Potassium Channels (Homo sapiens)

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1, 4, 9, 12, 17...5, 621163182620118, 107, 14, 15, 231913222202cytosolGABBR1 KCNS1 THIK1 homodimersKCNH4 KCNJ10 K+TRESK homodimerKCNN2 K+KCNJ8 KCNJ6 GABA KCNQ3 K+KCNK2 KCNJ12 K+ATPKCNK13 KCNJ12 GNG7 TWIK channelsKCNA6 KCNA7 ABCC9 TREK homodimersKCNAB2 KCNJ14 KCNJ4 KCNK4 GNGT1 KCNN1 KCNJ tetramerKCNS3 KCNJ11 TALK 1and 2KCND1 cAMP K+Potassium transportchannels (Kir 1.1and Kir 4.1/5.1)ATP sensitive K+channels-inwardlyrectifying (SUR1)KCNN3 KCND3 GNB3 K+GNGT2 HCN1 GNG12 ATP sensitive K+channels-inwardlyrectifying (SUR2)KCNV1 KCNA4 GNG5 GABBR2 KCNQ5 K+KCNA10 KCNA2 KCNJ16 K+K+KCNMA1 KCNJ5 KCNF1 KCNMB4 KCND2 Small conductanceCa2+ activatedpotassium channelcAMPKCNMB2 KCNK18 KCNJ2 KCNK10 HCN channelsKCNB1 KCNJ2 KCNAB3 K+KCNJ8 Octamer of Voltagegated K+ channelsKCNJ11 GNB1 KCNV2 KCNA1 K+KCNH7 GNB2 GNG10 KCNG4 HCN3 KCNJ9 KCNC1 KCNAB1 KCNC4 KCNH8 KCNJ3 GABA B receptorG-proteinbeta-gamma and Kir3channel complexKCNH1 KCNJ15 HCN2 K+KCNH3 KCNC2 KCNQ1 KCNG3 KCNB2 ABCC8 GNG2 KCNG2 GNG3 KCNS2 KCNMB3 K+KCNQ2 KCNJ4 KCNA5 KCNG1 GNG4 KCNH2 KCNH6 KCNQ4 K+HCN channel bound tocAMPKCNMB1 BK channelTASKKCNA3 HCN4 K+GNG8 K+KCNN4KCNH5 KCNC3


Description

Potassium channels are tetrameric ion channels that are widely distributed and are found in all cell types. Potassium channels control resting membrane potential in neurons, contribute to regulation of action potentials in cardiac muscle and help release of insulin form pancreatic beta cells.
Broadly K+ channels are classified into voltage gated K+ channels, Hyperpolarization activated cyclic nucleotide gated K+ channels (HCN), Tandem pore domain K+ channels, Ca2+ activated K+ channels and inwardly rectifying K+ channels. Source:Reactome.

