Analysis of M-OM-^CL dependent traits based on phenotypic and transcriptomic evaluation of the Listeria monocytogenes EGDe strain

ABSTRACT: The phenotypic and gene expression traits conferred by the alternative sigma factor protein M-OM-^CL in the food-borne pathogen L. monocytogenes were investigated. M-OM-^CL was shown to be important for the efficient growth of this pathogen exposed to food preservative measures such as low storage temperatures, elevated osmolarity and acidity. Based on high throughput phenotypic analysis, M-OM-^CL function was also found to be protective in L. monocytogenes EGDe cells exposed to several antimicrobial compounds including some of the antibiotics currently applied in listeriosis treatment. The expression of flagella genes and motility were significantly compromized upon loss of M-OM-^CL function. A comparative transcriptome analysis of exponential growth EGDe wild type and sigL null cells unveiled 394 genes that are positively controlled through M-OM-^CL dependent transcriptional regulation mechanisms in this bacterium during growth at low (3M-BM-0C) and optimized (37M-BM-0C) temperature conditions. Genes identified indicate that M-OM-^CL is a pleitropic transcription regulator mediating positive expression control of genes involved in diverse cellular processes including protein synthesis, molecular transport, energy metabolism, respiration, transcription regulation, metabolite biosynthesis, and cell envelope composition modification. Overall our observations have revealed that the loss of M-OM-^CL function leads to extensive gene expression defects in L. monocytogenes EGDe cells, and these are consistent with compromized nutrient assimilation, energy metabolism, protein synthesis, and metabolite biosynthesis processes as well as altered cell envelope composition and motility. Numerous gene expression changes imposed by M-OM-^CL loss in EGDe are thus also consistent with pleiotropic phenotypic defects detected in the L. monocytogenes EGDe M-bM-^HM-^FsigL strain. Gene expression DNA-microarray. Two-color hybridizations on 8*15K Agilent arrays. Wild type and three KO mutants in three temperatures, three biological replicates in each condition.

ORGANISM(S): Listeria monocytogenes EGD-e

SUBMITTER: Panu Somervuo 

PROVIDER: E-GEOD-32434 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress