title: Hyper(ADP-ribosyl)ation of histone H1.
abstract: Nucleosomal chains of various repeat unit lengths were generated by a mild micrococcal nuclease digestion of purified pancreatic nuclei. Maximal nucleosome associated poly(ADP-ribose) polymerase activity was recovered in trimeric to tetrameric chromatin fragments, after which the enzyme activity gradually decreased and stabilized towards oligomeric periodicities of 11 to 16 nucleosomes. Electrophoresis of [32P]ADP-ribosylated histones on first-dimension acid-urea or acid-urea-Triton gels and on second-dimension acid--urea--cetyltriammonium bromide gels revealed that, of all histones, only histone H1 could be significantly poly(ADP-ribosyl)ated while only minimal modification could be recovered with histone H1(0). Furthermore, the extent of ADP-ribosylation present on pancreatic histone H1 is shown to proportionally retard this protein's electrophoretic mobility in all gel systems and to consist of a distinct series of at least 12 modification intermediates which can be evidenced, in nuclei or nucleosomes, and fully recovered along with histone H1 upon its selective extraction with 5% perchloric acid. The generation of these increasingly ADP-ribosylated forms of histone H1 is also demonstrated to be time dependent and the more complex ADP-ribosylated forms of this histone are favored at high NAD+ concentrations. Moreover, the electrophoretic mobilities of all intermediates are unaffected by the presence of the nonionic detergent Triton X-100.
mesh_terms: D000818:Animals; D002843:Chromatin / Q000378:metabolism; D006657:Histones / Q000302:isolation & purification*; D008297:Male; D009243:NAD / Q000494:pharmacology; D009244:NAD+ Nucleosidase / Q000302:isolation & purification*; D009707:Nucleosomes / Q000201:enzymology; D010179:Pancreas / Q000201:enzymology*; D011064:Poly Adenosine Diphosphate Ribose / Q000302:isolation & purification; D011065:Poly(ADP-ribose) Polymerases / Q000302:isolation & purification*; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D002843:Chromatin; D006657:Histones; D009707:Nucleosomes; D009243:NAD; D011064:Poly Adenosine Diphosphate Ribose; D011065:Poly(ADP-ribose) Polymerases; D009244:NAD+ Nucleosidase