KCNK2

Potassium channel, two pore domain subfamily K, member 2
Available structures PDB Ortholog search: PDBe, RCSB List of PDB id codes 4TWK​
Identifiers
Symbols	KCNK2 ; K2p2.1; TPKC1; TREK; TREK-1; TREK1; hTREK-1c; hTREK-1e
External IDs	OMIM: 603219 MGI: 109366 HomoloGene: 7794 IUPHAR: 514 GeneCards: KCNK2 Gene
Gene ontology Molecular function • outward rectifier potassium channel activity • potassium channel inhibitor activity • potassium ion leak channel activity Cellular component • nucleus • endoplasmic reticulum • endoplasmic reticulum membrane • plasma membrane • integral component of plasma membrane • voltage-gated potassium channel complex • cell surface • apical plasma membrane • neuronal cell body • calyx of Held • astrocyte projection Biological process • cardiac ventricle development • G-protein coupled receptor signaling pathway • synaptic transmission • memory • response to mechanical stimulus • positive regulation of cell death • stabilization of membrane potential • response to axon injury • negative regulation of cardiac muscle cell proliferation • cellular response to hypoxia • potassium ion transmembrane transport • cochlea development • positive regulation of cellular response to hypoxia • negative regulation of DNA biosynthetic process Sources: Amigo / QuickGO
RNA expression pattern
More reference expression data
Orthologs
Species	Human	Mouse
Entrez	3776	16526
Ensembl	ENSG00000082482	ENSMUSG00000037624
UniProt	O95069	P97438
RefSeq (mRNA)	NM_001017424	NM_001159850
RefSeq (protein)	NP_001017424	NP_001153322
Location (UCSC)	Chr 1: 215.01 – 215.24 Mb	Chr 1: 189.21 – 189.4 Mb
PubMed search

Potassium channel subfamily K member 2 is a protein that in humans is encoded by the KCNK2 gene.^[1][2][3]

This gene encodes K_2P2.1, one of the members of the two-pore-domain background potassium channel protein family. This type of potassium channel is formed by two homodimers that create a channel that leaks potassium out of the cell to control resting membrane potential. The channel can be opened, however, by certain anesthetics, membrane stretching, intracellular acidosis, and heat. Three transcript variants encoding different isoforms have been found for this gene.^[3]

Function in neurons

Another name for this channel is TREK-1. TREK-1 is part of the subfamily of mechano-gated potassium channels that are present in mammalian neurons. They can be gated in both chemical and physical ways and can be opened via both physical stimuli and chemical stimuli. TREK-1 channels are found in a variety of tissues, but are particularly abundant in the brain and heart and are seen in various types of neurons.^[4] The C-terminal of TREK-1 channels plays a role in the mechanosensitivity of the channels.^[5]

In the neurons of the central nervous system, TREK-1 channels are important in physiological, pathophysiological, and pharmacological processes, including having a role in electrogenesis, ischemia, and anesthesia. TREK-1 has an important role in neuroprotection against epilepsy and brain and spinal cord ischemia and is being evaluated as a potential target for new developments of therapeutic agents for neurology and anesthesiology.^[6]

In the absence of a properly functioning cytoskeleton, TREK-1 channels can still open via mechanical gating.^[7] The cell membrane functions independently of the cytoskeleton and the thickness and curvature of the membrane is able to modulate the activity of the TREK-1 channels.^[8] The insertion of certain compounds into the membrane is thought to mediate the opening of TREK-1 by forming a curve in the membrane.^[9]

See also

• Tandem pore domain potassium channel

References

1. Lesage F, Lazdunski M (Oct 1998). "Mapping of human potassium channel genes TREK-1 (KCNK2) and TASK (KCNK3) to chromosomes 1q41 and 2p23". Genomics 51 (3): 478–9. doi:10.1006/geno.1998.5397. PMID 9721223.
2. Goldstein SA, Bayliss DA, Kim D, Lesage F, Plant LD, Rajan S (Dec 2005). "International Union of Pharmacology. LV. Nomenclature and molecular relationships of two-P potassium channels". Pharmacol Rev 57 (4): 527–40. doi:10.1124/pr.57.4.12. PMID 16382106.
3. "Entrez Gene: KCNK2 potassium channel, subfamily K, member 2".
4. Fink, M.; Duprat, F.; Lesage, F.; Reyes, R.; Romey, G.; Heurteaux, C.; Lazdunski, M. (1996). "Cloning, functional expression and brain localization of a novel unconventional outward rectifier K+ channel". The EMBO Journal 15 (24): 6854–6862. PMC 452511. PMID 9003761.
5. Patel, A. J.; Honoré, E.; Maingret, F.; Lesage, F.; Fink, M.; Duprat, F.; Lazdunski, M. (1998). "A mammalian two pore domain mechano-gated S-like K+ channel". The EMBO Journal 17 (15): 4283–4290. doi:10.1093/emboj/17.15.4283. PMC 1170762. PMID 9687497.
6. Giorda, R.; Weisberg, E. P.; Ip, T. K.; Trucco, M. (1992). "Genomic structure and strain-specific expression of the natural killer cell receptor NKR-P1". Journal of immunology (Baltimore, Md. : 1950) 149 (6): 1957–1963. PMID 1517565.
7. Patel, A. J.; Honoré, E.; Maingret, F.; Lesage, F.; Fink, M.; Duprat, F.; Lazdunski, M. (1998). "A mammalian two pore domain mechano-gated S-like K+ channel". The EMBO Journal 17 (15): 4283–4290. doi:10.1093/emboj/17.15.4283. PMC 1170762. PMID 9687497.
8. Patel, AJ; Lazdunski, M; Honoré, E (2001). "Lipid and mechano-gated 2P domain K(+) channels". Curr Opin Cell Biol 13 (4): 422–428. doi:10.1016/s0955-0674(00)00231-3.
9. Patel, A. J.; Honoré, E.; Maingret, F.; Lesage, F.; Fink, M.; Duprat, F.; Lazdunski, M. (1998). "A mammalian two pore domain mechano-gated S-like K+ channel". The EMBO Journal 17 (15): 4283–4290. doi:10.1093/emboj/17.15.4283. PMC 1170762. PMID 9687497.

