The yeast Pan2 protein is required for poly(A)-binding protein-stimulated poly(A)-nuclease activity

J Biol Chem. 1996 Jan 5;271(1):432-8. doi: 10.1074/jbc.271.1.432.

Abstract

The removal of the mRNA poly(A) tail in the yeast Saccharomyces cerevisiae is stimulated by the poly(A)-binding protein (Pab1p). A large scale purification of the Pab1p-stimulated poly(A) ribonuclease (PAN) identifies a 76-kDa and two 135-Da polypeptides as candidate enzyme subunits. Antibodies against the Pan1p protein, which is the minor 135-kDa protein in the preparation, can immunodeplete Pan1p but not PAN activity. The protein sequence of the major 135-kDa protein, Pan2p, reveals a novel protein that was also found in the previously reported PAN purification (Sachs, A. B., and Deardorff, J. A. (1992) Cell 70, 961-973). Deletion of the non-essential PAN2 gene results in an increase of the average length of mRNA poly(A) tails in vivo, and a loss of Pab1p-stimulated PAN activity in crude extracts. These data confirm that Pan2p and not Pan1p is required for PAN activity, and they suggest that ribonucleases other than the Pab1p-stimulated PAN are capable of shortening poly(A) tails in vivo.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Base Sequence
  • Cell Survival
  • DNA Primers
  • Exoribonucleases / metabolism*
  • Genome, Fungal
  • Molecular Sequence Data
  • Mutagenesis
  • Poly(A)-Binding Proteins
  • RNA-Binding Proteins / metabolism*
  • Receptors, Cytoplasmic and Nuclear / metabolism*
  • Saccharomyces cerevisiae / genetics
  • Saccharomyces cerevisiae / metabolism*

Substances

  • DNA Primers
  • Poly(A)-Binding Proteins
  • RNA-Binding Proteins
  • Receptors, Cytoplasmic and Nuclear
  • Exoribonucleases
  • poly(A)-specific ribonuclease

Associated data

  • GENBANK/U39204