Poly(ADP-ribosyl)ation of chromatin: kinetics of relaxation and its effect on chromatin solubility

作者：André Fréchette, Ann Huletsky, Rémy J. Aubin, Gilbert de MURCIA, Paul Mandel, A. Lord, Gilles G. Grondin, Guy G. Poirier · 发表于：Canadian Journal of Biochemistry and Cell Biology · 年份：1985 · DOI：10.1139/o85-096 · 被引用次数：19 · 研究领域：PARP inhibition in cancer therapy、Advancements in Photolithography Techniques、DNA Repair Mechanisms

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.