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Bibliography

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  1. Meuth SG, Kanyshkov T, Melzer N, Bittner S, Kieseier BC, Budde T, Wiendl H.; ''Altered neuronal expression of TASK1 and TASK3 potassium channels in rodent and human autoimmune CNS inflammation.''; PubMed Europe PMC Scholia
  2. Fowler CE, Aryal P, Suen KF, Slesinger PA.; ''Evidence for association of GABA(B) receptors with Kir3 channels and regulators of G protein signalling (RGS4) proteins.''; PubMed Europe PMC Scholia
  3. Kim J, Hoffman DA.; ''Potassium channels: newly found players in synaptic plasticity.''; PubMed Europe PMC Scholia
  4. Norris AJ, Foeger NC, Nerbonne JM.; ''Neuronal voltage-gated K+ (Kv) channels function in macromolecular complexes.''; PubMed Europe PMC Scholia
  5. Hill MA, Yang Y, Ella SR, Davis MJ, Braun AP.; ''Large conductance, Ca2+-activated K+ channels (BKCa) and arteriolar myogenic signaling.''; PubMed Europe PMC Scholia
  6. Alesutan I, Föller M, Sopjani M, Dërmaku-Sopjani M, Zelenak C, Fröhlich H, Velic A, Fraser S, Kemp BE, Seebohm G, Völkl H, Lang F.; ''Inhibition of the heterotetrameric K+ channel KCNQ1/KCNE1 by the AMP-activated protein kinase.''; PubMed Europe PMC Scholia
  7. Han J, Kang D, Kim D.; ''Functional properties of four splice variants of a human pancreatic tandem-pore K+ channel, TALK-1.''; PubMed Europe PMC Scholia
  8. Cramer NP, Best TK, Stoffel M, Siarey RJ, Galdzicki Z.; ''GABAB-GIRK2-mediated signaling in Down syndrome.''; PubMed Europe PMC Scholia
  9. MacKinnon R.; ''New insights into the structure and function of potassium channels.''; PubMed Europe PMC Scholia
  10. Ohya S, Fujimori T, Kimura T, Yamamura H, Imaizumi Y.; ''Novel spliced variants of large-conductance Ca(2+)-activated K(+)-channel β2-subunit in human and rodent pancreas.''; PubMed Europe PMC Scholia
  11. Biel M, Wahl-Schott C, Michalakis S, Zong X.; ''Hyperpolarization-activated cation channels: from genes to function.''; PubMed Europe PMC Scholia
  12. Kréneisz O, Benoit JP, Bayliss DA, Mulkey DK.; ''AMP-activated protein kinase inhibits TREK channels.''; PubMed Europe PMC Scholia
  13. Theilig F, Goranova I, Hirsch JR, Wieske M, Unsal S, Bachmann S, Veh RW, Derst C.; ''Cellular localization of THIK-1 (K(2P)13.1) and THIK-2 (K(2P)12.1) K channels in the mammalian kidney.''; PubMed Europe PMC Scholia
  14. Fallen K, Banerjee S, Sheehan J, Addison D, Lewis LM, Meiler J, Denton JS.; ''The Kir channel immunoglobulin domain is essential for Kir1.1 (ROMK) thermodynamic stability, trafficking and gating.''; PubMed Europe PMC Scholia
  15. Baruscotti M, Bottelli G, Milanesi R, DiFrancesco JC, DiFrancesco D.; ''HCN-related channelopathies.''; PubMed Europe PMC Scholia
  16. Sheng JZ, Ella S, Davis MJ, Hill MA, Braun AP.; ''Openers of SKCa and IKCa channels enhance agonist-evoked endothelial nitric oxide synthesis and arteriolar vasodilation.''; PubMed Europe PMC Scholia
