MilliporeSigma
  • Home
  • Search Results
  • The conserved hypothetical protein Rv0574c is required for cell wall integrity, stress tolerance, and virulence of Mycobacterium tuberculosis.

The conserved hypothetical protein Rv0574c is required for cell wall integrity, stress tolerance, and virulence of Mycobacterium tuberculosis.

Infection and immunity (2014-10-15)
Rajni Garg, Deeksha Tripathi, Sashi Kant, Harish Chandra, Rakesh Bhatnagar, Nirupama Banerjee
ABSTRACT

The virulence of Mycobacterium tuberculosis is intimately related to its distinctive cell wall. The biological significance of poly-α-L-glutamine (PLG), a component in the cell wall of virulent mycobacteria, has not been explored adequately. The focus of this study is to investigate the role of a locus, Rv0574c, coding for a polyglutamate synthase-like protein, in the synthesis of poly-α-L-glutamine in the context of mycobacterial virulence. Evaluation of Rv0574c gene expression in M. tuberculosis demonstrated its growth-phase-linked induction with concomitant accumulation of poly-α-L-glutamine in the cell wall. Rv0574c was activated under conditions prevalent in the tubercular granuloma, e.g., hypoxia, nitric oxide, and CO2. For functional characterization, we produced a deletion mutant of the Rv0574c gene by allelic exchange. The mutant produced smaller amounts of poly-α-L-glutamine in the cell wall than did the wild-type bacterium. Additionally, the increased sensitivity of the mutant to antitubercular drugs, SDS, lysozyme, and mechanical stress was accompanied by a drastic reduction in the ability to form biofilm. Growth of the ΔRv0574c strain was normal under in vitro conditions but was retarded in THP-1 macrophages and in the lungs and spleen of BALB/c mice. This was in agreement with histopathology of the lungs showing slow growth and less severe pathology than that of the wild-type strain. In summary, this study demonstrates that the protein encoded by the Rv0574c locus, by virtue of modulating PLG content in the cell wall, helps in maintaining cellular integrity in a hostile host environment. Also, its involvement in protecting the pathogen from host-generated lethal factors contributes to the infectious biology of M. tuberculosis.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
D-(+)-Glucose, ACS reagent
Sigma-Aldrich
D-(+)-Glucose, Hybri-Max, powder, BioReagent, suitable for hybridoma
Sigma-Aldrich
Glycerol solution, puriss., meets analytical specification of Ph. Eur., BP, 84-88%
Sigma-Aldrich
Glycerol solution, puriss. p.a., 86-89% (T)
USP
Glycerin, United States Pharmacopeia (USP) Reference Standard
Sigma-Aldrich
D-(+)-Glucose, powder, BioReagent, suitable for cell culture, suitable for insect cell culture, suitable for plant cell culture, ≥99.5%
Sigma-Aldrich
D-(+)-Glucose, suitable for mouse embryo cell culture, ≥99.5% (GC)
Sigma-Aldrich
D-(+)-Glucose, ≥99.5% (GC)
Sigma-Aldrich
D-(+)-Glucose, BioXtra, ≥99.5% (GC)
Sigma-Aldrich
Glycerin, meets USP testing specifications
Sigma-Aldrich
D-(+)-Glucose, BioUltra, anhydrous, ≥99.5% (sum of enantiomers, HPLC)
Sigma-Aldrich
Glycerol solution, 83.5-89.5% (T)
Sigma-Aldrich
D-(+)-Glucose, tested according to Ph. Eur.
Supelco
D-(+)-Glucose, analytical standard
Sigma-Aldrich
D-Glucose-12C6, 16O6, 99.9 atom % 16O, 99.9 atom % 12C
Supelco
Glycerin, Pharmaceutical Secondary Standard; Certified Reference Material
Sigma-Aldrich
Nitrogen, ≥99.998%
Supelco
Oleic acid, analytical standard
Sigma-Aldrich
Oleic acid, meets analytical specification of Ph, Eur., 65.0-88.0% (GC)
Sigma-Aldrich
Dextrose, meets EP, BP, JP, USP testing specifications, anhydrous
Sigma-Aldrich
Glycerol, puriss. p.a., ACS reagent, anhydrous, dist., ≥99.5% (GC)
Sigma-Aldrich
Glycerol, ReagentPlus®, ≥99.0% (GC)
Sigma-Aldrich
Glycerol, ACS reagent, ≥99.5%
Sigma-Aldrich
Glycerol, puriss., meets analytical specification of Ph. Eur., BP, USP, FCC, E422, anhydrous, 99.0-101.0% (alkalimetric)
Sigma-Aldrich
Glycerol, BioUltra, for molecular biology, anhydrous, ≥99.5% (GC)
Sigma-Aldrich
Glycerol, tested according to Ph. Eur., anhydrous
Sigma-Aldrich
Glycerol, BioReagent, suitable for cell culture, suitable for insect cell culture, suitable for electrophoresis, ≥99% (GC)
Sigma-Aldrich
Glycerol, for molecular biology, ≥99.0%
Sigma-Aldrich
Glycerol, ≥99.5%
Sigma-Aldrich
Glycerol, BioXtra, ≥99% (GC)