Click here to close Hello! We notice that you are using Internet Explorer, which is not supported by Xenbase and may cause the site to display incorrectly. We suggest using a current version of Chrome, FireFox, or Safari.
J Physiol 2001 May 01;532Pt 3:583-93.
Show Gene links Show Anatomy links

Functional roles of gamma2, gamma3 and gamma4, three new Ca2+ channel subunits, in P/Q-type Ca2+ channel expressed in Xenopus oocytes.

Rousset M , Cens T , Restituito S , Barrere C , Black JL , McEnery MW , Charnet P .

Stargazin or [gamma]2, the product of the gene mutated in the stargazer mouse, is a homologue of the [gamma]1 protein, an accessory subunit of the skeletal muscle L-type Ca2+ channel. [gamma]2 is selectively expressed in the brain, and considered to be a putative neuronal Ca2+ channel subunit based mainly on homology to [gamma]1. Two new members of the [gamma] family expressed in the brain have recently been identified: [gamma]3 and [gamma]4. We have co-expressed, in Xenopus oocytes, the human [gamma]2, [gamma]3 and [gamma]4 subunits with the P/Q-type (Ca(V)2.1) Ca2+ channel and different regulatory subunits ([alpha]2-[delta]; [beta]1, [beta]2, [beta]3 or [beta]4). Subcellular distribution of the [gamma] subunits confirmed their membrane localization. Ba2+ currents, recorded using two-electrode voltage clamp, showed that the effects of the [gamma] subunits on the electrophysiological properties of the channel are, most of the time, minor. However, a fraction of the oocytes expressing [beta] subunits displayed an unusual slow-inactivating Ba2+ current. Expression of both [beta] and [gamma] subunits increased the appearance of the slow-inactivating current. Our data support a role for the [gamma] subunit as a brain Ca2+ channel modulatory subunit and suggest that [beta] and [gamma] subunits are involved in a switch between two regulatory modes of the P/Q-type channel inactivation.

PubMed ID: 11313431
PMC ID: PMC2278567
Article link: J Physiol

Species referenced: Xenopus laevis
Genes referenced: cacng2

References [+] :
Black, Identification and cloning of putative human neuronal voltage-gated calcium channel gamma-2 and gamma-3 subunits: neurologic implications. 1999, Pubmed