title: Poly(ADP-ribosyl)ation of chromatin: kinetics of relaxation and its effect on chromatin solubility.
abstract: We have studied the kinetics of relaxation of poly(ADP-ribosyl)ated polynucleosomes produced by endogenous enzyme activity by comparing the generation of hyper(ADP-ribosyl)ated histone H1 and its effect on the chromatin structure as revealed by electron microscopy. A correlation can be established between the appearance of histone H1 modified forms and the localized relaxation of the chromatin. We have also noticed, in parallel, that poly(ADP-ribosyl)ated chromatin showed increased solubility in the presence of Mg2+ and 0.2 M NaCl. Electron microscopic examination of the solubilized chromatin produced by poly(ADP-ribosyl)ation shows polynucleosomes exhibiting more relaxed conformation, whereas an increasing amount of hyper(ADP-ribosyl)ated histone H1 is found in the pellet, as shown by acid-urea-polyacrylamide electrophoretic separation of histone extracts.
mesh_terms: D000818:Animals; D002843:Chromatin / Q000378:metabolism* / Q000648:ultrastructure; D004247:DNA / Q000302:isolation & purification; D006657:Histones / Q000302:isolation & purification / Q000378:metabolism*; D007700:Kinetics; D008854:Microscopy, Electron; D009690:Nucleic Acid Conformation; D009702:Nucleoside Diphosphate Sugars / Q000378:metabolism*; D009707:Nucleosomes / Q000378:metabolism / Q000648:ultrastructure; D010179:Pancreas / Q000378:metabolism; D011064:Poly Adenosine Diphosphate Ribose / Q000378:metabolism*; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism*; D051381:Rats; D012995:Solubility
chemical_list: D002843:Chromatin; D006657:Histones; D009702:Nucleoside Diphosphate Sugars; D009707:Nucleosomes; D011064:Poly Adenosine Diphosphate Ribose; D004247:DNA; D011065:Poly(ADP-ribose) Polymerases