  17. Lafrenière RG, Cader MZ, Poulin JF, Andres-Enguix I, Simoneau M, Gupta N, Boisvert K, Lafrenière F, McLaughlan S, Dubé MP, Marcinkiewicz MM, Ramagopalan S, Ansorge O, Brais B, Sequeiros J, Pereira-Monteiro JM, Griffiths LR, Tucker SJ, Ebers G, Rouleau GA.; ''A dominant-negative mutation in the TRESK potassium channel is linked to familial migraine with aura.''; PubMed Europe PMC Scholia
  18. Hibino H, Inanobe A, Furutani K, Murakami S, Findlay I, Kurachi Y.; ''Inwardly rectifying potassium channels: their structure, function, and physiological roles.''; PubMed Europe PMC Scholia
  19. Dallas ML, Scragg JL, Wyatt CN, Ross F, Hardie DG, Evans AM, Peers C.; ''Modulation of O(2) sensitive K (+) channels by AMP-activated protein kinase.''; PubMed Europe PMC Scholia
  20. Shorter K, Farjo NP, Picksley SM, Randall VA.; ''Human hair follicles contain two forms of ATP-sensitive potassium channels, only one of which is sensitive to minoxidil.''; PubMed Europe PMC Scholia
  21. Shin HG, Lu Z.; ''Mechanism of the voltage sensitivity of IRK1 inward-rectifier K+ channel block by the polyamine spermine.''; PubMed Europe PMC Scholia
  22. Feliciangeli S, Tardy MP, Sandoz G, Chatelain FC, Warth R, Barhanin J, Bendahhou S, Lesage F.; ''Potassium channel silencing by constitutive endocytosis and intracellular sequestration.''; PubMed Europe PMC Scholia
  23. Gestreau C, Heitzmann D, Thomas J, Dubreuil V, Bandulik S, Reichold M, Bendahhou S, Pierson P, Sterner C, Peyronnet-Roux J, Benfriha C, Tegtmeier I, Ehnes H, Georgieff M, Lesage F, Brunet JF, Goridis C, Warth R, Barhanin J.; ''Task2 potassium channels set central respiratory CO2 and O2 sensitivity.''; PubMed Europe PMC Scholia
  24. McKeown L, Swanton L, Robinson P, Jones OT.; ''Surface expression and distribution of voltage-gated potassium channels in neurons (Review).''; PubMed Europe PMC Scholia
  25. Pongs O, Schwarz JR.; ''Ancillary subunits associated with voltage-dependent K+ channels.''; PubMed Europe PMC Scholia
  26. Moroni A, Gorza L, Beltrame M, Gravante B, Vaccari T, Bianchi ME, Altomare C, Longhi R, Heurteaux C, Vitadello M, Malgaroli A, DiFrancesco D.; ''Hyperpolarization-activated cyclic nucleotide-gated channel 1 is a molecular determinant of the cardiac pacemaker current I(f).''; PubMed Europe PMC Scholia
  27. Toyoda H, Saito M, Okazawa M, Hirao K, Sato H, Abe H, Takada K, Funabiki K, Takada M, Kaneko T, Kang Y.; ''Protein kinase G dynamically modulates TASK1-mediated leak K+ currents in cholinergic neurons of the basal forebrain.''; PubMed Europe PMC Scholia
  28. Krenz M, Oldenburg O, Wimpee H, Cohen MV, Garlid KD, Critz SD, Downey JM, Benoit JN.; ''Opening of ATP-sensitive potassium channels causes generation of free radicals in vascular smooth muscle cells.''; PubMed Europe PMC Scholia
  29. Xie K, Allen KL, Kourrich S, Colón-Saez J, Thomas MJ, Wickman K, Martemyanov KA.; ''Gbeta5 recruits R7 RGS proteins to GIRK channels to regulate the timing of neuronal inhibitory signaling.''; PubMed Europe PMC Scholia

