The internalization of receptor-bound ligands involves concentration of cell surface receptors in specialized areas of the plasma membrane and subsequent formation of clathrin-coated vesicles. The complex process of invagination, constriction and budding of clathrin-coated vesicles employs the coordinated actions of several proteins. This review is focused on the GTPase dynamin, which plays a key role in the constriction of coated pits.
