title: Yeast RNase III triggers polyadenylation-independent transcription termination.
abstract: Transcription termination of messenger RNA (mRNA) is normally achieved by polyadenylation followed by Rat1p-dependent 5'-3' exoribonuleolytic degradation of the downstream transcript. Here we show that the yeast ortholog of the dsRNA-specific ribonuclease III (Rnt1p) may trigger Rat1p-dependent termination of RNA transcripts that fail to terminate near polyadenylation signals. Rnt1p cleavage sites were found downstream of several genes, and the deletion of RNT1 resulted in transcription readthrough. Inactivation of Rat1p impaired Rnt1p-dependent termination and resulted in the accumulation of 3' end cleavage products. These results support a model for transcription termination in which cotranscriptional cleavage by Rnt1p provides access for exoribonucleases in the absence of polyadenylation signals.
authors.affiliation: RNA Group, Département de Microbiologie et d'Infectiologie, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Sherbrooke, QC J1H 5N4, Canada.
authors.forename: Ghada
authors.initials: G
authors.lastname: Ghazal
authors.forename: Jules
authors.initials: J
authors.lastname: Gagnon
authors.forename: Pierre-Etienne
authors.initials: PE
authors.lastname: Jacques
authors.forename: Josette-Renée
authors.initials: JR
authors.lastname: Landry
authors.forename: François
authors.initials: F
authors.lastname: Robert
authors.forename: Sherif Abou
authors.initials: SA
authors.lastname: Elela
mesh_terms: D000199:Actins / Q000235:genetics; D000217:Acyltransferases / Q000235:genetics / Q000378:metabolism; D000426:Alcohol Dehydrogenase / Q000235:genetics; D004247:DNA / Q000378:metabolism; D005095:Exoribonucleases / Q000235:genetics; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D029543:Nucleocytoplasmic Transport Proteins / Q000235:genetics; D026723:Polyadenylation / Q000502:physiology; D011401:Promoter Regions, Genetic / Q000235:genetics; D011485:Protein Binding / Q000235:genetics; D012319:RNA Polymerase II / Q000378:metabolism; D012333:RNA, Messenger / Q000096:biosynthesis / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D043244:Ribonuclease III / Q000502:physiology*; D012269:Ribosomal Proteins / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000502:physiology*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D013728:Terminator Regions, Genetic / Q000502:physiology*; D014158:Transcription, Genetic / Q000502:physiology*
chemical_list: C465210:Act1 protein, S cerevisiae; D000199:Actins; C080773:NAB2 protein, S cerevisiae; C077734:NPL3 protein, S cerevisiae; D009687:Nuclear Proteins; D029543:Nucleocytoplasmic Transport Proteins; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D012269:Ribosomal Proteins; D029701:Saccharomyces cerevisiae Proteins; C056368:ribosomal protein L4; C075577:RAT1 protein, S cerevisiae; D004247:DNA; C516801:ADH1 protein, S cerevisiae; D000426:Alcohol Dehydrogenase; D000217:Acyltransferases; C081007:COOH-terminal signal transamidase; D012319:RNA Polymerase II; D005095:Exoribonucleases; C068398:XRN1 protein, S cerevisiae; C468367:RNT1 protein, S cerevisiae; D043244:Ribonuclease III