History

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CompareRevisionActionTimeUserComment
114844view16:34, 25 January 2021ReactomeTeamReactome version 75
113290view11:36, 2 November 2020ReactomeTeamReactome version 74
112502view15:46, 9 October 2020ReactomeTeamReactome version 73
101414view11:29, 1 November 2018ReactomeTeamreactome version 66
100952view21:06, 31 October 2018ReactomeTeamreactome version 65
100489view19:40, 31 October 2018ReactomeTeamreactome version 64
100034view16:23, 31 October 2018ReactomeTeamreactome version 63
99587view14:57, 31 October 2018ReactomeTeamreactome version 62 (2nd attempt)
93800view13:37, 16 August 2017ReactomeTeamreactome version 61
93337view11:20, 9 August 2017ReactomeTeamreactome version 61
88104view09:34, 26 July 2016RyanmillerOntology Term : 'ion transport pathway' added !
88103view09:33, 26 July 2016RyanmillerOntology Term : 'regulatory pathway' added !
86424view09:17, 11 July 2016ReactomeTeamreactome version 56
83272view10:37, 18 November 2015ReactomeTeamVersion54
81384view12:54, 21 August 2015ReactomeTeamVersion53
76853view08:12, 17 July 2014ReactomeTeamFixed remaining interactions
76558view11:54, 16 July 2014ReactomeTeamFixed remaining interactions
75891view09:54, 11 June 2014ReactomeTeamRe-fixing comment source
75591view10:43, 10 June 2014ReactomeTeamReactome 48 Update
74946view13:47, 8 May 2014AnweshaFixing comment source for displaying WikiPathways description
74590view08:38, 30 April 2014ReactomeTeamNew pathway

External references

DataNodes

View all...
NameTypeDatabase referenceComment
ABCC8 ProteinQ09428 (Uniprot-TrEMBL)
ABCC9 ProteinO60706 (Uniprot-TrEMBL)
ATP sensitive K+

channels-inwardly

rectifying (SUR1)
ComplexR-HSA-1297378 (Reactome)
ATP sensitive K+

channels-inwardly

rectifying (SUR2)
ComplexR-HSA-1369001 (Reactome)
ATPMetaboliteCHEBI:15422 (ChEBI)
BK channelComplexR-HSA-418473 (Reactome) BK channels (also called Maxi-K or slo1) are potassium ion channels. They are activated by changes in membrane electrical potential and increases in intracellular [Ca2+]. Opening of BK channels results in cell membrane hyperpolarization. BK channels are tetramers of dimer subunits formed by the association of a pore-forming alpha subunit, always derived from the same gene KCNMA1, and a modulatory beta subunit, dervied from one of 4 human genes KCNMB11-4. Intracellular calcium regulates the physical association between the alpha and beta subunits.
GABA B receptor

