Stability of ribosomal protein mRNA and translational feedback regulation in Escherichia coli

It was previously observed that the stability of ribosomal protein (r-protein) mRNA in Escherichia coli decreases under the conditions where its translation is feedback inhibited by repressor r-protein. We have now demonstrated that the stability of mRNA for r-proteins S13, S11 and S4 increases in a strain carrying a mutation in the gene for S4, a translational repressor regulating these r-proteins. The results confirm the previous observations that translational repression increases the decay rate of r-protein mRNA, and in addition, show that the half-life of S13-S4 r-protein mRNA in cells growing under ordinary conditions is significantly shorter than its inherent stability would predict, due to the operation of translational feedback regulation.