Project description:Comparison of gene expression profile of the whiB4 mutant strain of Mycobacterium tuberculosis with the wild type Mycobacterium tuberculosis H37RV Mtb WhiB4 mutant mRNA was compared with the mRNA of wtMtb H37RV under aerobic conditons
Project description:Comparison of gene expression profile of the whiB4 mutant strain of Mycobacterium tuberculosis with the wild type Mycobacterium tuberculosis H37RV Mtb WhiB4 mutant mRNA was compared with the mRNA of wtMtb H37RV under aerobic conditons Aerbic conditions OD600 nm of 0.4, MtbWhiB4KO vs wtMtb, biological replicates: 3 wt Mtb H37RV and 3 MtbWhiB4 KO
Project description:Mass Spectrometry based Phosphoproteomics was carried out on M. tuberculosis wild type strain H37Rv and the isogenic mutant strains MtbΔdosR, MtbΔdosS, and MtbΔdosT that were cultured in aerobic as well as hypoxic conditions. During later the oxygen was gradually deprived in cultures that were kept static.
Project description:In previously published work, we identified three Mycobacterium tuberculosis sigma (s) factor genes responding to heat shock (sigB, sigE and sigH ). Two of them (sigB and sigE ) also responded to SDS exposure. As these responses to stress suggested that the s factors encoded by these genes could be involved in pathogenicity, we are studying their role in physiology and virulence. In this work, we characterize a sigE mutant of M. tuberculosis H37Rv. The sigE mutant strain was more sensitive than the wild-type strain to heat shock, SDS and various oxidative stresses. It was also defective in the ability to grow inside both human and murine unactivated macrophages and was more sensitive than the wild-type strain to the killing activity of activated murine macrophages. Using microarray technology and quantitative reverse transcriptionÐpolymerase chain reaction (RTÐPCR), we started to define the sigmaE regulon of M. tuberculosis and its involvement in the global regulation of the stress induced by SDS. We showed the requirement for a functional sigE gene for full expression of sigB and for its induction after SDS exposure but not after heat shock. We also identified several genes that are no longer induced when sigmaE is absent. These genes encode proteins belonging to different classes including transcriptional regulators, enzymes involved in fatty acid degradation and classical heat shock proteins. Keywords: genetic modification design and comparative genome hybridization design
2007-08-03 | GSE8664 | GEO
Project description:Wild type H37Rv vs HtpX mutant strain
Project description:In previously published work, we identified three Mycobacterium tuberculosis sigma (s) factor genes responding to heat shock (sigB, sigE and sigH ). Two of them (sigB and sigE ) also responded to SDS exposure. As these responses to stress suggested that the s factors encoded by these genes could be involved in pathogenicity, we are studying their role in physiology and virulence. In this work, we characterize a sigE mutant of M. tuberculosis H37Rv. The sigE mutant strain was more sensitive than the wild-type strain to heat shock, SDS and various oxidative stresses. It was also defective in the ability to grow inside both human and murine unactivated macrophages and was more sensitive than the wild-type strain to the killing activity of activated murine macrophages. Using microarray technology and quantitative reverse transcriptionÐpolymerase chain reaction (RTÐPCR), we started to define the sigmaE regulon of M. tuberculosis and its involvement in the global regulation of the stress induced by SDS. We showed the requirement for a functional sigE gene for full expression of sigB and for its induction after SDS exposure but not after heat shock. We also identified several genes that are no longer induced when sigmaE is absent. These genes encode proteins belonging to different classes including transcriptional regulators, enzymes involved in fatty acid degradation and classical heat shock proteins. Keywords: genetic modification design and comparative genome hybridization design 15 samples were analyzed. The quality controls were biological replicate and technical replicate
Project description:Expression data from wild type (H37Rv) and GroEL1(H37RvΔgroEL1::Hyg) mutant strains under a range of environmental stresses The 60 kDa heat shock proteins, also known as GroELs are components of the essential protein folding machinery of the cell, but are also dominant antigens in many infectious diseases. Although generally essential for cellular survival, in some organisms such as Mycobacterium tuberculosis, one or more paralogous GroELs are known to be dispensable. In M. tuberculosis, groEL2 is essential for cell survival, but the biological role of the non-essential GroEL1 is still elusive. To understand the relevance of GroEL1 in M. tuberculosis physiology, detailed transcriptomic analyses for the wild type H37Rv and groEL1 knockout (groEL1 KO) were performed under in vitro stress conditions: stationary phase, cold shock, low aeration, mild cold shock and low pH. Additionally, the survival of the groEL1 KO was assessed in macrophages at multiplicity of infection (MOI) of 1:1 and 1:5. We observed that survival under low aeration was significantly compromised in the groEL1 KO. Further, the gene expression analyses under low aeration showed change in expression of several key virulence factors like two component system PhoP/R and MprA/B, sigma factors sigG, M and H and adversely affected known hypoxia response regulators Rv0081, Rv0023 and DosR. Our work is therefore suggestive of an important role of GroEL1 for survival under low aeration by affecting the expression of genes known for hypoxia response.