Tmic
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Record Information
Version2.0
Creation Date2009-03-06 18:58:05 UTC
Update Date2014-12-24 20:21:07 UTC
Accession NumberT3D0109
Identification
Common NameBarium
ClassSmall Molecule
DescriptionBarium is a dense alkaline earth metal that occurs in nature as a divalent cation in combination with other elements. Physiologically, it exists as an ion in the body. In addition to its natural presence in the Earth's crust, and therefore its natural occurrence in most surface waters, barium is also released to the environment via industrial emissions. The residence time of barium in the atmosphere may be up to several days. Barium sulfate exists as a white orthorhombic powder or crystals. Barite, the mineral from which barium sulfate is produced, is a moderately soft crystalline white opaque to transparent mineral. The most important impurities are iron(III) oxide, aluminium oxide, silica, and strontium sulfate.Barium sulfate has a low toxicity and relatively high density of about 4.5 g*cm-3 (and thus opacity to X-rays). For this reason it is used as a radiocontrast agent in X-ray imaging of the digestive system (barium meals and barium enemas). Lithopone, a pigment that contains barium sulfate and zinc sulfide, is a permanent white that has good covering power, and does not darken when exposed to sulfides. (Wikipedia). Barium hydroxide is strongly alkaline and therefore corrosive. Barium nitrate caused mild skin irritation and severe eye irritation in rabbits. The lack of reports of skin or eye irritation in humans, despite its widespread use, suggests that barium sulfate, often used as a contrast medium, is not a strong irritant. Useful information on the sensitization potential of barium compounds was not identified. Oral intake from drinking water and food is the most prevalent route of exposure to barium compounds for the general population. For the occupational environment, data from industry in the United Kingdom and predictions made using the Estimation and Assessment of Substance Exposure (EASE) model suggest that exposures can be controlled to less than 10 mg/m3 8 hours time weighted average (total inhalable dust). In some situations, control will be to levels significantly below this value. Short term exposures may be higher than 10 mg/m3 for some tasks.The critical end points in humans for toxicity resulting from exposure to barium and barium compounds appear to be hypertension and renal function. Using a no observed adverse effect level (NOAEL) in humans of 0.21 mg barium/kg body weight per day, a tolerable intake value of 0.02 mg/kg body weight per day for barium and barium compounds has been developed in this document.Dissolved barium in aquatic environments may represent a risk to aquatic organisms such as daphnids, but it is apparently of lesser risk to fish and aquatic plants, although data are limited. No adverse effects have been reported in ecological assessments of terrestrial plants or wildlife, although some plants are known to bioaccumulate barium from the soil.(Concise international chemical assessment document 33; http://www.inchem.org/documents/cicads/cicads/cicad33.htm).
Compound Type
  • Barium Compound
  • Food Toxin
  • Industrial/Workplace Toxin
  • Inorganic Compound
  • Metabolite
  • Metal
  • Natural Compound
Chemical Structure
Thumb
Synonyms
Synonym
Ba(2+)
Ba2+
Barium ion
Barium(2+)
Barium(2+) ion
Barium(II)
Barium(II) cation
Barium(II) ion
Chemical FormulaBa
Average Molecular Mass137.326 g/mol
Monoisotopic Mass137.904 g/mol
CAS Registry Number7440-39-3
IUPAC Namebarium(2+) ion
Traditional Namebarium(2+) ion
SMILES[Ba++]
InChI IdentifierInChI=1S/Ba/q+2
InChI KeyInChIKey=XDFCIPNJCBUZJN-UHFFFAOYSA-N
Chemical Taxonomy
Description belongs to the class of inorganic compounds known as homogeneous alkaline earth metal compounds. These are inorganic compounds containing only metal atoms,with the largest atom being a alkaline earth metal atom.
KingdomInorganic compounds
Super ClassHomogeneous metal compounds
ClassHomogeneous alkaline earth metal compounds
Sub ClassNot Available
Direct ParentHomogeneous alkaline earth metal compounds
Alternative ParentsNot Available
Substituents
  • Homogeneous alkaline earth metal
Molecular FrameworkNot Available
External Descriptors
Biological Properties
StatusDetected and Not Quantified
OriginExogenous
Cellular Locations
  • Cytoplasm
  • Extracellular
Biofluid LocationsNot Available
Tissue LocationsNot Available
PathwaysNot Available
ApplicationsNot Available
Biological RolesNot Available
Chemical RolesNot Available
Physical Properties
StateSolid
AppearanceSilvery white metal.
