8hkk | pdb_00008hkk
ion channel
Structural highlights
DiseaseKCNT1_HUMAN Malignant migrating focal seizures of infancy;Autosomal dominant nocturnal frontal lobe epilepsy. The disease is caused by variants affecting the gene represented in this entry. The disease is caused by variants affecting the gene represented in this entry. FunctionKCNT1_HUMAN Outwardly rectifying potassium channel subunit that may coassemble with other Slo-type channel subunits. Activated by high intracellular sodium or chloride levels. Activated upon stimulation of G-protein coupled receptors, such as CHRM1 and GRIA1. May be regulated by calcium in the absence of sodium ions (in vitro) (By similarity). Publication Abstract from PubMedThe sodium-activated Slo2.2 channel is abundantly expressed in the brain, playing a critical role in regulating neuronal excitability. The Na(+)-binding site and the underlying mechanisms of Na(+)-dependent activation remain unclear. Here, we present cryoelectron microscopy (cryo-EM) structures of human Slo2.2 in closed, open, and inhibitor-bound form at resolutions of 2.6-3.2 A, revealing gating mechanisms of Slo2.2 regulation by cations and a potent inhibitor. The cytoplasmic gating ring domain of the closed Slo2.2 harbors multiple K(+) and Zn(2+) sites, which stabilize the channel in the closed conformation. The open Slo2.2 structure reveals at least two Na(+)-sensitive sites where Na(+) binding induces expansion and rotation of the gating ring that opens the inner gate. Furthermore, a potent inhibitor wedges into a pocket formed by pore helix and S6 helix and blocks the pore. Together, our results provide a comprehensive structural framework for the investigation of Slo2.2 channel gating, Na(+) sensation, and inhibition. Structural basis of human Slo2.2 channel gating and modulation.,Zhang J, Liu S, Fan J, Yan R, Huang B, Zhou F, Yuan T, Gong J, Huang Z, Jiang D Cell Rep. 2023 Jul 25;42(8):112858. doi: 10.1016/j.celrep.2023.112858. PMID:37494189[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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