High impact information on PTA1

• Physical interactions of Ssu72 and Sub1 with Pta1 are mutually exclusive [1].
• Here, we report that depletion of Glc7 causes shortened poly(A) tails in vivo and accumulation of phosphorylated Pta1, a CPF subunit [2].
• Interestingly, levels of the polyadenylation factor Pta1 are also reduced in kin28 mutants, while several other polyadenylation factors remain stable [3].
• Extracts prepared from pta1 mutant strains are impaired in the cleavage and the poly(A) addition of both GAL7 and CYC1 substrates and exhibit little processing activity even after prolonged incubation [4].
• PTA1 has been mapped to the left arm of chromosome I near CDC24; the gene was sequenced and could encode a protein of 785 amino acids with a molecular weight of 88,417 [5].

Biological context of PTA1

• The PTA1 gene was isolated from a genomic library by complementation of the pta1-1 growth defect [5].
• Disruption of PTA1 near the carboxy terminus of the putative open reading frame was lethal [5].
• PTA1, an essential gene of Saccharomyces cerevisiae affecting pre-tRNA processing [5].
• Point mutations and deletion of the entire TTAGTAA sequence supported the involvement of this sequence in the binding of a transcriptional activator named penicillin transcriptional activator 1 (PTA1) [6].
• Polyadenylation is rescued by addition of Glc7 or Pta1, but not by phosphorylated Pta1 [2].

Other interactions of PTA1

• Six known components of the yeast (CPF) complex, together with Glc7p, were identified among the Pta1p-associated polypeptides using peptide mass fingerprint analysis [7].
• Ref2 and Pta1 similarly affect at least one snoRNA transcript [8].

References