A relationship between nuclear poly(adenosine diphosphate ribosylation) and acetylation posttranslational modifications. 2. Histone studies

Abstract

It was previously reported that certain acetylated domains of [human cervical carcinoma HeLa cell] chromatin were selectively retained by an anti-poly(ADP-Rib) antibody column. Investigations of this phenomenon at the molecular level of protein interactions are described. The majority of endogenously hyperacetylated histones have a high affinity toward the polymer antibody column. These proteins may have been bound to the column via endogenous poly(ADP ribose) [poly(ADP-Rib)] since the binding was reversed upon treatment of the histones with alkali prior to immunofractionation. In order to analyze the distributon of acetate and poly(ADP-Rib) on histone proteins, [3H]acetylated nuclei were incubated in vitro with [32P]NAD. Acetate was incorporated mainly into H3 and H4 while H1 was the major acceptor protein for poly(ADP-Rib). A correlation may exist in vivo between the 2 posttranslational modification processes and identical histone molecules may be accessible to both modifications.