A genetic screen identifies FAN1, a Fanconi anemia-associated nuclease necessary for DNA interstrand crosslink repair

Mol Cell. 2010 Jul 9;39(1):36-47. doi: 10.1016/j.molcel.2010.06.023.


The Fanconi anemia (FA) pathway is responsible for interstrand crosslink repair. At the heart of this pathway is the FANCI-FAND2 (ID) complex, which, upon ubiquitination by the FA core complex, travels to sites of damage to coordinate repair that includes nucleolytic modification of the DNA surrounding the lesion and translesion synthesis. How the ID complex regulates these events is unknown. Here we describe a shRNA screen that led to the identification of two nucleases necessary for crosslink repair, FAN1 (KIAA1018) and EXDL2. FAN1 colocalizes at sites of DNA damage with the ID complex in a manner dependent on FAN1's ubiquitin-binding domain (UBZ), the ID complex, and monoubiquitination of FANCD2. FAN1 possesses intrinsic 5'-3' exonuclease activity and endonuclease activity that cleaves nicked and branched structures. We propose that FAN1 is a repair nuclease that is recruited to sites of crosslink damage in part through binding the ubiquitinated ID complex through its UBZ domain.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Caenorhabditis elegans / metabolism
  • Cell Line
  • Cross-Linking Reagents / metabolism*
  • DNA Damage
  • DNA Mismatch Repair / drug effects
  • DNA Repair* / drug effects
  • Endodeoxyribonucleases
  • Endonucleases / metabolism
  • Exodeoxyribonucleases / chemistry
  • Exodeoxyribonucleases / metabolism*
  • Exonucleases / chemistry
  • Exonucleases / metabolism*
  • Fanconi Anemia / enzymology*
  • Fanconi Anemia / pathology
  • Fanconi Anemia Complementation Group D2 Protein / metabolism
  • Genetic Testing / methods*
  • Genome, Human / genetics
  • Humans
  • Mitomycin / pharmacology
  • Molecular Sequence Data
  • Multifunctional Enzymes
  • Protein Binding / drug effects
  • Protein Structure, Tertiary
  • Protein Transport / drug effects
  • RNA, Small Interfering / metabolism


  • Cross-Linking Reagents
  • Fanconi Anemia Complementation Group D2 Protein
  • Multifunctional Enzymes
  • RNA, Small Interfering
  • Mitomycin
  • Endodeoxyribonucleases
  • Endonucleases
  • Exodeoxyribonucleases
  • Exonucleases
  • FAN1 protein, human