PSOP1, putative secreted ookinete protein 1, is localized to the micronemes of Plasmodium yoelii and P. berghei ookinetes

• DOI: 10.1016/j.parint.2021.102407
• Publication Date: 2021-06-18T02:59:09Z
• Authors: Mayumi Tachibana; Hideyuki Iriko; Minami Baba; Motomi Torii; Tomoko Ishino
• Keywords: Organelles; 0106 biological sciences; Plasmodium berghei; Oocysts; Protozoan Proteins; Plasmodium yoelii; 01 natural sciences; Host-Parasite Interactions; Malaria; 3. Good health; Mice; Animals

Plasmodium parasites cause malaria in mammalian hosts and are transmitted by Anopheles mosquitoes. Activated gametocytes in the mosquito midgut egress from erythrocytes followed by fertilization and zygote formation. Zygotes differentiate into motile invasive ookinetes, which penetrate the midgut epithelium before forming oocysts beneath the basal lamina. Ookinete development and traversal across the mosquito midgut wall are major bottlenecks in the parasite life cycle. In ookinetes, surface proteins and proteins stored in apical organelles have been shown to be involved in parasite-host interactions. A group of ookinete proteins that are predicted to have such functions are named PSOPs (putative secreted ookinete protein). PSOP1 is possibly involved in migration through the midgut wall, and here its subcellular localization was examined in ookinetes by immunoelectron microscopy. PSOP1 localizes to the micronemes of Plasmodium yoelii and Plasmodium berghei ookinetes, indicating that it is stored and possibly apically secreted during ookinete penetration through the mosquito midgut wall.