Modulation of Cav1.3 Ca2+ channel gating by Rab3 interacting molecule.
Mol Cell Neurosci
; 44(3): 246-59, 2010 Jul.
Article
en En
| MEDLINE
| ID: mdl-20363327
ABSTRACT
Neurotransmitter release and spontaneous action potentials during cochlear inner hair cell (IHC) development depend on the activity of Ca(v)1.3 voltage-gated L-type Ca(2+) channels. Their voltage- and Ca(2+)-dependent inactivation kinetics are slower than in other tissues but the underlying molecular mechanisms are not yet understood. We found that Rab3-interacting molecule-2alpha (RIM2alpha) mRNA is expressed in immature cochlear IHCs and the protein co-localizes with Ca(v)1.3 in the same presynaptic compartment of IHCs. Expression of RIM proteins in tsA-201 cells revealed binding to the beta-subunit of the channel complex and RIM-induced slowing of both Ca(2+)- and voltage-dependent inactivation of Ca(v)1.3 channels. By inhibiting inactivation, RIM induced a non-inactivating current component typical for IHC Ca(v)1.3 currents which should allow these channels to carry a substantial window current during prolonged depolarizations. These data suggest that RIM2 contributes to the stabilization of Ca(v)1.3 gating kinetics in immature IHCs.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Activación del Canal Iónico
/
Proteínas de Unión al GTP
/
Isoformas de Proteínas
/
Proteínas de Unión al GTP rab3
/
Canales de Calcio Tipo L
/
Células Ciliadas Auditivas Internas
/
Proteínas del Tejido Nervioso
Límite:
Animals
/
Humans
Idioma:
En
Revista:
Mol Cell Neurosci
Asunto de la revista:
BIOLOGIA MOLECULAR
/
NEUROLOGIA
Año:
2010
Tipo del documento:
Article
País de afiliación:
Austria