A mutation in the β interaction domain of the Ca2+ channel α1C subunit reduces the affinity of the (+)‐[3H]isradipine binding site

FEBS Letters

Flucher, Bernhard E.¹  Hitzl, Monika¹  Striessnig, Jörg¹  Neuhuber, Birgit¹ 

[1]Department of Biochemical Pharmacology, University of Innsbruck, A-6020 Innsbruck, Austria

关键词: Calcium channel;    (+)-[3H]Isradipine;    Radioligand binding;    Immunoprecipitation;    Immunofluorescence;   

DOI  :  10.1016/S0014-5793(02)03054-5

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The molecular mechanisms of how α₁ and β subunits of voltage-gated Ca²⁺ channels interact with one another are still controversial. Here we show that despite a mutation in the β interaction domain that has previously been shown to disrupt binding, α_1CY467S and β_1a-myc still formed immunoprecipitable complexes when coexpressed in tsA201 cells. However, the α_1CY467S–β_1a-myc complexes had a decreased affinity to (+)-[³H]isradipine. This indicates that the β interaction domain in the I–II loop of the α₁ subunit is not merely an anchor required for the functional interaction of the two Ca²⁺ channel subunits but is itself part of the effector pathway for β-induced channel modulation.

【 授权许可】

Unknown