Proc Natl Acad Sci U S A
February 2006
Two-pore-domain K(+) channels provide neuronal background currents that establish resting membrane potential and input resistance; their modulation provides a prevalent mechanism for regulating cellular excitability. The so-called TASK channel subunits (TASK-1 and TASK-3) are widely expressed, and they are robustly inhibited by receptors that signal through Galphaq family proteins. Here, we manipulated G protein expression and membrane phosphatidylinositol 4,5-bisphosphate (PIP(2)) levels in intact and cell-free systems to provide electrophysiological and biochemical evidence that inhibition of TASK channels by Galphaq-linked receptors proceeds unabated in the absence of phospholipase C (PLC) activity, and instead involves association of activated Galphaq subunits with the channels.
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