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Identification of APN2, the Saccharomyces cerevisiae homolog of the major human AP endonuclease HAP1, and its role in the repair of abasic sites.

ABSTRACT: Abasic (AP) sites arise in DNA through spontaneous base loss and enzymatic removal of damaged bases. APN1 encodes the major AP-endonuclease of Saccharomyces cerevisiae. Human HAP1 (REF1) encodes the major AP endonuclease which, in addition to its role in DNA repair, functions as a redox regulatory protein. We identify APN2, the yeast homolog of HAP1 and provide evidence that Apn1 and Apn2 represent alternate pathways for repairing AP sites. The apn1Delta apn2Delta strain displays a highly elevated level of MMS-induced mutagenesis, which is dependent on the REV3, REV7, and REV1 genes. Our findings indicate that AP sites are highly cytotoxic and mutagenic in eukaryotes, and that the REV3, REV7-encoded DNA polymerase zeta mediates the mutagenic bypass of AP sites.

SUBMITTER: Johnson RE

PROVIDER: S-EPMC317187 | biostudies-literature | 1998 Oct

REPOSITORIES: biostudies-literature

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Identification of APN2, the Saccharomyces cerevisiae homolog of the major human AP endonuclease HAP1, and its role in the repair of abasic sites.

Johnson R E RE Torres-Ramos C A CA Izumi T T Mitra S S Prakash S S Prakash L L

Genes & development 19981001 19

Abasic (AP) sites arise in DNA through spontaneous base loss and enzymatic removal of damaged bases. APN1 encodes the major AP-endonuclease of Saccharomyces cerevisiae. Human HAP1 (REF1) encodes the major AP endonuclease which, in addition to its role in DNA repair, functions as a redox regulatory protein. We identify APN2, the yeast homolog of HAP1 and provide evidence that Apn1 and Apn2 represent alternate pathways for repairing AP sites. The apn1Delta apn2Delta strain displays a highly elevat ...[more]

PMID: 9765213

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