DNA polymerase beta -mediated long patch base excision repair. Poly(ADP-ribose)polymerase-1 stimulates strand displacement DNA synthesis.
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.
Prasad
R
R
Laboratory of Structural Biology, NIEHS, National Institutes of Health, Research Triangle Park, North Carolina 27709, USA.
Lavrik
O I
OI
Kim
S J
SJ
Kedar
P
P
Yang
X P
XP
Vande Berg
B J
BJ
Wilson
S H
SH
D019943:Amino Acid Substitution; D001483:Base Sequence; D002942:Circular Dichroism; D004247:DNA / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism*; D045647:DNA Glycosylases; D019951:DNA Polymerase beta / Q000737:chemistry / Q000378:metabolism*; D004260:DNA Repair; D004261:DNA Replication; D004706:Endodeoxyribonucleases / Q000378:metabolism; D045585:Flap Endonucleases; D006801:Humans; D016297:Mutagenesis, Site-Directed; D009699:N-Glycosyl Hydrolases / Q000378:metabolism; D009838:Oligodeoxyribonucleotides / Q000737:chemistry / Q000378:metabolism; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism*; D011487:Protein Conformation; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D051981:Uracil-DNA Glycosidase
D009838:Oligodeoxyribonucleotides; D011994:Recombinant Proteins; D004247:DNA; D011065:Poly(ADP-ribose) Polymerases; D019951:DNA Polymerase beta; D004706:Endodeoxyribonucleases; D045585:Flap Endonucleases; C468317:FEN1 protein, human; D045647:DNA Glycosylases; D009699:N-Glycosyl Hydrolases; D051981:Uracil-DNA Glycosidase