title: Novel interactions at the essential N-terminus of poly(A) polymerase that could regulate poly(A) addition in Saccharomyces cerevisiae.
abstract: Addition of poly(A) to the 3' ends of cleaved pre-mRNA is essential for mRNA maturation and is catalyzed by Pap1 in yeast. We have previously shown that a non-viable Pap1 mutant lacking the first 18 amino acids is fully active for polyadenylation of oligoA, but defective for pre-mRNA polyadenylation, suggesting that interactions at the N-terminus are important for enzyme function in the processing complex. We have now identified proteins that interact specifically with this region. Cft1 and Pta1 are subunits of the cleavage/polyadenylation factor, in which Pap1 resides, and Nab6 and Sub1 are nucleic-acid binding proteins with known links to 3' end processing. Our results suggest a novel mechanism for controlling Pap1 activity, and possible models invoking these newly-discovered interactions are discussed.
authors.affiliation: Tufts School of Medicine and the Sackler Graduate School of Biomedical Sciences, Boston, MA 02111, USA.
authors.forename: Chukwudi
authors.initials: C
authors.lastname: Ezeokonkwo
authors.forename: Mohamed A
authors.initials: MA
authors.lastname: Ghazy
authors.forename: Alexander
authors.initials: A
authors.lastname: Zhelkovsky
authors.forename: Pei-Chun
authors.initials: PC
authors.lastname: Yeh
authors.forename: Claire
authors.initials: C
authors.lastname: Moore
mesh_terms: D000073718:Pancreatitis-Associated Proteins; D011061:Poly A / Q000378:metabolism*; D011062:Polynucleotide Adenylyltransferase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D021122:Protein Subunits / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D039221:mRNA Cleavage and Polyadenylation Factors / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism
chemical_list: C465209:Cft1 protein, S cerevisiae; C076229:PTA1 protein, S cerevisiae; D000073718:Pancreatitis-Associated Proteins; D021122:Protein Subunits; C000612141:REG3A protein, human; D029701:Saccharomyces cerevisiae Proteins; D039221:mRNA Cleavage and Polyadenylation Factors; D011061:Poly A; C429559:PAP1 protein, S cerevisiae; D011062:Polynucleotide Adenylyltransferase