title: Coordination of RNA Polymerase II Pausing and 3' End Processing Factor Recruitment with Alternative Polyadenylation.
abstract: Most mammalian genes produce transcripts whose 3' ends are processed at multiple alternative positions by cleavage/polyadenylation (CPA). Poly(A) site cleavage frequently occurs cotranscriptionally and is facilitated by CPA factor binding to the RNA polymerase II (Pol II) C-terminal domain (CTD) phosphorylated on Ser2 residues of its heptad repeats (YS2PTSPS). The function of cotranscriptional events in the selection of alternative poly(A) sites is poorly understood. We investigated Pol II pausing, CTD Ser2 phosphorylation, and processing factor CstF recruitment at wild-type and mutant IgM transgenes that use alternative poly(A) sites to produce mRNAs encoding the secreted and membrane-bound forms of the immunoglobulin (Ig) heavy chain. The results show that the sites of Pol II pausing and processing factor recruitment change depending on which poly(A) site is utilized. In contrast, the extent of Pol II CTD Ser2 phosphorylation does not closely correlate with poly(A) site selection. We conclude that changes in properties of the transcription elongation complex closely correlate with utilization of different poly(A) sites, suggesting that cotranscriptional events may influence the decision between alternative modes of pre-mRNA 3' end processing.
authors.affiliation: Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Aurora, Colorado, USA.
authors.forename: Becky
authors.initials: B
authors.lastname: Fusby
authors.affiliation: Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Aurora, Colorado, USA.
authors.forename: Soojin
authors.initials: S
authors.lastname: Kim
authors.affiliation: Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Aurora, Colorado, USA.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Erickson
authors.affiliation: Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Aurora, Colorado, USA.
authors.forename: Hyunmin
authors.initials: H
authors.lastname: Kim
authors.affiliation: Department of Microbiology, Immunology & Molecular Genetics, University of Kentucky Medical Center, Lexington, Kentucky, USA.
authors.forename: Martha L
authors.initials: ML
authors.lastname: Peterson
authors.affiliation: Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Aurora, Colorado, USA david.bentley@ucdenver.edu.
authors.forename: David L
authors.initials: DL
authors.lastname: Bentley
mesh_terms: D000818:Animals; D002460:Cell Line; D007075:Immunoglobulin M / Q000235:genetics; D051379:Mice; D011061:Poly A / Q000378:metabolism; D026723:Polyadenylation; D017434:Protein Structure, Tertiary; D012319:RNA Polymerase II / Q000737:chemistry / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D015533:Transcriptional Activation; D039221:mRNA Cleavage and Polyadenylation Factors / Q000378:metabolism
chemical_list: D007075:Immunoglobulin M; D012333:RNA, Messenger; D039221:mRNA Cleavage and Polyadenylation Factors; D011061:Poly A; D012319:RNA Polymerase II