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