Cold-shock response in Escherichia coli: a model system to study post-transcriptional regulation

In Escherichia coli the response to an abrupt temperature downshift (cold-shock) involves an acclimation period during which bulk protein synthesis is drastically reduced whereas the expression of a set of cold-shock (CS) genes is transiently increased. Induction of several CS genes is mainly controlled by post-transcriptional events capable of affecting both stability and translation of the CS mRNAs at low temperature. The ability of the translational machinery to synthesize CS proteins despite the unfavorable conditions is due to cis-acting elements present on the CS mRNAs as well as to trans-acting factors which accumulate in the cells following cold-shock.