ADP-ribosylation of HeLa nonhistone proteins was investigated by using [3H]adenosine as an in vivo radioactive label. The aim was to determine basic differences in the patterns of modification of interphase and metaphase nonhistones. Fluorography revealed a relatively small number of modified proteins for isolated metaphase chromosomes. In addition to the core histones, a protein of 116 kDa, which is identified as poly(ADP-ribose) polymerase, was a primary acceptor of [3H]adenosine. Two-dimensional gels revealed a profound difference in the modification of metaphase and interphase nonhistones. For interphase nuclei, 3H label was distributed among a large number of nonhistone acceptors. ADP-ribosylation Nonhistone Metaphase chromosome Interphase nucleus [3H]Adenosine HeLa cell.
Bibliographical noteFunding Information:
This researchw as supportedb y funds from the GraduateS chool of the University of Minnesota, by funds from the Biomedical ResearchS upport Grant of the University of Minnesota Medical School, and by grant GM26440f rom the National Instituteso f Health. We areg ratefulf or usefula nd stimulatingd iscussionsw ith Professor James W. Bodley.