Synaptic vesicle endocytosis: calcium works overtime in the nerve terminal.
The functions of Ca2+ are many and varied within cells, but in the nerve terminals of neurons it has had a very defined role. That is, the influx of extracellular Ca2+ through voltage-dependent Ca2+ channels stimulates neurotransmitter release by exocytosis. For years this was assumed to be the main role for Ca2+ in this specialized subcellular region. However recent studies have shown that Ca2+ also has multiple roles in synaptic-vesicle endocytosis. This review will present evidence for three Ca2+-dependent and -independent steps; a high-affinity Ca2+-dependent triggering step, a Ca2+-independent maintenance phase, and a low-affinity Ca2+-dependent inhibition step. How the control of endocytosis by Ca2+ might impact on different neuronal functions such as synaptic transmission, the nucleation of SV endocytosis, and the repair of damaged membrane is then discussed.
Cousin
M A
MA
Division of Biomechanical and Clinical Laboratory Sciences, University of Edinburgh.
D000199:Actins / Q000502:physiology; D000818:Animals; D001464:Barium / Q000494:pharmacology; D019703:Calcineurin / Q000502:physiology; D002118:Calcium / Q000378:metabolism; D015220:Calcium Channels / Q000378:metabolism; D020013:Calcium Signaling / Q000502:physiology*; D002147:Calmodulin / Q000502:physiology; D002148:Calmodulin-Binding Proteins / Q000502:physiology; D002966:Clathrin / Q000502:physiology; D022163:Clathrin-Coated Vesicles / Q000502:physiology; D003599:Cytoskeleton / Q000187:drug effects / Q000502:physiology / Q000648:ultrastructure; D034281:Dynamins; D004705:Endocytosis / Q000187:drug effects / Q000502:physiology*; D020558:GTP Phosphohydrolases / Q000502:physiology; D006367:HeLa Cells; D006801:Humans; D017136:Ion Transport; D008959:Models, Neurological; D009411:Nerve Endings / Q000648:ultrastructure; D009419:Nerve Tissue Proteins / Q000502:physiology; D009479:Neuropeptides / Q000378:metabolism; D013324:Strontium / Q000494:pharmacology; D009435:Synaptic Transmission; D013572:Synaptic Vesicles / Q000187:drug effects / Q000502:physiology*
D000199:Actins; D015220:Calcium Channels; D002147:Calmodulin; D002148:Calmodulin-Binding Proteins; D002966:Clathrin; D009419:Nerve Tissue Proteins; D009479:Neuropeptides; D001464:Barium; D019703:Calcineurin; D020558:GTP Phosphohydrolases; D034281:Dynamins; D002118:Calcium; D013324:Strontium