title: Evidence for adenosine diphosphate ribosylation of Ca2+, Mg2+-dependent endonuclease.
abstract: The molecular basis for the inhibition of the Ca2+,Mg2+-dependent endonuclease resulting from the formation of poly(adenosine diphosphate ribose) (ADP-Rib) was studies in a simplified system containing purified rat liver or bull semen endonuclease, purified rat liver poly(ADP-Rib) synthetase, [3H]NAD+, and DNA. Poly-(adp-rib) synthetase activity was stimulated when Ca2+, Mg2+-dependent endonuclease was added to the reaction mixture in place of histones, suggesting that the endonuclease can act as an acceptor for ADP-Rib. Evidence was presented to show that the ADP-Rib moiety of [3H]NAD+ was incorporated in the endonuclease fraction. The [3H]ADP-Rib bound to the endonuclease was in the form of monomers and oligomers and not long chain polymers. The present results suggest that the Ca2+,Mg2+-dependent endonuclease was ADP-ribosylated when the endonuclease was incubated with poly(ADP-Rib) synthetase and NAD+.
mesh_terms: D000244:Adenosine Diphosphate / Q000378:metabolism*; D000818:Animals; D002118:Calcium; D002417:Cattle; D002843:Chromatin / Q000378:metabolism; D002850:Chromatography, Gel; D004247:DNA / Q000096:biosynthesis*; D004720:Endonucleases / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D008099:Liver / Q000378:metabolism; D008274:Magnesium; D008297:Male; D009243:NAD / Q000378:metabolism; D051381:Rats; D012266:Ribose / Q000378:metabolism*; D012661:Semen / Q000378:metabolism; D014316:Tritium
chemical_list: D002843:Chromatin; D009243:NAD; D014316:Tritium; D000244:Adenosine Diphosphate; D012266:Ribose; D004247:DNA; D004720:Endonucleases; D008274:Magnesium; D002118:Calcium