K2P18.1 channels
| Channel name | K2P18.1 |
| Description | Two-pore domain potassium channel subunit; open rectifier |
| Other names | KCNK18, TRESK-1/TRESK-2 (see “Comments”) |
| Molecular information | Human: 384aa, NM_181840, chr. 10q26.11, GeneID: 338567, PMID: 127542591 |
| Rat: 405aa, NM_001003820 | |
| Mouse: 394aa, NM_207261 | |
| Associated subunits | Not established |
| Functional assays | Electrophysiological1 |
| Current | Open rectifier |
| Conductance | 13pS at +60 mV and 16pS at –60 mV for mouse K2P183 |
| Ion selectivity | Not established |
| Activation | Rapid |
| Inactivation | Slow |
| Activators | Cytoplasmic Ca2+ via calcineurin, volatile anesthetics2,4 |
| Gating inhibitors | None |
| Blockers | Ba2+ (3 mM), quinine (100 mM) quinidine (100 mM), free fatty acids, external acidic pH |
| Radioligands | None |
| Channel distribution | Cerebrum, cerebellum, brain stem, spinal cord, and testis |
| Physiological functions | Not established |
| Mutations and pathophysiology | Not established |
| Pharmacological significance | Not established |
| Comments | Activation is instantaneous; single channel currents are noninactivating and time-dependent; TRESK2 was cloned from mouse testis and shares 65% homology with human K2P18; as study continues, it will become clear whether this is the true correlate of the human channel or a distinct gene (K2P19); personal communication indicates that distinct cDNAs for both TRESK-1 and TRESK-2 are present in human tissues (D. Kim, personal communication) |
aa, amino acids; chr., chromosome.
↵1. Sano Y, Inamura K, Miyake A, Mochizuki S, Kitada C, Yokoi H, Nozawa K, Okada H, Matsushime H, and Furuichi K (2003) A novel two-pore domain K+ channel, TRESK, is localized in the spinal cord. J Biol Chem 278:27406-27412
↵2. Czirjak G, Toth ZE, and Enyedi P (2004) The two-pore-domain K+ channel, TRESK, is activated by the cytoplasmic calcium signal through calcineurin. J Biol Chem 279:18550-18558
↵3. Kang D, Mariash E, and Kim D (2004) Functional expression of TRESK-2, a new member of the tandem-pore K + channel family. J Biol Chem 279:28063-28070
↵4. Liu C, Au JD, Zou HL, Cotton JF, and Yost CS (2004) Potent activation of the human tandem pore domain K channel TRESK with clinical concentrations of volatile anesthetics. Anesth Analg 99:1715-1722