Referenced in: none

Automatically associated channels: Slo1

Title: Inter-α/β subunits coupling mediating pre-inactivation and augmented activation of BKCa(β2).

Authors: Panpan Hou, Wenping Zeng, Geliang Gan, Caixia Lv, Xiying Guo, Zheng Zhang, Haowen Liu, Ying Wu, Jing Yao, Aguan D Wei, Sheng Wang, Jiuping Ding

Journal, date & volume: Sci Rep, 2013 , 3, 1666

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/23588888

Abstract
Large-conductance calcium-activated potassium (BK) channels regulate the electric properties and neurotransmitter release in excitable cells. Its auxiliary β2 subunits not only enhance gating, but also confer inactivation via a short-lived preinactivated state. However, the mechanism of enhancement and preinactivation of BK channels by β2 remains elusive. Using our newly developed methods, we demonstrated that electrostatic forces played a crucial role in forming multiple complementary pairs of binding sites between α and β subunits including a "PI site" required for channel preinactivation, an "E site" enhancing calcium sensitivity and an "ECaB" coupling site transferring force to gate from the Ca(2+)-bowl via the β2(K33, R34, K35), E site and S6-C linker, independent of another Ca(2+) binding site mSlo1(D362,D367). A comprehensive structural model of the BK(β2) complex was reconstructed based on these functional studies, which paves the way for a clearer understanding of the structural mechanisms of activation and preinactivation of other BK(β) complexes.