The DNA helicase Pfh1 promotes fork merging at replication termination sites to ensure genome stability
- 1Department of Biochemistry, University of Oxford, Oxford OX13QU, United Kingdom;
- 2Warwick Medical School, University of Warwick, Coventry CV47AL, United Kingdom
Abstract
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.
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Footnotes
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↵3 Corresponding author.
E-mail matthew.whitby{at}bioch.ox.ac.uk.
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Supplemental material is available for this article.
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Article is online at http://www.genesdev.org/cgi/doi/10.1101/gad.184663.111.
- Received December 29, 2011.
- Accepted February 7, 2012.
- Copyright © 2012 by Cold Spring Harbor Laboratory Press
Freely available online through the Genes & Development Open Access option.