Coexpression of the beta subunit significantly increased DHP binding and calcium channel activity in Chinese hamster ovary cells expressing the cardiac L-type calcium channel alpha 1 subunit.
The cardiac dihydropyridine-sensitive L-type calcium channel was stably expressed in Chinese hamster ovary cells by transfecting the rabbit cardiac calcium channel alpha 1 subunit cDNA with or without coexpression of the beta subunit of skeletal muscle calcium channel. Whereas coexpression of the beta subunit significantly increased DHP binding activity and calcium channel activity, it did not affect the amount of the alpha 1 subunit expressed, as judged by RNA blot hybridization analysis and immunoblotting analysis. The results suggest that association with the beta subunit is necessary for the alpha 1 subunit protein to take a proper conformation suitable for a functional calcium channel.
Nishimura et al. (Mon,) reported a other. Coexpression of the beta subunit of skeletal muscle calcium channel vs. Expression of alpha 1 subunit without beta subunit was evaluated on DHP binding activity and calcium channel activity. Coexpression of the beta subunit significantly increased DHP binding and calcium channel activity in Chinese hamster ovary cells expressing the cardiac L-type calcium channel alpha 1 subunit.