Structural highlights
Function
[KCJ11_MOUSE] This receptor is controlled by G proteins. Inward rectifier potassium channels are characterized by a greater tendency to allow potassium to flow into the cell rather than out of it. Their voltage dependence is regulated by the concentration of extracellular potassium; as external potassium is raised, the voltage range of the channel opening shifts to more positive voltages. The inward rectification is mainly due to the blockage of outward current by internal magnesium. Can be blocked by extracellular barium. Can form cardiac and smooth muscle-type KATP channels with ABCC9. KCNJ11 forms the channel pore while ABCC9 is required for activation and regulation (By similarity).
Publication Abstract from PubMed
ATP-sensitive potassium channels (KATP) are energy sensors on the plasma membrane. By sensing the intracellular ADP/ATP ratio of beta-cells, pancreatic KATP channels control insulin release and regulate metabolism at the whole body level. They are implicated in many metabolic disorders and diseases and are therefore important drug targets. Here, we present three structures of pancreatic KATP channels solved by cryo-electron microscopy (cryo-EM), at resolutions ranging from 4.1 to 4.5 A. These structures depict the binding site of the antidiabetic drug glibenclamide, indicate how Kir6.2 (inward-rectifying potassium channel 6.2) N-terminus participates in the coupling between the peripheral SUR1 (sulfonylurea receptor 1) subunit and the central Kir6.2 channel, reveal the binding mode of activating nucleotides, and suggest the mechanism of how Mg-ADP binding on nucleotide binding domains (NBDs) drives a conformational change of the SUR1 subunit.
Ligand binding and conformational changes of SUR1 subunit in pancreatic ATP-sensitive potassium channels.,Wu JX, Ding D, Wang M, Kang Y, Zeng X, Chen L Protein Cell. 2018 Mar 28. pii: 10.1007/s13238-018-0530-y. doi:, 10.1007/s13238-018-0530-y. PMID:29594720[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Wu JX, Ding D, Wang M, Kang Y, Zeng X, Chen L. Ligand binding and conformational changes of SUR1 subunit in pancreatic ATP-sensitive potassium channels. Protein Cell. 2018 Mar 28. pii: 10.1007/s13238-018-0530-y. doi:, 10.1007/s13238-018-0530-y. PMID:29594720 doi:http://dx.doi.org/10.1007/s13238-018-0530-y
