RNase Y of Staphylococcus aureus and its role in the activation of virulence genes

ABSTRACT: RNase Y of Bacillus subtilis is a key member of the degradosome and important for bulk mRNA turnover. In contrast to B. subtilis, the RNase Y homologue (rny/cvfA) of Staphylococcus aureus is not essential for growth. Here we found that RNase Y plays a major role in virulence gene regulation. Accordingly, rny deletion mutants demonstrated impaired virulence in a murine bacteraemia model. RNase Y is important for the processing and stabilisation of the immature transcript of the global virulence regulator system SaePQRS. Moreover, RNase Y is involved in the activation of virulence gene expression at the promoter level. This control is independent of both the virulence regulator agr and the saePQRS processing and may be mediated by small RNAs some of which were shown to be degraded by RNase Y. Besides this regulatory effect, mRNA levels of several operons were significantly increased in the rny mutant and the half-life of one of these operons was shown to be extremely extended. However, the half-life of many mRNA species was not significantly altered. Thus, RNase Y in S. aureus influences mRNA expression in a tightly controlled regulatory manner and is essential for coordinated activation of virulence genes. Three biological replicates of both wild type and rny (cvfA) mutant bacteria were grown in complex medium until the late exponential phase at which point RNA was prepared for microarray analysis on GeneChip S. aureus Genome Array (Affymetrix). Preliminary results indicated that during the late exponential growth phase, the most prominent differences between wild type and rny mutants were observed when selected gene expression was analysed by Northern hybridisation.

ORGANISM(S): Staphylococcus aureus

SUBMITTER: Gabriella Marincola 

PROVIDER: E-GEOD-34980 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress