Processing of a psoralen DNA interstrand cross-link by XPF-ERCC1 complex in vitro.
The processing of stalled forks caused by DNA interstrand cross-links (ICLs) has been proposed to be an important step in initiating mammalian ICL repair. To investigate a role of the XPF-ERCC1 complex in this process, we designed a model substrate DNA with a single psoralen ICL at a three-way junction (Y-shaped DNA), which mimics a stalled fork structure. We found that the XPF-ERCC1 complex makes an incision 5' to a psoralen lesion on Y-shaped DNA in a damage-dependent manner. Furthermore, the XPF-ERCC1 complex generates an ICL-specific incision on the 3'-side of an ICL. The ICL-specific 3'-incision, along with the 5'-incision, on the cross-linked Y-shaped DNA resulted in the separation of the two cross-linked strands (the unhooking of the ICL) and the induction of a double strand break near the cross-linked site. These results implicate the XPF-ERCC1 complex in initiating ICL repair by unhooking the ICL, which simultaneously induces a double strand break at a stalled fork.
Fisher
Laura A
LA
Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, Nebraska 68198-6805.
Bessho
Mika
M
Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, Nebraska 68198-6805.
Bessho
Tadayoshi
T
Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, Nebraska 68198-6805. Electronic address: tbessho@unmc.edu.
D000818:Animals; D016466:CHO Cells; D006224:Cricetinae; D003412:Cricetulus; D003432:Cross-Linking Reagents / Q000494:pharmacology*; D004247:DNA / Q000737:chemistry / Q000378:metabolism*; D053903:DNA Breaks, Double-Stranded / Q000187:drug effects; D004260:DNA Repair / Q000187:drug effects; D004261:DNA Replication / Q000187:drug effects; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D004720:Endonucleases / Q000302:isolation & purification / Q000378:metabolism*; D005363:Ficusin / Q000494:pharmacology*; D006801:Humans; D008954:Models, Biological; D009690:Nucleic Acid Conformation / Q000187:drug effects; D017434:Protein Structure, Tertiary; D013379:Substrate Specificity / Q000187:drug effects
D003432:Cross-Linking Reagents; D004268:DNA-Binding Proteins; C095888:xeroderma pigmentosum group F protein; D004247:DNA; C071447:ERCC1 protein, human; D004720:Endonucleases; D005363:Ficusin