LRRC26 is a Functional BK Channel Auxiliary γ Subunit in Arterial Smooth Muscle Cells

Rationale:Smooth muscle cell (myocyte) large-conductance calcium (Ca)2+-activated potassium (BK) channels are functionally significant modulators of arterial contractility. Arterial myocytes express both pore-forming BKα and auxiliary β1 subunits, which increase channel Ca2+ sensitivity. Recently, several leucine-rich repeat containing (LRRC) proteins have been identified as auxiliary γ subunits that elevate the voltage sensitivity of recombinant and prostate adenocarcinoma BK channels. LRRC expression and physiological functions in native cell types are unclear. Objective:Investigate the expression and physiological functions of leucine-rich repeat containing protein 26 (LRRC26) in arterial myocytes. Methods and Results:Reverse transcription polymerase chain reaction and Western blotting detected LRRC26 mRNA and protein in cerebral artery myocytes. Biotinylation, immunofluorescence resonance energy transfer microscopy, and coimmunoprecipitation indicated that LRRC26 was located in close spatial proximity...