Cell membrane glycoproteins that are selectively permeable to potassium ions. At least eight major groups of K channels exist and they are made up of dozens of different subunits.
An element in the alkali group of metals with an atomic symbol K, atomic number 19, and atomic weight 39.10. It is the chief cation in the intracellular fluid of muscle and other cells. Potassium ion is a strong electrolyte that plays a significant role in the regulation of fluid volume and maintenance of the WATER-ELECTROLYTE BALANCE.
Potassium channels where the flow of K+ ions into the cell is greater than the outward flow.
A class of drugs that act by inhibition of potassium efflux through cell membranes. Blockade of potassium channels prolongs the duration of ACTION POTENTIALS. They are used as ANTI-ARRHYTHMIA AGENTS and VASODILATOR AGENTS.
Potassium channel whose permeability to ions is extremely sensitive to the transmembrane potential difference. The opening of these channels is induced by the membrane depolarization of the ACTION POTENTIAL.
Gated, ion-selective glycoproteins that traverse membranes. The stimulus for ION CHANNEL GATING can be due to a variety of stimuli such as LIGANDS, a TRANSMEMBRANE POTENTIAL DIFFERENCE, mechanical deformation or through INTRACELLULAR SIGNALING PEPTIDES AND PROTEINS.
Voltage-dependent cell membrane glycoproteins selectively permeable to calcium ions. They are categorized as L-, T-, N-, P-, Q-, and R-types based on the activation and inactivation kinetics, ion specificity, and sensitivity to drugs and toxins. The L- and T-types are present throughout the cardiovascular and central nervous systems and the N-, P-, Q-, & R-types are located in neuronal tissue.
Voltage-gated potassium channels whose primary subunits contain six transmembrane segments and form tetramers to create a pore with a voltage sensor. They are related to their founding member, shaker protein, Drosophila.
A delayed rectifier subtype of shaker potassium channels that is the predominant VOLTAGE-GATED POTASSIUM CHANNEL of T-LYMPHOCYTES.
The opening and closing of ion channels due to a stimulus. The stimulus can be a change in membrane potential (voltage-gated), drugs or chemical transmitters (ligand-gated), or a mechanical deformation. Gating is thought to involve conformational changes of the ion channel which alters selective permeability.
A delayed rectifier subtype of shaker potassium channels that is selectively inhibited by a variety of SCORPION VENOMS.
Potassium channels whose activation is dependent on intracellular calcium concentrations.
A delayed rectifier subtype of shaker potassium channels that is commonly mutated in human episodic ATAXIA and MYOKYMIA.
A family of voltage-gated potassium channels that are characterized by long N-terminal and C-terminal intracellular tails. They are named from the Drosophila protein whose mutation causes abnormal leg shaking under ether anesthesia. Their activation kinetics are dependent on extracellular MAGNESIUM and PROTON concentration.
A shaker subfamily that is prominently expressed in NEURONS and are necessary for high-frequency, repetitive firing of ACTION POTENTIALS.
A voltage-gated potassium channel that is expressed primarily in the HEART.
Signal transduction mechanisms whereby calcium mobilization (from outside the cell or from intracellular storage pools) to the cytoplasm is triggered by external stimuli. Calcium signals are often seen to propagate as waves, oscillations, spikes, sparks, or puffs. The calcium acts as an intracellular messenger by activating calcium-responsive proteins.
A family of delayed rectifier voltage-gated potassium channels that share homology with their founding member, KCNQ1 PROTEIN. KCNQ potassium channels have been implicated in a variety of diseases including LONG QT SYNDROME; DEAFNESS; and EPILEPSY.
A delayed rectifier subtype of shaker potassium channels that conducts a delayed rectifier current. It contributes to ACTION POTENTIAL repolarization of MYOCYTES in HEART ATRIA.
A fast inactivating subtype of shaker potassium channels that contains two inactivation domains at its N terminus.
A major class of calcium activated potassium channels whose members are voltage-dependent. MaxiK channels are activated by either membrane depolarization or an increase in intracellular Ca(2+). They are key regulators of calcium and electrical signaling in a variety of tissues.
A subfamily of shaker potassium channels that shares homology with its founding member, Shab protein, Drosophila. They regulate delayed rectifier currents in the NERVOUS SYSTEM of DROSOPHILA and in the SKELETAL MUSCLE and HEART of VERTEBRATES.
Heteromultimers of Kir6 channels (the pore portion) and sulfonylurea receptor (the regulatory portion) which affect function of the HEART; PANCREATIC BETA CELLS; and KIDNEY COLLECTING DUCTS. KATP channel blockers include GLIBENCLAMIDE and mitiglinide whereas openers include CROMAKALIM and minoxidil sulfate.
A very slow opening and closing voltage-gated potassium channel that is expressed in NEURONS and is commonly mutated in BENIGN FAMILIAL NEONATAL CONVULSIONS.
The voltage differences across a membrane. For cellular membranes they are computed by subtracting the voltage measured outside the membrane from the voltage measured inside the membrane. They result from differences of inside versus outside concentration of potassium, sodium, chloride, and other ions across cells' or ORGANELLES membranes. For excitable cells, the resting membrane potentials range between -30 and -100 millivolts. Physical, chemical, or electrical stimuli can make a membrane potential more negative (hyperpolarization), or less negative (depolarization).
Potassium channels that contain two pores in tandem. They are responsible for baseline or leak currents and may be the most numerous of all K channels.
A very slow opening and closing voltage-gated potassium channel that is expressed in NEURONS and is closely related to KCNQ2 POTASSIUM CHANNEL. It is commonly mutated in BENIGN FAMILIAL NEONATAL CONVULSIONS.
A shaker subfamily of potassium channels that participate in transient outward potassium currents by activating at subthreshold MEMBRANE POTENTIALS, inactivating rapidly, and recovering from inactivation quickly.
Long-lasting voltage-gated CALCIUM CHANNELS found in both excitable and nonexcitable tissue. They are responsible for normal myocardial and vascular smooth muscle contractility. Five subunits (alpha-1, alpha-2, beta, gamma, and delta) make up the L-type channel. The alpha-1 subunit is the binding site for calcium-based antagonists. Dihydropyridine-based calcium antagonists are used as markers for these binding sites.
An electrophysiologic technique for studying cells, cell membranes, and occasionally isolated organelles. All patch-clamp methods rely on a very high-resistance seal between a micropipette and a membrane; the seal is usually attained by gentle suction. The four most common variants include on-cell patch, inside-out patch, outside-out patch, and whole-cell clamp. Patch-clamp methods are commonly used to voltage clamp, that is control the voltage across the membrane and measure current flow, but current-clamp methods, in which the current is controlled and the voltage is measured, are also used.
The study of the generation and behavior of electrical charges in living organisms particularly the nervous system and the effects of electricity on living organisms.
A class of drugs that act by selective inhibition of calcium influx through cellular membranes.
A family of inwardly-rectifying potassium channels that are activated by PERTUSSIS TOXIN sensitive G-PROTEIN-COUPLED RECEPTORS. GIRK potassium channels are primarily activated by the complex of GTP-BINDING PROTEIN BETA SUBUNITS and GTP-BINDING PROTEIN GAMMA SUBUNITS.
A major class of calcium-activated potassium channels that are found primarily in excitable CELLS. They play important roles in the transmission of ACTION POTENTIALS and generate a long-lasting hyperpolarization known as the slow afterhyperpolarization.
Cell membrane glycoproteins that form channels to selectively pass chloride ions. Nonselective blockers include FENAMATES; ETHACRYNIC ACID; and TAMOXIFEN.
A group of slow opening and closing voltage-gated potassium channels. Because of their delayed activation kinetics they play an important role in controlling ACTION POTENTIAL duration.
The ability of a substrate to allow the passage of ELECTRONS.
An antidiabetic sulfonylurea derivative with actions similar to those of chlorpropamide.
A potassium-selective ion channel blocker. (From J Gen Phys 1994;104(1):173-90)
Female germ cells derived from OOGONIA and termed OOCYTES when they enter MEIOSIS. The primary oocytes begin meiosis but are arrested at the diplotene state until OVULATION at PUBERTY to give rise to haploid secondary oocytes or ova (OVUM).
Calcium compounds used as food supplements or in food to supply the body with calcium. Dietary calcium is needed during growth for bone development and for maintenance of skeletal integrity later in life to prevent osteoporosis.
The commonest and widest ranging species of the clawed "frog" (Xenopus) in Africa. This species is used extensively in research. There is now a significant population in California derived from escaped laboratory animals.
CALCIUM CHANNELS that are concentrated in neural tissue. Omega toxins inhibit the actions of these channels by altering their voltage dependence.
A major class of calcium-activated potassium channels that were originally discovered in ERYTHROCYTES. They are found primarily in non-excitable CELLS and set up electrical gradients for PASSIVE ION TRANSPORT.
An aquatic genus of the family, Pipidae, occurring in Africa and distinguished by having black horny claws on three inner hind toes.
One of the POTASSIUM CHANNEL BLOCKERS, with secondary effect on calcium currents, which is used mainly as a research tool and to characterize channel subtypes.
A member of the alkali group of metals. It has the atomic symbol Na, atomic number 11, and atomic weight 23.
The pore-forming subunits of large-conductance calcium-activated potassium channels. They form tetramers in CELL MEMBRANES.
Venoms from animals of the order Scorpionida of the class Arachnida. They contain neuro- and hemotoxins, enzymes, and various other factors that may release acetylcholine and catecholamines from nerve endings. Of the several protein toxins that have been characterized, most are immunogenic.
The rate dynamics in chemical or physical systems.
Agents that increase calcium influx into calcium channels of excitable tissues. This causes vasoconstriction in VASCULAR SMOOTH MUSCLE and/or CARDIAC MUSCLE cells as well as stimulation of insulin release from pancreatic islets. Therefore, tissue-selective calcium agonists have the potential to combat cardiac failure and endocrinological disorders. They have been used primarily in experimental studies in cell and tissue culture.
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
A potassium-channel opening vasodilator that has been investigated in the management of hypertension. It has also been tried in patients with asthma. (Martindale, The Extra Pharmacopoeia, 30th ed, p352)
A class of drugs that act by inhibition of sodium influx through cell membranes. Blockade of sodium channels slows the rate and amplitude of initial rapid depolarization, reduces cell excitability, and reduces conduction velocity.
A 37-amino acid residue peptide isolated from the scorpion Leiurus quinquestriatus hebraeus. It is a neurotoxin that inhibits calcium activated potassium channels.
An adenine nucleotide containing three phosphate groups esterified to the sugar moiety. In addition to its crucial roles in metabolism adenosine triphosphate is a neurotransmitter.
Potassium or potassium compounds used in foods or as foods.
A guanidine that opens POTASSIUM CHANNELS producing direct peripheral vasodilatation of the ARTERIOLES. It reduces BLOOD PRESSURE and peripheral resistance and produces fluid retention. (Martindale The Extra Pharmacopoeia, 31st ed)
The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.
ATP-BINDING CASSETTE PROTEINS that are highly conserved and widely expressed in nature. They form an integral part of the ATP-sensitive potassium channel complex which has two intracellular nucleotide folds that bind to sulfonylureas and their analogs.
The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM.
Abrupt changes in the membrane potential that sweep along the CELL MEMBRANE of excitable cells in response to excitation stimuli.
The relationship between the dose of an administered drug and the response of the organism to the drug.
Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.
An element of the alkaline earth group of metals. It has an atomic symbol Ba, atomic number 56, and atomic weight 138. All of its acid-soluble salts are poisonous.
Inorganic compounds that contain barium as an integral part of the molecule.
A strain of albino rat used widely for experimental purposes because of its calmness and ease of handling. It was developed by the Sprague-Dawley Animal Company.
A condition due to decreased dietary intake of potassium, as in starvation or failure to administer in intravenous solutions, or to gastrointestinal loss in diarrhea, chronic laxative abuse, vomiting, gastric suction, or bowel diversion. Severe potassium deficiency may produce muscular weakness and lead to paralysis and respiratory failure. Muscular malfunction may result in hypoventilation, paralytic ileus, hypotension, muscle twitches, tetany, and rhabomyolysis. Nephropathy from potassium deficit impairs the concentrating mechanism, producing POLYURIA and decreased maximal urinary concentrating ability with secondary POLYDIPSIA. (Merck Manual, 16th ed)
A subgroup of TRP cation channels that contain 3-4 ANKYRIN REPEAT DOMAINS and a conserved C-terminal domain. Members are highly expressed in the CENTRAL NERVOUS SYSTEM. Selectivity for calcium over sodium ranges from 0.5 to 10.
A basic element found in nearly all organized tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.
Carbonic acid calcium salt (CaCO3). An odorless, tasteless powder or crystal that occurs in nature. It is used therapeutically as a phosphate buffer in hemodialysis patients and as a calcium supplement.
Inorganic compounds that contain potassium as an integral part of the molecule.
A white crystal or crystalline powder used in BUFFERS; FERTILIZERS; and EXPLOSIVES. It can be used to replenish ELECTROLYTES and restore WATER-ELECTROLYTE BALANCE in treating HYPOKALEMIA.
The movement of ions across energy-transducing cell membranes. Transport can be active, passive or facilitated. Ions may travel by themselves (uniport), or as a group of two or more ions in the same (symport) or opposite (antiport) directions.
A subgroup of cyclic nucleotide-regulated ION CHANNELS within the superfamily of pore-loop cation channels. They are expressed in OLFACTORY NERVE cilia and in PHOTORECEPTOR CELLS and some PLANTS.
A highly neurotoxic polypeptide from the venom of the honey bee (Apis mellifera). It consists of 18 amino acids with two disulfide bridges and causes hyperexcitability resulting in convulsions and respiratory paralysis.
Compounds with a core of fused benzo-pyran rings.
A heterogenous group of transient or low voltage activated type CALCIUM CHANNELS. They are found in cardiac myocyte membranes, the sinoatrial node, Purkinje cells of the heart and the central nervous system.
The regulatory subunits of large-conductance calcium-activated potassium channels.
Established cell cultures that have the potential to propagate indefinitely.
Proteins that bind specific drugs with high affinity and trigger intracellular changes influencing the behavior of cells. Drug receptors are generally thought to be receptors for some endogenous substance not otherwise specified.
The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.
Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.
A derivative of the NIACINAMIDE that is structurally combined with an organic nitrate. It is a potassium-channel opener that causes vasodilatation of arterioles and large coronary arteries. Its nitrate-like properties produce venous vasodilation through stimulation of guanylate cyclase.
A subgroup of TRP cation channels named after vanilloid receptor. They are very sensitive to TEMPERATURE and hot spicy food and CAPSAICIN. They have the TRP domain and ANKYRIN repeats. Selectivity for CALCIUM over SODIUM ranges from 3 to 100 fold.
The level of protein structure in which combinations of secondary protein structures (alpha helices, beta sheets, loop regions, and motifs) pack together to form folded shapes called domains. Disulfide bridges between cysteines in two different parts of the polypeptide chain along with other interactions between the chains play a role in the formation and stabilization of tertiary structure. Small proteins usually consist of only one domain but larger proteins may contain a number of domains connected by segments of polypeptide chain which lack regular secondary structure.
Single chains of amino acids that are the units of multimeric PROTEINS. Multimeric proteins can be composed of identical or non-identical subunits. One or more monomeric subunits may compose a protomer which itself is a subunit structure of a larger assembly.
A member of the alkali metals. It has an atomic symbol Cs, atomic number 50, and atomic weight 132.91. Cesium has many industrial applications, including the construction of atomic clocks based on its atomic vibrational frequency.
Elements of limited time intervals, contributing to particular results or situations.
A salt used to replenish calcium levels, as an acid-producing diuretic, and as an antidote for magnesium poisoning.
A benzothiadiazine derivative that is a peripheral vasodilator used for hypertensive emergencies. It lacks diuretic effect, apparently because it lacks a sulfonamide group.
A family of proton-gated sodium channels that are primarily expressed in neuronal tissue. They are AMILORIDE-sensitive and are implicated in the signaling of a variety of neurological stimuli, most notably that of pain in response to acidic conditions.
Sodium channels found on salt-reabsorbing EPITHELIAL CELLS that line the distal NEPHRON; the distal COLON; SALIVARY DUCTS; SWEAT GLANDS; and the LUNG. They are AMILORIDE-sensitive and play a critical role in the control of sodium balance, BLOOD VOLUME, and BLOOD PRESSURE.
