Project description:[1] Transcription profiling of one Burkholderia cenocepacia clinical isolate, J2315, versus a soil isolate, HI2424, in conditions mimicking CF sputum [2] Transcription profiling of Burkholderia cenocepacia isolates J2315 and HI2424 in media mimicking CF sputum or the soil environment
Project description:Hfq proteins are RNA chaperones that play a critical role in post-transcription regulation of gene expression. Bacteria of the Burkholderia cepacia complex harbor two distinct and functional Hfq proteins, the Hfq and Hfq2. We have previously performed the functional analysis of Hfq and Hfq2 in the pathogen Burkholderia cenocepacia J2315. In order to examine the impacts of each RNA chaperone on the global transcriptome of B. cenocepacia J2315, we performed comparative transcriptome profile of mutants on the hfq and hfq2 genes, using as reference the wild-type strain.
Project description:Members of the genus Burkholderia are versatile bacteria capable of colonizing highly diverse environmental niches. In this study, we investigated the global response of the opportunistic pathogen Burkholderia cenocepacia H111 to nitrogen limitation at the transcript and protein expression level. In addition to a classical response to nitrogen starvation, including the activation of glutamine synthetase, PII proteins and the two component regulatory system ntrBC, B. cenocepacia H111 also up-regulated polyhydroxybutyrate (PHB) accumulation and exopolysaccharide (EPS) production in response to nitrogen shortage. A search for consensus sequences in promoter regions of nitrogen responsive genes identified a s54 consensus sequence. The mapping of the s54 regulon as well as the characterization of a s54 mutant suggests an important role of s54 not only in control of nitrogen metabolism, but also in virulence of this organism.
Project description:Burkholderia cenocepacia is a versatile opportunistic pathogen that survives in a wide variety of environments, which can be limited in nutrients such as nitrogen. We previously showed that B. cenocepacia sigma factor s54 played a major role in control of nitrogen assimilation and virulence. In this work, we investigated the role of the s54 enhancer binding protein NtrC in controlling the response to nitrogen limitation and virulence. RNA-Seq analyses and phenotypical analysis on a ntrC mutant strain showed that, in addition to orchestrating uptake of nitrogen sources, NtrC is also regulating exopolysaccharide (EPS) production and motility. A search for NtrC consensus sequences identified a potential binding sequence in the promoter region of gene clusters involved in EPS formation and flagellar rotation suggesting that NtrC directly controls the expression of these phenotypic traits in B. cenocepacia H111.
