Rpb4 and Puf3 imprint and post-transcriptionally control stability of a common set of mRNAs in yeast

Gene expression involving RNA polymerase II is regulated by the concerted interplay between mRNA synthesis and degradation, a crosstalk where mRNA decay machinery impacts transcription and transcription machinery influences mRNA stability. Rpb4, and likely the dimer Rpb4/7 seem to be the central components of the RNA pol II governing these processes. In this work we unravel more precisely the molecular mechanisms participated by Rpb4 that mediates the posttranscriptional events regulating mRNA imprinting and stability. We analysed genome-wide, by RIP-seq, the association of Rpb4 with mRNAs and demonstrated that it targets a broad population of about 1400 transcripts. A group of mRNAs are also targets of the RPB, Puf3. We demonstrated that Rpb4 and Puf3, physically, genetically and functionally interact and cooperate to imprint and regulate stability of this group of mRNA. We also demonstrated, by the first time, that Puf3 associates with the chromatin, in an Rpb4-dependent manner. Our data also point to Rpb4 as the key element of the RNA pol II that interplay mRNA synthesis, imprinting and stability, in cooperation with RBPs. Overall design: We performed 2 biologically independent RIP-Seq experiments.