@article{f3ca99920c394d20b524466326afe97b,
title = "Regulation of cardiac L-type Ca2+ channel by coexpression of G(αs) in Xenopus oocytes",
abstract = "Activation of G(αs) via β-adrenergic receptors enhances the activity of cardiac voltage-dependent Ca2+ channels of the L-type, mainly via protein kinase A (PKA)-dependent phosphorylation. Contribution of a PKA-independent effect of G(αs) has been proposed but remains controversial. We demonstrate that, in Xenopus oocytes, antisense knockdown of endogenous G(αs) reduced, whereas coexpression of G(αs) enhanced, currents via expressed cardiac L-type channels, independently of the presence of the auxiliary subunits α2/δ or β(2A). Coexpression of G(αs) did not increase the amount of α(1C) protein in whole oocytes or in the plasma membrane (measured immunochemically). Activation of coexpressed β2 adrenergic receptors did not cause a detectable enhancement of channel activity; rather, a small cAMP-dependent decrease was observed. We conclude that coexpression of G(αs), but not its acute activation via β-adrenergic receptors, enhances the activity of the cardiac L-type Ca2+ channel via a PKA-independent effect on the α(1C) subunit.",
keywords = "Calcium channel, G-protein, Xenopus ocyte",
author = "Yakov Blumenstein and Tatiana Ivanina and Elena Shistik and Elena Bossi and Antonio Peres and Nathan Dascal",
note = "Funding Information: This work was supported in part by the Israel Academy of Sciences and by NIH Grant GM56260. We thank I. Lotan for many discussions and for a critical reading of the manuscript, Rachel Barzilay for subcloning the G protein α subunits into high-expression vectors, M. Hosey for the gift of the Card-I antibody, and M. Simon for providing the clones of G α proteins.",
year = "1999",
month = feb,
day = "5",
doi = "10.1016/S0014-5793(99)00035-6",
language = "אנגלית",
volume = "444",
pages = "78--84",
journal = "FEBS Letters",
issn = "0014-5793",
publisher = "John Wiley and Sons Inc.",
number = "1",
}