Introducing an alternative biophysical method to analyze direct G protein regulation of voltage-dependent calcium channels. - Inserm - Institut national de la santé et de la recherche médicale Accéder directement au contenu
Article Dans Une Revue Journal of Neuroscience Methods Année : 2007

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

Résumé

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.
Fichier principal
Vignette du fichier
inserm-00378040_edited.pdf (1.02 Mo) Télécharger le fichier
Figure_1.JPG (985.78 Ko) Télécharger le fichier
Figure_2.JPG (1.59 Mo) Télécharger le fichier
Figure_3.JPG (715.15 Ko) Télécharger le fichier
Figure_4.JPG (1.13 Mo) Télécharger le fichier
Figure_5.JPG (981.55 Ko) Télécharger le fichier
Figure_6.JPG (1.12 Mo) Télécharger le fichier
JNM-Weiss-2006-03.pdf (99.6 Ko) Télécharger le fichier
Origine Fichiers produits par l'(les) auteur(s)
Format Autre
Format Autre
Format Autre
Format Autre
Format Autre
Format Autre
Origine Fichiers produits par l'(les) auteur(s)
Loading...

Dates et versions

inserm-00378040 , version 1 (05-05-2009)

Identifiants

Citer

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, 2007, 160 (1), pp.26-36. ⟨10.1016/j.jneumeth.2006.08.010⟩. ⟨inserm-00378040⟩
121 Consultations
353 Téléchargements

Altmetric

Partager

Gmail Mastodon Facebook X LinkedIn More