CELL-CYCLE DEPENDENT ADP-RIBOSYLATION OF A UNICELLULAR ORGANISM, EUGLENA-GRACILIS Z

Poly and mono ADP-ribosylation activities occur in Euglena gracilis Z. The ADP-rihosylation activity changes depending on the stage of cell cycle in cells synchronized by a light-dark cycle and shows two differ ent peaks: the first in the S phase and the other in the G2-M transiti on. The latter has about two times greater activity compared to the fo rmer. Poly ADP-rihosylation occurred only in the S phase. Mono ADP-rib osylation occurred in the S phase and the G2-M transition. ADP-ribosyl ation activity was found in the cytosol, mitochondria and chloroplasts and also showed a change in activity dependent upon cell division.