuation of mycobacteria

Rex, Kervin and Kurthkoti, Krishna and Varshney, Umesh (2013) Hypersensitivity of hypoxia grown Mycobacterium smegmatis to DNA damaging agents: Implications of the DNA repair deficiencies in attenuation of mycobacteria. In: MECHANISMS OF AGEING AND DEVELOPMENT, 134 (10, SI). pp. 516-522.

PDF Mec_age_dev_134-10_516_2013.pdf - Published Version Restricted to Registered users only Download (1MB) | Request a copy

Abstract

Mycobacteria are an important group of pathogenic bacteria. We generated a series of DNA repair deficient strains of Mycobacterium smegmatis, a model organism, to understand the importance of various DNA repair proteins (UvrB, Ung, UdgB, MutY and Fpg) in survival of the pathogenic strains. Here, we compared tolerance of the M. smegmatis strains to genotoxic stress (ROS and RNI) under aerobic, hypoxic and recovery conditions of growth by monitoring their survival. We show an increased susceptibility of mycobacteria to genotoxic stress under hypoxia. UvrB deficiency led to high susceptibility of M. smegmatis to the DNA damaging agents. Ung was second in importance in strains with single deficiencies. Interestingly, we observed that while deficiency of UdgB had only a minor impact on the strain's susceptibility, its combination with Ung deficiency resulted in severe consequences on the strain's survival under genotoxic stress suggesting a strong interdependence of different DNA repair pathways in safeguarding genomic integrity. Our observations reinforce the possibility of targeting DNA repair processes in mycobacteria for therapeutic intervention during active growth and latency phase of the pathogen. High susceptibility of the UvrB, or the Ung/UdgB deficient strains to genotoxic stress may be exploited in generation of attenuated strains of mycobacteria. (C) 2013 Elsevier Ireland Ltd. All rights reserved.

Item Type:	Journal Article
Publication:	MECHANISMS OF AGEING AND DEVELOPMENT
Publisher:	ELSEVIER IRELAND LTD
Additional Information:	Copyright for this article belongs to ELSEVIER IRELAND LTD,IRELAND.
Keywords:	Mycobacterium tuberculosis; Attenuated strains; Growth in hypoxic conditions; BER; NER
Department/Centre:	Division of Biological Sciences > Microbiology & Cell Biology
Date Deposited:	31 Jan 2014 11:50
Last Modified:	31 Jan 2014 11:50
URI:	http://eprints.iisc.ac.in/id/eprint/48280

Actions (login required)

View Item