Introducing an alternative biophysical method to analyze direct G protein regulation of voltage-dependent calcium channels.

Abstract : Direct G protein inhibition of voltage-dependent calcium channels is currently indirectly assessed by the gain of current produced by depolarizing prepulse potentials (PP). Indeed, PPs produce a channel opening- and time-dependent dissociation of G proteins from the channel that is responsible for the increase in Ca(2+) permeation. Parameters of G protein dissociation are essential to describe the characteristic landmark modifications in channel activities that underlie G protein regulation. From the kinetics and opening-dependence of this dissociation, crucial biophysical parameters are extracted such as the extent and the rate of G protein unbinding from the channel. Unfortunately, the method used so far assumes that G protein regulated channels undergo the same inactivation kinetics than control channels. Herein, we demonstrate for the first time that G protein-bound channels undergo a much slower inactivation than control channels. We thus introduce a novel simple-to-use method that avoids the use of PPs and that is not affected by potential changes in channel inactivation kinetics conferred by G protein binding. This method extracts G protein unbinding parameters from ionic currents induced by regular depolarizing pulses by separating the ionic currents due to non-regulated channels from the ionic currents that result from a progressive departure of G proteins from regulated channels.
Type de document :
Article dans une revue
Journal of Neuroscience Methods, Elsevier, 2007, 160 (1), pp.26-36. 〈10.1016/j.jneumeth.2006.08.010〉
Liste complète des métadonnées

Littérature citée [23 références]  Voir  Masquer  Télécharger

http://www.hal.inserm.fr/inserm-00378040
Contributeur : Marco Canepari <>
Soumis le : mardi 5 mai 2009 - 11:28:50
Dernière modification le : mardi 5 mai 2009 - 13:58:58
Document(s) archivé(s) le : jeudi 10 juin 2010 - 18:33:54

Fichiers

Identifiants

Collections

CEA | U836 | UGA

Citation

Norbert Weiss, Michel De Waard. Introducing an alternative biophysical method to analyze direct G protein regulation of voltage-dependent calcium channels.. Journal of Neuroscience Methods, Elsevier, 2007, 160 (1), pp.26-36. 〈10.1016/j.jneumeth.2006.08.010〉. 〈inserm-00378040〉

Partager

Métriques

Consultations de la notice

149

Téléchargements de fichiers

458