Bacteria must express certain factors to successfully colonize and proliferate within a host. Many factors are controlled at the level of transcription. Roughly 60% of bacterial genomes encode the alternative sigma factor sigma-54, which activate a subset of promoters. Transcriptional initiation of sigma-54-dependent promoter requires energy from the hydrolysis of ATP, which is catalyzed by a bacterial enhance binding protein that binds upstream of the promoter. The overall goal of this proposal is to increase understanding of how bEBPs promote initial host-microbe interactions. To achieve this goal, the bEBPs encoded within the bacterium Vibrio fischeri will be investigated for their impact on the ability to associated with its natural host. V. fischeri cells colonize and grow within the light organs of certain invertebrates including the Hawaiian bobtail squid Euprymna scolopes. Research efforts with defined bEBP mutants include colonization analyses, which will determine the extent to which each bEBP impacts the ability of V. fischeri to colonize its host. Transcriptomic analyses are also proposed to determine how each bEBP affects cellular physiology of V. fischeri. Together, these results will determine the contribution of each bEBP to the ability of V. fischeri to establish a long-term association with its host. The candidate will receive post-baccalaureate training in microbiology research and opportunities for professional development, which will prepare the candidate for graduate studies in microbiology.
Proper spatiotemporal gene expression is necessary for bacteria to associate with higher organisms including humans. The proposed research investigates a family of transcription factors that promote the expression of genes in a manner that depends on an alternative sigma factor. The research findings will determine the extent to which each transcription factor contributes to how a bacterium associates with a natural host, thereby informing strategies that target these factors as a way to affect host-microbe interactions.
