Poly(ADP-ribose) polymerase (PARP-1) and p53 independently function in regulating double-strand break repair in primate cells.
PARP-1 is rapidly activated by DNA strand breaks, which finally leads to the modulation of multiple protein activities in DNA replication, DNA repair and checkpoint control. PARP-1 may be involved in homologous recombination, and poly(ADP-ribosyl)ation of p53 represents one possible mechanism that activates p53 as a recombination surveillance factor. Here, we examined the influence of PARP-1 on homology-directed double-strand break (DSB) repair by use of a fluorescence- and I-SceI- meganuclease-based assay with either episomal or chromosomally integrated DNA substrates. Surprisingly, the transient expression of both full-length PARP-1 and of a dominant negative mutant, retaining the DNA-binding but lacking the catalytic domain, down-regulated DSB repair in a dose-dependent manner. This effect was seen regardless of p53 status, however, with enhanced inhibition in the presence of wild-type p53. Taken together, our data reveal that PARP-1 overexpression counteracts DSB repair independently of its enzymatic activity and of poly(ADP-ribosyl)ation of p53 in particular, but synergizes with p53 in suppressing chromosomal rearrangements.
Süsse
Silke
S
Universitätsfrauenklinik, Prittwitzstrasse 43, D-89075 Ulm, Germany.
Scholz
Claus-Jürgen
CJ
Bürkle
Alexander
A
Wiesmüller
Lisa
L
D000818:Animals; D061945:Caspase Inhibitors; D020169:Caspases / Q000378:metabolism; D002460:Cell Line; D002869:Chromosome Aberrations; D004247:DNA / Q000235:genetics / Q000378:metabolism*; D004249:DNA Damage; D004260:DNA Repair; D006801:Humans; D020014:K562 Cells; D008253:Macaca mulatta; D011065:Poly(ADP-ribose) Polymerases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D011995:Recombination, Genetic / Q000235:genetics; D013379:Substrate Specificity; D014162:Transfection; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism*
D061945:Caspase Inhibitors; D016159:Tumor Suppressor Protein p53; D004247:DNA; D011065:Poly(ADP-ribose) Polymerases; D020169:Caspases