The intimate relationships of mRNA decay and translation

• Translation and decay have complex effects on mRNA expression. Translational repression is a prerequisite for the onset of decay of some mRNAs.
• Aberrant translation almost always triggers accelerated mRNA decay.
• Reductions in translation initiation frequently promote enhanced mRNA degradation.
• Inhibition of translation elongation or termination often leads to mRNA stabilization.

The decay rate of an mRNA and the efficiency with which it is translated are key determinants of eukaryotic gene expression. Although it was once thought that mRNA stability and translational efficiency were directly linked, the interrelationships between the two processes are considerably more complex. The decay of individual mRNAs can be triggered or antagonized by translational impairment, and alterations in the half-life of certain mRNAs can even alter translational fidelity. In this review we consider whether mRNA translation and turnover are distinct or overlapping phases of an mRNA life cycle, and then address some of the many ways in which the two processes influence each other in eukaryotic cells.