ERCC4

ERCC4 is a protein designated as DNA repair endonuclease XPF that in humans is encoded by the ERCC4 gene. Together with ERCC1, ERCC4 forms the ERCC1-XPF enzyme complex that participates in DNA repair and DNA recombination.

The nuclease enzyme ERCC1-XPF cuts specific structures of DNA. Many aspects of these two gene products are described together here because they are partners during DNA repair. The ERCC1-XPF nuclease is an essential activity in the pathway of DNA nucleotide excision repair (NER). The ERCC1-XPF nuclease also functions in pathways to repair double-strand breaks in DNA, and in the repair of “crosslink” damage that harmfully links the two DNA strands.

Cells with disabling mutations in ERCC4 are more sensitive than normal to particular DNA damaging agents, including ultraviolet radiation and to chemicals that cause crosslinking between DNA strands. Genetically engineered mice with disabling mutations in ERCC4 also have defects in DNA repair, accompanied by metabolic stress-induced changes in physiology that result in premature aging. Complete deletion of ERCC4 is incompatible with viability of mice, and no human individuals have been found with complete (homozygous) deletion of ERCC4. Rare individuals in the human population harbor inherited mutations that impair the function of ERCC4. When the normal genes are absent, these mutations can lead to human syndromes, including xeroderma pigmentosum, Cockayne syndrome and Fanconi anemia.