title: ADP-ribosylation in mammalian cell ghosts. Dependence of poly(ADP-ribose) synthesis on strand breakage in DNA.
abstract: Detergent-lysed BS-C-1, HeLa, and mouse L cells incorporate ADP-ribose from NAD+ into two classes of macromolecules. Metabolically stable products, which appear to be a variety of proteins to which are attached one or a few ADP-ribose residues, predominate when the cellular DNA remains intact. In addition, ghost cells have a potentially much greater capacity to synthesize poly(ADP-ribose), which is completely dependent upon the introduction of strand breaks into their DNA. The initial rate of poly(ADP-ribose) synthesis increases linearly with prior x-ray dose or with the concentration of endonuclease added and, once synthesized, the polymer is rapidly degraded with a half-life of 10 min or less. It appears that sites on the DNA capable of supporting a certain amount of poly(ADP-ribose) synthesis are created as a result of x-irradiation or nucleolytic cleavage and are rapidly eliminated, or "repaired," during subsequent incubation. The sites accumulate if cells are irradiated at 0 degree C; further incubation of the lysed cells with NAD+ at 35 degrees C results in both a burst of poly(ADP-ribose) synthesis and the elimination of the sites. NAD+ enhances the elimination of x-ray-induced sites. Thus, the synthesis of poly(ADP-ribose) may be required for the repair of DNA strand breaks.
mesh_terms: D000246:Adenosine Diphosphate Ribose / Q000378:metabolism*; D000818:Animals; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D004247:DNA / Q000378:metabolism / Q000528:radiation effects*; D006367:HeLa Cells / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D007739:L Cells / Q000378:metabolism; D051379:Mice; D009243:NAD / Q000378:metabolism; D009702:Nucleoside Diphosphate Sugars / Q000096:biosynthesis* / Q000378:metabolism*; D011064:Poly Adenosine Diphosphate Ribose / Q000096:biosynthesis*
chemical_list: D009702:Nucleoside Diphosphate Sugars; D009243:NAD; D000246:Adenosine Diphosphate Ribose; D011064:Poly Adenosine Diphosphate Ribose; D004247:DNA