Question

What do Rab GTPases do once a vesicle reaches its destination?

a) Promote vesicle fusion with the target membrane
b) Inhibit vesicle fusion with the target membrane
c) Initiate vesicle budding
d) Activate vesicle transport

Answer 1

Once a vesicle reaches its destination, Rab GTPases promote its fusion with the target membrane by facilitating the binding of V-SNARE and T-SNARE proteins, which leads to the merging of the vesicle and membrane.

Step-by-step explanation:

Rab GTPases play a critical role in the transport and delivery of vesicular cargo within a cell. Once a vesicle reaches its destination, Rab GTPases promote vesicle fusion with the target membrane. Specifically, they are involved in the vesicle docking process wherein V-SNARE proteins on vesicles bind to complementary T-SNARE proteins on target membranes, facilitating the fusion of the two membranes and allowing cargo delivery. This fusion event is crucial for processes such as exocytosis, where substances are expelled from cells, and the delivery of proteins and lipids to specific organelles.