Hayes, Polly, Vladimir Varga, Sofia Olego-Fernandez, Jack Sunter, Michael L. Ginger, and Keith Gull. “Modulation of a cytoskeletal calpain-like protein induces major transitions in trypanosome morphology.” Journal of Cell Biology 206, no. 3 (2014): 377-384.
Individual eukaryotic microbes, such as the kinetoplastid parasite Trypanosoma brucei , have a defined size, shape, and form yet transition through life cycle stages, each having a distinct morphology. In questioning the structural processes involved in these transitions, we have identified a large calpain-like protein that contains numerous GM6 repeats (ClpGM6) involved in determining T. brucei cell shape, size, and form. ClpGM6 is a cytoskeletal protein located within the flagellum along the flagellar attachment zone (FAZ). Depletion of ClpGM6 in trypomastigote forms produces cells with long free flagella and a shorter FAZ, accompanied by repositioning of the basal body, the kinetoplast, Golgi, and flagellar pocket, reflecting an epimastigote-like morphology. Hence, major changes in microbial cell form can be achieved by simple modulation of one or a few proteins via coordinated association and positioning of membrane and cytoskeletal components.