Snf1-Dependent Transcription Confers Glucose-Induced Decay upon the mRNA Product

In the yeastSaccharomyces cerevisiae , the switch from respiratory metabolism to fermentation causes rapid decay of transcripts encoding proteins uniquely required for aerobic metabolism. Snf1, the yeast ortholog of AMP-activated protein kinase, has been implicated in this process because inhibiting Snf1 mimics the addition of glucose. In this study, we show that theSNF1 -dependentADH2 promoter, or just the major transcription factor binding site, is sufficient to confer glucose-induced mRNA decay upon heterologous transcripts.SNF1 -independent expression from theADH2 promoter prevented glucose-induced mRNA decay without altering the start site of transcription.SNF1 -dependent transcripts are enriched for the binding motif of the RNA binding protein Vts1, an important mediator of mRNA decay and mRNA repression whose expression is correlated with decreased abundance ofSNF1 -dependent transcripts during the yeast metabolic cycle. However, deletion ofVTS1 did not slow the rate of glucose-induced mRNA decay.ADH2 mRNA rapidly dissociated from polysomes after glucose repletion, and sequences bound by RNA binding proteins were enriched in the transcripts from repressed cells. Inhibiting the protein kinase A pathway did not affect glucose-induced decay ofADH2 mRNA. Our results suggest that Snf1 may influence mRNA stability by altering the recruitment activity of the transcription factor Adr1.