ERCC1–XPF targeting to psoralen–DNA crosslinks depends on XPA and FANCD2

Abstract

The effectiveness of many DNA-damaging chemotherapeutic drugs depends on their ability to form monoadducts, intrastrand crosslinks and/or interstrand crosslinks (ICLs) that interfere with transcription and replication. The ERCC1-XPF endonuclease plays a critical role in removal of these lesions by incising DNA either as part of nucleotide excision repair (NER) or interstrand crosslink repair (ICLR). Engagement of ERCC1-XPF in NER is well characterized and is facilitated by binding to the XPA protein. However, ERCC1-XPF recruitment to ICLs is less well understood. Moreover, specific mutations in XPF have been found to disrupt its function in ICLR but not in NER, but whether this involves differences in lesion targeting is unknown. Here, we imaged GFP-tagged ERCC1, XPF and ICLR-defective XPF mutants to investigate how in human cells ERCC1-XPF is localized to different types of psoralen-induced DNA lesions, repaired by either NER or ICLR. Our results confirm its dependence on XPA in NER and furthermore show that its engagement in ICLR is dependent on FANCD2. Interestingly, we find that two ICLR-defective XPF mutants (R689S and S786F) are less well recruited to ICLs. These studies highlight the differential mechanisms that regulate ERCC1-XPF activity in DNA repair.

DNA Damage-Induced Neurodegeneration in Accelerated Ageing and Alzheimer’s Disease

“…The XPA protein plays a pivotal role in the NER pathway in which XPA can stimulate transcriptional factor TFIIH, as described earlier [89]. Together with the ssDNA binding protein RPA [20], TFIIH can coordinate the localization of endonucleases ERCC1-XPF [90] and XPG. XPA can also serve as a scaffold for repair proteins [91].…”

Association of ERCC1 and XPF polymorphisms with pediatric glioma susceptibility

“…This complex works by cleaving the damaged DNA, creating two incisions that remove damaged oligonucleotides, and then inducing the concerted action of exonucleases, polymerases, and ligases to repair the gap. [ 5 , 6 ]…”

“…They interact with each other through the HhH 2 domain, thus forming a highly conserved heterodimer and exhibiting endonuclease activity. This complex works by cleaving the damaged DNA, creating two incisions that remove damaged oligonucleotides, and then inducing the concerted action of exonucleases, polymerases, and ligases to repair the gap [5,6] …”

“…This complex works by cleaving the damaged DNA, creating two incisions that remove damaged oligonucleotides, and then inducing the concerted action of exonucleases, polymerases, and ligases to repair the gap. [5,6] Variations in some alleles of ERCC1 gene polymorphisms may attenuate the capacity of DNA repair, and these mutations are mainly concentrated in the 3 0 UTR while there are several polymorphisms in the coding region of XPF that bring about possible genetic instability. Therefore, some ERCC1/XPF genes SNPs may have effects on glioma.…”