Venoms from snakes of the family Elapidae, including cobras, kraits, mambas, coral, tiger, and Australian snakes. The venoms contain polypeptide toxins of various kinds, cytolytic, hemolytic, and neurotoxic factors, but fewer enzymes than viper or crotalid venoms. Many of the toxins have been characterized.
Stable calcium atoms that have the same atomic number as the element calcium, but differ in atomic weight. Ca-42-44, 46, and 48 are stable calcium isotopes.
A subgroup of TRP cation channels named after melastatin protein. They have the TRP domain but lack ANKYRIN repeats. Enzyme domains in the C-terminus leads to them being called chanzymes.
Stable potassium atoms that have the same atomic number as the element potassium, but differ in atomic weight. K-41 is a stable potassium isotope.
Calcium salts of phosphoric acid. These compounds are frequently used as calcium supplements.
Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.
Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.
The muscle tissue of the HEART. It is composed of striated, involuntary muscle cells (MYOCYTES, CARDIAC) connected to form the contractile pump to generate blood flow.
10-carbon saturated monocarboxylic acids.
CALCIUM CHANNELS located within the PURKINJE CELLS of the cerebellum. They are involved in stimulation-secretion coupling of neurons.
A potent vasodilator agent with calcium antagonistic action. It is a useful anti-anginal agent that also lowers blood pressure.
A strain of albino rat developed at the Wistar Institute that has spread widely at other institutions. This has markedly diluted the original strain.
Organic compounds containing both the hydroxyl and carboxyl radicals.
A metallic element that has the atomic symbol Mg, atomic number 12, and atomic weight 24.31. It is important for the activity of many enzymes, especially those involved in OXIDATIVE PHOSPHORYLATION.
The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH = log 1/2[1/(H+)], where (H+) is the hydrogen ion concentration in gram equivalents per liter of solution. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
Inorganic compounds derived from hydrochloric acid that contain the Cl- ion.
The species Oryctolagus cuniculus, in the family Leporidae, order LAGOMORPHA. Rabbits are born in burrows, furless, and with eyes and ears closed. In contrast with HARES, rabbits have 22 chromosome pairs.
Use of electric potential or currents to elicit biological responses.
A delayed rectifier subtype of shaker potassium channels that has been described in NEURONS and ASTROCYTES.
A tetrameric calcium release channel in the SARCOPLASMIC RETICULUM membrane of SMOOTH MUSCLE CELLS, acting oppositely to SARCOPLASMIC RETICULUM CALCIUM-TRANSPORTING ATPASES. It is important in skeletal and cardiac excitation-contraction coupling and studied by using RYANODINE. Abnormalities are implicated in CARDIAC ARRHYTHMIAS and MUSCULAR DISEASES.
Unstable isotopes of potassium that decay or disintegrate emitting radiation. K atoms with atomic weights 37, 38, 40, and 42-45 are radioactive potassium isotopes.
An element that is an alkali metal. It has an atomic symbol Rb, atomic number 37, and atomic weight 85.47. It is used as a chemical reagent and in the manufacture of photoelectric cells.
A common name used for the genus Cavia. The most common species is Cavia porcellus which is the domesticated guinea pig used for pets and biomedical research.
CALCIUM CHANNELS located in the neurons of the brain.
CELL LINE derived from the ovary of the Chinese hamster, Cricetulus griseus (CRICETULUS). The species is a favorite for cytogenetic studies because of its small chromosome number. The cell line has provided model systems for the study of genetic alterations in cultured mammalian cells.
The uptake of naked or purified DNA by CELLS, usually meaning the process as it occurs in eukaryotic cells. It is analogous to bacterial transformation (TRANSFORMATION, BACTERIAL) and both are routinely employed in GENE TRANSFER TECHNIQUES.
A family of neuronal calcium-sensor proteins that interact with and regulate potassium channels, type A.
An aminoperhydroquinazoline poison found mainly in the liver and ovaries of fishes in the order TETRAODONTIFORMES, which are eaten. The toxin causes paresthesia and paralysis through interference with neuromuscular conduction.
A subfamily in the family MURIDAE, comprising the hamsters. Four of the more common genera are Cricetus, CRICETULUS; MESOCRICETUS; and PHODOPUS.
An atom or group of atoms that have a positive or negative electric charge due to a gain (negative charge) or loss (positive charge) of one or more electrons. Atoms with a positive charge are known as CATIONS; those with a negative charge are ANIONS.
The parts of a macromolecule that directly participate in its specific combination with another molecule.
Drugs used to cause dilation of the blood vessels.
Arthropods of the order Scorpiones, of which 1500 to 2000 species have been described. The most common live in tropical or subtropical areas. They are nocturnal and feed principally on insects and other arthropods. They are large arachnids but do not attack man spontaneously. They have a venomous sting. Their medical significance varies considerably and is dependent on their habits and venom potency rather than on their size. At most, the sting is equivalent to that of a hornet but certain species possess a highly toxic venom potentially fatal to humans. (From Dorland, 27th ed; Smith, Insects and Other Arthropods of Medical Importance, 1973, p417; Barnes, Invertebrate Zoology, 5th ed, p503)
A quality of cell membranes which permits the passage of solvents and solutes into and out of cells.
The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).
The hollow, muscular organ that maintains the circulation of the blood.
A cell line generated from human embryonic kidney cells that were transformed with human adenovirus type 5.
A condition that is characterized by episodes of fainting (SYNCOPE) and varying degree of ventricular arrhythmia as indicated by the prolonged QT interval. The inherited forms are caused by mutation of genes encoding cardiac ion channel proteins. The two major forms are ROMANO-WARD SYNDROME and JERVELL-LANGE NIELSEN SYNDROME.
Pyridine moieties which are partially saturated by the addition of two hydrogen atoms in any position.
A broad group of eukaryotic six-transmembrane cation channels that are classified by sequence homology because their functional involvement with SENSATION is varied. They have only weak voltage sensitivity and ion selectivity. They are named after a DROSOPHILA mutant that displayed transient receptor potentials in response to light. A 25-amino-acid motif containing a TRP box (EWKFAR) just C-terminal to S6 is found in TRPC, TRPV and TRPM subgroups. ANKYRIN repeats are found in TRPC, TRPV & TRPN subgroups. Some are functionally associated with TYROSINE KINASE or TYPE C PHOSPHOLIPASES.
An actinomycete used for production of commercial ANTIBIOTICS and as a host for gene cloning.
A superorder of CEPHALOPODS comprised of squid, cuttlefish, and their relatives. Their distinguishing feature is the modification of their fourth pair of arms into tentacles, resulting in 10 limbs.
Pyridines substituted in any position with an amino group. May be hydrogenated, but must retain at least one double bond.
CALCIUM CHANNELS located in the neurons of the brain. They are inhibited by the marine snail toxin, omega conotoxin MVIIC.
Positively charged atoms, radicals or groups of atoms which travel to the cathode or negative pole during electrolysis.
Genetically engineered MUTAGENESIS at a specific site in the DNA molecule that introduces a base substitution, or an insertion or deletion.
Membrane proteins whose primary function is to facilitate the transport of positively charged molecules (cations) across a biological membrane.
The nonstriated involuntary muscle tissue of blood vessels.
Unstable isotopes of calcium that decay or disintegrate emitting radiation. Ca atoms with atomic weights 39, 41, 45, 47, 49, and 50 are radioactive calcium isotopes.
The study of PHYSICAL PHENOMENA and PHYSICAL PROCESSES as applied to living things.
The calcium salt of oxalic acid, occurring in the urine as crystals and in certain calculi.
Members of the class of compounds composed of AMINO ACIDS joined together by peptide bonds between adjacent amino acids into linear, branched or cyclical structures. OLIGOPEPTIDES are composed of approximately 2-12 amino acids. Polypeptides are composed of approximately 13 or more amino acids. PROTEINS are linear polypeptides that are normally synthesized on RIBOSOMES.
A group of compounds that are monomethyl derivatives of pyridines. (From Dorland, 28th ed)
A calcium channel blocker that is a class IV anti-arrhythmia agent.
A potent direct-acting peripheral vasodilator (VASODILATOR AGENTS) that reduces peripheral resistance and produces a fall in BLOOD PRESSURE. (From Martindale, The Extra Pharmacopoeia, 30th ed, p371)
Proteins prepared by recombinant DNA technology.
A subgroup of cyclic nucleotide-regulated ION CHANNELS of the superfamily of pore-loop cation channels that are opened by hyperpolarization rather than depolarization. The ion conducting pore passes SODIUM, CALCIUM, and POTASSIUM cations with a preference for potassium.
The calcium salt of gluconic acid. The compound has a variety of uses, including its use as a calcium replenisher in hypocalcemic states.
The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.
RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.
Abnormally low potassium concentration in the blood. It may result from potassium loss by renal secretion or by the gastrointestinal route, as by vomiting or diarrhea. It may be manifested clinically by neuromuscular disorders ranging from weakness to paralysis, by electrocardiographic abnormalities (depression of the T wave and elevation of the U wave), by renal disease, and by gastrointestinal disorders. (Dorland, 27th ed)
The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.
The physiological widening of BLOOD VESSELS by relaxing the underlying VASCULAR SMOOTH MUSCLE.
An inorganic compound that is used as a source of iodine in thyrotoxic crisis and in the preparation of thyrotoxic patients for thyroidectomy. (From Dorland, 27th ed)
A family of MEMBRANE TRANSPORT PROTEINS that require ATP hydrolysis for the transport of substrates across membranes. The protein family derives its name from the ATP-binding domain found on the protein.
The domestic dog, Canis familiaris, comprising about 400 breeds, of the carnivore family CANIDAE. They are worldwide in distribution and live in association with people. (Walker's Mammals of the World, 5th ed, p1065)
Derivatives of ammonium compounds, NH4+ Y-, in which all four of the hydrogens bonded to nitrogen have been replaced with hydrocarbyl groups. These are distinguished from IMINES which are RN=CR2.
An optical isomer of quinine, extracted from the bark of the CHINCHONA tree and similar plant species. This alkaloid dampens the excitability of cardiac and skeletal muscles by blocking sodium and potassium currents across cellular membranes. It prolongs cellular ACTION POTENTIALS, and decreases automaticity. Quinidine also blocks muscarinic and alpha-adrenergic neurotransmission.
Agents used for the treatment or prevention of cardiac arrhythmias. They may affect the polarization-repolarization phase of the action potential, its excitability or refractoriness, or impulse conduction or membrane responsiveness within cardiac fibers. Anti-arrhythmia agents are often classed into four main groups according to their mechanism of action: sodium channel blockade, beta-adrenergic blockade, repolarization prolongation, or calcium channel blockade.
Synthetic transcripts of a specific DNA molecule or fragment, made by an in vitro transcription system. This cRNA can be labeled with radioactive uracil and then used as a probe. (King & Stansfield, A Dictionary of Genetics, 4th ed)
A benzothiazepine derivative with vasodilating action due to its antagonism of the actions of CALCIUM ion on membrane functions.
The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.
Proteins which are found in membranes including cellular and intracellular membranes. They consist of two types, peripheral and integral proteins. They include most membrane-associated enzymes, antigenic proteins, transport proteins, and drug, hormone, and lectin receptors.
A chelating agent relatively more specific for calcium and less toxic than EDETIC ACID.
A voltage-gated sodium channel subtype that mediates the sodium ion PERMEABILITY of CARDIOMYOCYTES. Defects in the SCN5A gene, which codes for the alpha subunit of this sodium channel, are associated with a variety of CARDIAC DISEASES that result from loss of sodium channel function.
Body organ that filters blood for the secretion of URINE and that regulates ion concentrations.
The relationship between the chemical structure of a compound and its biological or pharmacological activity. Compounds are often classed together because they have structural characteristics in common including shape, size, stereochemical arrangement, and distribution of functional groups.
Layers of lipid molecules which are two molecules thick. Bilayer systems are frequently studied as models of biological membranes.
A sulphonylurea hypoglycemic agent with actions and uses similar to those of CHLORPROPAMIDE. (From Martindale, The Extra Pharmacopoeia, 30th ed, p290)
Striated muscle cells found in the heart. They are derived from cardiac myoblasts (MYOBLASTS, CARDIAC).
Compounds or agents that combine with an enzyme in such a manner as to prevent the normal substrate-enzyme combination and the catalytic reaction.
The physical characteristics and processes of biological systems.
Venoms from jellyfish; CORALS; SEA ANEMONES; etc. They contain hemo-, cardio-, dermo- , and neuro-toxic substances and probably ENZYMES. They include palytoxin, sarcophine, and anthopleurine.
A genus of the family Muridae consisting of eleven species. C. migratorius, the grey or Armenian hamster, and C. griseus, the Chinese hamster, are the two species used in biomedical research.
Interstitial space between cells, occupied by INTERSTITIAL FLUID as well as amorphous and fibrous substances. For organisms with a CELL WALL, the extracellular space includes everything outside of the CELL MEMBRANE including the PERIPLASM and the cell wall.
Unstable isotopes of rubidium that decay or disintegrate emitting radiation. Rb atoms with atomic weights 79-84, and 86-95 are radioactive rubidium isotopes.
Positively charged atoms, radicals or group of atoms with a valence of plus 1, which travel to the cathode or negative pole during electrolysis.
A curved elevation of GRAY MATTER extending the entire length of the floor of the TEMPORAL HORN of the LATERAL VENTRICLE (see also TEMPORAL LOBE). The hippocampus proper, subiculum, and DENTATE GYRUS constitute the hippocampal formation. Sometimes authors include the ENTORHINAL CORTEX in the hippocampal formation.
The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.
Chemicals that bind to and remove ions from solutions. Many chelating agents function through the formation of COORDINATION COMPLEXES with METALS.
Nerve fibers that are capable of rapidly conducting impulses away from the neuron cell body.
Contractile tissue that produces movement in animals.
A process leading to shortening and/or development of tension in muscle tissue. Muscle contraction occurs by a sliding filament mechanism whereby actin filaments slide inward among the myosin filaments.
A neurotransmitter found at neuromuscular junctions, autonomic ganglia, parasympathetic effector junctions, a subset of sympathetic effector junctions, and at many sites in the central nervous system.
The excitable plasma membrane of a muscle cell. (Glick, Glossary of Biochemistry and Molecular Biology, 1990)
The level of protein structure in which regular hydrogen-bond interactions within contiguous stretches of polypeptide chain give rise to alpha helices, beta strands (which align to form beta sheets) or other types of coils. This is the first folding level of protein conformation.
A powder that dissolves in water, which is administered orally, and is used as a diuretic, expectorant, systemic alkalizer, and electrolyte replenisher.
Unstriated and unstriped muscle, one of the muscles of the internal organs, blood vessels, hair follicles, etc. Contractile elements are elongated, usually spindle-shaped cells with centrally located nuclei. Smooth muscle fibers are bound together into sheets or bundles by reticular fibers and frequently elastic nets are also abundant. (From Stedman, 25th ed)
The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.
The naturally occurring or experimentally induced replacement of one or more AMINO ACIDS in a protein with another. If a functionally equivalent amino acid is substituted, the protein may retain wild-type activity. Substitution may also diminish, enhance, or eliminate protein function. Experimentally induced substitution is often used to study enzyme activities and binding site properties.
A neurotoxic peptide, which is a cleavage product (VIa) of the omega-Conotoxin precursor protein contained in venom from the marine snail, CONUS geographus. It is an antagonist of CALCIUM CHANNELS, N-TYPE.
CELL LINES derived from the CV-1 cell line by transformation with a replication origin defective mutant of SV40 VIRUS, which codes for wild type large T antigen (ANTIGENS, POLYOMAVIRUS TRANSFORMING). They are used for transfection and cloning. (The CV-1 cell line was derived from the kidney of an adult male African green monkey (CERCOPITHECUS AETHIOPS).)
Toxic substances from microorganisms, plants or animals that interfere with the functions of the nervous system. Most venoms contain neurotoxic substances. Myotoxins are included in this concept.
The concentration of osmotically active particles in solution expressed in terms of osmoles of solute per liter of solution. Osmolality is expressed in terms of osmoles of solute per kilogram of solvent.
An adenine nucleotide containing one phosphate group which is esterified to both the 3'- and 5'-positions of the sugar moiety. It is a second messenger and a key intracellular regulator, functioning as a mediator of activity for a number of hormones, including epinephrine, glucagon, and ACTH.
Refers to animals in the period of time just after birth.

