Project description:These data represent the global gene expression profile of Mycobacterium tuberculosis after 24 hrs and 72 hrs of inorganic phosphate starvation. Differentially regulated genes appear to include those encoding proteins involved in adaptation to phosphate starvation, namely those involved in phosphate regulation and phosphate assimilation, as well as those involved in the stringent response.
Project description:We analyzed the genes expressed, or the transcriptome, of bacilli (Mycobacterium tuberculosis) growing in fatty acids as sole carbon source. Using new technologies to massively sequence of RNA molecules we identified a group of genes that provides novel insight regarding the metabolic pathways and transcriptional regulation of latent M. Tuberculosis.
Project description:New chemotherapeutics are urgently required to control the tuberculosis pandemic fueled by the emergence of multidrug- and extensively-drug-resistant Mycobacterium tuberculosis strains and the bacterium`s catastrophic alliance with HIV. Here we describe a novel trehalose-to-α-glucan pathway in M. tuberculosis comprising four enzymatic steps mediated by TreS, Pep2, GlgB, and GlgE, identified as an essential maltosyltransferase capable of utilizing maltose 1-phosphate. Using traditional and chemical reverse genetics, we show that GlgE inactivation causes rapid death of M. tuberculosis in vitro and in mice, through self-poisoning by maltose 1-phosphate accumulation driven by a self-amplifying feedback loop promoting pleiotropic phosphosugar-induced stress responses. Moreover, this α-glucan pathway exhibited a synthetic lethal interaction with the glucosyltransferase Rv3032 involved in biosynthesis of specialized α-glucan derivatives. The unique combination of gene essentiality within a synthetic lethal pathway validates GlgE as a new class of drug targets, revealing novel synergistic mechanisms to induce death in M. tuberculosis. Transcriptional profiling was performed to characterize the lethality induced by maltose 1-phosphate accumulation. Triplicate 10 mL cultures of the conditional lethal Mtb mutant strain H37Rv Delta treS Delta glgE (pMV361::treS) and of the vector control strain H37Rv Delta treS Delta glgE (pMV361) were grown in liquid culture to log-phase in the presence of 5 mM validamycin A (VA) to suppress M1P formation. Subsequently, cells were washed to remove the inhibitor; after 48 h of starvation for VA cultures were harvested. Keywords: tuberculosis, trehalose, compound treatment design, genetic modification design, and stimulus or stress design
