Global view on the metabolism of RNA poly(A) tails in yeast Saccharomyces cerevisiae

Abstract The polyadenosine tail (poly[A]-tail) is a universal modification of eukaryotic messenger RNAs (mRNAs) and non-coding (ncRNAs). In budding yeast, Pap1-synthesized mRNA poly(A) tails enhance export translation, whereas Trf4/5-mediated polyadenylation ncRNAs facilitates degradation by the exosome. Using direct RNA sequencing, we decipher extent dynamics in yeast defective all relevant exonucleases, deadenylases, polymerases. Predominantly ncRNA are 20-60 adenosines long. Poly(A) newly transcribed mRNAs 50 adenosine long on average, with an upper limit 200. Exonucleolysis Trf5-assisted nuclear exosome cytoplasmic deadenylases trim to 40 average. Surprisingly, PAN2/3 CCR4-NOT deadenylase complexes have large pool non-overlapping substrates mainly defined expression level. Finally, demonstrate that length strongly responds growth conditions, such as heat nutrient deprivation.