protein kinase activity , assayed in the presence or absence of saturating exogenous cyclic amp in the reaction mixture , was lowest in early g1 phase ( 2 h after mitosis ) , increased 2-fold ( plus exogenous cyclic amp in reaction mixture ) or 3.5-fold ( minus cyclic amp in reaction mixture ) to maximum values in mid to late g1 phase ( 4-5 h after mitosis ) , and then decreased as cells entered s phase .
C0026255
mitosis
C0007634
cells