First Author | Shieh WM | Year | 1998 |
Journal | J Biol Chem | Volume | 273 |
Issue | 46 | Pages | 30069-72 |
PubMed ID | 9804757 | Mgi Jnum | J:50963 |
Mgi Id | MGI:1313088 | Doi | 10.1074/jbc.273.46.30069 |
Citation | Shieh WM, et al. (1998) Poly(ADP-ribose) polymerase null mouse cells synthesize ADP-ribose polymers. J Biol Chem 273(46):30069-72 |
abstractText | Poly(ADP-ribose) polymerase (PARP) (EC 2.4.2.30), the only enzyme known to synthesize ADP-ribose polymers from NAD+, is activated in response to DNA strand breaks and functions in the maintenance of genomic integrity. Mice homozygous for a disrupted gene encoding PARP are viable but have severe sensitivity to gamma-radiation and alkylating agents. We demonstrate here that both 3T3 and primary embryo cells derived from PARP-/- mice synthesized ADP-ribose polymers following treatment with the DNA-damaging agent, N-methyl-N'-nitro-N- nitrosoguanidine, despite the fact that no PARP protein was detected in these cells. ADP-ribose polymers isolated from PARP-/- cells were indistinguishable from that of PARP+/+ cells by several criteria. First, they bound to a boronate resin selective for ADP-ribose polymers. Second, treatment of polymers with snake venom phosphodiesterase and alkaline phosphatase yielded ribosyladenosine, a nucleoside diagnostic for the unique ribosyl-ribosyl linkages of ADP- ribose polymers. Third, they were digested by treatment with recombinant poly(ADP-ribose) glycohydrolase, an enzyme highly specific for ADP-ribose polymers. Collectively, these data demonstrate that ADP- ribose polymers are formed in PARP-/- cells in a DNA damage-dependent manner. Because the PARP gene has been disrupted, these results suggest the presence of a previously unreported activity capable of synthesizing ADP-ribose polymers in PARP-/- cells. |