The V-ATPase membrane domain is a sensor of granular pH that controls the exocytotic machinery.
J Cell Biol
; 203(2): 283-98, 2013 Oct 28.
Article
en En
| MEDLINE
| ID: mdl-24165939
ABSTRACT
Several studies have suggested that the V0 domain of the vacuolar-type H(+)-adenosine triphosphatase (V-ATPase) is directly implicated in secretory vesicle exocytosis through a role in membrane fusion. We report in this paper that there was a rapid decrease in neurotransmitter release after acute photoinactivation of the V0 a1-I subunit in neuronal pairs. Likewise, inactivation of the V0 a1-I subunit in chromaffin cells resulted in a decreased frequency and prolonged kinetics of amperometric spikes induced by depolarization, with shortening of the fusion pore open time. Dissipation of the granular pH gradient was associated with an inhibition of exocytosis and correlated with the V1-V0 association status in secretory granules. We thus conclude that V0 serves as a sensor of intragranular pH that controls exocytosis and synaptic transmission via the reversible dissociation of V1 at acidic pH. Hence, the V-ATPase membrane domain would allow the exocytotic machinery to discriminate fully loaded and acidified vesicles from vesicles undergoing neurotransmitter reloading.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Vesículas Sinápticas
/
Transmisión Sináptica
/
Vesículas Secretoras
/
ATPasas de Translocación de Protón Vacuolares
/
Exocitosis
/
Neuronas
Idioma:
En
Revista:
J Cell Biol
Año:
2013
Tipo del documento:
Article
País de afiliación:
Francia