Deoxyribonuclease II activity in relation to cell cycle in synchronized HeLa S3 cells

Studying the activity of DNase II in relation to cell cycle in synchronized HeLa S3 cells show a two to seven fold increase in DNase II activity at those times when DNA synthesis is taking place. The peaks of DNase II activity coincide with the peaks of DNA synthesis. The increased DNase II activity could be prevented by puromycin, suggesting that the enzyme activity increased at the S phase was caused by synthesis of new molecules rather than the activation of existing molecules. Acid phosphatase (as a marker for lysosomal enzymes) does not show an induction similar to that observed for DNase II in relation to cell cycle.