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BK‐type calcium‐activated potassium channels: coupling of metal ions and voltage sensing
Author(s) -
Cui Jianmin
Publication year - 2010
Publication title -
the journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1113/jphysiol.2010.194514
Subject(s) - biophysics , chemistry , phosphatase , coupling (piping) , membrane potential , potassium channel , ion channel , allosteric regulation , phosphorylation , biochemistry , materials science , biology , receptor , metallurgy
Ion channels and lipid phosphatases adopt a transmembrane voltage sensor domain (VSD) that moves in response to physiological variations of the membrane potential to control their activities. However, the VSD movements and coupling to the channel or phosphatase activities may differ depending on various interactions between the VSD and its host molecules. BK‐type voltage, Ca 2+ and Mg 2+ activated K + channels contain the VSD and a large cytosolic domain (CTD) that binds Ca 2+ and Mg 2+ . VSD movements are coupled to BK channel opening with a unique allosteric mechanism and are modulated by Ca 2+ and Mg 2+ binding via the interactions among the channel pore, VSD and CTD. These properties are energetically advantageous for the pore to be controlled by multiple stimuli, revealing the adaptability of the VSD to its host molecules and showing the potential for intracellular signals to affect the VSD in order to modulate the function of its host molecules.