Analysis of ADP-Ribosylation Patterns in Isolated Nuclei and Nucleosomal Fragments

Analysis of ADP-Ribosylation Patterns in Isolated Nuclei and Nucleosomal Fragments 

To determine the target proteins of the poly(ADP-ribose) synthetase, Giri et al. (75) incubated HeLa cell nuclei with a- P-labeled NAD and separated the labeled proteins on a two-dimensional gel system. His- 

Hayaishi and co-workers (149) were the first to observe that when a nuclear preparation from rat liver was incubated with radiolabeled NAD, the resulting newly synthesized poly(ADP-ribose) was associated with histones Hi, H2A, H2B, and H3 (149). As summarized in the previous section, other groups have corroborated this observation and extended it to include nonhistone nucleosomal proteins (2, 64, 84, 90, 164,178,179, 200, 215, 229). Differences in techniques for isolation of poly ADP-ribosylated proteins and the presence of poly(ADP-ribose) degradative enzymes [poly(ADP-ribose) glycohydrolase and various phosphodiesterases] may explain some of the conflicting reports as to primary acceptor protein, extent of modification, and length of polymer. 

Utilizing nuclei isolated from both rat liver and HeLa cells, Lichtenwalner and Suhadolnik (122) demonstrated that the Hi his- 

An average chain length of five units of ADP-ribose was observed. 

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