β Subunit heterogeneity of L‐type Ca2+ channels in smooth muscle tissues

FEBS Letters

Huber, Irene G.²  Haase, Hannelore³  Reimer, Daniel²  Striessnig, Jörg²  Garcia, Maria L.¹ 

[1] Merck Research Laboratories, Rahway, NJ, USA;Institut für Biochemische Pharmakologie, Peter-Mayrstrasse 1, A-6020 Innsbruck, Austria;Max-Delbrück Centrum für Molekulare Medizin, Berlin, Germany

关键词: Ca2+ channel;    Subunit;    Smooth muscle;    1;    4-Dihydropyridine;    AIDA;    α1A-β subunit interaction domain;    AO;    aortic smooth muscle;    GST;    glutathione-S-transferase;    HT;    heart muscle;    SDS;    sodium dodecylsulfate;    TR;    tracheal smooth muscle;    UT;    uterus smooth muscle;    WGA;    wheat germ agglutinin;   

DOI  :  10.1016/S0014-5793(00)01124-8

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Various β subunit isoforms stabilize different gating properties of voltage-gated L-type Ca²⁺ channels. We therefore investigated the expression of Ca²⁺ channel β subunit isoforms in different smooth muscle types on the protein level by immunoblotting and immunoprecipitation employing β subunit-selective sequence-directed antibodies. From the four known β subunit isoforms only β2 and β3 were detected in porcine uterus, bovine trachea and bovine aorta membranes. Multiple immunoreactive β2 bands were detected in a tissue-selective manner indicating structural heterogeneity of β2. Immunoprecipitation of (+)-[³H]isradipine-prelabeled channels revealed that β2 and β3 participate in Ca²⁺ channel formation in uterus and trachea, and β3 in aortic smooth muscle. We conclude that β2 and β3 subunits form L-type Ca²⁺ channels in smooth muscle tissues. This subunit heterogeneity may be important to fine-tune channel function.

【 授权许可】

Unknown