Coordination of dual incision and repair synthesis in human nucleotide excision repair.
Nucleotide excision repair (NER) requires the coordinated sequential assembly and actions of the involved proteins at sites of DNA damage. Following damage recognition, dual incision 5' to the lesion by ERCC1-XPF and 3' to the lesion by XPG leads to the removal of a lesion-containing oligonucleotide of about 30 nucleotides. The resulting single-stranded DNA (ssDNA) gap on the undamaged strand is filled in by DNA repair synthesis. Here, we have asked how dual incision and repair synthesis are coordinated in human cells to avoid the exposure of potentially harmful ssDNA intermediates. Using catalytically inactive mutants of ERCC1-XPF and XPG, we show that the 5' incision by ERCC1-XPF precedes the 3' incision by XPG and that the initiation of repair synthesis does not require the catalytic activity of XPG. We propose that a defined order of dual incision and repair synthesis exists in human cells in the form of a 'cut-patch-cut-patch' mechanism. This mechanism may aid the smooth progression through the NER pathway and contribute to genome integrity.
Staresincic
Lidija
L
Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY 11794-3400, USA.
Fagbemi
Adebanke F
AF
Enzlin
Jacqueline H
JH
Gourdin
Audrey M
AM
Wijgers
Nils
N
Dunand-Sauthier
Isabelle
I
Giglia-Mari
Giuseppina
G
Clarkson
Stuart G
SG
Vermeulen
Wim
W
Schärer
Orlando D
OD
D000818:Animals; D020134:Catalytic Domain; D002460:Cell Line; D004247:DNA / Q000235:genetics / Q000378:metabolism* / Q000528:radiation effects; D004249:DNA Damage; D004260:DNA Repair; D004277:DNA, Single-Stranded / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D004720:Endonucleases / Q000235:genetics / Q000378:metabolism; D006801:Humans; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D018809:Proliferating Cell Nuclear Antigen / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014466:Ultraviolet Rays; D000099250:DNA Excision Repair Protein ERCC-5
D004247:DNA; D004277:DNA, Single-Stranded; D004268:DNA-Binding Proteins; D004720:Endonucleases; D009687:Nuclear Proteins; D018809:Proliferating Cell Nuclear Antigen; D014157:Transcription Factors; D000099250:DNA Excision Repair Protein ERCC-5; C489780:CNOT8 protein, human; C095888:xeroderma pigmentosum group F protein; C071447:ERCC1 protein, human