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