Discussion

TbSmee1 (Tb927.10.8820) is a putative substrate of Polo-like kinase and a component of the Trypanosoma brucei hook complex, which wraps around the apex of the flagellar pocket. We show that depletion of TbSmee1 in the insect-resident procyclic form causes slow growth and multinucleated cells, suggesting a defect in cytokinesis. Cells lacking TbSmee1 undergo altered hook complex biogenesis and have accelerated endocytic uptake, as measured by the membrane marker FM4-64FX. These results suggest that hook complex biogenesis is essential for regulating endocytic flux.