Non-enzymatic roles of human RAD51 at stalled replication forks

Nat Commun. 2019 Sep 27;10(1):4410. doi: 10.1038/s41467-019-12297-0.

Abstract

The central recombination enzyme RAD51 has been implicated in replication fork processing and restart in response to replication stress. Here, we use a separation-of-function allele of RAD51 that retains DNA binding, but not D-loop activity, to reveal mechanistic aspects of RAD51's roles in the response to replication stress. Here, we find that cells lacking RAD51's enzymatic activity protect replication forks from MRE11-dependent degradation, as expected from previous studies. Unexpectedly, we find that RAD51's strand exchange activity is not required to convert stalled forks to a form that can be degraded by DNA2. Such conversion was shown previously to require replication fork regression, supporting a model in which fork regression depends on a non-enzymatic function of RAD51. We also show RAD51 promotes replication restart by both strand exchange-dependent and strand exchange-independent mechanisms.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • DNA / chemistry*
  • DNA / genetics
  • DNA / metabolism
  • DNA Replication*
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism*
  • Humans
  • Models, Genetic
  • Mutation
  • Nucleic Acid Conformation
  • Rad51 Recombinase / genetics
  • Rad51 Recombinase / metabolism*

Substances

  • DNA-Binding Proteins
  • DNA
  • RAD51 protein, human
  • Rad51 Recombinase