Proliferating cell nuclear antigen is required for DNA excision repair.
Fractionation of extracts from human cell lines allows nucleotide excision repair of damaged DNA to be resolved into discrete incision and polymerization stages. Generation of incised intermediates depends on the XP-A protein, a polypeptide that recognizes sites of damaged DNA, and on the human single-stranded DNA-binding protein HSSB. The proliferating cell nuclear antigen (PCNA) is required for the DNA synthesis that converts the nicked intermediates to completed repair events. This need for PCNA implies that repair synthesis is carried out by DNA polymerase delta or epsilon. The ability to visualize repair intermediates in the absence of PCNA facilitates dissection of the multiprotein reaction that leads to incision of damaged DNA in a major pathway of cellular defense against mutagens.
Shivji
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KK
Imperial Cancer Research Fund, Clare Hall Laboratories, South Mimms, Herts, England.
Kenny
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MK
Wood
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RD
D002457:Cell Extracts / Q000737:chemistry; D002458:Cell Fractionation; D004260:DNA Repair; D004268:DNA-Binding Proteins / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D009687:Nuclear Proteins / Q000378:metabolism*; D018809:Proliferating Cell Nuclear Antigen; D051716:Replication Protein A; D051760:Xeroderma Pigmentosum Group A Protein
D002457:Cell Extracts; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D018809:Proliferating Cell Nuclear Antigen; C497167:RPA1 protein, human; D051716:Replication Protein A; C497314:XPA protein, human; D051760:Xeroderma Pigmentosum Group A Protein