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

We examined the effects of calcium channel beta subunits upon the recovery from inactivation of eel subunits expressed in Xenopus oocytes, Recovery of the current carried by the L-type alpha (1) subunit (cyCa(v)1) from the je llyfish Cyanea capillata was accelerated by coexpression of any beta subuni t, but the degree of potentiation differed according to which beta isoform was coexpressed, The Cyanea beta subunit was most effective, followed by th e mammalian b(3), b(4), and beta (2a) subtypes, Recovery of the human Ca(v) 2,3 subunit was also modulated by beta subunits, but,vas slowed instead. be ta (3) was the most potent subunit tested, followed by beta (4). then beta (2a), which had virtually no effect. These results demonstrate that differe nt beta subunit isoforms can affect recovery of the channel to varying degr ees, and provide an additional mechanism by which beta subunits can differe ntially regulate al subunits, (C) 2000 Federation of European Biochemical S ocieties. Published by Elsevier Science B.V. All rights reserved.