title: The yeast Rat1 exonuclease promotes transcription termination by RNA polymerase II.
abstract: The carboxy-terminal domain (CTD) of the RNA polymerase II (RNApII) largest subunit consists of multiple heptapeptide repeats with the consensus sequence YSPTSPS. Different CTD phosphorylation patterns act as recognition sites for the binding of various messenger RNA processing factors, thereby coupling transcription and mRNA processing. Polyadenylation factors are co-transcriptionally recruited by phosphorylation of CTD serine 2 (ref. 2) and these factors are also required for transcription termination. RNApII transcribes past the poly(A) site, the RNA is cleaved by the polyadenylation machinery, and the RNA downstream of the cleavage site is degraded. Here we show that Rtt103 and the Rat1/Rai1 5' --> 3' exonuclease are localized at 3' ends of protein coding genes. In rat1-1 or rai1Delta cells, RNA 3' to polyadenylation sites is greatly stabilized and termination defects are seen at many genes. These findings support a model in which poly(A) site cleavage and subsequent degradation of the 3'-downstream RNA by Rat1 trigger transcription termination.
authors.affiliation: Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, 240 Longwood Avenue, Boston, Massachusetts 02115, USA.
authors.forename: Minkyu
authors.initials: M
authors.lastname: Kim
authors.forename: Nevan J
authors.initials: NJ
authors.lastname: Krogan
authors.forename: Lidia
authors.initials: L
authors.lastname: Vasiljeva
authors.forename: Oliver J
authors.initials: OJ
authors.lastname: Rando
authors.forename: Eduard
authors.initials: E
authors.lastname: Nedea
authors.forename: Jack F
authors.initials: JF
authors.lastname: Greenblatt
authors.forename: Stephen
authors.initials: S
authors.lastname: Buratowski
mesh_terms: D047369:Chromatin Immunoprecipitation; D005095:Exoribonucleases / Q000235:genetics / Q000378:metabolism*; D015966:Gene Expression Regulation, Fungal; D009154:Mutation / Q000235:genetics; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis; D010766:Phosphorylation; D011061:Poly A / Q000235:genetics / Q000378:metabolism; D026723:Polyadenylation; D012319:RNA Polymerase II / Q000378:metabolism*; D012323:RNA Processing, Post-Transcriptional; D012331:RNA, Fungal / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016601:RNA-Binding Proteins; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic
chemical_list: D009687:Nuclear Proteins; D012331:RNA, Fungal; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; C473024:Rai1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; C075577:RAT1 protein, S cerevisiae; D011061:Poly A; D012319:RNA Polymerase II; D005095:Exoribonucleases