| Literature DB >> 11440997 |
R Prasad1, O I Lavrik, S J Kim, P Kedar, X P Yang, B J Vande Berg, S H Wilson.
Abstract
Recently, photoaffinity labeling experiments with mouse cell extracts suggested that PARP-1 functions as a surveillance protein for a stalled BER intermediate. To further understand the role of PARP-1 in BER, we examined the DNA synthesis and flap excision steps in long patch BER using a reconstituted system containing a 34-base pair BER substrate and five purified human enzymes: uracil-DNA glycosylase, apurinic/apyrimidinic endonuclease, DNA polymerase beta, flap endonuclease-1 (FEN-1), and PARP-1. PARP-1 stimulates strand displacement DNA synthesis by DNA polymerase beta in this system; this stimulation is dependent on the presence of FEN-1. PARP-1 and FEN-1, therefore, cooperate to activate long patch BER. The results are discussed in the context of a model for BER sub-pathway choice, illustrating a dual role for PARP-1 as a surveillance protein for a stalled BER intermediate and an activating factor for long patch BER DNA synthesis.Entities:
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Year: 2001 PMID： 11440997 DOI： 10.1074/jbc.C100292200
Source DB: PubMed Journal: J Biol Chem ISSN： 0021-9258 Impact factor: 5.157