Autoregulation of RNase E synthesis in Escherichia coli.

RNase E plays a central role in controlling mRNA degradation in E. coli. We have investigated the mechanism of RNase E autoregulation. Our data indicate that RNase E autoregulates its synthesis by controlling the decay rate of its own transcript (rne mRNA), which is unusually sensitive to the level of cellular RNase E activity. Feedback regulation is mediated in cis by the rne 5' untranslated region (5' UTR), which can confer this property onto heterologous mRNAs to which it is fused. The marked sensitivity of rne mRNA to regulation by RNase E is also due in part to the susceptibility of nascent rne transcripts to RNase E-mediated degradation.