title: Phospho-carboxyl-terminal domain binding and the role of a prolyl isomerase in pre-mRNA 3'-End formation.
abstract: A phospho-carboxyl-terminal domain (CTD) affinity column created with yeast CTD kinase I and the CTD of RNA polymerase II was used to identify Ess1/Pin1 as a phospho-CTD-binding protein. Ess1/Pin1 is a peptidyl prolyl isomerase involved in both mitotic regulation and pre-mRNA 3'-end formation. Like native Ess1, a GSTEss1 fusion protein associates specifically with the phosphorylated but not with the unphosphorylated CTD. Further, hyperphosphorylated RNA polymerase II appears to be the dominant Ess1 binding protein in total yeast extracts. We demonstrate that phospho-CTD binding is mediated by the small WW domain of Ess1 rather than the isomerase domain. These findings suggest a mechanism in which the WW domain binds the phosphorylated CTD of elongating RNA polymerase II and the isomerase domain reconfigures the CTD though isomerization of proline residues perhaps by a processive mechanism. This process may be linked to a variety of pre-mRNA maturation events that use the phosphorylated CTD, including the coupled processes of pre-mRNA 3'-end formation and transcription termination.
authors.affiliation: Department of Biochemistry, Duke University Medical Center, Durham, North Carolina 27710, USA.
authors.forename: D P
authors.initials: DP
authors.lastname: Morris
authors.forename: H P
authors.initials: HP
authors.lastname: Phatnani
authors.forename: A L
authors.initials: AL
authors.lastname: Greenleaf
mesh_terms: D002846:Chromatography, Affinity; D000072340:NIMA-Interacting Peptidylprolyl Isomerase; D010446:Peptide Fragments / Q000378:metabolism; D019696:Peptidylprolyl Isomerase / Q000302:isolation & purification / Q000378:metabolism*; D010750:Phosphoproteins / Q000378:metabolism*; D011485:Protein Binding; D011494:Protein Kinases / Q000378:metabolism; D017434:Protein Structure, Tertiary; D012319:RNA Polymerase II / Q000235:genetics / Q000378:metabolism*; D012322:RNA Precursors / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae; D029701:Saccharomyces cerevisiae Proteins
chemical_list: D000072340:NIMA-Interacting Peptidylprolyl Isomerase; D010446:Peptide Fragments; D010750:Phosphoproteins; D012322:RNA Precursors; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; D029701:Saccharomyces cerevisiae Proteins; D011494:Protein Kinases; C060137:carboxy-terminal domain kinase; D012319:RNA Polymerase II; C000606845:ESS1 protein, S cerevisiae; D019696:Peptidylprolyl Isomerase