Final answer:
Dynamin is the GTP-binding protein needed for the release of clathrin-coated vesicles, functioning as a GTPase that uses energy from GTP hydrolysis to facilitate the vesicle scission from the plasma membrane.
Step-by-step explanation:
The GTP-binding protein required for the release of a clathrin-coated vesicle from the membrane is dynamin. This GTPase is instrumental in the process of receptor-mediated endocytosis, where it facilitates the final scission of the vesicle from the plasma membrane. Dynamin utilizes energy from GTP hydrolysis to constrict and sever the neck of the budding vesicle, allowing the clathrin-coated vesicle to release into the cytoplasm.
This process is crucial for the regulation of cellular uptake of nutrients, neurotransmitters, and other molecules via endocytosis, as well as for the sorting of cargo proteins during vesicular transport. The cycle of G-protein activation and deactivation is a recurring theme in cell signaling, involving the exchange of GDP for GTP, followed by hydrolysis back to GDP, which is directly connected to the functioning of dynamin in the vesicle formation process.