Exposure of single-stranded telomeric DNA causes G2/M cell cycle arrest in Saccharomyces cerevisiae

J Biol Chem. 2003 Mar 14;278(11):9318-21. doi: 10.1074/jbc.M208347200. Epub 2003 Jan 7.

Abstract

In Saccharomyces cerevisiae, Cdc13p is a single-stranded TG(1-3) DNA binding protein that protects telomeres and maintains telomere length. A mutant allele of CDC13, cdc13-1, causes accumulation of single-stranded TG(1-3) DNA near telomeres along with a G(2)/M cell cycle arrest at non-permissive temperatures. We report here that when the single-stranded TG(1-3) DNA is masked by its binding proteins, such as S. cerevisiae Gbp2p or Schizosaccharomyces pombe Tcg1, the growth arrest phenotype of cdc13-1 is rescued. Mutations on Gbp2p that disrupt its binding to the single-stranded TG(1-3) DNA render the protein unable to complement the defects of cdc13-1. These results indicate that the presence of a single-stranded TG(1-3) tail in cdc13-1 cells serves as the signal for the cell cycle checkpoint. Moreover, the binding activity of Gbp2p to single-stranded TG(1-3) DNA appears to be associated with its ability to restore the telomere-lengthening phenotype in cdc13-1 cells. These results indicate that Gbp2p is involved in modulating telomere length.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Motifs
  • Arginine / chemistry
  • Cell Cycle
  • Cloning, Molecular
  • DNA / metabolism
  • DNA, Complementary / metabolism
  • DNA, Single-Stranded / chemistry*
  • Escherichia coli / metabolism
  • G2 Phase
  • Gene Library
  • Glutathione Transferase / metabolism
  • Mitosis
  • Mutagenesis, Site-Directed
  • Mutation
  • Plasmids / metabolism
  • Protein Binding
  • Recombinant Fusion Proteins / metabolism
  • Saccharomyces cerevisiae / metabolism*
  • Telomere / metabolism*
  • Temperature

Substances

  • DNA, Complementary
  • DNA, Single-Stranded
  • Recombinant Fusion Proteins
  • DNA
  • Arginine
  • Glutathione Transferase