Cloning and characterization of the promoters of the maxiK channel alpha and beta subunits. (1/1050)

Large conductance, calcium-activated potassium (maxiK) channels are expressed in nerve, muscle, and other cell types and are important determinants of smooth muscle tone. To determine the mechanisms involved in the transcriptional regulation of maxiK channels, we characterized the promoter regions of the pore forming (alpha) and regulatory (beta) subunits of the human channel complex. Maximum promoter activity (up to 12.3-fold over control) occurred between nucleotides -567 and -220 for the alpha subunit (hSlo) gene. The minimal promoter is GC-rich with 5 Sp-1 binding sites and several TCC repeats. Other transcription factor-binding motifs, including c/EBP, NF-kB, PU.1, PEA-3, Myo-D, and E2A, were observed in the 5'-flanking sequence. Additionally, a CCTCCC sequence, which increases the transcriptional activity of the SM1/2 gene in smooth muscle, is located 27 bp upstream of the TATA-like sequence, a location identical to that found in the SM1/2 5'-flanking region. However, the promoter directed equivalent expression when transfected into smooth muscle and other cell types. Analysis of the hSlo beta subunit 5'-flanking region revealed a TATA box at position -77 and maximum promoter activity (up to 11.0-fold) in a 200 bp region upstream from the cap site. Binding sites for GATA-1, Myo-D, c-myb, Ets-1/Elk-1, Ap-1, and Ik-2 were identified within this sequence. Two CCTCCC elements are present in the hSlo beta subunit promoter, but tissue-specific transcriptional activity was not observed. The lack of tissue-specific promoter activity, particularly the finding of promoter activity in cells from tissues in which the maxiK gene is not expressed, suggests a complex channel regulatory mechanism for hSlo genes. Moreover, the lack of similarity of the promoters of the two genes suggests that regulation of coordinate expression of the subunits does not occur through equivalent cis-acting sequences.  (+info)

RINm5f cells express inactivating BK channels whereas HIT cells express noninactivating BK channels. (2/1050)

Large-conductance Ca2+- and voltage-activated BK-type K+ channels are expressed abundantly in normal rat pancreatic islet cells and in the clonal rat insulinoma tumor (RINm5f) and hamster insulinoma tumor (HIT) beta cell lines. Previous work has suggested that the Ca2+ sensitivity of BK channels in RIN cells is substantially less than that in HIT cells, perhaps contributing to differences between the cell lines in responsiveness to glucose in mediating insulin secretion. In both RIN cells and normal pancreatic beta cells, BK channels are thought to play a limited role in responses of beta cells to secretagogues and in the electrical activity of beta cells. Here we examine in detail the properties of BK channels in RIN and HIT cells using inside-out patches and whole cell recordings. BK channels in RIN cells exhibit rapid inactivation that results in an anomalous steady-state Ca2+ dependence of activation. In contrast, BK channels in HIT cells exhibit the more usual noninactivating behavior. When BK inactivation is taken into account, the Ca2+ and voltage dependence of activation of BK channels in RIN and HIT cells is essentially indistinguishable. The properties of BK channel inactivation in RIN cells are similar to those of inactivating BK channels (termed BKi channels) previously identified in rat chromaffin cells. Inactivation involves multiple, trypsin-sensitive cytosolic domains and exhibits a dependence on Ca2+ and voltage that appears to arise from coupling to channel activation. In addition, the rates of inactivation onset and recovery are similar to that of BKi channels in chromaffin cells. The charybdotoxin (CTX) sensitivity of BKi currents is somewhat less than that of the noninactivating BK variant. Action potential voltage-clamp waveforms indicate that BK current is activated only weakly by Ca2+ influx in RIN cells but more strongly activated in HIT cells even when Ca2+ current magnitude is comparable. Concentrations of CTX sufficient to block BKi current in RIN cells have no effect on action potential activity initiated by glucose or DC injection. Despite its abundant expression in RIN cells, BKi current appears to play little role in action potential activity initiated by glucose or DC injection in RIN cells, but BK current may play an important role in action potential repolarization in HIT cells.  (+info)

The beta subunit increases the Ca2+ sensitivity of large conductance Ca2+-activated potassium channels by retaining the gating in the bursting states. (3/1050)

Coexpression of the beta subunit (KV,Cabeta) with the alpha subunit of mammalian large conductance Ca2+- activated K+ (BK) channels greatly increases the apparent Ca2+ sensitivity of the channel. Using single-channel analysis to investigate the mechanism for this increase, we found that the beta subunit increased open probability (Po) by increasing burst duration 20-100-fold, while having little effect on the durations of the gaps (closed intervals) between bursts or on the numbers of detected open and closed states entered during gating. The effect of the beta subunit was not equivalent to raising intracellular Ca2+ in the absence of the beta subunit, suggesting that the beta subunit does not act by increasing all the Ca2+ binding rates proportionally. The beta subunit also inhibited transitions to subconductance levels. It is the retention of the BK channel in the bursting states by the beta subunit that increases the apparent Ca2+ sensitivity of the channel. In the presence of the beta subunit, each burst of openings is greatly amplified in duration through increases in both the numbers of openings per burst and in the mean open times. Native BK channels from cultured rat skeletal muscle were found to have bursting kinetics similar to channels expressed from alpha subunits alone.  (+info)

ATP inhibition of a mouse brain large-conductance K+ (mslo) channel variant by a mechanism independent of protein phosphorylation. (4/1050)

1. We investigated the effect of ATP in the regulation of two closely related cloned mouse brain large conductance calcium- and voltage-activated potassium (BK) channel alpha-subunit variants, expressed in human embryonic kidney (HEK 293) cells, using the excised inside-out configuration of the patch-clamp technique. 2. The mB2 BK channel alpha-subunit variant expressed alone was potently inhibited by application of ATP to the intracellular surface of the patch with an IC50 of 30 microM. The effect of ATP was largely independent of protein phosphorylation events as the effect of ATP was mimicked by the non-hydrolysable analogue 5'-adenylylimidodiphosphate (AMP-PNP) and the inhibitory effect of ATPgammaS was reversible. 3. In contrast, under identical conditions, direct nucleotide inhibition was not observed in the closely related mouse brain BK channel alpha-subunit variant mbr5. Furthermore, direct nucleotide regulation was not observed when mB2 was functionally coupled to regulatory beta-subunits. 4. These data suggest that the mB2 alpha-subunit splice variant could provide a dynamic link between cellular metabolism and cell excitability.  (+info)

Molecular basis of fast inactivation in voltage and Ca2+-activated K+ channels: a transmembrane beta-subunit homolog. (5/1050)

Voltage-dependent and calcium-sensitive K+ (MaxiK) channels are key regulators of neuronal excitability, secretion, and vascular tone because of their ability to sense transmembrane voltage and intracellular Ca2+. In most tissues, their stimulation results in a noninactivating hyperpolarizing K+ current that reduces excitability. In addition to noninactivating MaxiK currents, an inactivating MaxiK channel phenotype is found in cells like chromaffin cells and hippocampal neurons. The molecular determinants underlying inactivating MaxiK channels remain unknown. Herein, we report a transmembrane beta subunit (beta2) that yields inactivating MaxiK currents on coexpression with the pore-forming alpha subunit of MaxiK channels. Intracellular application of trypsin as well as deletion of 19 N-terminal amino acids of the beta2 subunit abolished inactivation of the alpha subunit. Conversely, fusion of these N-terminal amino acids to the noninactivating smooth muscle beta1 subunit leads to an inactivating phenotype of MaxiK channels. Furthermore, addition of a synthetic N-terminal peptide of the beta2 subunit causes inactivation of the MaxiK channel alpha subunit by occluding its K+-conducting pore resembling the inactivation caused by the "ball" peptide in voltage-dependent K+ channels. Thus, the inactivating phenotype of MaxiK channels in native tissues can result from the association with different beta subunits.  (+info)

Activation of recombinant human SK4 channels by metal cations. (6/1050)

The effects of metal cations on the activation of recombinant human SK4 (also known as hIK1 or hKCa4) channels, expressed in HEK 293 cells, were tested using patch clamp recording. Of the nine metals tested, cobalt, iron, magnesium, and zinc did not activate the SK4 channels when applied, at concentrations up to 100 microM, to the inside of SK4 channel-expressing membrane patches. Barium, cadmium, calcium, lead, and strontium activated SK4 channels in a concentration-dependent manner. The rank order of potency was at Ca2+ > Pb2+ > Cd2+ > Sr2+ > Ba2+.  (+info)

Cyclic GMP-dependent protein kinase activates cloned BKCa channels expressed in mammalian cells by direct phosphorylation at serine 1072. (7/1050)

NO-induced activation of cGMP-dependent protein kinase (PKG) increases the open probability of large conductance Ca2+-activated K+ channels and results in smooth muscle relaxation. However, the molecular mechanism of channel regulation by the NO-PKG pathway has not been determined on cloned channels. The present study was designed to clarify PKG-mediated modulation of channels at the molecular level. The cDNA encoding the alpha-subunit of the large conductance Ca2+-activated K+ channel, cslo-alpha, was expressed in HEK293 cells. Whole cell and single channel characteristics of cslo-alpha exhibited functional features of native large conductance Ca2+-activated K+ channels in smooth muscle cells. The NO-donor sodium nitroprusside increased outward current 2.3-fold in whole cell recordings. In cell-attached patches, sodium nitroprusside increased the channel open probability (NPo) of cslo-alpha channels 3.3-fold without affecting unitary conductance. The stimulatory effect of sodium nitroprusside was inhibited by the PKG-inhibitor KT5823. Direct application of PKG-Ialpha to the cytosolic surface of inside-out patches increased NPo 3.2-fold only in the presence of ATP and cGMP without affecting unitary conductance. A point mutation of cslo-alpha in which Ser-1072 (the only optimal consensus sequence for PKG phosphorylation) was replaced by Ala abolished the PKG effect on NPo in inside-out patches and the effect of SNP in cell attached patches. These results indicate that PKG activates cslo-alpha by direct phosphorylation at serine 1072.  (+info)

No evidence for involvement of KCNN3 (hSKCa3) potassium channel gene in familial and isolated cases of schizophrenia. (8/1050)

Several studies have reported in schizophrenia a decrease of age of onset in successive family generations, and this observation is consistent with anticipation. Anticipation is known to result from expansion of CAG repeats in several neurodegenerative disorders. Longer alleles of the KCNN3 gene, which contains a highly polymorphic CAG repeat, and encodes a neuronal small conductance calcium-activated potassium channel, have recently been shown to be over-represented in sporadic cases of schizophrenia. In this report, we tested the hypothesis of an association between longer alleles of CAG repeat in the KCNN3 gene and schizophrenia in 20 families with clinical evidence for anticipation and in 151 unrelated schizophrenic cases. No significant difference in the distributions of allele frequencies was observed between familial cases of schizophrenia and controls, and between unrelated cases and controls. Furthermore, no intergenerational CAG repeat instability was detected in the 20 families. Our results do not support the involvement of the KCNN3 (hSKCa3) gene in the etiology of schizophrenia.  (+info)

