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Record Information
Version2.0
Creation Date2009-06-19 21:58:19 UTC
Update Date2014-12-24 20:23:10 UTC
Accession NumberT3D1117
Identification
Common NameBarium oxide
ClassSmall Molecule
DescriptionBarium oxide is an oxide of barium. It is used as a coating for hot cathodes, in cathode ray tubes, and in the production of certain kinds of glass, such as optical crown glass. Barium is a metallic alkaline earth metal with the symbol Ba, and atomic number 56. It never occurs in nature in its pure form due to its reactivity with air, but combines with other chemicals such as sulfur or carbon and oxygen to form barium compounds that may be found as minerals. (4, 3)
Compound Type
  • Barium Compound
  • Industrial/Workplace Toxin
  • Inorganic Compound
  • Synthetic Compound
Chemical Structure
Thumb
Synonyms
Synonym
BAO
Barium oxide (bao)
Barium oxide, bao
Barium oxide, obtained BY calcining witherite
Barium protoxide
Barsito
Baryta
Calcined barsito
Calcined baryta
Oxyde de baryum
Chemical FormulaBaO
Average Molecular Mass153.326 g/mol
Monoisotopic Mass153.900 g/mol
CAS Registry Number1304-28-5
IUPAC Nameoxobarium
Traditional Namebarium oxide
SMILESO=[Ba]
InChI IdentifierInChI=1S/Ba.O
InChI KeyInChIKey=QVQLCTNNEUAWMS-UHFFFAOYSA-N
Chemical Taxonomy
DescriptionThis compound belongs to the class of chemical entities known as alkaline earth metal oxides. These are inorganic compounds containing an oxygen atom of an oxidation state of -2, in which the heaviest atom bonded to the oxygen is an alkaline earth metal.
KingdomChemical entities
Super ClassInorganic compounds
ClassMixed metal/non-metal compounds
Sub ClassAlkaline earth metal organides
Direct ParentAlkaline earth metal oxides
Alternative Parents
Substituents
  • Alkaline earth metal oxide
  • Inorganic oxide
Molecular FrameworkNot Available
External DescriptorsNot Available
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
AppearanceWhite-yellow powder.
Experimental Properties
PropertyValue
Melting Point1923°C
Boiling PointNot Available
SolubilityNot Available
LogPNot Available
Predicted Properties
PropertyValueSource
logP-0.55ChemAxon
pKa (Strongest Basic)-0.21ChemAxon
Physiological Charge0ChemAxon
Hydrogen Acceptor Count1ChemAxon
Hydrogen Donor Count0ChemAxon
Polar Surface Area17.07 Å2ChemAxon
Rotatable Bond Count0ChemAxon
Refractivity1.44 m3·mol-1ChemAxon
Polarizability2.88 Å3ChemAxon
Number of Rings0ChemAxon
Bioavailability1ChemAxon
Rule of FiveYesChemAxon
Ghose FilterYesChemAxon
Veber's RuleYesChemAxon
MDDR-like RuleYesChemAxon
Spectra
SpectraNot Available
Toxicity Profile
Route of ExposureOral (4) ; inhalation (4)
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. Some of these barium's effects may also be due to barium induced neuromuscular blockade and membrane depolarization. (4)
MetabolismBarium compounds are absorbed via ingestion and inhalation, the extent of which depends on the individual compound. In the body, the majority of the barium is found in the bone, while small amounts exists in the muscle, adipose, skin, and connective tissue. Barium is not metabolized in the body, but it may be transported or incorporated into complexes or tissues. Barium is excreted in the urine and faeces. (4)
Toxicity ValuesLD50: 50 mg/kg (Oral, Rat) (5)
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 oxide is used as a coating for hot cathodes, in cathode ray tubes, and in the production of certain kinds of glass, such as optical crown glass. (3)
Minimum Risk LevelIntermediate Oral: 0.2 mg/kg/day (2) Chronic Oral: 0.2 mg/kg/day (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. (4)
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. (4)
TreatmentIntravenous infusion of potassium often relieves many of the symptoms of barium toxicity. (4)
Normal Concentrations
Not Available
Abnormal Concentrations
Not Available
DrugBank IDNot Available
HMDB IDNot Available
PubChem Compound ID62392
ChEMBL IDNot Available
ChemSpider ID56180
KEGG IDNot Available
UniProt IDNot Available
OMIM ID
ChEBI IDNot Available
BioCyc IDNot Available
CTD IDC077606
Stitch IDBarium oxide
PDB IDNot Available
ACToR IDNot Available
Wikipedia LinkNot Available
References
Synthesis ReferenceNot Available
MSDST3D1117.pdf
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. Wikipedia. Barium oxide. Last Updated 21 May 2009. [Link]
  4. 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]
  5. The Physical and Theoretical Chemistry Laboratory of Oxford University (2005). Material Safety Data Sheet (MSDS) for barium oxide. [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 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 ]