Abstract
Cell cycle variations in the modification of histones and nonhistones by ADPribosylation were investigated. Proteins of HeLa interphase nuclei and metaphase chromosomes were radioactively labeled in vivo with [3H]adenosine. Histones of metaphase chromosomes were extensively modified by ADPribosylation, with H2B, H2A and H4 being predominant acceptors of [3H]adenosine label. For histones of interphase nuclei from synchronized cells, the highest level of 3H labeling was observed by two-dimensional gel electrophoresis to occur in S phase. The minimum level was noted in G1 phase. ADPribosylation of histones is, however, significant during all phases of the cell cycle. These conclusions were confirmed by experiments using [32P]NAD. The results with the specific inhibitor of ADPribosylation, 3-aminobenzamide, and with snake venom phosphodiesterase indicated that the radioactive isotopes were incorporated as ADPribose. Two-dimensional gels of HeLa nonhistones labeled with [3H]adenosine showed strikingly different patterns for interphase and metaphase samples. Over 100 ADPribosylated species were found for interphase nuclei, but poly(ADPribose) polymerase was the only major acceptor for metaphase chromosomes. A simple pattern was also revealed for nuclear scaffolds, with the 'lamins' and poly(ADPribose) polymerase being identifiable as modified species.
Original language | English (US) |
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Pages (from-to) | 222-230 |
Number of pages | 9 |
Journal | BBA - Gene Structure and Expression |
Volume | 909 |
Issue number | 3 |
DOIs | |
State | Published - Aug 25 1987 |
Bibliographical note
Funding Information:This researchw as supportedb y grants from the Minnesota Medical Foundation and the National Instituteso f Health.
Keywords
- ADPribosylation
- Adenosine
- HeLa cell cycle
- Histone
- Nonhistone
- [H]Adenosine label