Regulation of Ca‐sensitive inactivation of a l‐type Ca2+ channel by specific domains of β subunits

FEBS Letters

Restituito, Sophie¹  Cens, Thierry¹  Charnet, Pierre¹ 

[1] CRBM, CNRS UPR 1086, IFR 24, 1919 Route de Mende, 34293 Montpellier Cedex 5, France

关键词: Voltage clamp;    β2/β1 chimera;    Heterologous expression;    Xenopus oocyte;    AID;    alpha interaction domain;    BAPTA;    1;    2-bis(2-aminophenoxy)-ethane-N;    N;    N’;    N’-tetraacetic acid;    BID;    β interaction domain;    HEPES;    N-(2-hydroxyethyl)piperazine-N’-(2-ethanesulfonic acid);    NMDG;    N-methyl-D-glucamine;    TEAOH;    tetra-ethyl ammonium hydroxide;   

DOI  :  10.1016/S0014-5793(99)00463-9

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Ca²⁺ channel auxiliary β subunits have been shown to modulate voltage-dependent inactivation of various types of Ca²⁺ channels. The β₁ and β₂ subunits, that are differentially expressed with the L-type α₁ Ca²⁺ channel subunit in heart, muscle and brain, can specifically modulate the Ca²⁺-dependent inactivation kinetics. Their expression in Xenopus oocytes with the α_1C subunit leads, in both cases, to biphasic Ca²⁺ current decays, the second phase being markedly slowed by expression of the β₂ subunit. Using a series of β subunit deletion mutants and chimeric constructs of β₁ and β₂ subunits, we show that the inhibitory site located on the amino-terminal region of the β_2a subunit is the major element of this regulation. These results thus suggest that different splice variants of the β₂ subunit can modulate, in a specific way, the Ca²⁺ entry through L-type Ca²⁺ channels in different brain or heart regions.

【 授权许可】

Unknown