Fanconi Anemia Pathway and DNA Damage Repair

The Fanconi anaemia pathway is a multi-component DNA damage response system devoted to the recognition and repair of DNA interstrand crosslinks (ICLs) that impede replication and transcription. Central to this process is the FANCD2–FANCI (ID) complex, which is monoubiquitinated by a core ubiquitin ligase assembly and recruits downstream nucleases, translesion synthesis polymerases and homologous recombination factors. This orchestrated sequence ensures incision of crosslinks, stabilisation of stalled replication forks and error-free repair through homologous recombination. The pathway intricately crosstalks with BRCA1/2-mediated repair, reflecting overlapping roles in genome stability. Dysfunction of any FA component leads to chromosomal fragility, bone marrow failure and cancer predisposition, while tumour cells often exploit residual FA activity to resist crosslinking chemotherapies. Understanding mechanistic details of lesion recognition, fork protection and interplay with other repair pathways has opened avenues for targeted therapies such as PARP inhibitors and E3 ligase modulators.

Research from Nature Portfolio

Recent studies have unveiled how the ID complex physically surveys DNA for damage and distinguishes physiologically relevant structures. Single-molecule imaging and cryogenic electron microscopy have shown that the FANCD2–FANCI complex behaves as a sliding clamp on double-stranded DNA and stalls specifically at single-strand–double-strand junctions. This behaviour explains how stalled replication forks are identified and engaged by the FA pathway. Independent work has revealed a critical non-redundant role for Fanconi anaemia associated protein 20 (FAAP20) in homology-directed repair of double-strand breaks. FAAP20 supports RAD51 filament formation independently of its partner FANCA and also collaborates with FANCA in single-strand annealing, underlining multiple layers of FA pathway involvement in double-strand break repair.

Fanconi Anemia Pathway and DNA Damage Repair publication trend

The graph below shows the total number of articles in fanconi anemia pathway and dna damage repair across all publications each year (not limited to Nature Index journals).

Technical terms

Interstrand crosslink (ICL): A covalent linkage between opposite DNA strands that blocks replication and transcription.

Monoubiquitination: Attachment of a single ubiquitin molecule to a protein, regulating its activity or localisation.

Replication fork: The Y-shaped structure formed during DNA replication where the two strands are unwound.

Homologous recombination: An error-free repair mechanism that uses a homologous template to mend double-strand breaks.

Sliding clamp: A ring-shaped protein complex that encircles DNA to facilitate the movement or localisation of repair factors.

Single-strand–double-strand (ss–ds) DNA junction: A structural interface arising at stalled replication forks where one strand is unpaired and the other remains double-stranded.

References

1. FANCD2–FANCI surveys DNA and recognizes double- to single-stranded junctions. Nature (2024).
2. FBXL12 degrades FANCD2 to regulate replication recovery and promote cancer cell survival under conditions of replication stress. Molecular Cell (2023).
3. Fanconi anemia associated protein 20 (FAAP20) plays an essential role in homology-directed repair of DNA double-strand breaks. Communications Biology (2023).
4. Interplay between Fanconi anemia and homologous recombination pathways in genome integrity. The EMBO Journal (2016).