Experimental Properties
PropertyValue
Melting Point710°C
Boiling PointNot Available
SolubilityNot Available
LogPNot Available
Predicted Properties
PropertyValueSource
logP-0.2ChemAxon
Physiological Charge2ChemAxon
Hydrogen Acceptor Count0ChemAxon
Hydrogen Donor Count0ChemAxon
Polar Surface Area0 ŲChemAxon
Rotatable Bond Count0ChemAxon
Refractivity0 m³·mol⁻¹ChemAxon
Polarizability1.78 ųChemAxon
Number of Rings0ChemAxon
Bioavailability1ChemAxon
Rule of FiveYesChemAxon
Ghose FilterYesChemAxon
Veber's RuleYesChemAxon
MDDR-like RuleYesChemAxon
Spectra
SpectraNot Available
Toxicity Profile
Route of ExposureOral (3) ; inhalation (3)
Mechanism of ToxicityBarium is a competitive potassium channel antagonist that blocks the passive efflux of intracellular potassium, resulting in a shift of potassium from extracellular to intracellular compartments. The intracellular translocation of potassium results in a decreased resting membrane potential, making the muscle fibers electrically unexcitable and causing paralysis. (3)
MetabolismBarium compounds are absorbed via ingestion and inhalation. Barium is principally found in the bone, while small amounts exists in the muscle, adipose tissue, skin, and connective tissue. Barium is not metabolized, but may be transported and incorporated into complexes or tissues. Barium is excreted in the urine and faeces. (3)
Toxicity ValuesNot Available
Lethal Dose1 to 15 grams for an adult human (barium salts). (1)
Carcinogenicity (IARC Classification)No indication of carcinogenicity to humans (not listed by IARC).
Uses/SourcesBarium compounds are used by the oil and gas industries to make drilling muds, and can also be used in the production of paint, bricks, ceramics, glass, and rubber. They are also often used in pyrotechnics, as they emit a green light when burned. (3, 4)
Minimum Risk LevelIntermediate Oral: 0.2 mg/kg/day (Barium salts) (2) Chronic Oral: 0.2 mg/kg/day (Barium salts) (2)
Health EffectsThe health effects of the different barium compounds depend on how well the compound dissolves in water or the stomach contents. At low doses, barium acts as a muscle stimulant, while higher doses affect the nervous system, causing cardiac irregularities, tremors, weakness, anxiety, dyspnea, paralysisand possibly death. Barium may also cause gastrointestinal disturbances, damage the kidneys and cause decreases in body weight. (3)
SymptomsIngesting excess barium may cause vomiting, abdominal cramps, diarrhea, difficulties in breathing, increased or decreased blood pressure, numbness around the face, and muscle weakness. High levels may result in changes in heart rhythm or paralysis and possibly death. (3)
TreatmentIntravenous infusion of potassium often relieves many of the symptoms of barium toxicity. (3)
Normal Concentrations
Not Available
Abnormal Concentrations
Not Available
DrugBank IDNot Available
HMDB IDHMDB04142
PubChem Compound ID104810
ChEMBL IDNot Available
ChemSpider ID94609
KEGG IDC13881
UniProt IDNot Available
OMIM ID
ChEBI ID37136
BioCyc IDCPD0-1592
CTD IDD001464
Stitch IDBarium
PDB IDBA
ACToR ID6373
Wikipedia LinkBarium
References
Synthesis ReferenceNot Available
MSDSLink
General References
  1. Gosselin RE, Smith RP, and Hodge HC (1984). Clinical Toxicology of Commercial Products. 5th ed. Baltimore: Williams and Wilkins.
  2. ATSDR - Agency for Toxic Substances and Disease Registry (2001). Minimal Risk Levels (MRLs) for Hazardous Substances. U.S. Public Health Service in collaboration with U.S. Environmental Protection Agency (EPA). [Link]
  3. ATSDR - Agency for Toxic Substances and Disease Registry (2007). Toxicological profile for barium. U.S. Public Health Service in collaboration with U.S. Environmental Protection Agency (EPA). [Link]
  4. Wikipedia. Barium. Last Updated 21 May 2009. [Link]
Gene Regulation
Up-Regulated GenesNot Available
Down-Regulated GenesNot Available

Targets

General Function:
Phosphatidylinositol-4,5-bisphosphate binding
Specific Function:
In the kidney, probably plays a major role in potassium homeostasis. Inward rectifier potassium channels are characterized by a greater tendency to allow potassium to flow into the cell rather than out of it. Their voltage dependence is regulated by the concentration of extracellular potassium; as external potassium is raised, the voltage range of the channel opening shifts to more positive voltages. The inward rectification is mainly due to the blockage of outward current by internal magnesium. This channel is activated by internal ATP and can be blocked by external barium.
