Final answer:
SNAREs are responsible for the final docking between vesicle and target membranes, with V-SNARE located on the vesicle and T-SNARE on the target membrane facilitating membrane fusion.
Step-by-step explanation:
The proteins responsible for mediating the final docking between vesicle and target membranes are known as SNAREs. Specifically, V-SNARE (vesicle-SNARE) proteins on vesicles and T-SNARE (target-SNARE) proteins on target membranes interact to facilitate membrane fusion, which is a critical step in vesicular transport within cells.
Different cargo proteins are sorted into the vesicles at the trans face of the Golgi apparatus, and as they bud off, they acquire V-SNARE proteins. When the vesicles reach their target, their V-SNARE proteins bind with T-SNARE proteins on the target membrane, leading to membrane fusion and delivery of the cargo into the target compartment. This process is essential for the proper distribution of molecules throughout the cell and for maintaining cellular function.
It is not the COPI and COPII proteins, as these are involved in vesicle formation and budding from the endoplasmic reticulum (ER). Clathrin is another protein involved in forming coated vesicles for transport but is not responsible for membrane docking and fusion. Thus, the answer to the question is SNAREs.