title: Transcriptional activators enhance polyadenylation of mRNA precursors.
abstract: Polyadenylation of mRNA precursors is frequently coupled to transcription by RNA polymerase II. Although this coupling is known to involve interactions with the C-terminal domain of the RNA polymerase II largest subunit, the possible role of other factors is not known. Here we show that a prototypical transcriptional activator, GAL4-VP16, stimulates transcription-coupled polyadenylation in vitro. In the absence of GAL4-VP16, specifically initiated transcripts accumulated but little polyadenylation was observed, while in its presence polyadenylation was strongly enhanced. We further show that this stimulation requires the transcription elongation-associated PAF complex (PAF1c), as PAF1c depletion blocked GAL4-VP16-stimulated polyadenylation. Furthermore, knockdown of PAF subunits by siRNA resulted in decreased 3' cleavage, and nuclear export, of mRNA in vivo. Finally, we show that GAL4-VP16 interacts directly with PAF1c and recruits it to DNA templates. Our results indicate that a transcription activator can stimulate transcription-coupled 3' processing and does so via interaction with PAF1c.
authors.affiliation: Department of Biological Sciences, Columbia University, New York, NY 10027, USA.
authors.forename: Takashi
authors.initials: T
authors.lastname: Nagaike
authors.forename: Charlotte
authors.initials: C
authors.lastname: Logan
authors.forename: Ikuko
authors.initials: I
authors.lastname: Hotta
authors.forename: Orit
authors.initials: O
authors.lastname: Rozenblatt-Rosen
authors.forename: Matthew
authors.initials: M
authors.lastname: Meyerson
authors.forename: James L
authors.initials: JL
authors.lastname: Manley
mesh_terms: D002478:Cells, Cultured; D006801:Humans; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D026723:Polyadenylation; D012319:RNA Polymerase II / Q000235:genetics / Q000378:metabolism; D012322:RNA Precursors / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000378:metabolism; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic; D014162:Transfection
chemical_list: C070633:Gal-VP16; D009687:Nuclear Proteins; D012322:RNA Precursors; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D015534:Trans-Activators; D012319:RNA Polymerase II; C410949:RNA polymerase II largest subunit