Gene Name:
KCNJ1
Uniprot ID:
P48048
Molecular Weight:
44794.6 Da
References
  1. Alagem N, Dvir M, Reuveny E: Mechanism of Ba(2+) block of a mouse inwardly rectifying K+ channel: differential contribution by two discrete residues. J Physiol. 2001 Jul 15;534(Pt. 2):381-93. [11454958 ]
General Function:
Voltage-gated potassium channel activity
Specific Function:
This receptor is controlled by G proteins. Inward rectifier potassium channels are characterized by a greater tendency to allow potassium to flow into the cell rather than out of it. Their voltage dependence is regulated by the concentration of extracellular potassium; as external potassium is raised, the voltage range of the channel opening shifts to more positive voltages. The inward rectification is mainly due to the blockage of outward current by internal magnesium. Can be blocked by extracellular barium (By similarity). Subunit of ATP-sensitive potassium channels (KATP). Can form cardiac and smooth muscle-type KATP channels with ABCC9. KCNJ11 forms the channel pore while ABCC9 is required for activation and regulation.
Gene Name:
KCNJ11
Uniprot ID:
Q14654
Molecular Weight:
43540.375 Da
References
  1. Alagem N, Dvir M, Reuveny E: Mechanism of Ba(2+) block of a mouse inwardly rectifying K+ channel: differential contribution by two discrete residues. J Physiol. 2001 Jul 15;534(Pt. 2):381-93. [11454958 ]
General Function:
Inward rectifier potassium channel activity
Specific Function:
Inward rectifying potassium channel that is activated by phosphatidylinositol 4,5-bisphosphate and that probably participates in controlling the resting membrane potential in electrically excitable cells. Probably participates in establishing action potential waveform and excitability of neuronal and muscle tissues. Inward rectifier potassium channels are characterized by a greater tendency to allow potassium to flow into the cell rather than out of it. Their voltage dependence is regulated by the concentration of extracellular potassium; as external potassium is raised, the voltage range of the channel opening shifts to more positive voltages. The inward rectification is mainly due to the blockage of outward current by internal magnesium.
Gene Name:
KCNJ12
Uniprot ID:
Q14500
Molecular Weight:
49000.6 Da
References
  1. Alagem N, Dvir M, Reuveny E: Mechanism of Ba(2+) block of a mouse inwardly rectifying K+ channel: differential contribution by two discrete residues. J Physiol. 2001 Jul 15;534(Pt. 2):381-93. [11454958 ]
General Function:
Inward rectifier potassium channel activity
Specific Function:
This potassium channel is controlled by G proteins. Inward rectifier potassium channels are characterized by a greater tendency to allow potassium to flow into the cell rather than out of it. Their voltage dependence is regulated by the concentration of extracellular potassium; as external potassium is raised, the voltage range of the channel opening shifts to more positive voltages. The inward rectification is mainly due to the blockage of outward current by internal magnesium. Can be blocked by external barium (By similarity).
Gene Name:
KCNJ8
Uniprot ID:
Q15842
Molecular Weight:
47967.455 Da
References
  1. Alagem N, Dvir M, Reuveny E: Mechanism of Ba(2+) block of a mouse inwardly rectifying K+ channel: differential contribution by two discrete residues. J Physiol. 2001 Jul 15;534(Pt. 2):381-93. [11454958 ]
5. ATP-sensitive potassium channel (Protein Group)
General Function:
Phosphatidylinositol-4,5-bisphosphate binding
Specific Function:
In the kidney, probably plays a major role in potassium homeostasis. Inward rectifier potassium channels are characterized by a greater tendency to allow potassium to flow into the cell rather than out of it. Their voltage dependence is regulated by the concentration of extracellular potassium; as external potassium is raised, the voltage range of the channel opening shifts to more positive voltages. The inward rectification is mainly due to the blockage of outward current by internal magnesium. This channel is activated by internal ATP and can be blocked by external barium.
