The Modification of Nuclear Proteins by ADP‐ribosylation

Abstract

When incubated in vitro purified mouse nuclei incorporate NAD into poly(ADP‐Rib). Analysis of the product on CsCl/urea gradients showed that a large proportion of the poly(ADP‐Rib) was not attached to protein. The free poly(ADP‐Rib) did not appear to arise through degradation and its chain length was significantly longer than the poly(ADP‐Rib) attached to proteins. Fractionation of the proteins on hydroxyapatite revealed that tissue‐specific modification of both the histones and non‐histone proteins, had occurred. In the case of one protein species there was evidence for the existence of several forms with different numbers of ADP‐Rib residues. Copyright © 1977, Wiley Blackwell. All rights reserved