National Natural Science Foundation of China (NSFC)
32371261
中国
National Natural Science Foundation of China (NSFC)
32301011
中国
Ministry of Education (MoE, China)
2632024ZD10
中国
引用
ジャーナル: Nat Struct Mol Biol / 年: 2025 タイトル: Gating mechanism of the two-pore-domain potassium channel THIK1. 著者: Xiangyun Fang / Haichao Jin / Jin Wang / Ran Zhang / Baobin Li / 要旨: TWIK-related halothane-inhibited potassium channel (THIK1) maintains the resting membrane potential and regulates potassium efflux in microglia. It is a potential therapeutic target for ...TWIK-related halothane-inhibited potassium channel (THIK1) maintains the resting membrane potential and regulates potassium efflux in microglia. It is a potential therapeutic target for neurodegenerative disorders, neuropathic pain and inflammation. However, the mechanism underlying its function remains unclear. Here we used cryo-electron microscopy to solve the structures of full-length human THIK1, revealing two inner gates and a C-type selectivity filter gate, distinct from other two-pore-domain potassium channels. One inner gate, formed by a short helix in the distal C terminus, introduces a unique gating mechanism involving the distal cytoplasmic domain. The other, beneath the selectivity filter, is constricted by Y273 in the M4 helix, dividing the cavity. In addition, the selectivity filter gate is modulated by polyunsaturated fatty acids. These structural insights into THIK1 gating, through the distal C-terminal helices, hydrophilic residues and selectivity filter, advance our understanding of THIK1's role in microglial homeostasis and neuropathologies.