Calcium accelerates endocytosis of vSNAREs at hippocampal synapses.

TitleCalcium accelerates endocytosis of vSNAREs at hippocampal synapses.
Publication TypeJournal Article
Year of Publication2001
AuthorsSankaranarayanan S, Ryan TA
JournalNat Neurosci
Date Published2001 Feb
KeywordsAction Potentials, Alkalies, Animals, Calcium, Electric Stimulation, Endocytosis, Exocytosis, Hippocampus, Intracellular Membranes, Membrane Proteins, Rats, Rats, Sprague-Dawley, SNARE Proteins, Synapses, Synaptic Vesicles, Vesicular Transport Proteins

A pH-sensitive form of green-fluorescent protein (GFP) fused to the lumenal domain of VAMP (synapto-pHluorin) provides a sensitive optical probe to track the net balance between exocytosis and endocytosis of this protein at small synaptic terminals of the central nervous system. Here we used a reversible proton-pump blocker that prevents vesicle re-acidification upon endocytosis to trap vesicles in the alkaline state during recycling. In combination with optical measurements of synapto-pHluorin, we used alkaline trapping to examine the kinetic components of exocytosis and endocytosis separately at synaptic terminals. Using this approach, we show that, in addition to controlling exocytosis, intracellular calcium levels tightly regulate the speed of endocytosis, increasing it to a maximal speed of approximately one vesicle per second.

Alternate JournalNat. Neurosci.
PubMed ID11175872
Grant ListNS24692 / NS / NINDS NIH HHS / United States