Gene expression is a complex process that all organisms must carry out in a precisely controlled fashion and is in part controlled by the differential degradation of mRNA. One of the major question that remains to be answered is how some mRNAs are targeted for rapid degradation, while other mRNAs are relatively stable.

We are trying to understand the interaction between the mRNA decay machinery and its substrates, using mRNAs that lack a stop codon as a model system. Such "nonstop" mRNAs are extremely rapidly degraded in both human and yeast cells. The degradation of nonstop mRNAs is likely a quality control function, whereby mRNAs that arose by premature polyadenylation or other mistakes are rapidly degraded. We use the yeast Saccharomyces cerevisiae to study nonstop mRNA decay, because it allows a combination of genetic and biochemical approaches to the problem. We expect that the specific recognition of nonstop mRNAs will also reveal general principles governing the decay of normal mRNAs.