Aim Endothelial cell (EC) KCa2.3 and KCa3.1, calcium-activated potassium channels, play a crucial role in NO- and EDHF-mediated regulation of vascular tone by controlling membrane potential and intracellular calcium levels. Since laminar shear stress (LS) is a major determinant of EC function in a calcium-dependent manner, we hypothesized that LS upregulates KCa2.3 and KCa3.1 via activating calcium/calmodulin (CaM) kinase cascade.. Methods Human coronary artery ECs were exposed to static, LS (15 dyn/cm2) or oscillatory shear stress (OS; +/−5 dyn/cm2 × 1Hz) condition for 24 hours in the absence or presence of STO-609 (CaM-dependent kinase kinase (CaMKK) inhibitor, 10μg/ml), Compound C (AMP-activated protein kinase (AMPK) inhibitor, 10μM), KN-62 (calcium/CaM-dependent kinase (CaMK) inhibitor, 10μM), KG-501 (cAMP response element binding protein (CREB) inhibitor, 25μM), or tumor necrosis factor-α (TNF-α; 1 or 10 ng/ml). The mRNA expression and CREB phosphorylation were determined by ...
Calcium management differs in T and B lymphocytes. [Ca2+]i elevation in response to calcium ionophores is up to 10 times greater in T cells than B cells. There is no difference between them in ionophore uptake. T cells, but not B cells, possess a calcium-sensitive potassium channel which produces membrane hyperpolarization at [Ca2+]i above 200 nM. This alters T cell density providing a rapid and easy method of cell separation. In contrast, B cells depolarize when [Ca2+]i is increased. Isolated B cell membrane vesicle ATP-dependent calcium pump activity is higher than T cell vesicles. Membrane depolarization reduces the [Ca2+]i response to ionomycin, most dramatically in T cells because they are hyperpolarized by increased [Ca2+]i. The most likely basis of this behavior is an effect of membrane potential on lymphocyte membrane calcium pump activity. This mechanism provides an explanation of the inhibitory effect of membrane depolarization on T lymphocyte responses. ...
Fingerprint Dive into the research topics of The antidepressant fluoxetine blocks the human small conductance calcium-activated potassium channels SK1, SK2 and SK3. Together they form a unique fingerprint. ...
Action potentials in vertebrate neurons are followed by an afterhyperpolarization (AHP) that may persist for several seconds and may have profound consequences for the firing pattern of the neuron. Each component of the AHP is kinetically distinct and is mediated by different calcium-activated potassium channels. The protein encoded by this gene is activated before membrane hyperpolarization and is thought to regulate neuronal excitability by contributing to the slow component of synaptic AHP. This gene is a member of the KCNN family of potassium channel genes. The encoded protein is an integral membrane protein that forms a voltage-independent calcium-activated channel with three other calmodulin-binding subunits. Alternate splicing of this gene results in multiple transcript variants. [provided by RefSeq, May 2013 ...
Forms a voltage-independent potassium channel activated by intracellular calcium. Activation is followed by membrane hyperpolarization. Thought to regulate neuronal excitability by contributing to the slow component of synaptic afterhyperpolarization. The channel is blocked by apamin (By similarity).
The properties of single Ca2+-activated K+ (BK) channels in neonatal rat intracardiac neurons were investigated using the patch-clamp recording technique. In symmetrical 140 mM K+. the single-channel slope conductance was linear in the voltage range -60/+60 mV, and was 207±19 pS. Na+ ions were not measurably permeant through the open channel. Channel activity increased with the cytoplasmic free Ca2+ concentration ([Ca2+]i) with a Hill plot giving a half-saturating [Ca2+] (K0.5) of 1.35 μM and slope of ≅3. The BK channel was inhibited reversibly by external tetraethylammonium (TEA) ions, charybdotoxin, and quinine and was resistant to block by 4-aminopyridine and apamin. Ionomycin (1-10 μM) increased BK channel activity in the cell-attached recording configuration. The resting activity was consistent with a [Ca2+]i |100 nM and the increased channel activity evoked by ionomycin was consistent with a rise in|[Ca2+]i to ≥ 0.3 μM. TEA (0.2-1 mM) increased the action potential duration 1.5-fold and
[ChEMBL Target Description] ID:CHEMBL3381, Name:Small conductance calcium-activated potassium channel protein 3, Description:, Synonyms:
Department of Anatomy and Neurobiology, Washington University School of Medicine, St. Louis, Missouri (A.D.W.); Departments of Microbiology and Molecular Genetics (G.A.G.) and Physiology and Biophysics (K.G.C.), University of California, Irvine, Irvine, California; Molecular and Cellular Physiology Department, Stanford University, Stanford, California (R.A.); Department of Medical Pharmacology and Toxicology, University of California, Davis, Davis, California (H.W.); and Department of Applied Physiology, University Ulm, Ulm, Germany (S.G.) ...
There is ample evidence that ion channel modulation by accessory proteins within a macromolecular complex can regulate channel activity and thereby impact neuronal excitability. However, the downstream consequences of ion channel modulation remain largely undetermined. The Drosophila melanogaster large conductance calcium-activated potassium channel SLOWPOKE (SLO) undergoes modulation via its binding partner SLO-binding protein (SLOB). Regulation of SLO by SLOB influences the voltage dependence of SLO activation and modulates synaptic transmission. SLO and SLOB are expressed especially prominently in median neurosecretory cells (mNSCs) in the pars intercerebralis (PI) region of the brain; these cells also express and secrete Drosophila insulin like peptides (dILPs). Previously, we found that flies lacking SLOB exhibit increased resistance to starvation, and we reasoned that SLOB may regulate aspects of insulin signaling and metabolism. Here we investigate the role of SLOB in metabolism and find that
Then there are the big conductance channels BKCa is a potassium channel that opens in response to high internal concentrations of calcium (highly positive) or when the membrane of the cell is highly depolarised (highly positive). This causes potassium to flood out of the cell making the inside of the cell less positive, it resets the nerve allowing it to fire again, unless it makes the inside of the cell very less positive, it can stop nerves firing again and it stops damage. ...
Recently, we reported that the activities of large conductance Ca2+-activated K+(BK) channels are inhibited by caveolae microdomain targeting in vascular endothelial cells. The molecular mechanism of this negative regulation of BK channels by caveolae is unknown. In this study, we tested the hypotheses that BK channels are inhibited by physical interaction with the scaffolding domain of caveolin-1, which alters the properties of the channel. Using HEK293 cells stably expressing hSlo (which encodes human BK channels) with and without transient transfection with caveolin-1, We found that hSlo channels were enriched in the low buoyant density fraction when co-expressed with caveolin-1 and the channels were co-immunoprecipitated by anti-caveolin-1 antibodies. Co-expression of caveolin-1 resulted in inhibition of whole-cell hSlo current densities from 77.0±18.0 pA/pF in control (HP=−60 mV, TP=+80 mV, 1 μM free Ca2+, n=10) to 12.0±3.9 pA/pF (n=8, p,0.01 vs. control). In contrast, co-expression of ...
annotations (the reliablity of the annotated protein expression using immunohistochemically (IH) stained on human tissues, the reliablity of the annotated protein expression in immunofluorescently (IF) stained human cell lines, tissue specificity (the distribution of antibody staining or protein expression in human cell types), cell line specificity (the distribution of RNA abundance in cell lines) and subcellular location (based on immunofluorescent staining of cell lines ...
Summary is not available for the mouse gene. This summary is for the human ortholog.] MaxiK channels are large conductance, voltage and calcium-sensitive potassium channels which are fundamental to the control of smooth muscle tone and neuronal excitability. MaxiK channels can be formed by 2 subunits: the pore-forming alpha subunit, which is the product of this gene, and the modulatory beta subunit. Intracellular calcium regulates the physical association between the alpha and beta subunits. Alternatively spliced transcript variants encoding different isoforms have been identified. [provided by RefSeq, Jul 2008 ...
MaxiK channels are large conductance, voltage and calcium-sensitive potassium channels which are fundamental to the control of smooth muscle tone and neuronal excitability. MaxiK channels can be formed by 2 subunits: the pore-forming alpha subunit and the product of this gene, the modulatory beta subunit. Intracellular calcium regulates the physical association between the alpha and beta subunits ...
Our previous study demonstrated that pregnancy increased large-conductance Ca2+-activated potassium channel β1 subunit (BKβ1) expression and large-conductance Ca2+-activated potassium channel activity in uterine arteries, which were abrogated by chronic hypoxia. The present study tested the hypothesis that promoter methylation/demethylation is a key mechanism in epigenetic reprogramming of BKβ1 expression patterns in uterine arteries. Ovine BKβ1 promoter of 2315 bp spanning from −2211 to +104 of the transcription start site was cloned, and an Sp1−380 binding site that contains CpG dinucleotide in its core binding sequences was identified. Site-directed deletion of the Sp1 site significantly decreased the BKβ1 promoter activity. Estrogen receptor-α bound to the Sp1 site through tethering to Sp1 and upregulated the expression of BKβ1. The Sp1 binding site at BKβ1 promoter was highly methylated in uterine arteries of nonpregnant sheep, and methylation inhibited transcription factor ...
Large-conductance calcium-activated (maxi-K, BK) potassium channels are widely distributed in the brain. Maxi-K channels function as neuronal calcium sensors and contribute to the control of cellular excitability and the regulation of neurotransmitter release. Little is currently known of any significant role of maxi-K channels in the genesis of neurological disease. Recent advances in the molecular biology and pharmacology of these channels have revealed sources of phenotypic variability and demonstrated that they can be successfully modulated by pharmacological agents. A potential role is suggested in the treatment of conditions such as ischemic stroke and cognitive disorders ...
Characterisation and interaction between β₂ adrenoceptor (AR) and the large conductance calcium-activated potassium (BK_C_a) channel in human myometrium during pregnancy ...
1. DDT1 MF-2 smooth muscle cells responded to the bath application of histamine or ATP with an increase in the cytosolic Ca2+ concentration ([Ca2+]c) and the whole-cell K+ current, IK(BA). 2. In cell-attached patches, histamine (100 microM) activated currents through a 200 pS K+ channel (BKA channel). In the absence of agonists, the BKA channel was activated by excision of the patch. Both histamine and patch excision increased the channel activity (NPo; where N is the number of channels per patch and Po is the open probability) by reducing the long closures between the bursts of openings. 3. In inside-out patches, the BKA channel had a conductance of 201 +/- 4 pS (symmetrical solutions of 150 mM KCl, 2 mM MgCl2 and 2 mM EGTA). Replacement of K+ in the patch electrode by Na+, Li+ or Cs+ prevented the flow of inward currents and reduced the outward K+ conductance to 113 pS. 4. NPo was insensitive to changes in [Ca2+]c from 10 nM to 1 microM. NPo was also not modified either by cytosolic Na+, ATP, GTP,
Summary is not available for the mouse gene. This summary is for the human ortholog.] Action potentials in vertebrate neurons are followed by an afterhyperpolarization (AHP) that may persist for several seconds and may have profound consequences for the firing pattern of the neuron. Each component of the AHP is kinetically distinct and is mediated by different calcium-activated potassium channels. This gene belongs to the KCNN family of potassium channels. It encodes an integral membrane protein that forms a voltage-independent calcium-activated channel, which is thought to regulate neuronal excitability by contributing to the slow component of synaptic AHP. This gene contains two CAG repeat regions in the coding sequence. It was thought that expansion of one or both of these repeats could lead to an increased susceptibility to schizophrenia or bipolar disorder, but studies indicate that this is probably not the case. Alternatively spliced transcript variants encoding different isoforms have ...
KCNN4 antibody (potassium intermediate/small conductance calcium-activated channel, subfamily N, member 4) for ELISA, WB. Anti-KCNN4 pAb (GTX87069) is tested in Human, Mouse, Rat samples. 100% Ab-Assurance.
The high-conductance Ca(2+)-activated K channel (BK channel) is not only regulated by a number of physiological stimuli, but it is also sensitive to pharmacological modulation. We have stably expressed the alpha-subunit of the human BK channel, hslo, in HEK 293 cells and studied by patch-clamp techn …
The NucleoSpin Food Kit allows you to quickly isolate genomic DNA from many types of processed food or animal feed of plant or animal origin. We have optimized the lysis buffer and purification process to extract DNA from a variety of food products.
Resveratrol has been reported to stimulate BKCa currents in human vascular endothelial cells and human cardiac fibroblasts [24, 51], which might be associated with its cardioprotective effect. The present study demonstrated that resveratrol could stimulate the activities of BKCa channels in cortical neurons. In fact, BKCa channel is considered to be one of the intrinsic molecular determinants for the control of neuronal excitability in the central nervous system and play a role in the etiology of some neurological diseases. Recent studies have demonstrated the implication of BKCa channels in Fragile X Syndrome (FXS) pathology [22]. In fact, a selective BKCa channel opener molecule (BMS-204352) rescues a broad spectrum of behavioral impairments (social, emotional and cognitive) in an animal model of FXS [17]. Resveratrol might be also beneficial to patients with FXS.. BKCa channels also play an important role in seizure etiology. Loss-of-function BKCa channel mutations can lead to temporal lobe ...
Blocks small conductance calcium-activated potassium channels (PubMed:12239213). Shows activity on KCa2.2/KCNN2 (IC(50)=0.0243 nM), KCa2.3/KCNN3 (IC(50)=1.7 nM), and KCa2.1/KCNN1 (IC(50)=42 nM) (PubMed:12239213). Induces cell death when tested on Jurkat E6-1 and human mammary breast cancer MDA-MB-231 which constituvely express KCa2.2/KCNN2, but not on human peripheral blood lymphocytes (which do not express KCa2.2/KCNN2) (PubMed:24821061).
PubMed Central Canada (PMC Canada) provides free access to a stable and permanent online digital archive of full-text, peer-reviewed health and life sciences research publications. It builds on PubMed Central (PMC), the U.S. National Institutes of Health (NIH) free digital archive of biomedical and life sciences journal literature and is a member of the broader PMC International (PMCI) network of e-repositories.
