14-3-3 gamma, a novel regulator of the large-conductance Ca2+-activated K+ channels.

14-3-3 gamma, a novel regulator of the large-conductance Ca2+-activated K+ channels. Am J Physiol Renal Physiol. 2020 May 28;: Authors: Chen S, Feng X, Chen X, Zhuang Z, Xiao J, Fu H, Klein JD, Wang XH, Hoover RS, Eaton DC, Cai H Abstract 14-3-3 gamma (γ) is a small protein regulating the target proteins through binding to the phosphorylated serine/threonine residues. Sequence analysis of large-conductance Ca2+-activated K+ (BK) channel revealed a putative 14-3-3 binding site in the C-terminal region. Our previous data showed that 14-3-3γ is widely expressed in the mouse kidney. We, therefore, hypothesized that 14-3-3γ has a novel role in the regulation of BK channel activity and protein expression. We first demonstrated the interaction of 14-3-3γ with BKα by co-immunoprecipitation. In HEK293 cells stably expressing BKα (HEK BKα cells), overexpression of 14-3-3γ significantly decreased BK channel activity and channel open probability. 14-3-3γ inhibited both total and cell surface BKα protein expression while enhancing ERK 1/2 phosphorylation in Cos-7 cells co-transfected with flag-14-3-3γ and myc-BK. Knockdown of 14-3-3γ by siRNA transfection markedly increased BKα expression. Blockade of the ERK1/2 pathway by incubation with the MEK-specific inhibitor U0126 partially abolished 14-3-3γ-mediated inhibition of BK protein expression. Similarly, pretreatment of the lysosomal inhibitor, bafilomycin A1 reversed the inhibitory...
Source: American Journal of Physiology. Renal Physiology - Category: Physiology Authors: Tags: Am J Physiol Renal Physiol Source Type: research