title: ADPribosylation of nuclear proteins labeled with [3H]adenosine: changes during the HeLa cycle.
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.
mesh_terms: D000241:Adenosine / Q000378:metabolism*; D000246:Adenosine Diphosphate Ribose / Q000378:metabolism*; D001549:Benzamides / Q000494:pharmacology; D002453:Cell Cycle; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism*; D002868:Chromosomal Proteins, Non-Histone / Q000378:metabolism; D006367:HeLa Cells; D006657:Histones / Q000378:metabolism; D006801:Humans; D007399:Interphase; D034882:Lamins; D008677:Metaphase; D009243:NAD / Q000378:metabolism; D009698:Nucleoproteins / Q000378:metabolism*; D010727:Phosphoric Diester Hydrolases / Q000494:pharmacology
chemical_list: D001549:Benzamides; D002868:Chromosomal Proteins, Non-Histone; D006657:Histones; D034882:Lamins; D009698:Nucleoproteins; D009243:NAD; D000246:Adenosine Diphosphate Ribose; C025160:3-aminobenzamide; D010727:Phosphoric Diester Hydrolases; D000241:Adenosine