Calcium channel β subunits differentially modulate recovery of the channel from inactivation

摘要

>We examined the effects of calcium channel β subunits upon the recovery from inactivation of α₁ subunits expressed in Xenopus oocytes. Recovery of the current carried by the L-type α₁ subunit (cyCa_v1) from the jellyfish Cyanea capillata was accelerated by coexpression of any β subunit, but the degree of potentiation differed according to which β isoform was coexpressed. The Cyanea β subunit was most effective, followed by the mammalian b₃, b₄, and β_2a subtypes. Recovery of the human Ca_v2.3 subunit was also modulated by β subunits, but was slowed instead. β₃ was the most potent subunit tested, followed by β₄, then β_2a, which had virtually no effect. These results demonstrate that different β subunit isoforms can affect recovery of the channel to varying degrees, and provide an additional mechanism by which β subunits can differentially regulate α₁ subunits.