Figure 9.

Model of proposed roles for ESCRT and CORVET in ROMK post-endocytic regulation. After endocytosis, ROMK (gray cylinders) accumulates in early endosomes. The hexameric CORVET complex (dotted circles, “Vps” gene numbers indicated) tethers post-endocytic Rab5-positive vesicles to promote their fusion and maturation into early endosomes. ESCRT proteins (dashed circles, complexes 0, I, II, and III) recognize ubiquitinated ROMK and sequester the channel into intraluminal vesicles in late endosomes/multivesicular bodies. These late endosomes eventually mature and fuse with lysosomes in mammalian cells or vacuoles in yeast, where ROMK is degraded.