A genome-wide homologous recombination screen identifies the RNA-binding protein RBMX as a component of the DNA-damage response

Nat Cell Biol. 2012 Feb 19;14(3):318-28. doi: 10.1038/ncb2426.


Repair of DNA double-strand breaks is critical to genomic stability and the prevention of developmental disorders and cancer. A central pathway for this repair is homologous recombination (HR). Most knowledge of HR is derived from work in prokaryotic and eukaryotic model organisms. We carried out a genome-wide siRNA-based screen in human cells. Among positive regulators of HR we identified networks of DNA-damage-response and pre-mRNA-processing proteins, and among negative regulators we identified a phosphatase network. Three candidate proteins localized to DNA lesions, including RBMX, a heterogeneous nuclear ribonucleoprotein that has a role in alternative splicing. RBMX accumulated at DNA lesions through multiple domains in a poly(ADP-ribose) polymerase 1-dependent manner and promoted HR by facilitating proper BRCA2 expression. Our screen also revealed that off-target depletion of RAD51 is a common source of RNAi false positives, raising a cautionary note for siRNA screens and RNAi-based studies of HR.

Publication types

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

MeSH terms

  • BRCA2 Protein / genetics
  • BRCA2 Protein / metabolism
  • Cell Cycle Proteins / genetics
  • Cell Cycle Proteins / metabolism
  • Cell Line, Tumor
  • DNA Damage*
  • DNA Repair
  • Gene Regulatory Networks
  • Genome, Human / genetics*
  • Green Fluorescent Proteins / genetics
  • Green Fluorescent Proteins / metabolism
  • Heterogeneous-Nuclear Ribonucleoproteins / genetics*
  • Heterogeneous-Nuclear Ribonucleoproteins / metabolism
  • Histone Chaperones / genetics
  • Histone Chaperones / metabolism
  • Homologous Recombination*
  • Humans
  • Immunoblotting
  • Microscopy, Fluorescence
  • Models, Genetic
  • Nuclear Pore Complex Proteins / genetics
  • Nuclear Pore Complex Proteins / metabolism
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism
  • Poly(ADP-ribose) Polymerases / genetics
  • Poly(ADP-ribose) Polymerases / metabolism
  • RNA Interference
  • RNA Precursors / genetics
  • RNA Precursors / metabolism
  • RNA, Small Interfering / genetics
  • RNA-Binding Proteins / genetics
  • RNA-Binding Proteins / metabolism
  • Rad51 Recombinase / genetics
  • Rad51 Recombinase / metabolism
  • Reverse Transcriptase Polymerase Chain Reaction
  • Transcription Factors / genetics
  • Transcription Factors / metabolism


  • BRCA2 Protein
  • Cell Cycle Proteins
  • HIRA protein, human
  • Heterogeneous-Nuclear Ribonucleoproteins
  • Histone Chaperones
  • NUP214 protein, human
  • Nuclear Pore Complex Proteins
  • Nuclear Proteins
  • RBMX protein, human
  • RNA Precursors
  • RNA, Small Interfering
  • RNA-Binding Proteins
  • Transcription Factors
  • UBN1 protein, human
  • Green Fluorescent Proteins
  • Poly(ADP-ribose) Polymerases
  • Rad51 Recombinase