Regulation of yeast mRNA 3' end processing by phosphorylation

Mol Cell. 2005 Sep 2;19(5):619-29. doi: 10.1016/j.molcel.2005.07.016.


Recent studies have found that the phosphatase Glc7 associates with the yeast cleavage/polyadenylation factor (CPF), but the role of Glc7 in 3' end processing has not been investigated. Here, we report that depletion of Glc7 causes shortened poly(A) tails in vivo and accumulation of phosphorylated Pta1, a CPF subunit. Removal of Glc7 also gives extract defective for poly(A) addition but normal for cleavage at the poly(A) site. Polyadenylation is rescued by addition of Glc7 or Pta1, but not by phosphorylated Pta1. Moreover, Ypi1, a Glc7-specific inhibitor, or the Cka1 kinase blocks poly(A) addition in wild-type (wt) extract. Pta1 interacts physically and genetically with Glc7, suggesting that Pta1 may also regulate Glc7 or recruit it to CPF. A weakened association of Fip1 with phosphorylated CPF may explain the specific effect on polyadenylation. These results support a model in which poly(A) synthesis is controlled by cycles of phosphorylation and dephosphorylation that require the action of Glc7.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Casein Kinase II / metabolism
  • Gene Expression Regulation, Fungal / physiology*
  • Phosphoprotein Phosphatases / deficiency
  • Phosphoprotein Phosphatases / genetics*
  • Phosphoprotein Phosphatases / physiology
  • Phosphorylation
  • Polyadenylation
  • Protein Phosphatase 1
  • RNA Processing, Post-Transcriptional / physiology*
  • RNA, Messenger / biosynthesis
  • RNA, Messenger / metabolism*
  • Saccharomyces cerevisiae / genetics*
  • Saccharomyces cerevisiae Proteins / genetics*
  • Saccharomyces cerevisiae Proteins / metabolism
  • Saccharomyces cerevisiae Proteins / physiology
  • mRNA Cleavage and Polyadenylation Factors / metabolism


  • FIP1 protein, S cerevisiae
  • PTA1 protein, S cerevisiae
  • RNA, Messenger
  • Saccharomyces cerevisiae Proteins
  • mRNA Cleavage and Polyadenylation Factors
  • Casein Kinase II
  • GLC7 protein, S cerevisiae
  • Phosphoprotein Phosphatases
  • Protein Phosphatase 1