Rif1 controls DNA replication timing in yeast through the PP1 phosphatase Glc7

Cell Rep. 2014 Apr 10;7(1):62-9. doi: 10.1016/j.celrep.2014.03.010. Epub 2014 Mar 27.

Abstract

The Rif1 protein, originally identified as a telomere-binding factor in yeast, has recently been implicated in DNA replication control from yeast to metazoans. Here, we show that budding yeast Rif1 protein inhibits activation of prereplication complexes (pre-RCs). This inhibitory function requires two N-terminal motifs, RVxF and SILK, associated with recruitment of PP1 phosphatase (Glc7). In G1 phase, we show both that Glc7 interacts with Rif1 in an RVxF/SILK-dependent manner and that two proteins implicated in pre-RC activation, Mcm4 and Sld3, display increased Dbf4-dependent kinase (DDK) phosphorylation in rif1 mutants. Rif1 also interacts with Dbf4 in yeast two-hybrid assays, further implicating this protein in direct modulation of pre-RC activation through the DDK. Finally, we demonstrate Rif1 RVxF/SILK motif-dependent recruitment of Glc7 to telomeres and earlier replication of these regions in cells where the motifs are mutated. Our data thus link Rif1 to negative regulation of replication origin firing through recruitment of the Glc7 phosphatase.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Cycle Proteins / metabolism
  • DNA Replication / physiology*
  • Phosphorylation
  • Protein Binding
  • Protein Phosphatase 1 / genetics
  • Protein Phosphatase 1 / metabolism*
  • Protein-Serine-Threonine Kinases / metabolism
  • Replication Origin / physiology*
  • Repressor Proteins / genetics
  • Repressor Proteins / metabolism*
  • Saccharomyces cerevisiae / metabolism*
  • Saccharomyces cerevisiae Proteins / genetics
  • Saccharomyces cerevisiae Proteins / metabolism*
  • Telomere / genetics
  • Telomere / metabolism
  • Telomere-Binding Proteins / genetics
  • Telomere-Binding Proteins / metabolism*

Substances

  • Cell Cycle Proteins
  • Repressor Proteins
  • Saccharomyces cerevisiae Proteins
  • Telomere-Binding Proteins
  • RIF1 protein, S cerevisiae
  • CDC7 protein, S cerevisiae
  • Protein-Serine-Threonine Kinases
  • GLC7 protein, S cerevisiae
  • Protein Phosphatase 1