A v-SNARE participates in synaptic vesicle formation mediated by the AP3 adaptor complex.
Reconstitution of synaptic vesicle formation in vitro has revealed a pathway of synaptic vesicle biogenesis from endosomes that requires the heterotetrameric adaptor complex AP3. Because synaptic vesicles have a distinct protein composition, the AP3 complex should selectively recognize some or all of the synaptic vesicle proteins. Here we show that one element of this recognition process is the v-SNARE, VAMP-2, because tetanus toxin, which cleaves VAMP-2, inhibited the formation of synaptic vesicles and their coating with AP3 in vitro. Mutant tetanus toxin and botulinum toxins, which cleave t-SNAREs, did not inhibit synaptic vesicle production. AP3-containing complexes isolated from coated vesicles could be immunoprecipitated by a VAMP-2 antibody. These data imply that AP3 recognizes a component of the fusion machinery, which may prevent the production of inert synaptic vesicles.
Salem
N
N
Department of Biochemistry & Biophysics, University of California, San Francisco 94143-0534, USA.
Faúndez
V
V
Horng
J T
JT
Kelly
R B
RB
D033963:Adaptor Protein Complex 3; D033965:Adaptor Protein Complex alpha Subunits; D033942:Adaptor Proteins, Vesicular Transport; D000818:Animals; D001905:Botulinum Toxins / Q000494:pharmacology; D018699:Coated Vesicles / Q000187:drug effects / Q000502:physiology; D018390:Gene Targeting; D008565:Membrane Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000502:physiology*; D034041:Monomeric Clathrin Assembly Proteins; D016716:PC12 Cells; D050683:R-SNARE Proteins; D051381:Rats; D013572:Synaptic Vesicles / Q000187:drug effects / Q000502:physiology*; D013744:Tetanus Toxin / Q000494:pharmacology
D033963:Adaptor Protein Complex 3; D033965:Adaptor Protein Complex alpha Subunits; D033942:Adaptor Proteins, Vesicular Transport; D008565:Membrane Proteins; D034041:Monomeric Clathrin Assembly Proteins; D050683:R-SNARE Proteins; D013744:Tetanus Toxin; C439023:clathrin assembly protein AP180; D001905:Botulinum Toxins