Total poly(A)+ RNA sequencing

Nuclear 3’ to 5’ nuclease RNA exosome plays a key role in quality control and processing of multiple protein-coding and non-coding transcripts made by RNA polymerase II. A mechanistic understanding of exosome function remains a challenge given the large number of RNA species and intervening RNA processing factors. Here we analysed changes in the poly(A)+ RNA proteins interactome provoked by mutations in three distinct subunits of the nuclear RNA exosome. Our data demonstrate a functional connection between Rrp6 and Mtl1 in controlling processing and levels of multiple protein-coding and non-coding transcripts. Furthermore, we show that exosome mutants accumulate components of U1 and U2 snRNPs and show depletion of NTC components from RNA suggesting that the stage prior to the activation of the spliceosome represents a critical quality control step. We have also identified potential new RNA binding factors involved in exosome regulation, including a zinc-finger protein called Mub1 that controls levels of selected transcripts encoding for proteins implicated in stress response. Collectively, our data have provided a global view of RNA metabolism alterations in exosome deficient cells and revealed RNA binding proteins that may act as novel exosome cofactors. 4 samples in triplicates