DEOXYRIBOSE 5-PHOSPHATE ALDOLASE - ENZYME THAT PEAKS IN THE G2-PHASE OF RAT HEPATOMA-CELLS

The activity of deoxyribose 5-P aldolase (2-deoxy-d-ribose 5-phosphate acetaldehyde lyase, EC 4.1.2.4) increases three- to fourfold in cultures of rat hepatoma cells that have reached stationary growth and have stopped in the G2 phase of the cell cycle. We have shown that in cell cultures synchronized by three independent methods the enzyme activity peaks in late G2, followed by a rapid decline during mitosis. Two compounds, dibutyryl cAMP and isoproterenol, that appear to block these cells in G2, also cause a two- to fourfold increase in deoxyribose 5-P aldolase activity. It is suggested that this enzyme may play a role in lowering the pools of deoxyribonucleotides in the late G2 M phase of the cell cycle. © 1979.