Final answer:
Coat proteins associate with trans-Golgi vesicles and the cytoplasmic domains of membrane cargo proteins/receptors, helping to promote vesicle budding and sorting to different destinations.
Step-by-step explanation:
Coat proteins, such as clathrin and COP, associate with the trans-Golgi vesicles and the cytoplasmic domains of membrane cargo proteins/receptors. These coat proteins help promote the budding of trans-Golgi vesicles that contain packaged cargo proteins. The cargo proteins and their associated coat proteins then sort to separate vesicles with different destinations within the cell or outside of the cell.