Included Proteins:
P48048 , P78508 , Q14654 , Q14500 , Q9UNX9 , Q99712 , Q15842
References
  1. Alagem N, Dvir M, Reuveny E: Mechanism of Ba(2+) block of a mouse inwardly rectifying K+ channel: differential contribution by two discrete residues. J Physiol. 2001 Jul 15;534(Pt. 2):381-93. [11454958 ]
6. ATP-sensitive potassium channel (Protein Group)
General Function:
Phosphatidylinositol-4,5-bisphosphate binding
Specific Function:
In the kidney, probably plays a major role in potassium homeostasis. Inward rectifier potassium channels are characterized by a greater tendency to allow potassium to flow into the cell rather than out of it. Their voltage dependence is regulated by the concentration of extracellular potassium; as external potassium is raised, the voltage range of the channel opening shifts to more positive voltages. The inward rectification is mainly due to the blockage of outward current by internal magnesium. This channel is activated by internal ATP and can be blocked by external barium.
Included Proteins:
P48048 , P78508 , Q14654 , Q14500 , Q9UNX9 , Q99712 , Q15842
References
  1. Alagem N, Dvir M, Reuveny E: Mechanism of Ba(2+) block of a mouse inwardly rectifying K+ channel: differential contribution by two discrete residues. J Physiol. 2001 Jul 15;534(Pt. 2):381-93. [11454958 ]
7. ATP-sensitive potassium channel (Protein Group)
General Function:
Phosphatidylinositol-4,5-bisphosphate binding
Specific Function:
In the kidney, probably plays a major role in potassium homeostasis. Inward rectifier potassium channels are characterized by a greater tendency to allow potassium to flow into the cell rather than out of it. Their voltage dependence is regulated by the concentration of extracellular potassium; as external potassium is raised, the voltage range of the channel opening shifts to more positive voltages. The inward rectification is mainly due to the blockage of outward current by internal magnesium. This channel is activated by internal ATP and can be blocked by external barium.
Included Proteins:
P48048 , P78508 , Q14654 , Q14500 , Q9UNX9 , Q99712 , Q15842
References
  1. Alagem N, Dvir M, Reuveny E: Mechanism of Ba(2+) block of a mouse inwardly rectifying K+ channel: differential contribution by two discrete residues. J Physiol. 2001 Jul 15;534(Pt. 2):381-93. [11454958 ]
General Function:
Titin binding
Specific Function:
Calmodulin mediates the control of a large number of enzymes, ion channels, aquaporins and other proteins by Ca(2+). Among the enzymes to be stimulated by the calmodulin-Ca(2+) complex are a number of protein kinases and phosphatases. Together with CCP110 and centrin, is involved in a genetic pathway that regulates the centrosome cycle and progression through cytokinesis.
Gene Name:
CALM1
Uniprot ID:
P0DP23
Molecular Weight:
16837.47 Da
References
  1. Kursula P, Majava V: A structural insight into lead neurotoxicity and calmodulin activation by heavy metals. Acta Crystallogr Sect F Struct Biol Cryst Commun. 2007 Aug 1;63(Pt 8):653-6. Epub 2007 Jul 28. [17671360 ]
General Function:
G-protein activated inward rectifier potassium channel activity
Specific Function:
This potassium channel is controlled by G proteins. Inward rectifier potassium channels are characterized by a greater tendency to allow potassium to flow into the cell rather than out of it. Their voltage dependence is regulated by the concentration of extracellular potassium; as external potassium is raised, the voltage range of the channel opening shifts to more positive voltages. The inward rectification is mainly due to the blockage of outward current by internal magnesium. This receptor plays a crucial role in regulating the heartbeat.
Gene Name:
KCNJ3
Uniprot ID:
P48549
Molecular Weight:
56602.84 Da
References
  1. Alagem N, Dvir M, Reuveny E: Mechanism of Ba(2+) block of a mouse inwardly rectifying K+ channel: differential contribution by two discrete residues. J Physiol. 2001 Jul 15;534(Pt. 2):381-93. [11454958 ]
General Function:
Inward rectifier potassium channel activity
Specific Function:
This potassium channel may be involved in the regulation of insulin secretion by glucose and/or neurotransmitters acting through G-protein-coupled receptors. Inward rectifier potassium channels are characterized by a greater tendency to allow potassium to flow into the cell rather than out of it. Their voltage dependence is regulated by the concentration of extracellular potassium; as external potassium is raised, the voltage range of the channel opening shifts to more positive voltages. The inward rectification is mainly due to the blockage of outward current by internal magnesium.
