CtsR Regulon in Listeria monocytogenes

The foodborne pathogen Listeria monocytogenes uses a number of transcriptional regulators, including the negative regulator CtsR, to control gene expression under different environmental conditions and in response to stress. Gene expression patterns of DctsR log phase cells were compared to both wt and ictsR-mcsA log phase cells grown with 0.5mM IPTG to identify CtsR-dependent genes.We identified 62 CtsR-dependent genes that showed significant expression ratios (adj. P < 0.05), with ≥ 1.5-fold differential expression either between ΔctsR and wt or between ΔctsR and ictsR-mcsA. Keywords: Listeria monocytogenes, CtsR regulon, log phase Independent RNA isolations were performed for each growth experiment (log phase cells). For wt vs. ctsR null mutant comparisons, three biological replicates were used in competitive whole-genome microarray experiments. For ictsR-mcsA vs ctsR null mutant comparisons, two biological replicates were used in competitive whole-genome microarray experiments. For each set of hybridizations, RNA from the parent strain (10403S) or the ictsR-mcsA strain were hybridized to RNA from the ctsR null mutant.