title: A cooperative interaction between U2AF65 and mBBP/SF1 facilitates branchpoint region recognition.
abstract: During the early events of pre-mRNA splicing, intronic cis-acting sequences are recognized and interact through a network of RNA-RNA, RNA-protein, and protein-protein contacts. Recently, we identified a branchpoint sequence binding protein in yeast (BBP). The mammalian ortholog (mBBP/SF1) also binds specifically to branchpoint sequences and interacts with the well studied mammalian splicing factor U2AF65, which binds to the adjacent polypyrimidine (PY) tract. In this paper we demonstrate that the mBBP/SF1-U2AF65 interaction promotes cooperative binding to a branchpoint sequence-polypyrimidine tract-containing RNA, and we suggest that this cooperative RNA binding contributes to initial recognition of the branchpoint sequence (BPS) during pre-mRNA splicing. We also demonstrate the essential nature of the third RBD of U2AF65 for the interaction between the two proteins, both in the presence and absence of RNA.
authors.affiliation: Howard Hughes Medical Institute and Departments of Biology and Biochemistry, Brandeis University, Waltham, Massachusetts 02254, USA.
authors.forename: J A
authors.initials: JA
authors.lastname: Berglund
authors.forename: N
authors.initials: N
authors.lastname: Abovich
authors.forename: M
authors.initials: M
authors.lastname: Rosbash
mesh_terms: D001665:Binding Sites; D004268:DNA-Binding Proteins; D009154:Mutation / Q000235:genetics / Q000502:physiology; D009687:Nuclear Proteins; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D012322:RNA Precursors / Q000235:genetics; D012326:RNA Splicing; D000072260:RNA Splicing Factors; D016601:RNA-Binding Proteins / Q000737:chemistry / Q000378:metabolism*; D012261:Ribonucleoproteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000072668:Splicing Factor U2AF; D014157:Transcription Factors; D015003:Yeasts / Q000235:genetics
chemical_list: D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D012322:RNA Precursors; D000072260:RNA Splicing Factors; D016601:RNA-Binding Proteins; D012261:Ribonucleoproteins; C107467:SF1 protein, human; D000072668:Splicing Factor U2AF; D014157:Transcription Factors; C000607494:U2AF2 protein, human