Figure 7.

Model for GCC185 function as a tether and Golgi organizer. (A) Dimensions of GCC185 if fully extended, transport vesicles and Golgi stacks. (B) A model for GCC185 in vesicle tethering. In this model, cytosolic GCC185 would first associate with Rab9-positive transport vesicles via GCC185 coiled-coil 3. GCC185 on vesicles brought close to the Golgi by cytoplasmic dynein could then engage Rab6 and Arl1 GTPases at the target membrane. SNARES would then drive fusion. (C) Although GCC185 is potentially long enough to reach across the stack, most molecules do not seem to; for details, see Figure 8 and text.