Sequential steps in clathrin-mediated synaptic vesicle endocytosis

Synaptic vesicles are recycled with remarkable speed and precision in nerve terminals. A major recycling pathway involves clathrin-mediated endocytosi s at endocytic zones located around sites of release. Different 'accessory' proteins linked to this pathway have been shown to alter the shape and com position of lipid membranes, to modify membrane-coat protein interactions, and to influence actin polymerization. These include the GTPase dynamin, th e lysophosphatidic acid acyl transferase endophilin, and the phosphoinositi de phosphatase synaptojanin. Protein perturbation studies in living nerve t erminals are now beginning to link the actions of these proteins with morph ologically defined steps of endocytosis.