HrcA Regulon in Listeria monocytogenes

The foodborne pathogen Listeria monocytogenes uses a number of transcriptional regulators, including the negative regulator HrcA, to control gene expression under different environmental conditions and in response to stress. Gene expression patterns of DhrcA stationary phase cells were compared to wt to identify hrcA-dependent genes. We identified 61 HrcA-dependent genes that showed significant expression ratios (adj. P < 0.05), with ≥ 1.5-fold differential expression between ΔhrcA and wt. Combined with microarray analysis, Hidden Markov Model searches show HrcA directly repress at least 8 genes. Keywords: Listeria monocytogenes, HrcA regulon, stationary phase Independent RNA isolations were performed for each growth experiment (log phase cells). For wt vs. hrcA null mutant comparisons, three biological replicates were used in competitive whole-genome microarray experiments. For each set of hybridizations, RNA from the parent strain (10403S) was hybridized to RNA from the hrcA null mutant.