Fig. 9. Schematic representation of membrane flow between endosomes and cell surface. Membrane areas are drawn as spheres and are approximately to scale (based on Grünfelder et al., 2002). The green colour indicates the localization of the EP:GFP reporter. Dark arrows indicate membrane flow and light grey arrows symbolize the impaired flow of membrane caused by RNAi. F, flagellum; FP, flagellar pocket; E, endosomes. The dotted lines mark membrane compartments that are connected to either the pellicular microtubule cytoskeleton or the flagellar axoneme. In wild-type cells endo- and exocytic traffic are balanced. The EP:GFP reporter is shuttled between endosomes and the flagellar pocket. In trypanosomes depleted of clathrin heavy chain (TbCLH) endocytosis halts while exocytosis continues. This results in a specific enlargement of the flagellar pocket. The EP:GFP reporter is found exclusively in the flagellar pocket. After downregulation of TbRAB11 endocytosis continues while exocytosis is blocked, resulting in the clearance of EP:GFP from the flagellar pocket. Knockdown of TbMBAP1 affects both endocytosis and exocytosis.