Further reading

• Goldstein SA, Bockenhauer D, O'Kelly I, Zilberberg N (2001). "Potassium leak channels and the KCNK family of two-P-domain subunits.". Nat. Rev. Neurosci. 2 (3): 175–84. doi:10.1038/35058574. PMID 11256078.
• Honoré E (2007). "The neuronal background K2P channels: focus on TREK1.". Nat. Rev. Neurosci. 8 (4): 251–61. doi:10.1038/nrn2117. PMID 17375039.
• Fink M, Duprat F, Lesage F, et al. (1997). "Cloning, functional expression and brain localization of a novel unconventional outward rectifier K+ channel.". EMBO J. 15 (24): 6854–62. PMC 452511. PMID 9003761.
• Patel AJ, Honoré E, Lesage F, et al. (1999). "Inhalational anesthetics activate two-pore-domain background K+ channels.". Nat. Neurosci. 2 (5): 422–6. doi:10.1038/8084. PMID 10321245.
• Meadows HJ, Benham CD, Cairns W, et al. (2000). "Cloning, localisation and functional expression of the human orthologue of the TREK-1 potassium channel.". Pflugers Arch. 439 (6): 714–22. doi:10.1007/s004240050997. PMID 10784345.
• Maylie J, Adelman JP (2001). "Beam me up, Scottie! TREK channels swing both ways.". Nat. Neurosci. 4 (5): 457–8. doi:10.1038/87402. PMID 11319549.
• Bockenhauer D, Zilberberg N, Goldstein SA (2001). "KCNK2: reversible conversion of a hippocampal potassium leak into a voltage-dependent channel.". Nat. Neurosci. 4 (5): 486–91. doi:10.1038/87434. PMID 11319556.
• Enyeart JJ, Xu L, Danthi S, Enyeart JA (2003). "An ACTH- and ATP-regulated background K+ channel in adrenocortical cells is TREK-1.". J. Biol. Chem. 277 (51): 49186–99. doi:10.1074/jbc.M207233200. PMID 12368289.
• Strausberg RL, Feingold EA, Grouse LH, et al. (2003). "Generation and initial analysis of more than 15,000 full-length human and mouse cDNA sequences.". Proc. Natl. Acad. Sci. U.S.A. 99 (26): 16899–903. doi:10.1073/pnas.242603899. PMC 139241. PMID 12477932.
• Imabayashi H, Mori T, Gojo S, et al. (2003). "Redifferentiation of dedifferentiated chondrocytes and chondrogenesis of human bone marrow stromal cells via chondrosphere formation with expression profiling by large-scale cDNA analysis.". Exp. Cell Res. 288 (1): 35–50. doi:10.1016/S0014-4827(03)00130-7. PMID 12878157.
• Miller P, Peers C, Kemp PJ (2004). "Polymodal regulation of hTREK1 by pH, arachidonic acid, and hypoxia: physiological impact in acidosis and alkalosis.". Am. J. Physiol., Cell Physiol. 286 (2): C272–82. doi:10.1152/ajpcell.00334.2003. PMID 14522822.
• Fu GK, Wang JT, Yang J, et al. (2005). "Circular rapid amplification of cDNA ends for high-throughput extension cloning of partial genes.". Genomics 84 (1): 205–10. doi:10.1016/j.ygeno.2004.01.011. PMID 15203218.
• Kennard LE, Chumbley JR, Ranatunga KM, et al. (2005). "Inhibition of the human two-pore domain potassium channel, TREK-1, by fluoxetine and its metabolite norfluoxetine.". Br. J. Pharmacol. 144 (6): 821–9. doi:10.1038/sj.bjp.0706068. PMC 1576064. PMID 15685212.
• Miller P, Kemp PJ, Peers C (2005). "Structural requirements for O2 sensing by the human tandem-P domain channel, hTREK1.". Biochem. Biophys. Res. Commun. 331 (4): 1253–6. doi:10.1016/j.bbrc.2005.04.042. PMID 15883010.
• Murbartián J, Lei Q, Sando JJ, Bayliss DA (2005). "Sequential phosphorylation mediates receptor- and kinase-induced inhibition of TREK-1 background potassium channels.". J. Biol. Chem. 280 (34): 30175–84. doi:10.1074/jbc.M503862200. PMID 16006563.
• Hughes S, Magnay J, Foreman M, et al. (2006). "Expression of the mechanosensitive 2PK+ channel TREK-1 in human osteoblasts.". J. Cell. Physiol. 206 (3): 738–48. doi:10.1002/jcp.20536. PMID 16250016.
• Kimura K, Wakamatsu A, Suzuki Y, et al. (2006). "Diversification of transcriptional modulation: large-scale identification and characterization of putative alternative promoters of human genes.". Genome Res. 16 (1): 55–65. doi:10.1101/gr.4039406. PMC 1356129. PMID 16344560.

External links

• KCNK2 protein, human at the US National Library of Medicine Medical Subject Headings (MeSH)

This article incorporates text from the United States National Library of Medicine, which is in the public domain.