Zaprinast (PKG inhibitor) induces rapid discharge of exonemes and micronemes. (B) Zaprinast treatment of schizonts (in the presence of E64) induces rapid relocalisation of PfAMA1 and loss of PfSUB1. Fixed, permeabilized schizonts were examined by IFA with the antibodies indicated. Zaprinast-induced relocalisation of PfSUB1 and PfAMA1 was evident even in immature (non-segmented) schizonts, but here took the form of translocation of both proteins to a striking circumferential punctate pattern, perhaps indicating accumulation of immature micronemes and exonemes at the periphery of the schizont.

Collins CR, Hackett F, Strath M, Penzo M, Withers-Martinez C, Baker DA, Blackman MJ. Malaria parasite cGMP-dependent protein kinase regulates blood stage merozoite secretory organelle discharge and egress. PLoS Pathog. 2013 9(5):e1003344.