Overlapping and distinct roles of CDPK family members in the pre-erythrocytic stages of the rodent malaria parasite, Plasmodium berghei
Fig 5
CDPKs have partially overlapping but distinct roles in pre-erythrocytic stages.
A) Gliding motility of sporozoites was quantified as the percentage of sporozoites that engage in circular motion (± SEM). The experiment was performed 3–4 times for each parasite line. B) Sporozoite invasion was examined by determining the percentage of sporozoites that become intracellular within 90 min of addition to HepG2 cells. Results shown are average of 3–4 experiments, each with 3–4 technical replicates (± SEM), normalized to vehicle-treated samples. C) Interaction between CDPK1, CDPK4 and PKG in sporozoites was studied by determining the number of liver stages formed by sporozoites in which CDPK1 and CDPK4 functions are inhibited, when PKG is activated. Results shown are average of 3 experiments, each with 3 technical replicates (± SEM), normalized to vehicle-treated samples. D) Interaction between CDPK5, CDPK4 and PKG in sporozoites was studied by determining the number of liver stages formed by sporozoites in which CDPK5 and CDPK4 functions are inhibited, in the presence of increased cGMP. Results shown are average of 3 experiments, each with 3 technical replicates (± SEM), normalized to vehicle-treated samples for each assay. E) Merosome formation and release was determined by quantifying the number of merosomes present in media of infected cells at 65–67 h p.i. Results shown are average of 2 experiments with CDPK1-aid-HA and 3 experiments with CDPK5-aid-HA, each with 3 technical replicates (± SEM), normalized to vehicle-treated samples. F) Infectivity of CDPK5-aid-HA merosomes and hepatic merozoites was quantified by FACS detection of GFP-positive events in 100,000 events at 24 h p.i. (iRBCs ± SEM). The experiment was performed 4 times with intact merosomes (5 mice/each group/experiment), and 2 times with ruptured merosomes (4–5 mice/each group/experiment). Data were analyzed using an unpaired t-test or one-way ANOVA, Dunnett’s multiple comparisons test, non-significant (n.s.) P > 0.05, * P value < 0.05, ** P value < 0.005, *** P value < 0.0005.