Project description:This SuperSeries is composed of the following subset Series: GSE11696: Gene expression profile of M.tuberculosis espR (Rv3849) mutant GSE12379: Gene expression profile of M.tuberculosis espR (Rv3849) mutant complemented with an N-terminal Flag espR gene GSE12380: Gene expression profile of M.tuberculosis espR (Rv3849) mutants containing N- or C-terminal mutations in the espR gene GSE12381: Comparative analysis of the gene expression profiles of M.tuberculosis espR (Rv3849) transposon and knockout mutants Refer to individual Series
Project description:The principal virulence determinant of Mycobacterium tuberculosis (Mtb), the ESX-1 protein secretion system, is positively controlled at the transcriptional level by EspR. Depletion of EspR reportedly affects a small number of genes, both positively or negatively, including a key ESX-1 component, the espACD operon. EspR is also thought to be an ESX-1 substrate. Using EspR-specific antibodies in ChIP-Seq experiments (chromatin immunoprecipitation followed by ultra-high throughput DNA sequencing) we show that EspR binds to at least 165 loci on the Mtb genome. Included in the EspR regulon are genes encoding not only EspA, but also EspR itself, the ESX-2 and ESX-5 systems, a host of diverse cell wall functions, such as production of the complex lipid PDIM (phenolthiocerol dimycocerosate) and the PE/PPE cell-surface proteins. EspR binding sites are not restricted to promoter regions and can be clustered. This suggests that rather than functioning as a classical regulatory protein EspR acts globally as a nucleoid-associated protein capable of long-range interactions consistent with a recently established structural model. EspR expression was shown to be growth phase-dependent, peaking in the stationary phase. Overexpression in Mtb strain H37Rv revealed that EspR influences target gene expression both positively or negatively leading to growth arrest. At no stage was EspR secreted into the culture filtrate. Thus, rather than serving as a specific activator of a virulence locus, EspR is a novel nucleoid-associated protein, with both architectural and regulatory roles, that impacts cell wall functions and pathogenesis through multiple genes.
Project description:Transcriptional profiling of M.tuberculosis to 10 mM vitamin C at 0.25, 0.5, 1, 2 , 4, 8 and 24 h compared to gene expression profile of untreated M. tuberculosis culture (0 h).
Project description:The principal virulence determinant of Mycobacterium tuberculosis (Mtb), the ESX-1 protein secretion system, is positively controlled at the transcriptional level by EspR. Depletion of EspR reportedly affects a small number of genes, both positively or negatively, including a key ESX-1 component, the espACD operon. EspR is also thought to be an ESX-1 substrate. Using EspR-specific antibodies in ChIP-Seq experiments (chromatin immunoprecipitation followed by ultra-high throughput DNA sequencing) we show that EspR binds to at least 165 loci on the Mtb genome. Included in the EspR regulon are genes encoding not only EspA, but also EspR itself, the ESX-2 and ESX-5 systems, a host of diverse cell wall functions, such as production of the complex lipid PDIM (phenolthiocerol dimycocerosate) and the PE/PPE cell-surface proteins. EspR binding sites are not restricted to promoter regions and can be clustered. This suggests that rather than functioning as a classical regulatory protein EspR acts globally as a nucleoid-associated protein capable of long-range interactions consistent with a recently established structural model. EspR expression was shown to be growth phase-dependent, peaking in the stationary phase. Overexpression in Mtb strain H37Rv revealed that EspR influences target gene expression both positively or negatively leading to growth arrest. At no stage was EspR secreted into the culture filtrate. Thus, rather than serving as a specific activator of a virulence locus, EspR is a novel nucleoid-associated protein, with both architectural and regulatory roles, that impacts cell wall functions and pathogenesis through multiple genes. ChIP-Seq of EspR in Mtb H37Rv at mid-log phase of growth. Two independent experiments were performed. Input DNA (No IP) was used as a control.
Project description:Mycobacterium tuberculosis, a pathogen of global importance, utilizes the ESX-1 protein secretion system to export virulence factors that disarm host macrophages. Although this secretory pathway is critical for virulence, how ESX-1 is regulated is completely unknown. Here we show that EspR (Rv3849) is a key regulator of ESX-1. EspR activates transcription of an operon that includes three ESX-1 components, Rv3616c-Rv3614c, whose expression in turn promotes secretion of ESX-1 substrates. Keywords: Strain comparison Comparison of the global gene expression of the following M.tb strains grown in log phase: Erdman strain of M.tb (WT), espR transposon mutant (R-), the espR transposon mutant complemented with the espR gene (R+), the espR mutant (R-) complemented with an espR gene containing an R8A amino acid subsitution (R- R8A), the espR mutant (R-) complemented with an espR gene containing an R21A amino acid subsitution (R- R21A), espR mutant (R-) complemented with an espR gene containing a C-terminal 10-amino acid truncation (R- delta10), and the espR mutant (R-) complemented with an espR gene containing a C-terminal 5-amino acid truncation (R- delta5).
Project description:We investigated transcriptional responses of different lung macrophage lineages during M.tuberculosis infection by RNAseq. Our data revealed that different lineages of macrophages respond differentially to M.Tuberculosis infection.
Project description:The new microarray described for Mycobacterium tuberculosis in our study has a more complete reprensentation of the genome than any other array design reported till date. Further, protocols for sample preparation, labelling and hybridisation for accurate gene expression profiling of M.tuberculosis have been optimised.