Yhh1p/Cft1p directly links poly(A) site recognition and RNA polymerase II transcription termination.
RNA polymerase II (pol II) transcription termination requires co-transcriptional recognition of a functional polyadenylation signal, but the molecular mechanisms that transduce this signal to pol II remain unclear. We show that Yhh1p/Cft1p, the yeast homologue of the mammalian AAUAAA interacting protein CPSF 160, is an RNA-binding protein and provide evidence that it participates in poly(A) site recognition. Interestingly, RNA binding is mediated by a central domain composed of predicted beta-propeller-forming repeats, which occurs in proteins of diverse cellular functions. We also found that Yhh1p/Cft1p bound specifically to the phosphorylated C-terminal domain (CTD) of pol II in vitro and in a two-hybrid test in vivo. Furthermore, transcriptional run-on analysis demonstrated that yhh1 mutants were defective in transcription termination, suggesting that Yhh1p/Cft1p functions in the coupling of transcription and 3'-end formation. We propose that direct interactions of Yhh1p/Cft1p with both the RNA transcript and the CTD are required to communicate poly(A) site recognition to elongating pol II to initiate transcription termination.
Pubmed ID: 12145212 RIS Download
Actins | Amino Acid Sequence | Binding Sites | Escherichia coli | Macromolecular Substances | Molecular Sequence Data | Peptide Chain Elongation, Translational | Peptide Chain Termination, Translational | Poly A | Protein Structure, Tertiary | RNA Polymerase II | RNA, Fungal | RNA, Messenger | RNA-Binding Proteins | Recombinant Fusion Proteins | Saccharomyces cerevisiae Proteins | Sequence Alignment | Sequence Homology, Amino Acid | Transcription, Genetic | Two-Hybrid System Techniques | mRNA Cleavage and Polyadenylation Factors