K2P16.1 channels

Channel name K2P16.1
Description Two-pore domain potassium channel subunit; open rectifier
Other names KCNK16, TALK-1
Molecular information Human: 309aa, NM_032115, chr0.6p21.1-2, KCNK16, GeneID: 83795, PMID: 112639991
Rat: not cloned
Mouse: 337aa, XM_138942
Associated subunits Not established
Functional assays Electrophysiological1
Current Open rectifier
Conductance 21pS at -60 mV and 10 pS at +60 mV2
Ion selectivity Not established
Activation See “Comments”
Inactivation See “Comments”
Activators Isoflurane (∼800 mM), nitric oxide and reactive oxygen species3
Gating inhibitors None
Blockers Ba2+ (1 mM), quinidine (100 mM), chloroform (∼800 mM), external pH (see “Comments”)
Radioligands None
Channel distribution Heart, lung, liver, pancreas,1 and placenta
Physiological functions Not established
Mutations and pathophysiology Not established
Pharmacological significance Not established
Comments Activation and deactivation with voltage steps seem to be instantaneous; the open probability of both K2P16 and 17 increases with external pH–at present, it is unclear whether this represents proton block at physiological levels or activation of the channel by supraphysiological alkaline pHo; there are four splice variants of K2P16, two of which are functional4
  • aa, amino acids; chr., chromosome.

  • 1. Girard C, Duprat F, Terrenoire C, Tinel N, Fosset M, Romey G, Lazdunski M, and Lesage F (2001) Genomic and functional characteristics of novel human pancreatic 2P domain K(+) channels. Biochem Biophys Res Commun 282:249-256

  • 2. Kang D and Kim D (2004) Single-channel properties and pH sensitivity of two-pore domain K+ channels of the TALK family. Biochem Biophys Res Commun 315:836-844

  • 3. Duprat F, Girard C, Jarretou G, and Lazdunski M (2004) Pancreatic two P domain K+ channels TALK-1 and TALK-2 are activated by nitric oxide and reactive oxygen species. J Physiol 562:235-244

  • 4. Han JH, Kang D, and Kim D (2003) Functional properties of four splice variants of a human pancreatic tandem-pore K+ channel, TALK-1. Am J Physiol 285:C529-C538