Gerhard DS, Wagner L, Feingold EA, Shenmen CM, Grouse LH, Schuler G, Klein SL, Old S, Rasooly R, Good P, Guyer M, Peck AM, Derge JG, Lipman D, Collins FS, Jang W, Sherry S, Feolo M, Misquitta L, Lee E, Rotmistrovsky K, Greenhut SF, Schaefer CF, Buetow K, Bonner TI, Haussler D, Kent J, Kiekhaus M, Furey T, Brent M, Prange C, Schreiber K, Shapiro N, Bhat NK, Hopkins RF, Hsie F, Driscoll T, Soares MB, Casavant TL, Scheetz TE, Brown-stein MJ, Usdin TB, Toshiyuki S, Carninci P, Piao Y, Dudekula DB, Ko MS, Kawakami K, Suzuki Y, Sugano S, Gruber CE, Smith MR, Simmons B, Moore T, Waterman R, Johnson SL, Ruan Y, Wei CL, Mathavan S, Gunaratne PH, Wu J, Garcia AM, Hulyk SW, Fuh E, Yuan Y, Sneed A, Kowis C, Hodgson A, Muzny DM, McPherson J, Gibbs RA, Fahey J, Helton E, Ketteman M, Madan A, Rodrigues S, Sanchez A, Whiting M, Madari A, Young AC, Wetherby KD, Granite SJ, Kwong PN, Brinkley CP, Pearson RL, Bouffard GG, Blakesly RW, Green ED, Dickson MC, Rodriguez AC, Grimwood J, Schmutz J, Myers RM, Butterfield ...
anti-Potassium Large Conductance Calcium-Activated Channel, Subfamily M, beta Member 1 (KCNMB1) antibody (Alexa Fluor 647) ABIN903516 from antibodies-online
conductance calcium-activated potassium channels (BKCa), iberiotoxin, and a blocker of KV7 channels, XE991. Patch clamp studies in vascular smooth muscle revealed pirfenidone increased iberiotoxin-sensitive current. In the aorta and mesenteric small arteries from diabetic db/db mice relaxations induced by the endothelium-dependent vasodilator, acetylcholine, were markedly reduced compared to db/db + mice. Pirfenidone enhanced the relaxations induced by acetylcholine in the aorta from diabetic male and female db/db mice. An opener of KV7 channels, flupirtine, had the same effect as pirfenidone. XE991 reduced the effect of pirfenidone and flupirtine and further reduced acetylcholine relaxations in the aorta. In the presence of iberiotoxin, pirfenidone ...
Large-conductance calcium and voltage-activated potassium channels, termed SLO-1 (or BK), are pivotal players in the regulation of cell excitability across the animal phyla. Furthermore, emerging evidence indicates that these channels are key mediators of a number of neuroactive drugs, including the most recent new anthelmintic, the cyclo-octadepsipeptide emodepside. Detailed reviews of the structure, function and pharmacology of BK channels have recently been provided (Salkoff et al. in Nat Rev Neurosci 7:921-931, 2006; Ghatta et al. in Pharmacol Ther 110:103-116, 2006) and therefore these aspects will only briefly be covered here. The purpose of this review is to discuss how SLO-1 channels might function as regulators of neural transmission and network activity. In particular, we focus on the role of SLO-1 in the regulation of Caenorhabditis elegans behaviour and highlight the role of this channel as an effector for pleiotropic actions of neuroactive drugs, including emodepside. On the premise ...
K+ channel expression and function is closely related to vascular smooth muscle cell (SMC) phenotype. Large conductance Ca2+-activated K+ channels (BKCa) control excitation-contraction coupling and predominate in SMCs with a contractile phenotype1. Intermediate conductance Ca2+-activated K+ channels (IKCa) regulate proliferation during vasculogenesis and are expressed in SMCs with an immature or synthetic phenotype1. We previously demonstrated fetoplacental arterial SMCs have a mixed phenotype and express both contractile and synthetic proteins2. Here we test the hypothesis that SMCs isolated from fetoplacental arteries express BKCa and IKCa channels. SMCs were isolated from chorionic plate arteries of normal term placentas using methods reported previously1. Whole-cell patch clamp was used to assess K+ currents, (5mM [K+]e, 140mM [K+]i, 0.5mM EGTAi, 0mM [ATP]i). Cells were clamped at -60mV and depolarised from -70mV to +80mV for 500ms to record current-voltage relationships. KCa channel ...
Drosophila SLOWPOKE (SLO) is a voltage and calcium dependent, large conductance potassium channel important for action potential repolarization, neuronal excitability, neurotransmitter release, and hormone secretion. SLO binding protein (SLOB) binds to and modulates SLO activity. We have shown previously that modulation of SLO by SLOB has profound effects on SLO channel currents, synaptic transmisison, and metabolism. Multiple isoforms of SLOB exist and are encoded by multiple transcripts; the isoforms are named based on their predicted protein molecular weights, in kilodaltons. In the Drosophila brain, SLOB57/51 proteins are expressed especially prominently in insulin producing neurons of the pars intercerebralis, while SLOB71/65 proteins are enriched in the lateral neurons that participate in the generation of circadian rhythms. Here we sought to determine the transcription initiation sites in the slob gene and investigated promoter elements responsible for expression of the different slob
Our results obtained from humans demonstrate that KCa channels are involved in regulation of the mechanical properties of peripheral conduit arteries, supporting a role for EDHF at this level in vivo. In addition, the synergistic effect of l-NMMA and TEA on radial artery constriction and arterial wall stiffening in absence of such effects after administration of l-NMMA alone shows that KCa channels compensate for the loss of NO synthesis to maintain peripheral conduit artery diameter and mechanics.. The present study was performed in healthy subjects at the level of the radial artery to assess in vivo the role of NO and vascular KCa channels and their potential interaction in the regulation of basal conduit artery diameter and mechanics. All experiments were performed after administration of aspirin to inhibit vascular cyclooxygenase and to exclude a role for PGI2 in our results.15,24 The inhibition of endothelial NO synthesis was obtained with l-NMMA, infused at a dose of 8 μmol/min, known to ...
TY - JOUR. T1 - SK channels and NMDA receptors form a Ca2+-mediated feedback loop in dendritic spines. AU - Ngo-Anh, Thu Jennifer. AU - Bloodgood, Brenda L.. AU - Lin, Michael. AU - Sabatini, Bernardo L.. AU - Maylie, James. AU - Adelman, John. PY - 2005/5. Y1 - 2005/5. N2 - Small-conductance Ca2+-activated K+ channels (SK channels) influence the induction of synaptic plasticity at hippocampal CA3-CA1 synapses. We find that in mice, SK channels are localized to dendritic spines, and their activity reduces the amplitude of evoked synaptic potentials in an NMDA receptor (NMDAR)-dependent manner. Using combined two-photon laser scanning microscopy and two-photon laser uncaging of glutamate, we show that SK channels regulate NMDAR-dependent Ca2+ influx within individual spines. SK channels are tightly coupled to synaptically activated Ca2+ sources, and their activity reduces the amplitude of NMDAR-dependent Ca2+ transients. These effects are mediated by a feedback loop within the spine head; during ...
Serotonin neurons in chronically isolated mice become less responsive to excitatory stimulation, but inhibiting a distinctive calcium-activated potassium channel can restore both neuronal activity and behavior.
TY - JOUR. T1 - Erratum. T2 - Wanderlust kinetics and variable Ca2+-sensitivity of dSlo, a large conductance Ca2+-activated K+ channel, expressed in oocytes (Biophysical Journal (1996) 70 (2640-2651)). AU - Silberberg, S. D.. AU - Lagrutta, A.. AU - Adelman, J. P.. AU - Magleby, K. L.. PY - 1996/1/1. Y1 - 1996/1/1. UR - http://www.scopus.com/inward/record.url?scp=0030006619&partnerID=8YFLogxK. UR - http://www.scopus.com/inward/citedby.url?scp=0030006619&partnerID=8YFLogxK. M3 - Comment/debate. AN - SCOPUS:0030006619. VL - 71. JO - Biophysical Journal. JF - Biophysical Journal. SN - 0006-3495. IS - 1. ER - ...
Drosophila nociceptive neurons convert high-intensity stimuli into characteristic fluctuations of firing rates, quiescent periods of which are regulated by hyperpolarization through small conductance Ca2+-activated K+ channels.
How is intermediate-conductance K+ channel abbreviated? i-K+ stands for intermediate-conductance K+ channel. i-K+ is defined as intermediate-conductance K+ channel rarely.
The purpose of the present study was to examine how apamin interacts with the three cloned subtypes of small-conductance Ca2+-activated K+ channels (hSK1, rSK2 and rSK3). Expression of the SK channel subtypes in Xenopus laevis oocytes resulted in large outward currents (0.5-5 microA) after direct in …
COMMENT 26 Ago 2002 Modification of original channel to allow variable time step and to correct an initialization error. Done by Michael Hines([email protected]) and Ruggero Scorcioni([email protected]) at EU Advance Course in Computational Neuroscience. Obidos, Portugal kca.mod Calcium-dependent potassium channel Based on Pennefather (1990) -- sympathetic ganglion cells taken from Reuveni et al (1993) -- neocortical cells Author: Zach Mainen, Salk Institute, 1995, [email protected] ENDCOMMENT INDEPENDENT {t FROM 0 TO 1 WITH 1 (ms)} NEURON { SUFFIX kca USEION k READ ek WRITE ik USEION ca READ cai RANGE n, gk, gbar RANGE ninf, ntau GLOBAL Ra, Rb, caix GLOBAL q10, temp, tadj, vmin, vmax } UNITS { (mA) = (milliamp) (mV) = (millivolt) (pS) = (picosiemens) (um) = (micron) } PARAMETER { gbar = 10 (pS/um2) : 0.03 mho/cm2 v (mV) cai (mM) caix = 1 Ra = 0.01 (/ms) : max act rate Rb = 0.02 (/ms) : max deact rate dt (ms) celsius (degC) temp = 23 (degC) : original temp q10 = 2.3 : temperature sensitivity vmin ...
Endothelial cell, Ca2+-activated K channels (SKCa and IKCa channels) generate hyperpolarization that passes to the adjacent vascular smooth muscle cells to cause vasodilation in small resistance arterioles. IKCa channels expressed within endothelial cell projections toward the SMCs are activated by spontaneous Ca2+ events (Ca2+ puffs/pulsars). TRPV4 channels also cluster within this microdomain and are selectively activated at low intravascular pressure resulting in activation of endothelial cell IKCa channels and vasodilation, reducing the myogenic tone that underpins tissue blood-flow autoregulation. ...
Kun, Attila (2013) A MAGAS KONDUKTANCIÁJÚ CA2+ AKTIVÁLTA K+ CSATORNÁK BEFOLYÁSOLÁSA A DIABETESES ÉRSZÖVŐDMÉNYEK KEZELÉSÉRE = MODULATION OF LARGE-CONDUCTANCE CALCIUM-ACTIVATED K+ CHANNELS TO TREAT DIABETIC VASCULAR DYSFUNCTION. Project Report. OTKA. Varró, András and Acsai, Károly and Baczkó, István and Biliczki, Péter and Bitay, Miklós and Farkas, Attila and Farkas, András and Hála, Ottó and Jost, Norbert László and Koncz, István and Kormányos, Zsolt and Kovács, Mária and Krassói, Irén and Kun, Attila and Lengyel, Csaba Attila and Leprán, István and Márton, Zoltán and Nagy, Zsolt Ákos and Ördög, Balázs and Papp, Gyula and Papp, Rita and Pataricza, János and Prandovszky, Emese and Prorok, János and Sághy, László and Szuts, Viktória and Tóth, András and Vajda, Szilvia and Ványi, József and Végh, Ágnes and Virág, László (2009) A szívritmuszavarok és a myocardiális repolarizáció mechanizmusainak vizsgálata; antiaritmiás és proaritmiás ...
KCNMB2 antibody (potassium large conductance calcium-activated channel, subfamily M, beta member 2) for IHC, WB. Anti-KCNMB2 pAb (GTX16645) is tested in Human, Rat samples. 100% Ab-Assurance.
4J9Z: Unstructured to structured transition of an intrinsically disordered protein peptide in coupling Ca2+-sensing and SK channel activation.
Background: Large-conductance, calcium-activated potassium (Maxi-K) channels are implicated in the modulation of human uterine contractions and myometrial Ca2+ homeostasis. However, the regulatory mechanism(s) governing ...
KCNN3兔多克隆抗体(ab28631)可与人样本反应并经WB, ELISA实验严格验证,被1篇文献引用。所有产品均提供质保服务,中国75%以上现货。
Our results demonstrate that maxi-K channels in smooth muscle cells are regulated by agents that alter the redox state of sulfhydryl groups. We have shown that sulfhydryl reduction increases nPo of the channel whereas oxidation has the opposite effect. Maxi-K channels in patches pulled from smooth muscle cells appear to exist in a mixed redox state, since either reduction or oxidation markedly affected channel activity. This mixed redox state could occur either because some channels in the patch exist in the reduced state whereas others are in the oxidized state, or because each channel has more than one redox modulatory site existing in different redox states. Since membrane patches from airway myocytes always contain multiple channels, we could not differentiate between these two possibilities.. We compared the normalized conductance-voltage curves constructed from macroscopic currents in response to step-depolarization during control and after sulfhydryl reduction to determine whether ...
BACKGROUND Accumulating data point to intermediate-conductance calcium-activated potassium channel (IKCa1) as a key player in controlling cell cycle progression and proliferation of human cancer cells. However, the role that IKCa1 plays in the growth of human cervical cancer cells is largely unexplored. MATERIAL AND METHODS In this study, Western blot analysis, immunohistochemical staining, and RT-PCR were first used for IKCa1protein and gene expression assays in cervical cancer tissues and HeLa cells. Then, IKCa1 channel blocker and siRNA were employed to inhibit the functionality of IKCa1 and downregulate gene expression in HeLa cells, respectively. After these treatments, we examined the level of cell proliferation by MTT method and measured IKCa1 currents by conventional whole-cell patch clamp technique. Cell apoptosis was assessed using the Annexin V-FITC/Propidium Iodide (PI) double-staining apoptosis detection kit. RESULTS We demonstrated that IKCa1 mRNA and protein are preferentially expressed
The activation of large conductance Ca2+-activated K+ (BK) channels results in cellular hyperpolarization and decreased excitation. Protein kinase C (PKC), adenosine 3′,5′-monophosphate (cAMP)-dependent protein kinase (PKA), and guanosine 3′,5′-monophosphate (cGMP)-dependent protein kinase (PKG) regulate the activity of BK channels. However, the mechanism by which these kinases regulate BK channel activity remains largely unknown. Zhou et al. cloned three isoforms of the BK channel α subunit, which differ only in their COOH-termini: both the A (BKA) and B (BKB) isoforms have two serine residues that serve as sites for protein kinase C (PKC)-mediated phosphorylation, whereas the C (BKC) isoform does not. Inside-out cell membrane patches from HEK293 cells that expressed BKA or BKB were activated by the application of PKG but not by PKA, whereas BKC-containing inside-out patches were only activated by the application of PKA. Upon mutation of the PKC-mediated phosphorylation sites (serine ...
TY - JOUR. T1 - Expression of intermediate-conductance, Ca2+-activated K+ channel (KCNN4) in H441 human distal airway epithelial cells. AU - Wilson, Stuart M.. AU - Brown, Sean G.. AU - McTavish, Niall. AU - McNeill, R. P.. AU - Husband, E. M.. AU - Inglis, Sarah K.. AU - Olver, Richard E.. AU - Clunes, M. T.. PY - 2006/6/9. Y1 - 2006/6/9. N2 - Electrophysiological studies of H441 human distal airway epithelial cells showed that thapsigargin caused a Ca2+-dependent increase in membrane conductance (GTot) and hyperpolarization of membrane potential (Vm). These effects reflected a rapid rise in cellular K+ conductance (GK) and a slow fall in amiloride-sensitive Na+ conductance (GNa). The increase in GTot was antagonized by Ba2+, a nonselective K+ channel blocker, and abolished by clotrimazole, a KCNN4 inhibitor, but unaffected by other selective K+ channel blockers. Moreover, 1-ethyl-2-benzimidazolinone (1-EBIO), which is known to activate KCNN4, increased GK with no effect on GNa. RT-PCR-based ...
Biological membranes, defining the boundary of cells and eukaryotic organelles, are mainly composed of lipids and membrane proteins. Interactions between these lipids and proteins are needed to preserve the tight seal of the membrane, but also to induce structure for proper function in many membrane proteins. In this thesis, interactions between three different kinds of peptides, i.e. small proteins, and model membranes are studied by spectroscopic methods.. First, the membrane interaction of two paddle domains, KvAPp, from the voltage-gated potassium channel KvAP from Aeropyrum pernix, and HsapBKp, from the human, large conductance, calcium-activated potassium channel HsapBK, was studied (paper I and II). In paper I, a high-resolution solution NMR structure of HsapBKp in detergent micelles is presented revealing a helix-turn-helix motif. Small structural differences between HsapBKp and KvAPp, positioning the arginines differently, are presented. These structural differences may explain why BK ...
