Polyadenylation of pre-mRNAs, a critical step in eukaryotic gene expression, is mediated by cis elements collectively called the polyadenylation signal. Genome-wide analysis of such polyadenylation signals was missing in fission yeast, even though it is an important model organism. We demonstrate that the canonical AATAAA motif is the most frequent and functional polyadenylation signal in Schizosaccharomyces pombe. Using analysis of RNA-Seq data sets from cells grown under various physiological conditions, we identify 3' UTRs for nearly 90% of the yeast genes. Heterogeneity of cleavage sites is common, as is alternative polyadenylation within and between conditions. We validated the computationally identified sequence elements likely to promote polyadenylation by functional assays, including qRT-PCR and 3'RACE analysis. The biological importance of the AATAAA motif is underlined by functional analysis of the genes containing it. Furthermore, it has been shown that convergent genes require trans elements, like cohesin for efficient transcription termination. Here we show that convergent genes lacking cohesin (on chromosome 2) are generally associated with longer overlapping mRNA transcripts. Our bioinformatic and experimental genome-wide results are summarized and can be accessed and customized in a user-friendly database Pomb(A).
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledged KAUST grant number(s): KUK-C1-013-04
Acknowledgements: We thank Konrad Krawczyk for valuable advice and support. This work was supported in part by the King Abdullah University of Science and Technology (KAUST) (KUK-C1-013-04); the Engineering and Physical Sciences Research Council (to M. S.); the L'Oreal/UNESCO Woman in Science UK and Ireland award (to M. G.), the MRC Career Development Award (to M. G.); the Wellcome Trust Senior Investigator Award (to J.B.), the Wellcome Trust programme grant (to N.J.P.), and the European Research Council grant agreement (239870 to R. E.); Royal Society for a University Research Fellowship; Brasenose College, University of Oxford (to R. E.); a Nicholas Kurti Junior Fellowship (to R. E.); and the Leverhulme Trust Philip Leverhulme Prize (to R.E.).
This publication acknowledges KAUST support, but has no KAUST affiliated authors.