G-protein beta-gamma and Kir3

channel complex
ComplexR-HSA-1013011 (Reactome)
GABA MetaboliteCHEBI:16865 (ChEBI)
GABBR1 ProteinQ9UBS5 (Uniprot-TrEMBL)
GABBR2 ProteinO75899 (Uniprot-TrEMBL)
GNB1 ProteinP62873 (Uniprot-TrEMBL)
GNB2 ProteinP62879 (Uniprot-TrEMBL)
GNB3 ProteinP16520 (Uniprot-TrEMBL)
GNG10 ProteinP50151 (Uniprot-TrEMBL)
GNG12 ProteinQ9UBI6 (Uniprot-TrEMBL)
GNG2 ProteinP59768 (Uniprot-TrEMBL)
GNG3 ProteinP63215 (Uniprot-TrEMBL)
GNG4 ProteinP50150 (Uniprot-TrEMBL)
GNG5 ProteinP63218 (Uniprot-TrEMBL)
GNG7 ProteinO60262 (Uniprot-TrEMBL)
GNG8 ProteinQ9UK08 (Uniprot-TrEMBL)
GNGT1 ProteinP63211 (Uniprot-TrEMBL)
GNGT2 ProteinO14610 (Uniprot-TrEMBL)
HCN channel bound to cAMPComplexR-HSA-1297435 (Reactome)
HCN channelsR-HSA-1297434 (Reactome)
HCN1 ProteinO60741 (Uniprot-TrEMBL)
HCN2 ProteinQ9UL51 (Uniprot-TrEMBL)
HCN3 ProteinQ9P1Z3 (Uniprot-TrEMBL)
HCN4 ProteinQ9Y3Q4 (Uniprot-TrEMBL)
K+MetaboliteCHEBI:29103 (ChEBI)
KCNA1 ProteinQ09470 (Uniprot-TrEMBL)
KCNA10 ProteinQ16322 (Uniprot-TrEMBL)
KCNA2 ProteinP16389 (Uniprot-TrEMBL)
KCNA3 ProteinP22001 (Uniprot-TrEMBL)
KCNA4 ProteinP22459 (Uniprot-TrEMBL)
KCNA5 ProteinP22460 (Uniprot-TrEMBL)
KCNA6 ProteinP17658 (Uniprot-TrEMBL)
KCNA7 ProteinQ96RP8 (Uniprot-TrEMBL)
KCNAB1 ProteinQ14722 (Uniprot-TrEMBL)
KCNAB2 ProteinQ13303 (Uniprot-TrEMBL)
KCNAB3 ProteinO43448 (Uniprot-TrEMBL)
KCNB1 ProteinQ14721 (Uniprot-TrEMBL)
KCNB2 ProteinQ92953 (Uniprot-TrEMBL)
KCNC1 ProteinP48547 (Uniprot-TrEMBL)
KCNC2 ProteinQ96PR1 (Uniprot-TrEMBL)
KCNC3 ProteinQ14003 (Uniprot-TrEMBL)
KCNC4 ProteinQ03721 (Uniprot-TrEMBL)
KCND1 ProteinQ9NSA2 (Uniprot-TrEMBL)
KCND2 ProteinQ9NZV8 (Uniprot-TrEMBL)
KCND3 ProteinQ9UK17 (Uniprot-TrEMBL)
KCNF1 ProteinQ9H3M0 (Uniprot-TrEMBL)
KCNG1 ProteinQ9UIX4 (Uniprot-TrEMBL)
KCNG2 ProteinQ9UJ96 (Uniprot-TrEMBL)
KCNG3 ProteinQ8TAE7 (Uniprot-TrEMBL)
KCNG4 ProteinQ8TDN1 (Uniprot-TrEMBL)
KCNH1 ProteinO95259 (Uniprot-TrEMBL)
KCNH2 ProteinQ12809 (Uniprot-TrEMBL)
KCNH3 ProteinQ9ULD8 (Uniprot-TrEMBL)
KCNH4 ProteinQ9UQ05 (Uniprot-TrEMBL)
KCNH5 ProteinQ8NCM2 (Uniprot-TrEMBL)
KCNH6 ProteinQ9H252 (Uniprot-TrEMBL)
KCNH7 ProteinQ9NS40 (Uniprot-TrEMBL)
KCNH8 ProteinQ96L42 (Uniprot-TrEMBL)
KCNJ tetramerComplexR-HSA-1299200 (Reactome) Kir 2 channels form heterotetramers of any two of the four subunits.
KCNJ10 ProteinP78508 (Uniprot-TrEMBL)
KCNJ11 ProteinQ14654 (Uniprot-TrEMBL)
KCNJ12 ProteinQ14500 (Uniprot-TrEMBL)
KCNJ14 ProteinQ9UNX9 (Uniprot-TrEMBL)
KCNJ15 ProteinQ99712 (Uniprot-TrEMBL)
KCNJ16 ProteinQ9NPI9 (Uniprot-TrEMBL)
KCNJ2 ProteinP63252 (Uniprot-TrEMBL)
KCNJ3 ProteinP48549 (Uniprot-TrEMBL)
KCNJ4 ProteinP48050 (Uniprot-TrEMBL)
KCNJ5 ProteinP48544 (Uniprot-TrEMBL)
KCNJ6 ProteinP48051 (Uniprot-TrEMBL)
KCNJ8 ProteinQ15842 (Uniprot-TrEMBL)
KCNJ9 ProteinQ92806 (Uniprot-TrEMBL)
KCNK10 ProteinP57789 (Uniprot-TrEMBL)
KCNK13 ProteinQ9HB14 (Uniprot-TrEMBL)
KCNK18 ProteinQ7Z418 (Uniprot-TrEMBL)
KCNK2 ProteinO95069 (Uniprot-TrEMBL)
KCNK4 ProteinQ9NYG8 (Uniprot-TrEMBL)
KCNMA1 ProteinQ12791 (Uniprot-TrEMBL)
KCNMB1 ProteinQ16558 (Uniprot-TrEMBL)
KCNMB2 ProteinQ9Y691 (Uniprot-TrEMBL)
KCNMB3 ProteinQ9NPA1 (Uniprot-TrEMBL)
KCNMB4 ProteinQ86W47 (Uniprot-TrEMBL)
KCNN1 ProteinQ92952 (Uniprot-TrEMBL)
KCNN2 ProteinQ9H2S1 (Uniprot-TrEMBL)
KCNN3 ProteinQ9UGI6 (Uniprot-TrEMBL)
KCNN4ProteinO15554 (Uniprot-TrEMBL)
KCNQ1 ProteinP51787 (Uniprot-TrEMBL)
KCNQ2 ProteinO43526 (Uniprot-TrEMBL)
KCNQ3 ProteinO43525 (Uniprot-TrEMBL)
KCNQ4 ProteinP56696 (Uniprot-TrEMBL)
KCNQ5 ProteinQ9NR82 (Uniprot-TrEMBL)
KCNS1 ProteinQ96KK3 (Uniprot-TrEMBL)
KCNS2 ProteinQ9ULS6 (Uniprot-TrEMBL)
KCNS3 ProteinQ9BQ31 (Uniprot-TrEMBL)
KCNV1 ProteinQ6PIU1 (Uniprot-TrEMBL)
KCNV2 ProteinQ8TDN2 (Uniprot-TrEMBL)
Octamer of Voltage gated K+ channelsComplexR-HSA-1297370 (Reactome)
Potassium transport

