Cyclic fluctuations of the mitotic Ca2+-ATPase during the cell cycle of the myxomycete Physarum polycephalum.

The occurrence of the mitotic Ca2+-ATPase, resembling the enzyme described for higher organisms, is demonstrated in multinuclear plasmodia of the myxomycete Physarum polycephalum. The activity of this enzyme undergoes cyclic fluctuations during the synchronous nuclear cycle with a minimum in early G2-phase and a maximum around the time of mitosis.