Structural insights into the mechanism of pancreatic K<sub>ATP</sub> channel regulation by nucleotides.

Wang, Mengmeng; Wu, Jing-Xiang; Ding, Dian; Chen, Lei · Nat Commun · 2022

basic_science · Level V

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Abstract

ATP-sensitive potassium channels (K<sub>ATP</sub>) are metabolic sensors that convert the intracellular ATP/ADP ratio to the excitability of cells. They are involved in many physiological processes and implicated in several human diseases. Here we present the cryo-EM structures of the pancreatic K<sub>ATP</sub> channel in both the closed state and the pre-open state, resolved in the same sample. We observe the binding of nucleotides at the inhibitory sites of the Kir6.2 channel in the closed but not in the pre-open state. Structural comparisons reveal the mechanism for ATP inhibition and Mg-ADP activation, two fundamental properties of K<sub>ATP</sub> channels. Moreover, the structures also uncover the activation mechanism of diazoxide-type K<sub>ATP</sub> openers.

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