A Genomic Screen of Saccharomyces cerevisiae Reveals a Potential Link Between Nonstop Decay and Autophagy

Little has been described about the mechanisms of the Nonstop Decay (NSD) pathway. To discover new genes involved in NSD, we performed a genome wide investigation in Saccharomyces cerevisiae which yielded 446 gene candidates that when deleted, allowed production of a nonstop mRNA. Of the gene families found in our screen, we decided to follow up on the autophagy candidates. First, we used the autophagy inhibiting drug verteporfin to confirm that autophagy does not occur in our candidates. The results confirm our prediction that autophagy is inhibited in our two autophagy candidates. Next, we assessed the abundance of nonstop mRNA using qRT-PCR analysis. This resulted in lower than expected nonstop mRNA abundance relative to the WT, which led us to investigate nonstop protein abundance. Interestingly, we see an increase in the abundance of nonstop protein abundance relative to the WT. Our results suggest that NSD may occur through autophagy.