Gene Name:
KCNJ6
Uniprot ID:
P48051
Molecular Weight:
48450.96 Da
References
  1. Alagem N, Dvir M, Reuveny E: Mechanism of Ba(2+) block of a mouse inwardly rectifying K+ channel: differential contribution by two discrete residues. J Physiol. 2001 Jul 15;534(Pt. 2):381-93. [11454958 ]
General Function:
G-protein activated inward rectifier potassium channel activity
Specific Function:
This receptor is controlled by G proteins. Inward rectifier potassium channels are characterized by a greater tendency to allow potassium to flow into the cell rather than out of it. Their voltage dependence is regulated by the concentration of extracellular potassium; as external potassium is raised, the voltage range of the channel opening shifts to more positive voltages. The inward rectification is mainly due to the blockage of outward current by internal magnesium (By similarity).
Gene Name:
KCNJ9
Uniprot ID:
Q92806
Molecular Weight:
44019.45 Da
References
  1. Alagem N, Dvir M, Reuveny E: Mechanism of Ba(2+) block of a mouse inwardly rectifying K+ channel: differential contribution by two discrete residues. J Physiol. 2001 Jul 15;534(Pt. 2):381-93. [11454958 ]
General Function:
G-protein activated inward rectifier potassium channel activity
Specific Function:
This potassium channel is controlled by G proteins. Inward rectifier potassium channels are characterized by a greater tendency to allow potassium to flow into the cell rather than out of it. Their voltage dependence is regulated by the concentration of extracellular potassium; as external potassium is raised, the voltage range of the channel opening shifts to more positive voltages. The inward rectification is mainly due to the blockage of outward current by internal magnesium. Can be blocked by external barium.
Gene Name:
KCNJ5
Uniprot ID:
P48544
Molecular Weight:
47667.3 Da
References
  1. Alagem N, Dvir M, Reuveny E: Mechanism of Ba(2+) block of a mouse inwardly rectifying K+ channel: differential contribution by two discrete residues. J Physiol. 2001 Jul 15;534(Pt. 2):381-93. [11454958 ]
General Function:
Inward rectifier potassium channel activity
Specific Function:
Inward rectifier potassium channels are characterized by a greater tendency to allow potassium to flow into the cell rather than out of it. Their voltage dependence is regulated by the concentration of extracellular potassium; as external potassium is raised, the voltage range of the channel opening shifts to more positive voltages. The inward rectification is mainly due to the blockage of outward current by internal magnesium. KCNJ13 has a very low single channel conductance, low sensitivity to block by external barium and cesium, and no dependence of its inward rectification properties on the internal blocking particle magnesium.
Gene Name:
KCNJ13
Uniprot ID:
O60928
Molecular Weight:
40529.195 Da
References
  1. Alagem N, Dvir M, Reuveny E: Mechanism of Ba(2+) block of a mouse inwardly rectifying K+ channel: differential contribution by two discrete residues. J Physiol. 2001 Jul 15;534(Pt. 2):381-93. [11454958 ]
General Function:
Inward rectifier potassium channel activity
Specific Function:
Inward rectifier potassium channels are characterized by a greater tendency to allow potassium to flow into the cell rather than out of it. Their voltage dependence is regulated by the concentration of extracellular potassium; as external potassium is raised, the voltage range of the channel opening shifts to more positive voltages. The inward rectification is mainly due to the blockage of outward current by internal magnesium. KCNJ16 may be involved in the regulation of fluid and pH balance.
Gene Name:
KCNJ16
Uniprot ID:
Q9NPI9
Molecular Weight:
47948.585 Da
References
  1. Alagem N, Dvir M, Reuveny E: Mechanism of Ba(2+) block of a mouse inwardly rectifying K+ channel: differential contribution by two discrete residues. J Physiol. 2001 Jul 15;534(Pt. 2):381-93. [11454958 ]
General Function:
Voltage-gated potassium channel activity involved in cardiac muscle cell action potential repolarization
Specific Function:
Probably participates in establishing action potential waveform and excitability of neuronal and muscle tissues. Inward rectifier potassium channels are characterized by a greater tendency to allow potassium to flow into the cell rather than out of it. Their voltage dependence is regulated by the concentration of extracellular potassium; as external potassium is raised, the voltage range of the channel opening shifts to more positive voltages. The inward rectification is mainly due to the blockage of outward current by internal magnesium. Can be blocked by extracellular barium or cesium.
