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Regulation of Ca‐sensitive inactivation of a l‐type Ca 2+ channel by specific domains of β subunits
Author(s) -
Cens Thierry,
Restituito Sophie,
Charnet Pierre
Publication year - 1999
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(99)00463-9
Subject(s) - protein subunit , xenopus , r type calcium channel , chemistry , n type calcium channel , biology , biophysics , microbiology and biotechnology , voltage dependent calcium channel , biochemistry , gene , calcium , t type calcium channel , organic chemistry
Ca 2+ channel auxiliary β subunits have been shown to modulate voltage‐dependent inactivation of various types of Ca 2+ channels. The β 1 and β 2 subunits, that are differentially expressed with the L‐type α 1 Ca 2+ channel subunit in heart, muscle and brain, can specifically modulate the Ca 2+ ‐dependent inactivation kinetics. Their expression in Xenopus oocytes with the α 1C subunit leads, in both cases, to biphasic Ca 2+ current decays, the second phase being markedly slowed by expression of the β 2 subunit. Using a series of β subunit deletion mutants and chimeric constructs of β 1 and β 2 subunits, we show that the inhibitory site located on the amino‐terminal region of the β 2a subunit is the major element of this regulation. These results thus suggest that different splice variants of the β 2 subunit can modulate, in a specific way, the Ca 2+ entry through L‐type Ca 2+ channels in different brain or heart regions.