Phosphorylation of the L‐type calcium channel β subunit is involved in β‐adrenergic signal transduction in canine myocardium

FEBS Letters

Beckert, Ralf¹  Haase, Hannelore¹  Krause, Ernst Georg¹  Karczewski, Peter¹ 

[1] Max Delbrück Centre for Molecular Medicine, Molecular Cardiology, Robert-Rossle-Str. 10, D-13125 Berlin-Buch, Germany

关键词: Calcium channel;    Canine heart;    Immunoprecipitation;    Peptide antibody;    Protein phosphorylation;    β Subunit;    DHP;    dihydropyridine;    PKA;    cAMP-dependent protein kinase;    PN200-110;    isopropyi 4-(2;    1;    3-benzoxadiazol-4-yl)-1;    4-dihydro-2;    6-dimethyl-5-(methoxy-carbonyl)pyridine-3-carboxylate;   

DOI  :  10.1016/0014-5793(93)80733-B

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Cyclic AMP-mediated phosphorylation of calcium channel submits was studied in vitro and in vivo in preparations from dog heart. Calcium channels in native cardiac membranes were phosphorylated by cAMP-dependent protein kinase (PKA) solubilized with digitonin and subsequently immunoprecipitated using a polyclonal antibody generated against the deduced carboxy-terminal sequence of the cardiac β subunit. A 62 kDa protein was identified as the major PKA-substrate in the immunoprecipitates. In the intact myocardium, this putative β subunit was found to be phosphorylated in response to cAMP elevating agents. In contrast, no phosphorylation of a protein with an electrophoretic mobility similar to the α₁ subunit was detected, although 1,4-dihydropyridine receptor sites were recovered in the immunoprecipitates. Thus, we suggest that PKA-mediated phosphorylation of the β subunit is the major mechanism for β-adrenergic regulation of cardiac L-type calcium channel activity.

【 授权许可】

Unknown