channels (Kir 1.1

and Kir 4.1/5.1)
R-HSA-1299206 (Reactome)
Small conductance

Ca2+ activated

potassium channel
ComplexR-HSA-1297362 (Reactome)
TALK 1and 2R-HSA-1299271 (Reactome)
TASKR-HSA-1299270 (Reactome)
THIK1 homodimersComplexR-HSA-1299264 (Reactome)
TREK homodimersComplexR-HSA-1299260 (Reactome)
TRESK homodimerComplexR-HSA-1299256 (Reactome)
TWIK channelsR-HSA-1299255 (Reactome)
cAMP MetaboliteCHEBI:17489 (ChEBI)
cAMPMetaboliteCHEBI:17489 (ChEBI)

Annotated Interactions

View all...
SourceTargetTypeDatabase referenceComment
ATP sensitive K+

channels-inwardly

rectifying (SUR1)
mim-catalysisR-HSA-1296024 (Reactome)
ATP sensitive K+

channels-inwardly

rectifying (SUR2)
mim-catalysisR-HSA-1369017 (Reactome)
ATPTBarR-HSA-1296024 (Reactome)
BK channelmim-catalysisR-HSA-1296037 (Reactome)
GABA B receptor

G-protein beta-gamma and Kir3

channel complex
mim-catalysisR-HSA-1013020 (Reactome)
HCN channel bound to cAMPArrowR-HSA-1297444 (Reactome)
HCN channel bound to cAMPmim-catalysisR-HSA-1296043 (Reactome)
HCN channelsR-HSA-1297444 (Reactome)
K+ArrowR-HSA-1013020 (Reactome)
K+ArrowR-HSA-1296024 (Reactome)
K+ArrowR-HSA-1296035 (Reactome)
K+ArrowR-HSA-1296037 (Reactome)
K+ArrowR-HSA-1296039 (Reactome)
K+ArrowR-HSA-1296043 (Reactome)
K+ArrowR-HSA-1296045 (Reactome)
K+ArrowR-HSA-1296046 (Reactome)
K+ArrowR-HSA-1296127 (Reactome)
K+ArrowR-HSA-1296348 (Reactome)
K+ArrowR-HSA-1299297 (Reactome)
K+ArrowR-HSA-1299304 (Reactome)
K+ArrowR-HSA-1299318 (Reactome)
K+ArrowR-HSA-1299338 (Reactome)
K+ArrowR-HSA-1299359 (Reactome)
K+ArrowR-HSA-1369017 (Reactome)
K+R-HSA-1013020 (Reactome)
K+R-HSA-1296024 (Reactome)
K+R-HSA-1296035 (Reactome)
K+R-HSA-1296037 (Reactome)
K+R-HSA-1296039 (Reactome)
K+R-HSA-1296043 (Reactome)
K+R-HSA-1296045 (Reactome)
K+R-HSA-1296046 (Reactome)
K+R-HSA-1296127 (Reactome)
K+R-HSA-1296348 (Reactome)
K+R-HSA-1299297 (Reactome)
K+R-HSA-1299304 (Reactome)
K+R-HSA-1299318 (Reactome)
K+R-HSA-1299338 (Reactome)
K+R-HSA-1299359 (Reactome)
K+R-HSA-1369017 (Reactome)
KCNJ tetramermim-catalysisR-HSA-1296046 (Reactome)
KCNN4mim-catalysisR-HSA-1296035 (Reactome)
Octamer of Voltage gated K+ channelsmim-catalysisR-HSA-1296127 (Reactome)
Potassium transport

channels (Kir 1.1

and Kir 4.1/5.1)
mim-catalysisR-HSA-1296045 (Reactome)
R-HSA-1013020 (Reactome) Binding of G beta gamma activates the GIRK/Kir3 channels that allow the efflux of K+ out of the cell resulting in a hyperpolarized membrane potential. This negative membrane potential prevents the activation of voltage dependent Ca2+ channels.
R-HSA-1296024 (Reactome) In neuroendocrine cells such as pancreatic alpha-, beta-, and delta-cells and in the brain, ATP sensitive K+ channels assemble as octamers of four Kir 6.1, 6.2 subunits and four high-affinity sulfonyl urea receptor 1 subunits (SUR1). These channels are blocked by excess intracellular levels of ATP. When the ATP is low, ATP dissociates and the channel opens to allow K+ efflux.
R-HSA-1296035 (Reactome) Intermediate conductance K+ channels are restricted to non neuronal tissues like epithelia, blood cells and are activated by intracellular Ca2+ ion concentration. Activation of Ca2+ activated K+ channels with intermediate conductance leads to K+ efflux in to the extracellular space.
R-HSA-1296037 (Reactome) Increase in intracellular concentration of Ca2+ ions and membrane depolarization cooperatively activates BKca, which exhibit large unitary conductance. Ca2+ activated potassium channels. Activation leads to K+ efflux which changes the membrane potential, which leads to inactivation voltage activated Ca2+ channels. BKca are involved in regulation of smooth muscle tone, microbial killing in leukocytes and modulation of neurotransmitter release. Activation of BKca channel with increase in intracellular concentration of Ca2+ leads to efflux of K+ into the extracellular space, which contributes to hyperpolarization of the membrane potential.
R-HSA-1296039 (Reactome) Small conductance Ca2+ activated potassium channels (SKca) are solely activated by intracellular Ca2+ concentration. SKca channels form functional tetramers. SKca channels control the contractility of uterus, maintian vascular tone, modulate hormone secretion, control cell volume in red blood cells and activation of microglia and lymphocytes. Actiavtion of SKca channels is triggered by increase in the intracellular Ca2+ ion concentration. Activation of Skca channels leads to relatively small K+ ion effluxes.
R-HSA-1296043 (Reactome) HCN channels are activated upon hyperpolarization of membrane potential and cAMP binding leading to K+ efflux.
R-HSA-1296045 (Reactome) Homotetramers of Kir 1.1 function as inwardly rectifying potassium transport channels. Ki 1.1 are found on the apical side of the cells in the ascending limp of loop of henle and upon activation transport K+ into the extracellular space. Heterotetramers of Kir 4.1 and Ki 5.1 are found on the basolateral side of cells in the distal convoluted tube. Activation of kir 4.1 and 5.1 heterotetramers leads to efflux of K+ into the extracellular space.
R-HSA-1296046 (Reactome) Activation of classical Kir (K+ inwardly rectifying) channels (KCNJ2, 4, 12 and 14) results in K+ influx which contributes to the maintenance of the membrane potential (Phase 4 of the action potential). The current created by this flow of K+ is called the inward rectifying current (IK1). A channel that is inwardly-rectifying is one that passes current more easily into the cell than out of the cell. At membrane potentials negative to potassium's reversal potential, KCNJs support the flow of K+ ions into the cell, pushing the membrane potential back to the resting potential. Two factors regulate K+ permeability - cell permeability to K+ is increased at more negative membrane potentials and increasing extracellular K+ concentrations.