The large conductance calcium- and voltage-activated K+ channel (KCa1.1, BK, MaxiK) is ubiquitously expressed in the body, and holds the ability to integrate changes in intracellular calcium and membrane potential. This makes the BK channel an important negative feedback system linking increases in intracellular calcium to outward hyperpolarizing potassium currents. Consequently, the channel has many important physiological roles including regulation of smooth muscle tone, neurotransmitter release and neuronal excitability. Additionally, cardioprotective roles have been revealed in recent years. After a short introduction to the structure, function and regulation of BK channels, we review the small organic molecules activating BK channels and how these tool compounds have helped delineate the roles of BK channels in health and disease.
The role of K+ channels in nitric oxide (NO)-induced vasorelaxation has been largely investigated in resistance vessels where iberiotoxin-sensitive MaxiK channels play a predominant role. However, the nature of the K+ channel(s) involved in the relaxation triggered by NO-releasing compounds [nitroglycerin, NTG; NOR 3 [(±)-(E)-4-ethyl-2-[(E)-hydroxyimino]-5-nitro-3-hexenamide]] or atrial natriuretic peptide (ANP) in the conduit vessel aorta has remained elusive. We now demonstrate that, in rat aorta, the relaxation due to these vasorelaxants is not affected by the MaxiK channel blocker iberiotoxin (10-7-10-6 M) as was the control vascular bed used (mesenteric artery). The inability of iberiotoxin to prevent NO/ANP-induced aortic relaxations was not due to lower expression of MaxiK in aorta or due to the predominance of iberiotoxin-resistant channels in this conduit vessel. Aortic relaxations were strongly diminished by 4-aminopyridine (4-AP) (≥5 × 10-3 M) or by tetraethylammonium (,2 × 10-3 ...
BK channels are critical regulators of neuronal activity, controlling firing, neurotransmitter release, cerebellar function, and BK channel mutations have been linked to seizure disorders. Modulation of BK channel gating is well characterized, regulated by accessory subunit interactions, intracellular signaling pathways, and membrane potential. In contrast, the role of intracellular trafficking mechanisms in controlling BK channel function, especially in live cells, has been less studied. Fluorogen activating peptides (FAPs) are well-suited for trafficking and physiological studies due to the binding of malachite green (MG) based dyes with sub-nanomolar affinity to the FAP, resulting in bright, photostable, far-red fluorescence. Cell-excluded MG dyes enable the selective tagging of surface protein and tracking through endocytic pathways. We used CRISPR to insert the FAP at the extracellular N-terminus of BKα in the first exon of its native locus, enabling regulation by the native promoter elements and
Data Availability StatementAll relevant data are within the paper. generate outward potassium currents that bring the membrane potential back to resting levels and oppose vasoconstriction [2C4]. In vascular clean muscle, BK channels have been reported to consist of a pore-forming alpha subunit and two types of accessory subunits: beta1 protein (BK beta1 subunit) and leucine-rich repeat containing protein 26 (BK gamma subunit) [1, 5C6]. Accessory proteins cannot form functional channels, but enable BK channel activation at lower transmembrane voltages when compared to homomeric channels created by BK alpha subunit tetramers [7C8]. BK beta 1 subunits also improve the channels pharmacological profile by conferring, enhancing, or diminishing level of sensitivity to several endogenous and synthetic chemical regulators [9C13]. BK channels remain a constant focus of drug finding, including BK focusing on by newly developed compounds that modulate cerebral artery diameter and could potentially mitigate ...
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MMPokerNab: https://i.imgur.com/NLsxM.jpg While I discovered StarCraft Broodwar back in 2008, it seems people found online poker. And while I spent my time
K+: Potassium channel. Calcium-activated. *BK channel *α1. *β1. *β2. *β3. *β4 ... gap junction channel activity. Cellular component. • cytoplasm. • integral component of membrane. • gap junction. • cell ... Connexins are membrane-spanning proteins that assemble to form gap junction channels that facilitate the transfer of ions and ... Typically the GJB1 protein forms channels through the myelin to the internal Schwann cell or oligodendrocyte, allowing ...
Kaczorowski, GJ; Knaus, HG; Leonard, RJ; McManus, OB; Garcia, ML (1996). "High-conductance calcium-activated potassium channels ... IPA acts on the large-conductance calcium activated K+ channels (BK channels). BK channels are formed by α subunits and ... Isopimaric acid (IPA) is a toxin which acts as a large conductance Ca2+-activated K+ channel (BK channel) opener. IPA ... or voltage sensitivity of the α subunit of BK channels without affecting the channel conductance. In this state BK channels can ...
CANT1: Calcium-activated nucleotidase 1 (17q25.3). *BIRC5: Survivin (17q25.3). *CHMP6: Charged multivesicular body protein 6 ( ... KCNJ2: potassium inwardly-rectifying channel, subfamily J, member 2 (17q24.3). *ACTG1: actin, gamma 1 (17q25) ... TRPV1: encoding protein Transient receptor potential cation channel subfamily V member 1 ... TMC6 and TMC8: Transmembrane channel-like 6 and 8 (epidermodysplasia verruciformis) (17q25.3) ...
KCa4.1 is a member of the calcium-activated potassium channel protein family Mutations in the KCNT1 gene has been shown to be a ... Nomenclature and molecular relationships of calcium-activated potassium channels". Pharmacol. Rev. 57 (4): 463-72. doi:10.1124/ ... SK channel Voltage-gated potassium channel GRCh38: Ensembl release 89: ENSG00000107147 - Ensembl, May 2017 GRCm38: Ensembl ... Potassium channel subfamily T, member 1, also known as KCNT1 is a human gene that encodes the KCa4.1 protein. ...
Potassium intermediate/small conductance calcium-activated channel, subfamily N, member 4, also known as KCNN4, is a human gene ... The channels is also named Gardos channel because of its discoverer. SK channel Voltage-gated potassium channel Senicapoc ... "Entrez Gene: KCNN4 potassium intermediate/small conductance calcium-activated channel, subfamily N, member 4". Gardos G (1958 ... The encoded protein may be part of the predominant calcium-activated potassium channel in T-lymphocytes. This gene is similar ...
Although this channel is structurally related to the calcium-activated potassium channels, it cannot be classified as such ... Nomenclature and molecular relationships of calcium-activated potassium channels". Pharmacol Rev. 57 (4): 463-72. doi:10.1124/ ... Nomenclature and molecular relationships of calcium-activated potassium channels". Pharmacol. Rev. 57 (4): 463-72. doi:10.1124/ ... Potassium channel, subfamily U, member 1, also known as KCNU1, is a gene encoding the KCa5.1 protein. ...
... sequence like an intermediate calcium channel) is an outwardly rectifying potassium channel activated by internal raises in ... Nomenclature and molecular relationships of calcium-activated potassium channels". Pharmacol. Rev. 57 (4): 463-72. doi:10.1124/ ... 2003). "Slick (Slo2.1), a rapidly-gating sodium-activated potassium channel inhibited by ATP". J. Neurosci. 23 (37): 11681-91. ... SK channel Voltage-gated potassium channel GRCh38: Ensembl release 89: ENSG00000162687 - Ensembl, May 2017 GRCm38: Ensembl ...
Potassium intermediate/small conductance calcium-activated channel, subfamily N, member 2, also known as KCNN2, is a protein ... "Entrez Gene: KCNN2 potassium intermediate/small conductance calcium-activated channel, subfamily N, member 2". Mitra R, ... Each component of the AHP is kinetically distinct and is mediated by different calcium-activated potassium channels. The KCa2.2 ... This protein is a member of the calcium-activated potassium channel family. Two transcript variants encoding different isoforms ...
... is a small-conductance calcium-activated potassium channel partly responsible for the calcium-dependent after ... SK3 (small conductance calcium-activated potassium channel 3) also known as KCa2.3 is a protein that in humans is encoded by ... 2006). "Schizophrenia and polymorphic CAG repeats array of calcium-activated potassium channel (KCNN3) gene in Serbian ... 2008). "Analysis of Single Nucleotide Polymorphisms (SNPs) of the small-conductance calcium activated potassium channel (SK3) ...
"Bicuculline block of small-conductance calcium-activated potassium channels". Pflugers Archiv. 438 (3): 314-21. doi:10.1007/ ... bicuculline can be used to block Ca2+-activated potassium channels. Sensitivity to bicuculline is defined by IUPHAR as a major ... The action of bicuculline is primarily on the ionotropic GABAA receptors, which are ligand-gated ion channels concerned chiefly ...
It blocks two potassium channel subtypes; voltage-gated and calcium-activated channels. Coba is a region in Mexico where the ... Other voltage-dependent K+-channels that are blocked by Cobatoxin 1 are the Kv1.2 K+-channels in rats and Kv1.3 K+-channels in ... Cobatoxin 1 also blocks the IKCa1 Ca2+-activated K+-channel. Cobatoxin 1 is a pore-blocking toxin. The interaction between ... Cobatoxin 1 and 2 both block the Kv1.1 K+-channels in mice and the Shaker B K+ channels in insects, which are voltage-dependent ...
K+: Potassium channel. Calcium-activated. *BK channel *α1. *β1. *β2. *β3. *β4 ... This gene encodes an alpha-1 subunit of a voltage-dependent calcium channel. Calcium channels mediate the influx of calcium ... calcium channel activity. • metal ion binding. • voltage-gated ion channel activity. • ion channel activity. • protein binding ... high voltage-gated calcium channel activity. • voltage-gated calcium channel activity involved in AV node cell action potential ...
K+: Potassium channel. Calcium-activated. *BK channel *α1. *β1. *β2. *β3. *β4 ... ion channel activity. • protein binding. • actin binding. • calcium channel activity. • cation channel activity. • protein ... John's wort specifically activates TRPC6 channels". FASEB Journal. 21 (14): 4101-11. doi:10.1096/fj.07-8110com. PMID 17666455. ... cation channel complex. Biological process. • regulation of cytosolic calcium ion concentration. • positive regulation of ...
K+: Potassium channel. Calcium-activated. *BK channel *α1. *β1. *β2. *β3. *β4 ... Inositol trisphosphate receptor (InsP3R) is a membrane glycoprotein complex acting as a Ca2+ channel activated by inositol ...
K+: Potassium channel. Calcium-activated. *BK channel *α1. *β1. *β2. *β3. *β4 ... Channel composition influences the function of gap junction channels. Before innexins and connexins were well characterized, ... When two identical hemichannel proteins come together to form a Gap junction channel, it is called a homotypic GJ channel. When ... 3) and calcium (Ca2+. ),[7] although different hemichannel subunits can impart different selectivity for particular small ...
K+: Potassium channel. Calcium-activated. *BK channel *α1. *β1. *β2. *β3. *β4 ... channel regulator activity. • calcium channel activity. • voltage-gated calcium channel activity. • calcium channel regulator ... Voltage-dependent calcium channel gamma-4 subunit is a protein that in humans is encoded by the CACNG4 gene.[5][6] ... CACNG4, calcium voltage-gated channel auxiliary subunit gamma 4. External IDs. OMIM: 606404 MGI: 1859167 HomoloGene: 8674 ...
... is a multi-pass membrane protein and is thought to form a receptor-activated non-selective calcium permeant cation channel. The ... ion channel activity. • store-operated calcium channel activity. • protein binding. • calcium channel activity. • clathrin ... regulation of cytosolic calcium ion concentration. • calcium ion transmembrane transport. • calcium ion transport. • nervous ... calcium channel complex. • membrane. • cytoplasm. • growth cone. • neuronal cell body. • dendrite. • membrane raft. • cation ...
K+: Potassium channel. Calcium-activated. *BK channel *α1. *β1. *β2. *β3. *β4 ... calcium channel activity. • metal ion binding. • voltage-gated ion channel activity. • voltage-gated calcium channel activity. ... a protein in the voltage-dependent calcium channel complex. Calcium channels mediate the influx of calcium ions into the cell ... Voltage-dependent calcium channel subunit alpha2delta-2 is a protein that in humans is encoded by the CACNA2D2 gene.[5] ...
... inhibits conduction in activated potassium channels. Isoflurane also affects intracellular molecules. It activates ... "Effects of halothane and isoflurane on calcium and potassium channel currents in canine coronary arterial cells". ... Serious side effects can include malignant hyperthermia or high blood potassium. It should not be used in people with a history ... Jones MV, Brooks PA, Harrison NL (April 1992). "Enhancement of gamma-aminobutyric acid-activated Cl- currents in cultured rat ...
... scorpion Centruroides noxius Hoffmann which block voltage-dependent potassium channels and calcium-activated potassium channels ... Furthermore, it affects calcium-activated potassium channels of skeletal muscles. In the squid axon, NTX was found to have ... "Potassium channel toxin alpha-KTx 2.1 - Centruroides noxius (Mexican scorpion)". www.uniprot.org. Retrieved 2017-10-09. Possani ... The blocking of K+ channels by NTX is never complete, which indicates that NTX is either not able to fully block a channel or ...
It is a potent blocker of calcium-activated potassium channels. Both verruculogen and its isoprenyl derivative fumitremorgin A ...
... binds to the outer face of the large-conductance calcium-activated potassium channels (maxiK or BK channels) with ... Iberiotoxin selectively inhibits the current through large-conductance calcium-activated potassium channels. Iberiotoxin is a ... peptidyl probe for the high conductance calcium-activated potassium channel from venom of the scorpion Buthus tamulus". The ... It is also known as "Potassium channel toxin alpha-KTx 1.3" or IbTx. The complete amino acid sequence has been defined and it ...
... s D, E and G have also been found to block activity on large-conductance calcium-activated potassium channels. ... strain HKI0459) with blocking activity on large-conductance calcium-activated potassium channels". Tetrahedron. 63 (2): 435-444 ...
This toxin is a selective blocker of BK channels, calcium-activated potassium channels. Limbatustoxin is purified from the ... Limbatustoxin is highly selective for calcium-activated potassium channels, also called maxi-K channels, slo1 or BK (big ... peptidyl probe for the high conductance calcium-activated potassium channel from venom of the scorpion Buthus tamulus". Journal ... "Functional role of the β subunit of high conductance calcium-activated potassium channels". Neuron, 14(3), 645-650. PMID ...
Calcium-activated potassium channel subunit beta-2 is a protein that in humans is encoded by the KCNMB2 gene. Big Potassium (BK ... and a C-terminal calcium-activated potassium channel beta subunit domain. The N-terminal domain only occurs in calcium- ... "Entrez Gene: KCNMB2 potassium large conductance calcium-activated channel, subfamily M, beta member 2". Bentrop D, Beyermann M ... 2000). "Cloning and functional characterization of novel large conductance calcium-activated potassium channel beta subunits, ...
