Double-strand break repair in yeast requires both leading and lagging strand DNA polymerases

Cell. 1999 Feb 5;96(3):415-24. doi: 10.1016/s0092-8674(00)80554-1.

Abstract

Mitotic double-strand break (DSB)-induced gene conversion at MAT in Saccharomyces cerevisiae was analyzed molecularly in mutant strains thermosensitive for essential replication factors. The processivity cofactors PCNA and RFC are essential even to synthesize as little as 30 nucleotides following strand invasion. Both PCNA-associated DNA polymerases delta and epsilon are important for gene conversion, though a temperature-sensitive Pol epsilon mutant is more severe than one in Pol delta. Surprisingly, mutants of lagging strand replication, DNA polymerase alpha (pol1-17), DNA primase (pri2-1), and Rad27p (rad27 delta) also greatly inhibit completion of DSB repair, even in G1-arrested cells. We propose a novel model for DSB-induced gene conversion in which a strand invasion creates a modified replication fork, involving leading and lagging strand synthesis from the donor template. Replication is terminated by capture of the second end of the DSB.

Publication types

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

MeSH terms

  • Alleles
  • Cold Temperature
  • DNA Polymerase II / physiology
  • DNA Polymerase III / physiology
  • DNA Repair*
  • DNA Replication
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism
  • DNA-Directed DNA Polymerase / physiology*
  • Genes, Switch
  • Homeodomain Proteins*
  • Minor Histocompatibility Antigens
  • Mutation
  • Proliferating Cell Nuclear Antigen / genetics
  • Proliferating Cell Nuclear Antigen / physiology
  • Proto-Oncogene Proteins c-bcl-2*
  • Replication Origin
  • Replication Protein C
  • Repressor Proteins*
  • Saccharomyces cerevisiae / genetics*
  • Saccharomyces cerevisiae / physiology
  • Saccharomyces cerevisiae Proteins*

Substances

  • BCL2-related protein A1
  • DNA-Binding Proteins
  • Homeodomain Proteins
  • MATA1 protein, S cerevisiae
  • Minor Histocompatibility Antigens
  • Proliferating Cell Nuclear Antigen
  • Proto-Oncogene Proteins c-bcl-2
  • Repressor Proteins
  • Saccharomyces cerevisiae Proteins
  • DNA Polymerase II
  • DNA Polymerase III
  • DNA-Directed DNA Polymerase
  • Replication Protein C