Final answer:
Uncoating in vesicle targeting and fusion is the process where the vesicle loses its protein coat, allowing it to fuse with an early endosome and eventually become a lysosome for digestion of the contents.
Step-by-step explanation:
In vesicle targeting and fusion, "uncoating" refers to the removal of vesicle coat. This process occurs after a vesicle has been internalized by the cell via endocytosis. The vesicle, initially coated with proteins such as clathrin and associated adaptor proteins, loses this coating in order to fuse with an early endosome and subsequently form a sorting vesicle or late endosome. This uncoated vesicle then undergoes further transformations and can become a lysosome, where digestive enzymes break down the contents for cellular use.