Gene Name:
KCNJ2
Uniprot ID:
P63252
Molecular Weight:
48287.82 Da
References
  1. Alagem N, Dvir M, Reuveny E: Mechanism of Ba(2+) block of a mouse inwardly rectifying K+ channel: differential contribution by two discrete residues. J Physiol. 2001 Jul 15;534(Pt. 2):381-93. [11454958 ]
General Function:
Pdz domain binding
Specific Function:
Inward rectifier potassium channels are characterized by a greater tendency to allow potassium to flow into the cell rather than out of it. Their voltage dependence is regulated by the concentration of extracellular potassium; as external potassium is raised, the voltage range of the channel opening shifts to more positive voltages. The inward rectification is mainly due to the blockage of outward current by internal magnesium. Can be blocked by extracellular barium and cesium (By similarity).
Gene Name:
KCNJ4
Uniprot ID:
P48050
Molecular Weight:
49499.61 Da
References
  1. Alagem N, Dvir M, Reuveny E: Mechanism of Ba(2+) block of a mouse inwardly rectifying K+ channel: differential contribution by two discrete residues. J Physiol. 2001 Jul 15;534(Pt. 2):381-93. [11454958 ]
General Function:
Voltage-gated potassium channel activity
Specific Function:
Pore-forming (alpha) subunit of voltage-gated potassium channel. Elicits an outward current with fast inactivation. Channel properties may be modulated by cAMP and subunit assembly.
Gene Name:
KCNH3
Uniprot ID:
Q9ULD8
Molecular Weight:
117127.74 Da
References
  1. Becchetti A, De Fusco M, Crociani O, Cherubini A, Restano-Cassulini R, Lecchi M, Masi A, Arcangeli A, Casari G, Wanke E: The functional properties of the human ether-a-go-go-like (HELK2) K+ channel. Eur J Neurosci. 2002 Aug;16(3):415-28. [12193184 ]
General Function:
Voltage-gated potassium channel activity involved in ventricular cardiac muscle cell action potential repolarization
Specific Function:
Potassium channel that plays an important role in a number of tissues, including heart, inner ear, stomach and colon (By similarity) (PubMed:10646604). Associates with KCNE beta subunits that modulates current kinetics (By similarity) (PubMed:9312006, PubMed:9108097, PubMed:8900283, PubMed:10646604, PubMed:11101505, PubMed:19687231). Induces a voltage-dependent by rapidly activating and slowly deactivating potassium-selective outward current (By similarity) (PubMed:9312006, PubMed:9108097, PubMed:8900283, PubMed:10646604, PubMed:11101505). Promotes also a delayed voltage activated potassium current showing outward rectification characteristic (By similarity). During beta-adrenergic receptor stimulation participates in cardiac repolarization by associating with KCNE1 to form the I(Ks) cardiac potassium current that increases the amplitude and slows down the activation kinetics of outward potassium current I(Ks) (By similarity) (PubMed:9312006, PubMed:9108097, PubMed:8900283, PubMed:10646604, PubMed:11101505). Muscarinic agonist oxotremorine-M strongly suppresses KCNQ1/KCNE1 current (PubMed:10713961). When associated with KCNE3, forms the potassium channel that is important for cyclic AMP-stimulated intestinal secretion of chloride ions (PubMed:10646604). This interaction with KCNE3 is reduced by 17beta-estradiol, resulting in the reduction of currents (By similarity). During conditions of increased substrate load, maintains the driving force for proximal tubular and intestinal sodium ions absorption, gastric acid secretion, and cAMP-induced jejunal chloride ions secretion (By similarity). Allows the provision of potassium ions to the luminal membrane of the secretory canaliculus in the resting state as well as during stimulated acid secretion (By similarity). When associated with KCNE2, forms an heterooligomer complex leading to currents with an apparently instantaneous activation, a rapid deactivation process and a linear current-voltage relationship and decreases the amplitude of the outward current (PubMed:11101505). When associated with KCNE4, inhibits voltage-gated potassium channel activity (PubMed:19687231). When associated with KCNE5, this complex only conducts current upon strong and continued depolarization (PubMed:12324418). Also forms an heterotetramer with KCNQ5; has a voltage-gated potassium channel activity (PubMed:24855057). Binds with phosphatidylinositol 4,5-bisphosphate (PubMed:25037568).Isoform 2: Non-functional alone but modulatory when coexpressed with the full-length isoform 1.
