Localization of PfCK2 subunits over the life cycle of the blood-stage parasite. (A-C) Hemagglutinin (HA)-tagged PfCK2 subunits (green) localized to both nuclear and cytoplasmic compartments in rings, trophozoites and schizonts. The limits of the parasitophorous vacuole membrane (PVM) are marked by Exp-2 (red). (D) HA-tagged PfCK2 subunits were detected in both the cytoplasmic and nuclear fraction. Western-blot analysis was performed on the cytoplasmic (C) and nuclear (N) fraction of unsynchronized PfCK2α, PfCK2β1, and PfCK2β2 parasites using anti-HA antibody, which gave bands in both the fractions. Predicted molecular weights of the proteins are: PfCK2α, 39.8 kDa; PfCK2β1, 28.3 kDa; PfCK2β2, 45.2 kDa. (E) The same C and N fractions were probed with antibodies against aldolase, a cytoplasmic marker, and histone H3, a nuclear marker, to assess the purity of the fractions. Aldolase gave a band at 40 kDa in the cytoplasmic fractions only, whereas the histone H3 band at 17 kDa was seen only in the nuclear fractions.