July 14, 2011
New Clues To The Structural Dynamics Of BK Channels
BK channels (large-conductance, Ca2+-dependent K+ channels) are essential for the regulation of important biological processes such as smooth muscle tone and neuronal excitability. New research shows that BK channel activation involves structural rearrangements formerly not understood. The study appears in the August 2011 issue of the Journal of General Physiology.
Previous research pointed to a possible unified theory of activation gating in K+ channels, with the "activation gate" formed by the bundle crossing of four S6 transmembrane helices from the four subunits. Recent studies, however, have suggested a different structure for BK channels, but the exact location of the activation gate remained a mystery.
The findings point to new directions for research regarding the molecular mechanisms of BK channel activation, according to Commentary by Daniel Cox (Tufts University School of Medicine) and Toshinori Hoshi (University of Pennsylvania). Importantly, they say, the study demonstrates that BK channel activation is not an open-and-shut case as previously suspected.
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