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Poly(ADP-Ribosyl)ation of Polynucleosomes Causes Relaxation of Chromatin Structure
Guy G. Poirier, Gilbert De Murcia, Jenny Jongstra-Bilen, Claude Niedergang and Paul Mandel
Proceedings of the National Academy of Sciences of the United States of America
Vol. 79, No. 11, [Part 1: Biological Sciences] (Jun. 1, 1982), pp. 3423-3427
Published by: National Academy of Sciences
Stable URL: http://www.jstor.org/stable/12294
Page Count: 5
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When rat pancreatic polynucleosomes were poly(ADP-ribosyl)ated with purified calf thymus poly(ADP-ribose) polymerase and examined by electron microscopy, a relaxation of their native zigzag structure was observed. At high ionic strengths control nucleosomes condensed into 250- angstrom -thick fibers, but poly(ADP-ribosyl)ated polynucleosomes did not; they showed a close resemblance to chromatin depleted of histone H1. The relaxed state of poly(ADP-ribosyl)ated polynucleosomes was also confirmed by sedimentation velocity analysis. Histone H1 was found to be the major histone acceptor of poly(ADP-ribose). Poly(ADP-ribose) linked to histone H1 did not seem to cause its dissociation from the chromatin, but it impaired significantly its effect on chromatin condensation.
Proceedings of the National Academy of Sciences of the United States of America © 1982 National Academy of Sciences