Decoy calcium channel beta subunits modulate contractile function in myocytes.
Mol Cell Biochem
; 242(1-2): 3-10, 2003 Jan.
Article
en En
| MEDLINE
| ID: mdl-12619859
To test the hypothesis that mutated beta2-subunits of the L-type calcium channel could serve as a decoy and interdict calcium channel trafficking and function, we engineered a beta2 subunit that contained the beta interaction domain for alpha1c subunit interaction, but lacked N- and C-terminal domains that might be essential for sarcolemmal localization. An adenoviral vector was constructed containing the gene for the beta-interaction domain (BID) fused to green fluorescence protein (GFP), using a vector containing only GFP as control. Freshly plated, dissociated adult rat myocytes were infected and expression and function were assessed at 60 h. Fluorescence microscopy confirmed GFP expression; immunoblot analysis confirmed dose-dependent GFP-BID expression. Mechanical properties of adult rat ventricular myocytes were evaluated using a video edge-detection system. Contractility analysis (optical/video, field stimulation) demonstrated that contracting cells decreased from 60 to 2%. Contractile amplitude (percent shortening) decreases significantly from 5.6 vs. 2.4% with no change in time to peak twitch. Recombinant adenovirus overexpressing mutated beta2 subunits in adult mammalian myocytes can markedly alter excitation-contraction coupling. This paradigm may offer new approaches to understanding and modulating EC coupling.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Canales de Calcio
/
Subunidades de Proteína
/
Células Musculares
/
Contracción Muscular
Límite:
Animals
Idioma:
En
Revista:
Mol Cell Biochem
Año:
2003
Tipo del documento:
Article
País de afiliación:
Estados Unidos
Pais de publicación:
Países Bajos