Localization and co-localization of PfPK4, RAP-1, PF14_0102, PF83/AMA-1 PF11_0344 and MSP1 PFI1475w. (A) A segmenter, stained for PfPK4 (red) and RAP-1 (green), with a composite of both labels on the right ; (B) schizont ; (C) segmenter ; (D) and (E) free merozoites, stained for PfPK4 (red) and PF83/AMA-1 (green), with composites on the right ; (F) a free merozoite, a composite of PfPK4 (red) and RAP-1 (green); (G) free merozoites stained for PfPK4 (red) and MSP-1 (green), with a composite of both labels on the right. The scale bars represent 2 mm. PfPK4 distributed throughout the trophozoite, whereas it was found in discrete foci (punctate distribution) in segmenters. PfPK4 co-localizes with AMA-1 at the apical complex in segmenters and merozoites, but does not co-localize with RAP-1.Reproduced with permission, from Möhrle JJ, Zhao Y, Wernli B, Franklin RM, Kappes B. Molecular cloning, characterization and localization of PfPK4, an eIF-2a kinase-related enzyme from the malarial parasite Plasmodium falciparum. Biochem J. 1997 328:677-87. © the Biochemical Society.