An extracellular domain of the accessory β1 subunit is required for modulating BK channel voltage sensor and gate.

ABSTRACT: A family of tissue-specific auxiliary β subunits modulates large conductance voltage- and calcium-activated potassium (BK) channel gating properties to suit their diverse functions. Paradoxically, β subunits both promote BK channel activation through a stabilization of voltage sensor activation and reduce BK channel openings through an increased energetic barrier of the closed-to-open transition. The molecular determinants underlying β subunit function, including the dual gating effects, remain unknown. In this study, we report the first identification of a β1 functional domain consisting of Y74, S104, Y105, and I106 residues located in the extracellular loop of β1. These amino acids reside within two regions of highest conservation among related β1, β2, and β4 subunits. Analysis in the co

SUBMITTER: Gruslova A 

PROVIDER: S-EPMC3250105 | biostudies-literature | 2012 Jan

REPOSITORIES: biostudies-literature