Rectification and rapid activation at low Ca2+ of Ca2+-activated, voltage-dependent BK currents: consequences of rapid inactivation by a novel beta subunit.

ABSTRACT: A family of accessory beta subunits significantly contributes to the functional diversity of large-conductance, Ca(2+)- and voltage-dependent potassium (BK) channels in native cells. Here we describe the functional properties of one variant of the beta subunit family, which confers properties on BK channels totally unlike any that have as yet been observed. Coexpression of this subunit (termed beta3) with Slo alpha subunits results in rectifying outward currents and, at more positive potentials, rapidly inactivating ( approximately 1 msec) currents. The underlying rapid inactivation process results in an increase in the apparent activation rate of macroscopic currents, which is coupled with a shift in the activation range of the currents at low Ca(2+). As a consequence, the currents exhibi

SUBMITTER: Xia XM 

PROVIDER: S-EPMC6772275 | biostudies-literature | 2000 Jul

REPOSITORIES: biostudies-literature