The Fanconi Anemia Pathway Protects Genome Integrity from R-loops

PLoS Genet. 2015 Nov 19;11(11):e1005674. doi: 10.1371/journal.pgen.1005674. eCollection 2015 Nov.


Co-transcriptional RNA-DNA hybrids (R loops) cause genome instability. To prevent harmful R loop accumulation, cells have evolved specific eukaryotic factors, one being the BRCA2 double-strand break repair protein. As BRCA2 also protects stalled replication forks and is the FANCD1 member of the Fanconi Anemia (FA) pathway, we investigated the FA role in R loop-dependent genome instability. Using human and murine cells defective in FANCD2 or FANCA and primary bone marrow cells from FANCD2 deficient mice, we show that the FA pathway removes R loops, and that many DNA breaks accumulated in FA cells are R loop-dependent. Importantly, FANCD2 foci in untreated and MMC-treated cells are largely R loop dependent, suggesting that the FA functions at R loop-containing sites. We conclude that co-transcriptional R loops and R loop-mediated DNA damage greatly contribute to genome instability and that one major function of the FA pathway is to protect cells from R loops.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • BRCA2 Protein / genetics*
  • DNA / chemistry
  • DNA / genetics
  • DNA Damage / genetics
  • DNA Repair / genetics
  • DNA Replication / genetics
  • Fanconi Anemia Complementation Group A Protein / genetics*
  • Fanconi Anemia Complementation Group D2 Protein / genetics*
  • Genomic Instability / genetics*
  • HeLa Cells
  • Humans
  • Mice
  • RNA / chemistry
  • RNA / genetics


  • BRCA2 Protein
  • FANCA protein, human
  • FANCD2 protein, human
  • Fanconi Anemia Complementation Group A Protein
  • Fanconi Anemia Complementation Group D2 Protein
  • RNA
  • DNA