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Ser 1901 of α 1C subunit is required for the PKA‐mediated enhancement of L‐type Ca 2+ channel currents but not for the negative shift of activation
Author(s) -
Naguro Isao,
Nagao Taku,
Adachi-Akahane Satomi
Publication year - 2001
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(01)02079-8
Subject(s) - forskolin , protein subunit , phosphorylation , protein kinase a , biophysics , chemistry , kinase , biology , microbiology and biotechnology , biochemistry , receptor , gene
Cardiac L‐type Ca 2+ channel is facilitated by protein kinase A (PKA)‐mediated phosphorylation. Here, we investigated the role of Ser 1901 , a putative phosphorylation site in the carboxy‐terminal of rat brain type‐II α 1C subunit (rbCII), in the PKA‐mediated regulation. Forskolin (3 μM) enhanced Ca 2+ channel currents ( I Ca ) and shifted the activation curve to negative voltages, which were abolished by protein kinase inhibitor. Replacement of Ser 1901 of rbCII by Ala abolished the enhancement of I Ca by forskolin but not the shift of the activation curve. These results indicate that Ser 1901 is required for the PKA‐mediated enhancement of I Ca , and that the voltage‐dependence of the activation of I Ca appears to be modulated via another PKA phosphorylation site.