V-ATPase membrane sector associates with synaptobrevin to modulate neurotransmitter release.
Acidification of synaptic vesicles by the vacuolar proton ATPase is essential for loading with neurotransmitter. Debated findings have suggested that V-ATPase membrane domain (V0) also contributes to Ca(2+)-dependent transmitter release via a direct role in vesicle membrane fusion, but the underlying mechanisms remain obscure. We now report a direct interaction between V0 c-subunit and the v-SNARE synaptobrevin, constituting a molecular link between the V-ATPase and SNARE-mediated fusion. Interaction domains were mapped to the membrane-proximal domain of VAMP2 and the cytosolic 3.4 loop of c-subunit. Acute perturbation of this interaction with c-subunit 3.4 loop peptides did not affect synaptic vesicle proton pump activity, but induced a substantial decrease in neurotransmitter release probability, inhibiting glutamatergic as well as cholinergic transmission in cortical slices and cultured sympathetic neurons, respectively. Thus, V-ATPase may ensure two independent functions: proton transport by a fully assembled V-ATPase and a role in SNARE-dependent exocytosis by the V0 sector.
Di Giovanni
Jérôme
J
INSERM U641, Marseille, France.
Boudkkazi
Sami
S
Mochida
Sumiko
S
Bialowas
Andrzej
A
Samari
Nada
N
Lévêque
Christian
C
Youssouf
Fahamoe
F
Brechet
Aline
A
Iborra
Cécile
C
Maulet
Yves
Y
Moutot
Nicole
N
Debanne
Dominique
D
Seagar
Michael
M
El Far
Oussama
O
D000818:Animals; D000831:Animals, Newborn; D002118:Calcium / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D002540:Cerebral Cortex / Q000166:cytology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects; D066298:In Vitro Techniques; D008081:Liposomes / Q000378:metabolism; D018942:Macrolides / Q000494:pharmacology; D009154:Mutation / Q000235:genetics; D009474:Neurons / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D018377:Neurotransmitter Agents / Q000378:metabolism* / Q000494:pharmacology; D010455:Peptides / Q000378:metabolism / Q000494:pharmacology; D011485:Protein Binding / Q000187:drug effects / Q000502:physiology; D021122:Protein Subunits / Q000235:genetics / Q000378:metabolism; D011510:Proteolipids / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D050600:SNARE Proteins / Q000378:metabolism; D016415:Sequence Alignment / Q000379:methods; D013569:Synapses / Q000502:physiology*; D013572:Synaptic Vesicles / Q000378:metabolism*; D020798:Two-Hybrid System Techniques; D025262:Vacuolar Proton-Translocating ATPases / Q000737:chemistry / Q000378:metabolism*; D050988:Vesicle-Associated Membrane Protein 2 / Q000235:genetics / Q000378:metabolism
D004791:Enzyme Inhibitors; D008081:Liposomes; D018942:Macrolides; D018377:Neurotransmitter Agents; D010455:Peptides; D021122:Protein Subunits; D011510:Proteolipids; D050600:SNARE Proteins; C494706:Vamp2 protein, rat; D050988:Vesicle-Associated Membrane Protein 2; C020485:proteoliposomes; C057620:bafilomycin A; D025262:Vacuolar Proton-Translocating ATPases; D002118:Calcium