Gene Name:
KCNQ1
Uniprot ID:
P51787
Molecular Weight:
74697.925 Da
References
  1. Gibor G, Yakubovich D, Peretz A, Attali B: External barium affects the gating of KCNQ1 potassium channels and produces a pore block via two discrete sites. J Gen Physiol. 2004 Jul;124(1):83-102. [15226366 ]
General Function:
Voltage-gated potassium channel activity
Specific Function:
Probably important in the regulation of neuronal excitability. Associates with KCNQ3 to form a potassium channel with essentially identical properties to the channel underlying the native M-current, a slowly activating and deactivating potassium conductance which plays a critical role in determining the subthreshold electrical excitability of neurons as well as the responsiveness to synaptic inputs. KCNQ2/KCNQ3 current is blocked by linopirdine and XE991, and activated by the anticonvulsant retigabine. Muscarinic agonist oxotremorine-M strongly suppress KCNQ2/KCNQ3 current in cells in which cloned KCNQ2/KCNQ3 channels were coexpressed with M1 muscarinic receptors.
Gene Name:
KCNQ2
Uniprot ID:
O43526
Molecular Weight:
95846.575 Da
References
  1. Gibor G, Yakubovich D, Peretz A, Attali B: External barium affects the gating of KCNQ1 potassium channels and produces a pore block via two discrete sites. J Gen Physiol. 2004 Jul;124(1):83-102. [15226366 ]
General Function:
Voltage-gated potassium channel activity
Specific Function:
Probably important in the regulation of neuronal excitability. Associates with KCNQ2 or KCNQ5 to form a potassium channel with essentially identical properties to the channel underlying the native M-current, a slowly activating and deactivating potassium conductance which plays a critical role in determining the subthreshold electrical excitability of neurons as well as the responsiveness to synaptic inputs.
Gene Name:
KCNQ3
Uniprot ID:
O43525
Molecular Weight:
96741.515 Da
References
  1. Gibor G, Yakubovich D, Peretz A, Attali B: External barium affects the gating of KCNQ1 potassium channels and produces a pore block via two discrete sites. J Gen Physiol. 2004 Jul;124(1):83-102. [15226366 ]
General Function:
Potassium channel activity
Specific Function:
Probably important in the regulation of neuronal excitability. May underlie a potassium current involved in regulating the excitability of sensory cells of the cochlea. KCNQ4 channels are blocked by linopirdin, XE991 and bepridil, whereas clofilium is without significant effect. Muscarinic agonist oxotremorine-M strongly suppress KCNQ4 current in CHO cells in which cloned KCNQ4 channels were coexpressed with M1 muscarinic receptors.
Gene Name:
KCNQ4
Uniprot ID:
P56696
Molecular Weight:
77099.99 Da
References
  1. Gibor G, Yakubovich D, Peretz A, Attali B: External barium affects the gating of KCNQ1 potassium channels and produces a pore block via two discrete sites. J Gen Physiol. 2004 Jul;124(1):83-102. [15226366 ]
General Function:
Voltage-gated potassium channel activity
Specific Function:
Probably important in the regulation of neuronal excitability. Associates with KCNQ3 to form a potassium channel which contributes to M-type current, a slowly activating and deactivating potassium conductance which plays a critical role in determining the subthreshold electrical excitability of neurons. May contribute, with other potassium channels, to the molecular diversity of a heterogeneous population of M-channels, varying in kinetic and pharmacological properties, which underlie this physiologically important current. Insensitive to tetraethylammonium, but inhibited by barium, linopirdine and XE991. Activated by niflumic acid and the anticonvulsant retigabine. Muscarine suppresses KCNQ5 current in Xenopus oocytes in which cloned KCNQ5 channels were coexpressed with M(1) muscarinic receptors.
Gene Name:
KCNQ5
Uniprot ID:
Q9NR82
Molecular Weight:
102178.015 Da
References
  1. Gibor G, Yakubovich D, Peretz A, Attali B: External barium affects the gating of KCNQ1 potassium channels and produces a pore block via two discrete sites. J Gen Physiol. 2004 Jul;124(1):83-102. [15226366 ]