When the membrane potential is positive to the channel's resting potential (such as in Phase 3 of the action potential), these channels pass very little charge out of the cell. This may be due to the channel's pores being blocked by internal Mg2+ and endogenous polyamines such as spermine (Shin & Lu 2005).

Inwardly rectifying (Kir) channels contribute to potassium leak, stabilizing cells near the equilibrium reversal potential of potassium (EK). Kir channels pass small outward currents because of pore blockade by internal magnesium and polyamines; at potentials negative to EK, large inward currents are passed upon relief from blockade.
R-HSA-1296127 (Reactome) Activation of voltage gated potassium channel is triggered by membrane potential changes that is sensed by the channel assembly. Activation of voltage-gated potassium channel leads to selective outward current of K+ ions.
R-HSA-1296348 (Reactome) TREK channels are activated by mechanical stretch, pH temperature and arachidonic acid which leads to efflux of K+ into the extracellular space resulting in membrane hyperpolarization.
R-HSA-1297444 (Reactome) HCN channels require cAMP binding and hyperpolarization of membrane potential for channel opening.
R-HSA-1299297 (Reactome) THIK subfamily has 2 members, THIK1 and THIK 2. THIK 1 forms functional homodimers whereas THIK2 function has not been demonstrated. THIK1 channels are inhibited by halothane. THICK1 channels form K+ leak channels and are not regulated by acidity or alkalanity changes.
R-HSA-1299304 (Reactome) Activation of TWIK channels results in low outward K+ currents.
R-HSA-1299318 (Reactome) TASK are tandem repeat K+ channels that are sensitive to extracellular pH. Activation of TASK results in efflux of K+ into the extracellular space.
R-HSA-1299338 (Reactome) TRESK is expressed in spinal cord and brain and is involved in K+ efflux. TRESK activation may be mediated by calcineurin.
R-HSA-1299359 (Reactome) TALK is activated by increase in pH alkalinity in the extracellular fluid. Potassium is pumped out into the extracellular fluid.
R-HSA-1369017 (Reactome) In muscle cells such as cardiac, skeletal, vascular and nonvascular smooth muscle, ATP sensitive K+ channels assemble as octamers of four Kir 6.x subunits and four low-affinity sulfonyl urea receptor 2 subunits (SUR2). The human gene encoding SUR2 gives rise to two splice variants, SUR2A and SUR2B. These channels are blocked by excess intracellular levels of ATP. When the ATP is low, ATP dissociates and the channel opens to allow K+ efflux ().
Small conductance

Ca2+ activated

potassium channel
mim-catalysisR-HSA-1296039 (Reactome)
TALK 1and 2mim-catalysisR-HSA-1299359 (Reactome)
TASKmim-catalysisR-HSA-1299318 (Reactome)
THIK1 homodimersmim-catalysisR-HSA-1299297 (Reactome)
TREK homodimersmim-catalysisR-HSA-1296348 (Reactome)
TRESK homodimermim-catalysisR-HSA-1299338 (Reactome)
TWIK channelsmim-catalysisR-HSA-1299304 (Reactome)
cAMPR-HSA-1297444 (Reactome)
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