Fanconi anemia DNA repair complex proteins (FA complex)

The Fanconi anemia (FA) DNA repair complex is a critical multi-component system responsible for identifying and repairing DNA interstrand cross-links (ICLs), which are highly toxic lesions that stall replication forks (Kottemann & Huang, 2013, PubMed: 23459318). The pathway involves at least 22 proteins (FANC A-W) organized into functional groups: the FA core complex, the ID complex (FANCD2-FANCI), and downstream effector proteins including BRCA2 (FANCD1) (Ceccaldi et al., 2016, PubMed: 26778213). Upon DNA damage detection, the core complex acts as an E3 ubiquitin ligase to monoubiquitinate the ID complex, triggering the recruitment of nucleases to 'unhook' the cross-link and allowing repair via homologous recombination (Walden & Deans, 2014, PubMed: 24584920). Deficiencies in this pathway lead to Fanconi anemia, a syndrome marked by developmental defects, progressive bone marrow failure, and a high risk of leukemia and solid tumors (Nalepa & Clapp, 2018, PubMed: 29439118). In therapeutic contexts, the FA pathway is exploited through synthetic lethality; for instance, FA-deficient tumor cells are exceptionally sensitive to PARP inhibitors and DNA-cross-linking agents like cisplatin (Lord & Ashworth, 2016, PubMed: 26867118). Conversely, inhibitors of the FA pathway are being explored to sensitize cancer cells to conventional chemotherapy.

Other names

FANC proteinsFanconi anemia pathwayFA core complexDNA interstrand cross-link repair complexFANC-BRCA pathway

The complex facilitates the repair of DNA interstrand cross-links through a coordinated process involving E3 ubiquitin ligase-mediated activation of the FANCD2-FANCI heterodimer, which subsequently recruits nucleases and homologous recombination factors to resolve DNA damage.