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The α2δ subunit augments functional expression and modifies the pharmacology of CaV1.3 L-type channels
Journal article   Peer reviewed

The α2δ subunit augments functional expression and modifies the pharmacology of CaV1.3 L-type channels

Arturo Andrade, Alejandro Sandoval, Ricardo González-Ramírez, Diane Lipscombe, Kevin P Campbell and Ricardo Felix
Cell calcium (Edinburgh), Vol.46(4), pp.282-292
10/2009
DOI: 10.1016/j.ceca.2009.08.006
PMID: 19796812

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Abstract

The auxiliary Ca V α 2 δ-1 subunit is an important component of voltage-gated Ca2+ (CaV) channel complexes in many tissues and of great interest as a drug target. Nevertheless, its exact role in specific cell functions is still unknown. This is particularly important in the case of the neuronal L-type Ca V channels where these proteins play a key role in the secretion of neurotransmitters and hormones, gene expression, and the activation of other ion channels. Therefore, using a combined approach of patch clamp recordings and molecular biology, we studied the role of the Ca V α 2 δ-1 subunit on the functional expression and the pharmacology of recombinant L-type Ca V 1.3 channels in HEK-293 cells. Co-expression of Ca V α 2 δ-1 significantly increased macroscopic currents and conferred the Ca V 1.3α 1 /Ca V β 3 channels sensitivity to the antiepileptic/analgesic drugs gabapentin and AdGABA. In contrast, Ca V α 2 δ-1 subunits harboring point mutations in N -glycosylation consensus sequences or the proteolytic site as well as in conserved cysteines in the transmembrane δ domain of the protein, reduced functionality in terms of enhancement of Ca V 1.3α 1 /Ca V β 3 currents. In addition, co-expression of the δ domain drastically inhibited macroscopic currents through recombinant Ca V 1.3 channels possibly by affecting channel synthesis. Together these results provide several lines of evidence that the Ca V α 2 δ-1 auxiliary subunit may interact with Ca V 1.3 channels and regulate their functional expression.
CaVα2δ subunit Ca2+ channels gabapentin L-type calcium channels

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