Christopher Johnson

E-mail: john5771@umn.edu

Thesis advisor: Gary Dunny

Year entered: 2006

Degrees received:
B.S., Biology, Harvey Mudd College, Claremont, CA 1996

Thesis research:
pCF10 is a pheromone-inducible conjugative plasmid of Enterococcus faecalis, originally identified as a tetracycline resistance vector. Transfer of the plasmid via conjugation is triggered in response to a peptide pheromone secreted by potential recipient cells. Regulation of transcripts initiating at the convergent prgQ (PQ) and Qa (PQa) promoters of pCF10 is a critical component of the pheromone response. Recent findings suggest that proximal RNAs transcribed from each of these promoters regulates expression of distal genes transcribed from the other promoter. To the best of our knowledge, such a reciprocal relationship has not been previously described. I am analyzing the effects mediated by Qa on transcripts from PQ as well as those by prgQ transcripts on transcripts from PQa. I have established a system by which I can examine the behavior of transcripts from either promoter in the presence and absence of the other. This work will further our understanding of bacterial cell-cell communication, transcriptional regulation and the spread of antibiotic resistance.