"Distinct acyl protein transferases and thioesterases control surface expression of calcium-activated potassium channels". The ... and another study suggested that the protein may play a role in the depalmitoylation of calcium-activated potassium channels. ...
"Distinct acyl protein transferases and thioesterases control surface expression of calcium-activated potassium channels". The ... Cellular targets include trimeric G-alpha proteins, ion channels and GAP-43. Moreover, human acyl-protein thioesterases 1 and 2 ...
Calcium-activated potassium channel subunit beta-3 is a protein that in humans is encoded by the KCNMB3 gene. MaxiK channels ... "Entrez Gene: KCNMB3 potassium large conductance calcium-activated channel, subfamily M beta member 3". Orio P, Rojas P, ... 2000). "Cloning and functional characterization of novel large conductance calcium-activated potassium channel beta subunits, ... "Identification of a putative regulatory subunit of a calcium-activated potassium channel in the dup(3q) syndrome region and a ...
"Role of large-conductance calcium-activated potassium channels of coronary arteries in heart preservation". J Heart Lung ... channel reduces ischemic injury in rat cardiac myocytes by activating mitochondrial K(Ca) channel". J Pharmacol Sci. 108 (1): ... Other BKCa++ channel openers are reported to limit the mitochondrial calcium overload due to ischemia. Rottlerin is also ... Kang SH, Park WS, Kim N, Youm JB, Warda M, Ko JH, Ko EA, Han J. "Mitochondrial Ca2+-activated K+ channels more efficiently ...
Calcium-activated potassium channel subunit beta-1 is a protein that in humans is encoded by the KCNMB1 gene. MaxiK channels ... "Entrez Gene: KCNMB1 potassium large conductance calcium-activated channel, subfamily M, beta member 1". Tano, J.-Y.; Gollasch, ... Mazzone JN, Kaiser RA, Buxton IL (2003). "Calcium-activated potassium channel expression in human myometrium: effect of ... potassium channel beta-subunit can interact with and modulate the functional properties of a calcium-activated chloride channel ...
... and is responsible for the activation of calcium-dependent potassium channels. Calcium-activated nonselective cation currents ... Other potassium channels like large conductance calcium-dependent potassium channels and sodium chloride dependent potassium ... voltage gated calcium channels become activated and calcium is able to flow into the cell which usually leads to the release of ... P/Q-type calcium channels are mainly responsible for the release of neurotransmitters that excite, or activate, postsynaptic ...
... which opens ion channels (largely sodium channels, though calcium can enter through these channels as well). The positive ... Each transducin then activates the enzyme cGMP-specific phosphodiesterase (PDE).. *PDE then catalyzes the hydrolysis of cGMP to ... The chief function of the inner segment is to provide ATP (energy) for the sodium-potassium pump. Finally, closest to the brain ... This change in the cell's membrane potential causes voltage-gated calcium channels to close. This leads to a decrease in the ...
... but could relate to actions of the drug on voltage-activated calcium channels. Lamotrigine blocks T-type calcium channels ... At high concentrations, it had no effect on spontaneous or potassium evoked amino acid release.[45] ... However, it does inhibit native and recombinant high-voltage-activated calcium channels (N- and P/Q/R-types) at therapeutic ... It also blocks L-, N-, and P-type calcium channels and has weak 5-hydroxytryptamine-3 (5-HT3) receptor inhibition. These ...
regulation of intracellular calcium activated chloride channel activity. • negative regulation of dendritic spine maintenance. ... regulation of potassium ion transmembrane transport. • long-term memory. • positive regulation of cell death. • negative ... calcium-mediated signaling using intracellular calcium source. • negative regulation of catalytic activity. • positive ... ion channel binding. • microtubule binding. • ATP-dependent protein binding. • metal ion binding. • tubulin binding. • protein ...
2013). "Chapter 3 Sodium/Potassium homeostasis, Chapter 5 Calcium homeostasis, Chapter 6 Manganese homeostasis". Metallomics ... by activating the basolateral Na+/K+ pumps of the tubular epithelial cells. These sodium/potassium exchangers pump three sodium ... "Calcium block of Na+ channels and its effect on closing rate". Proceedings of the National Academy of Sciences of the United ... Potassium concentration[edit]. Main articles: Potassium § Homeostasis, and Potassium in biology. High potassium concentrations ...
Potassium pump[edit]. Malfunction of the sodium-potassium pump may be a factor in some ataxias. The Na+. -K+. pump has been ... With an intact check reflex, the patients check and activate the opposing triceps to slow and stop the movement.[11] ... "Fundamental Mechanisms of Autoantibody-Induced Impairments on Ion Channels and Synapses in Immune-Mediated Cerebellar Ataxias" ... Disulfiram-like drugs: disulfiram, calcium carbimide, cyanamide. Sulfonic acids: Acamprosate. Religion and alcohol. *Christian ...
N-type calcium-channel blocker.. Intrathecal.. Protein binding = 50%; half-life = 2.9-6.5 hours; excretion = urine (,1%).[122] ... Potassium channel (Kv7) opener.[116]. PO, rectal.. Bioavailability = 90% (oral), 72.5% (rectal); protein binding = 80%; volume ... Metabolised to morphine, which activates the opioid receptors.. PO, IM, IV.. Extensive hepatic metabolism, mostly via CYP2D6, ... Binds to the α2δ-1 subunit of voltage gated calcium ion channels in the spinal cord. May also modulate NMDA receptors and ...
The NMDA receptor is a glutamate and ion channel protein receptor that is activated when glycine and glutamate bind to it.[2] ... and calcium (Ca2+) ions into the cell and potassium (K+) out of the cell.[5][6][7][8] Ca2+ flux through NMDA receptors in ... Thus, the channel acts as a "coincidence detector" and only once both of these conditions are met, the channel opens and it ... enter the channel of the NMDA receptor after it has been activated and thereby block the flow of ions.[11][13] MK-801, ketamine ...
"Effects of ethanol on calcium channels, potassium channels, and vasopressin release". Ann. N. Y. Acad. Sci. 625: 249-63. doi: ... If the time of the overdose is known and presentation is within two hours of ingestion, activated charcoal, gastric lavage, and ... Calcium channel blockers (CCB), calcium channel antagonists or calcium antagonists[2] are a group of medications that disrupt ... "Calcium-Channel Blockers (CCBs)". CV Pharmacology. Retrieved 2020-02-07.. *^ Domenic A. Sica, MD. "Calcium Channel Blocker- ...
... and activation of ATP-sensitive potassium channels.[50] In those with severe sepsis and septic shock, this sequence of events ... Recombinant activated protein C (drotrecogin alpha) was originally introduced for severe sepsis (as identified by a high APACHE ... impaired calcium transport, and low production of adenosine triphosphate (ATP), can cause myocardial depression, reducing ... An uncontrolled immune response is then activated because leukocytes are not recruited to the specific site of infection, but ...
In 2012, salicylic acid was found to activate AMP-activated protein kinase, which has been suggested as a possible explanation ... Other preparations use calcium carbonate.[98] Taking it with vitamin C has been investigated as a method of protecting the ... Aspirin and other NSAIDs can cause abnormally high blood levels of potassium by inducing a hyporeninemic hypoaldosteronic state ... "The ancient drug salicylate directly activates AMP-activated protein kinase". Science. 336 (6083): 918-22. Bibcode:2012Sci... ...
However, AMPAR endocytosis has also been activated by voltage-dependent calcium channels, agonism of AMPA receptors, and ... If an AMPAR lacks a GluA2 subunit, then it will be permeable to sodium, potassium, and calcium. The presence of a GluA2 subunit ... The calcium entry also phosphorylates CaMKII, which phosphorylates AMPARs, increasing their single-channel conductance. ... CaMKII activates the Ras proteins, which go on to activate p42/44 MAPK, which drives AMPAR insertion directly into the ...
... mechanism of action for chloroform is that it increases movement of potassium ions through certain types of potassium channels ... "Inhalational anesthetics activate two-pore-domain background K+ channels". Nature Neuroscience. 2 (5): 422-426. doi:10.1038/ ... calcium hypochlorite) with ethanol; however, he mistook it for Chloräther (chloric ether, 1,2-dichloroethane).[14][15] ... Furthermore, if chloroform is boiled with potassium hydroxide, one of the products is potassium formate. On p. 654, Dumas names ...
Mg2+ ions close certain types of calcium channels, which conduct positively charged calcium ions into neurons. With an excess ... March 2008). "Magnesium, calcium, potassium, and sodium intakes and risk of stroke in male smokers". Arch. Intern. Med. 168 (5 ... Mn2+ can also replace Mg2+ as the activating ion for a number of Mg2+-dependent enzymes, although some enzyme activity is ... Mg2+ ions block Ca2+ channels such as (NMDA channels) and have been shown to affect gap junction channels forming electrical ...
These ATP-sensitive potassium ion channels are normally open and the calcium ion channels are normally closed.[3] Potassium ... Then the cytokines activate CD8+ cytotoxic-T cells, which lead to beta-cell destruction.[18] The destruction of these cells ... Voltage-gated calcium channels and ATP-sensitive potassium ion channels are embedded in the plasma membrane of beta cells.[7][8 ... The ATP-sensitive potassium ion channels close when this ratio rises.[8] This means that potassium ions can no longer diffuse ...
"Calcium Fact Sheet". Retrieved April 29, 2014.. *^ a b c Mangels, Reed. "Calcium in the Vegan Diet". Retrieved April 29, 2014. ... "Vegetarian and vegan eating , Better Health Channel". Betterhealth.vic.gov.au. Archived from the original on April 2, 2015. ... potassium, folate, and antioxidants such as vitamins C and E and phytochemicals.[55][56] ... which in turn is created when ultraviolet light activates ergosterol (which is found in fungi and named as a sterol from ergot ...
"Neuronal Calcium Channel Antagonists. Discrimination between Calcium Channel Subtypes Using .omega.-conotoxin from Conus Magus ... "Ethanol Inhibits NMDA-activated Ion Current in Hippocampal Neurons." Science, 243 (4899): 1721-724. ... Stanfield, Peter R (1983) "Tetraethylammonium Ions and the Potassium Permeability of Excitable Cells." Reviews of Physiology, ... Choi, D (1988) "Calcium-mediated Neurotoxicity: Relationship to Specific Channel Types and Role in Ischemic Damage." Trends in ...
When whole mustard seeds are wetted and crushed, an enzyme is activated that releases pungent sulphurous compounds; but they ... and acidity-sensing TRPV ion channel TRPV1 on nociceptors (pain sensing nerve cell) in the mouth and nasal passages. The heat ...
... and ion channels are activated by stretching to allow ions such as calcium, sodium, or potassium to enter the cell.[35] ... Changes in the actin cytoskeleton can activate integrins, which mediate "outside-in" and "inside-out" signaling between the ... and calcium.[1][2] The collagen portion is made up of 97-98% type I collagen, with small amounts of other types of collagen. ...
Potassium channels are then activated, and there is an outward current of potassium ions, returning the electrochemical ... In addition, further potassium channels open in response to the influx of calcium ions during the action potential. The ... b) Potassium (K+) ion. c) Sodium channel. d) Potassium channel. e) Sodium-potassium pump.. In the stages of an action potential ... where the sodium channels close and potassium channels open, allowing potassium ions to cross the membrane into the ...
Shortly thereafter, Major William J. L. Lyster of the Army Medical Department used a solution of calcium hypochlorite in a ... A primitive indoor, tree bark lined, two-channel, stone, fresh and wastewater system appears to have featured in the houses of ... The nitrate rich-earth would be then further processed to produce saltpeter, or potassium nitrate, an important ingredient in ... after scientists at the University of Manchester discovered the sewage treatment process of activated sludge in 1912.[45] ...
N-type calcium-channel blocker.. Intrathecal.. Protein binding = 50%; half-life = 2.9-6.5 hours; excretion = urine (,1%).[124] ... Potassium channel (Kv7) opener.[118]. PO, rectal.. Bioavailability = 90% (oral), 72.5% (rectal); protein binding = 80%; volume ... Metabolised to morphine, which activates the opioid receptors.. PO, IM, IV.. Extensive hepatic metabolism, mostly via CYP2D6, ... Ziconotide, a blocker of potent N‐type voltage‐gated calcium channels, is administered intrathecally for the relief of severe, ...
... ion channel in hepatocytes and pancreatic islets causing calcium entry and subsequent insulin release.[12] ... from fully activating the CB1 [6][better source needed] ... Hetacillin potassium. *Hyperforin. *Hypericum perforatum (St ... pregnenolone sulfate has been shown to activate the transient receptor potential M3 (TRPM3) ... "Transient receptor potential M3 channels are ionotropic steroid receptors in pancreatic beta cells". Nature Cell Biology. 10 ...
... s cause loss of blood potassium, while conserving blood calcium. Thiazides can decrease placental perfusion and ... This activates the renin-angiotensin system, stimulates the secretion of aldosterone, thus activating Na+/K+-ATPase, increasing ... recommend calcium channel blockers (CCBs) as first line agents in hypertension and advise that thiazide-like diuretics should ... Thiazides also lower urinary calcium excretion, making them useful in preventing calcium-containing kidney stones. This effect ...
Calcium 33.6 1.55 52 35% 2.002 0.35 Potassium 72.0 0.89 64 43% 4.291 0.43 ... Small holes in cell membranes, called ion channels, are selective to specific ions and determine the membrane resistance. ... Liquid nitrogen boils at 77 K, cold enough to activate high-temperature superconductors, but not nearly cold enough for ... Calcium and the alkali metals have the best resistivity-density products, but are rarely used for conductors due to their high ...
Examples include coupling to and activating G protein-coupled inwardly-rectifying potassium channels. ... PTH - Increases blood calcium levels. This is accomplished via the Parathyroid hormone 1 receptor (PTH1) in the kidneys and ... Receptor-activated G proteins are bound to the inner surface of the cell membrane. They consist of the Gα and the tightly ... Gαs activates the cAMP-dependent pathway by stimulating the production of cyclic AMP (cAMP) from ATP. This is accomplished by ...
Calcitriol, the activated form of vitamin D, promotes intestinal absorption of calcium and the renal reabsorption of phosphate ... Examples of substances secreted are hydrogen, ammonium, potassium and uric acid. The kidneys also carry out functions ... the kidneys were considered the beginning of the excursion channels system, the 'head' of the Mutra Srotas, receiving from all ...
Single channel studies have identified two types of calcium-activated potassium channel which can also be separated on ... Channels underlying neuronal calcium-activated potassium currents.. Sah P1, Faber ES. ... In this review, we discuss the properties of the different types of calcium-activated potassium channels and the relationship ... In neurons, these currents are largely activated following calcium influx via voltage gated calcium channels active during the ...
