The DNA helicase Pfh1 promotes fork merging at replication termination sites to ensure genome stability

Genes Dev. 2012 Mar 15;26(6):594-602. doi: 10.1101/gad.184663.111.


Bidirectionally moving DNA replication forks merge at termination sites composed of accidental or programmed DNA-protein barriers. If merging fails, then regions of unreplicated DNA can result in the breakage of DNA during mitosis, which in turn can give rise to genome instability. Despite its importance, little is known about the mechanisms that promote the final stages of fork merging in eukaryotes. Here we show that the Pif1 family DNA helicase Pfh1 plays a dual role in promoting replication fork termination. First, it facilitates replication past DNA-protein barriers, and second, it promotes the merging of replication forks. A failure of these processes in Pfh1-deficient cells results in aberrant chromosome segregation and heightened genome instability.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Chromosome Segregation
  • DNA Helicases / genetics
  • DNA Helicases / metabolism*
  • DNA Replication*
  • DNA, Fungal / genetics
  • DNA, Ribosomal / genetics
  • Genomic Instability*
  • Schizosaccharomyces / enzymology
  • Schizosaccharomyces / genetics*
  • Schizosaccharomyces pombe Proteins / genetics
  • Schizosaccharomyces pombe Proteins / metabolism*


  • DNA, Fungal
  • DNA, Ribosomal
  • Schizosaccharomyces pombe Proteins
  • DNA Helicases
  • Pfh1 protein, S pombe