Biochemical elucidation of the novel ECP bacterial stress response

This PhD project will focus on the detailed elucidation of the biochemical mechanism of a recently discovered gene regulatory network in bacteria. In a previous study we demonstrated that under conditions of both osmotic and translation stress E. coli cells undergo an excretion cytoplasmic proteins (ECP) phenomenon, whereby abundant cellular components are expelled into the extracellular environment. The motivation of this current study is that understanding bacterial stress responses has important implications for bacterial physiology, host-pathogen interactions, and for the biotechnological application of using bacterial cells as bio-production hosts.

This PhD project will focus on the detailed elucidation of the biochemical mechanism of post-transcriptional regulation of arfA and mscL. The mRNA of the both these genes will be prepared by in vitro transcription, and subjected to RNase III mediated processing either or in isolation or in complex with each other. The resultant sRNA products will be analyzed by denaturing urea-PAGE and sequenced following cDNA synthesis. Inside the cells the abundance and half-life of the two transcripts, and the dependency of these upon the cell cycle and the onset of ECP will be studied using qRT-PCR.