RGD Reference Report - A role for DNA polymerase beta in mutagenic UV lesion bypass. - Rat Genome Database

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A role for DNA polymerase beta in mutagenic UV lesion bypass.

Authors: Servant, L  Cazaux, C  Bieth, A  Iwai, S  Hanaoka, F  Hoffmann, JS 
Citation: Servant L, etal., J Biol Chem 2002 Dec 20;277(51):50046-53.
RGD ID: 633643
Pubmed: (View Article at PubMed) PMID:12388548
DOI: Full-text: DOI:10.1074/jbc.M207101200

We report here that DNA polymerase beta (pol beta), the base excision repair polymerase, is highly expressed in human melanoma tissues, known to be associated with UV radiation exposure. To investigate the potential role of pol beta in UV-induced genetic instability, we analyzed the cellular and molecular effects of excess pol beta. We firstly demonstrated that mammalian cells overexpressing pol beta are resistant and hypermutagenic after UV irradiation and that replicative extracts from these cells are able to catalyze complete translesion replication of a thymine-thymine cyclobutane pyrimidine dimer (CPD). By using in vitro primer extension reactions with purified pol beta, we showed that CPD as well as, to a lesser extent, the thymine-thymine pyrimidine-pyrimidone (6-4) photoproduct, were bypassed. pol beta mostly incorporates the correct dATP opposite the 3'-terminus of both CPD and the (6-4) photoproduct but can also misinsert dCTP at a frequency of 32 and 26%, respectively. In the case of CPD, efficient and error-prone extension of the correct dATP was found. These data support a biological role of pol beta in UV lesion bypass and suggest that deregulated pol beta may enhance UV-induced genetic instability.

Annotation

Gene Ontology Annotations    

Biological Process

Molecular Function

Objects Annotated

Genes (Rattus norvegicus)
Polb  (DNA polymerase beta)


Additional Information