Lemke T, Welling A, Christel CJ, Blaich A, Bernhard D, Lenhardt P, Hofmann F, Moosmang S. Unchanged beta-adrenergic stimulation of cardiac L-type calcium channels in Ca v 1.2 phosphorylation site S1928A mutant mice.
J Biol Chem 2008;
283:34738-44. [PMID:
18829456 DOI:
10.1074/jbc.m804981200]
[Citation(s) in RCA: 98] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Phosphorylation of serine 1928 (Ser(1928)) of the cardiac Ca(v)1.2 subunit of L-type Ca(2+) channels has been proposed as the mechanism for regulation of L-type Ca(2+) channels by protein kinase A (PKA). To test this directly in vivo, we generated a knock-in mouse with targeted mutation of Ser(1928) to alanine. This mutation did not affect basal L-type current characteristics or regulation of the L-type current by PKA and the beta-adrenergic receptor, whereas the mutation abolished phosphorylation of Ca(v)1.2 by PKA. Therefore, our data show that PKA phosphorylation of Ser(1928) of Ca(v)1.2 is not functionally involved in beta-adrenergic stimulation of Ca(v)1.2-mediated Ca(2+) influx into the cardiomyocyte.
Collapse