title: The yeast SR-like protein Npl3 links chromatin modification to mRNA processing.
abstract: Eukaryotic gene expression involves tight coordination between transcription and pre-mRNA splicing; however, factors responsible for this coordination remain incompletely defined. Here, we explored the genetic, functional, and biochemical interactions of a likely coordinator, Npl3, an SR-like protein in Saccharomyces cerevisiae that we recently showed is required for efficient co-transcriptional recruitment of the splicing machinery. We surveyed the NPL3 genetic interaction space and observed a significant enrichment for genes involved in histone modification and chromatin remodeling. Specifically, we found that Npl3 genetically interacts with both Bre1, which mono-ubiquitinates histone H2B as part of the RAD6 Complex, and Ubp8, the de-ubiquitinase of the SAGA Complex. In support of these genetic data, we show that Bre1 physically interacts with Npl3 in an RNA-independent manner. Furthermore, using a genome-wide splicing microarray, we found that the known splicing defect of a strain lacking Npl3 is exacerbated by deletion of BRE1 or UBP8, a phenomenon phenocopied by a point mutation in H2B that abrogates ubiquitination. Intriguingly, even in the presence of wild-type NPL3, deletion of BRE1 exhibits a mild splicing defect and elicits a growth defect in combination with deletions of early and late splicing factors. Taken together, our data reveal a connection between Npl3 and an extensive array of chromatin factors and describe an unanticipated functional link between histone H2B ubiquitination and pre-mRNA splicing.
authors.affiliation: Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, California, United States of America.
authors.forename: Erica A
authors.initials: EA
authors.lastname: Moehle
authors.forename: Colm J
authors.initials: CJ
authors.lastname: Ryan
authors.forename: Nevan J
authors.initials: NJ
authors.lastname: Krogan
authors.forename: Tracy L
authors.initials: TL
authors.lastname: Kress
authors.forename: Christine
authors.initials: C
authors.lastname: Guthrie
mesh_terms: D042002:Chromatin Assembly and Disassembly / Q000235:genetics*; D010450:Endopeptidases / Q000235:genetics / Q000378:metabolism; D006657:Histones / Q000235:genetics / Q000378:metabolism; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D012322:RNA Precursors / Q000235:genetics / Q000378:metabolism; D012323:RNA Processing, Post-Transcriptional / Q000235:genetics; D012326:RNA Splicing; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic; D044763:Ubiquitin-Conjugating Enzymes / Q000235:genetics / Q000378:metabolism; D054875:Ubiquitination / Q000235:genetics
chemical_list: C472168:Bre1 protein, S cerevisiae; D006657:Histones; C077734:NPL3 protein, S cerevisiae; D009687:Nuclear Proteins; D012322:RNA Precursors; D016601:RNA-Binding Proteins; C507785:SAGA complex, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D015534:Trans-Activators; C471606:RAD6 protein, S cerevisiae; D044763:Ubiquitin-Conjugating Enzymes; D010450:Endopeptidases; C503322:UBP8 protein, S cerevisiae