Fast Inactivation of CaV2.2 Channels Is Prevented by the Gß1 Subunit in Rat Sympathetic Neurons.
J Mol Neurosci
; 63(3-4): 377-384, 2017 Dec.
Article
em En
| MEDLINE
| ID: mdl-29063444
ABSTRACT
Voltage-dependent regulation of CaV2.2 channels by G-proteins is performed by the ß (Gß) subunit. Most studies of regulation by G-proteins have focused on channel activation; however, little is known regarding channel inactivation. This study investigated inactivation of CaV2.2 channels in superior cervical ganglion neurons that overexpressed Gß subunits. CaV2.2 currents were recorded by whole-cell patch clamping configuration. We found that the Gß1 subunit reduced inactivation, while Gß5 subunit did not alter at all inactivation kinetics compared to control recordings. CaV2.2 current decay in control neurons consisted of both fast and slow inactivation; however, Gß1-overexpressing neurons displayed only the slow inactivation. Fast inactivation was restored by a strong depolarization of Gß1-overexpressing neurons, therefore, through a voltage-dependent mechanism. The Gß1 subunit shifted the voltage dependence of inactivation to more positive voltages and reduced the fraction of CaV2.2 channels resting in the inactivated state. These results support that the Gß1 subunit inhibits the fast inactivation of CaV2.2 channels in SCG neurons. They explain the long-observed sustained Ca2+ current under G-protein modulation.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Ativação do Canal Iônico
/
Gânglio Cervical Superior
/
Canais de Cálcio Tipo N
/
Subunidades beta da Proteína de Ligação ao GTP
/
Neurônios
Limite:
Animals
Idioma:
En
Revista:
J Mol Neurosci
Assunto da revista:
BIOLOGIA MOLECULAR
/
NEUROLOGIA
Ano de publicação:
2017
Tipo de documento:
Article
País de afiliação:
México