Analysis of ubiquitylated proteins along Plasmodium falciparum intra-erythrocytic cycle. A. Schematic representation of the parasite cycle in blood stages. It starts when merozoites invade uRBC resulting in the first phase called ring stage. After 24 hrs, the parasite enters in a phase with high metabolic activity, the trophozoite. A few hours later, at the schizont stage, the parasite produces merozoites that will rupture the RBC membrane, looking for new uRBCs to invade and start a new cycle. B. Western blot analysis with P4D1 antibody shows basal levels of ubiquitylated proteins in rings, trophozoites and schizonts. C. Effect of proteasome inhibitors MG132 (1.15 μM) and epoxomicin (0.26 μM), on the levels of ubiquitylated proteins from rings, trophozoites and schizonts. Atovaquone at 0.02 μM was used as negative control.