The FIP1 gene encodes a component of a yeast pre-mRNA polyadenylation factor that directly interacts with poly(A) polymerase.
We have identified an essential gene, called FIP1, encoding a 327 amino acid protein interacting with yeast poly(A) polymerase (PAP1) in the two-hybrid assay. Recombinant FIP1 protein forms a 1:1 complex with PAP1 in vitro. At 37 degrees C, a thermosensitive allele of FIP1 shows a shortening of poly(A) tails and a decrease in the steady-state level of actin transcripts. When assayed for 3'-end processing in vitro, fip1 mutant extracts exhibit normal cleavage activity, but fail to polyadenylate the upstream cleavage product. Polyadenylation activity is restored by adding polyadenylation factor I (PF I). Antibodies directed against FIP1 specifically recognize a polypeptide in these fractions. Coimmunoprecipitation experiments reveal that RNA14, a subunit of cleavage factor I (CF I), directly interacts with FIP1, but not with PAP1. We propose a model in which PF I tethers PAP1 to CF I, thereby conferring specificity to poly(A) polymerase for pre-mRNA substrates.
Preker
P J
PJ
Department of Cell Biology, University of Basel, Switzerland.
Lingner
J
J
Minvielle-Sebastia
L
L
Keller
W
W
D000199:Actins / Q000235:genetics; D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D005800:Genes, Fungal / Q000235:genetics; D008957:Models, Genetic; D008969:Molecular Sequence Data; D016296:Mutagenesis; D000073718:Pancreatitis-Associated Proteins; D011061:Poly A / Q000032:analysis; D011062:Polynucleotide Adenylyltransferase / Q000378:metabolism*; D011485:Protein Binding; D011489:Protein Denaturation; D012322:RNA Precursors / Q000378:metabolism*; D012323:RNA Processing, Post-Transcriptional; D012333:RNA, Messenger / Q000032:analysis / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012045:Regulatory Sequences, Nucleic Acid; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D017422:Sequence Analysis, DNA; D039221:mRNA Cleavage and Polyadenylation Factors
D000199:Actins; D000073718:Pancreatitis-Associated Proteins; C000612141:REG3A protein, human; D012322:RNA Precursors; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D011993:Recombinant Fusion Proteins; D039221:mRNA Cleavage and Polyadenylation Factors; D011061:Poly A; D011062:Polynucleotide Adenylyltransferase