Calcium-activated potassium channels mediate prejunctional inhibition of peripheral sensory nerves. D Stretton, M Miura, M G ... Calcium-activated potassium channels mediate prejunctional inhibition of peripheral sensory nerves. D Stretton, M Miura, M G ... Calcium-activated potassium channels mediate prejunctional inhibition of peripheral sensory nerves. D Stretton, M Miura, M G ... Calcium-activated potassium channels mediate prejunctional inhibition of peripheral sensory nerves Message Subject (Your Name) ...
Small-Conductance, Calcium-Activated Potassium Channels from Mammalian Brain. By M. Köhler, B. Hirschberg, C. T. Bond, J. M. ... Small-Conductance, Calcium-Activated Potassium Channels from Mammalian Brain. By M. Köhler, B. Hirschberg, C. T. Bond, J. M. ... Small-Conductance, Calcium-Activated Potassium Channels from Mammalian Brain Message Subject. (Your Name) has forwarded a page ... Expression of the messenger RNAs in Xenopus oocytes resulted in calcium-activated, voltage-independent potassium channels. The ...
Homo sapiens potassium calcium-activated channel subfamily M alpha 1 (KCNMA1), t... Homo sapiens potassium calcium-activated ... Homo sapiens potassium calcium-activated channel subfamily M alpha 1 (KCNMA1), transcript variant 2, mRNA. NCBI Reference ... channel subfamily M alpha 1 (KCNMA1), transcript variant 2, mRNA. gi,238624127,ref,NM_002247.3, ...
These channels are thought to be involved in the regulation of different cellular... ... In this chapter we discuss the data obtained for a calcium-activated potassium channel of large unitary conductance. ... Calcium dependence of open and shut interval distributions from calcium-activated potassium channels in cultured rat muscle, J ... Magleby, K. L., and Pallota, B. S., 1983b, Burst kinetics of single calcium-activated potassium channels in cultured rat muscle ...
Small-Conductance, Calcium-Activated Potassium Channels from Mammalian Brain. By M. Köhler, B. Hirschberg, C. T. Bond, J. M. ... Small-Conductance, Calcium-Activated Potassium Channels from Mammalian Brain. By M. Köhler, B. Hirschberg, C. T. Bond, J. M. ... Small-Conductance, Calcium-Activated Potassium Channels from Mammalian Brain Message Subject. (Your Name) has forwarded a page ...
Calcium-Activated Potassium Channels and NO Regulate Human Peripheral Conduit Artery Mechanics. Jeremy Bellien, Robinson ... Block of calcium-activated potassium channels in mammalian arterial myocytes by tetraethylammonium ions. Am J Physiol. 1991; ... Calcium-Activated Potassium Channels and NO Regulate Human Peripheral Conduit Artery Mechanics ... Calcium-Activated Potassium Channels and NO Regulate Human Peripheral Conduit Artery Mechanics ...
Term: small/intermediate conductance calcium-activated potassium channel protein. ID: PIRSF038511 Mouse Protein Superfamily ...
Calcium-activated potassium channels are potassium channels gated by calcium, or that are structurally or phylogenetically ... Calcium-Activated+Potassium+Channels at the US National Library of Medicine Medical Subject Headings (MeSH) "Calcium-Activated ... Subtypes of IK Channels KCa3.1 (IKCa1, SK4, KCNN4) Small conductance calcium activate potassium channels are quite different ... Like other potassium channels they are involved in hyperpolarization of cells after an action potential. The calcium activated ...
1993) Calcium channels and calcium-gated potassium channels at the frog neuromuscular junction. J Physiol (Paris) 87:15-24. ... calcium-activated potassium (BK) channels. BK channels in hair cells are encoded by the alternatively spliced slo gene and may ... calcium-activated potassium (BK) channels play a prominent role in vertebrate hair cell function. BK channels in hair cells may ... 1995) The calcium-activated potassium channels of turtle hair cells. J Gen Physiol 105:49-72. ...
Potassium calcium-activated channel subfamily N member 3. Predicted membrane proteins. Voltage-gated ion channels. ... Potassium calcium-activated channel subfamily M alpha 1. Disease related genes. FDA approved drug targets. Predicted ... Potassium calcium-activated channel subfamily N member 4. Disease related genes. FDA approved drug targets. Predicted ... Potassium calcium-activated channel subfamily N member 2. Plasma proteins. Predicted membrane proteins. Transporters. Voltage- ...
2. The channel had a conductance of 210 pS in a 150 mM:150 mM K+ gradient, was highly selective for K+ ov … ... A high-conductance calcium-activated potassium channel (BK KCa) was characterized at a cholinergic presynaptic nerve terminal ... Single-channel properties of BK-type calcium-activated potassium channels at a cholinergic presynaptic nerve terminal J Physiol ... suggesting that the channel can be activated by calcium ion influx through neighbouring calcium channels. 5. The properties of ...
Calcium-activated potassium channel subunit beta-2. Details. Name. Calcium-activated potassium channel subunit beta-2. Kind. ... Calcium-activated potassium channel subunit beta-2. Q9Y691. Details. Drug Relations. Drug Relations. DrugBank ID. Name. Drug ...
One important target of PKGI in smooth muscle is the large-conductance, calcium-activated potassium (BK) channel, which upon ... Erectile dysfunction in mice lacking the large-conductance calcium-activated potassium (BK) channel J Physiol. 2005 Sep 1;567( ... One important target of PKGI in smooth muscle is the large-conductance, calcium-activated potassium (BK) channel, which upon ... Potassium Channels, Calcium-Activated / deficiency * Potassium Channels, Calcium-Activated / genetics * Potassium Channels, ...
... the calcium-activated potassium channel beta subunit is a family of proteins comprising the beta subunits of calcium-activated ... "Functional role of the beta subunit of high conductance calcium-activated potassium channels". Neuron. 14 (3): 645-50. doi: ... potassium channels. The functional diversity of potassium channels can arise through homo- or hetero-associations of alpha ... "The beta subunit increases the Ca2+ sensitivity of large conductance Ca2+-activated potassium channels by retaining the gating ...
Forms a voltage-independent potassium channel activated by intracellular calcium. Activation is followed by membrane ... The complex is composed of 4 channel subunits each of which binds to a calmodulin subunit which regulates the channel activity ...
Calcium-activated potassium channel.... Calcium-activated potassium channel subunit beta-2 (BK channel subunit beta-2, BKbeta2 ... Calcium-activated potassium channel.... Calcium-activated potassium channel subunit beta-2 (Large-conductance Ca2+-activated K+ ... Calcium-activated potassium channel subunit beta-2Imported. ,p>Information which has been imported from another database using ... tr,E7EM81,E7EM81_HUMAN Calcium-activated potassium channel subunit beta-2 (Fragment) OS=Homo sapiens OX=9606 GN=KCNMB2 PE=4 SV= ...
... channel. Modulates the calcium sensitivity and gating kinetics of KCNMA1, thereby contributing to KCNMA1 channel diversity. ... Increases the apparent Ca(2+)/voltage sensitivity of the KCNMA1 channel. It also modifies KCNMA1 channel kinetics and alters ... It slows down the activation and the deactivation kinetics of the channel. Acts as a negative regulator of smooth muscle ... Its presence is also a requirement for internal binding of the KCNMA1 channel opener dehydrosoyasaponin I (DHS-1) triterpene ...
Among the different potassium channels present in cardiac myocytes, the small conductance Ca2+ activated potassium channels (SK ... Effects of small conductance calcium activated potassium channels in atrial myocytes. dc.contributor.author. Peñaranda Ayllón, ... Peñaranda, A. [et al.]. Effects of small conductance calcium activated potassium channels in atrial myocytes. A: Computers in ... The dependence of SK channels with changes in intracellular calcium dynamics helps decreasing the proarrhythmic effect of ...
A major class of calcium activated potassium channels whose members are voltage-dependent. MaxiK channels are activated by ... either membrane depolarization or an increase in intracellular Ca(2+). They are key regulators of calcium and electrical ... Potassium Channels: 2108*Calcium-Activated Potassium Channels: 183*Large-Conductance Calcium-Activated Potassium Channels: 162* ... Potassium Channels: 2108*Calcium-Activated Potassium Channels: 183*Large-Conductance Calcium-Activated Potassium Channels: 162* ...
... potassium calcium-activated channel subfamily N member 3), Authors: Dessen P. Published in: Atlas Genet Cytogenet Oncol ... potassium channel, calcium activated intermediate/small conductance subfamily N alpha, member 3. ... of membrane small conductance calcium-activated potassium channel activity neuron projection neuronal cell body potassium ion ... of membrane small conductance calcium-activated potassium channel activity neuron projection neuronal cell body potassium ion ...
... potassium calcium-activated channel subfamily M alpha 1), Authors: Dessen P. Published in: Atlas Genet Cytogenet Oncol Haematol ... stress voltage-gated potassium channel complex calcium-activated potassium channel activity calcium-activated potassium channel ... stress voltage-gated potassium channel complex calcium-activated potassium channel activity calcium-activated potassium channel ... to calcium ion large conductance calcium-activated potassium channel activity large conductance calcium-activated potassium ...
... and KCa3.1 Calcium-activated Potassium Channels via Activating Calmodulin-dependent Protein Kinase Kinase and AMP-activated ... and KCa3.1 Calcium-activated Potassium Channels via Activating Calmodulin-dependent Protein Kinase Kinase and AMP-activated ... and KCa3.1 Calcium-activated Potassium Channels via Activating Calmodulin-dependent Protein Kinase Kinase and AMP-activated ... and KCa3.1 Calcium-activated Potassium Channels via Activating Calmodulin-dependent Protein Kinase Kinase and AMP-activated ...
... including the large conductance calcium-activated potassium channels (BKCa).13 These channels contain 4 α subunits forming the ... Calcium-activated potassium channels and the regulation of vascular tone. Physiology (Bethesda). 2006; 21: 69-78. ... Because calcium-activated potassium (BKCa) channels are essential for vascular smooth muscle cell (VSMC) relaxation, we ... Aldosterone-Induced Coronary Dysfunction in Transgenic Mice Involves the Calcium-Activated Potassium (BKCa) Channels of ...
Calcium activated potassium channel triggers cardioprotection of ischemic preconditioning. Chun-mei Cao, Qiang Xia, Qin Gao, ... Calcium activated potassium channel triggers cardioprotection of ischemic preconditioning. Chun-mei Cao, Qiang Xia, Qin Gao, ... Calcium activated potassium channel triggers cardioprotection of ischemic preconditioning. Chun-mei Cao, Qiang Xia, Qin Gao, ... Calcium activated potassium channel triggers cardioprotection of ischemic preconditioning Message Subject (Your Name) has ...
The family of calcium-activated potassium channels consists of four members with varying biological functions and conductances ... An Inducible Expression System of the Calcium-Activated Potassium Channel 4 to Study the Differential Impact on Embryonic Stem ... We chose SK channel subtype 4 as a potential candidate influencing embryonic stem cell differentiation. Methods. We generated a ... Distinct SK channel subtype expression in ES cells might elucidate their precise impact during cardiac development. ...
Nomenclature and Molecular Relationships of Calcium-Activated Potassium Channels. Aguan D. Wei, George A. Gutman, Richard ... Nomenclature and Molecular Relationships of Calcium-Activated Potassium Channels. Aguan D. Wei, George A. Gutman, Richard ... Nomenclature and Molecular Relationships of Calcium-Activated Potassium Channels. Aguan D. Wei, George A. Gutman, Richard ... Nomenclature and Molecular Relationships of Calcium-Activated Potassium Channels Message Subject (Your Name) has forwarded a ...
KCNMB4, potassium calcium-activated channel subfamily M regulatory beta subunit 4. Orthology source: HomoloGene, HGNC ... J:250373 Whitmire LE, et al., Downregulation of KCNMB4 expression and changes in BK channel subtype in hippocampal granule ...
... ... Using human intermediate-conductance calcium-activated potassium (hIKCa1) channels as a model we aimed to characterize ... We report here that the block of MTX, but not of CTX on current through hIKCa1 channels is pH0 dependent. The replacement of ... In contrast, CTX binding affinity to the hIKCa1_H236C channel mutant was increased suggesting that His236 might play a role in ...
large-conductance calcium-activated potassium channel. EDP. epoxydocosapentaenoic acid. EEQ. epoxyeicosaquatraenoic acid. DHDP ... of Docosahexaenoate Potently Dilate Coronary Arterioles by Activating Large-Conductance Calcium-Activated Potassium Channels. ... of Docosahexaenoate Potently Dilate Coronary Arterioles by Activating Large-Conductance Calcium-Activated Potassium Channels. ... of Docosahexaenoate Potently Dilate Coronary Arterioles by Activating Large-Conductance Calcium-Activated Potassium Channels. ...
  • The distribution, function, and pharmacology of these channels are consistent with the SK class of small-conductance,calcium-activated potassium channels, which contribute to the afterhyperpolarization in central neurons and other cell types. (sciencemag.org)
  • In humans they are divided into three subtypes: large conductance or BK channels, which have very high conductance which range from 100 to 300 pS, intermediate conductance or IK channels, with intermediate conductance ranging from 25 to 100 pS, and small conductance or SK channels with small conductances from 2-25 pS. (wikipedia.org)
  • Among the different potassium channels present in cardiac myocytes, the small conductance Ca2+ activated potassium channels (SK channels) are particular because they are affected by changes in intracellular calcium. (upc.edu)
  • Small-conductance, calcium-activated potassium channels, which are gated by the increases in intracellular calcium during activation, contribute to the interval between action potentials by generating an afterhyperpolarization current. (biomedcentral.com)
  • demonstrate that proper membrane localization of a small-conductance Ca(2+)-activated K(+) channel (SK2 or K(Ca)2.2) is dependent on its interacting protein, alpha-actinin2, a major F-actin crosslinking protein. (nih.gov)
  • To avoid ventricular adverse effects, a new target has been considered, the small conductance calcium-activated K + channels (K Ca 2.X, SK channels). (sophion.com)
  • Dissertation zur Erlangung des Doktorgradesder Fakultät für Chemie und Pharmazieder Ludwig-Maximilians-Universität MünchenStructure-function analyses of small-conductance,calcium-activated potassium channels.Dieter D'hoedtOostende (Belgium)2005 Erklärung Diese Dissertation wurde im Sinne von § 13 Abs. (youscribe.com)
  • In particular, small-conductance calcium-activated potassium channels (SK) are conducting potassium ions and areactivated by binding of calcium ions to calmodulin, which is constitutively bound to the carboxy-terminus of each SK channel α-subunit.Until now, only three SK channel subunits have been cloned, SK1, SK2 and SK3. (youscribe.com)
  • In particular, small- conductance calcium-activated potassium channels (SK) are conducting potassium ions and are activated by binding of calcium ions to calmodulin, which is constitutively bound to the carboxy- terminus of each SK channel α-subunit. (youscribe.com)
  • BACKGROUND: Small-conductance calcium-activated potassium (SK) channels have been found to play an important role in atrial repolarization and atrial fibrillation (AF). (ku.dk)
  • a]quinoxalin-1-one (ODQ, 10 μM), guanylyl cyclase inhibitors, or charybdotoxin (CTX: 0.1 μM), iberiotoxin (ITX, 0.1 μM) and apamin (APA, 0.1 μM), large conductance Ca 2+ -activated K + channels (BK(Ca)) blocker and small conductance Ca 2+ -activated K + channel, (SK(Ca)) blocker, respectively. (elsevier.com)
  • Small conductance Ca2+-activated K+ channel knock-out mice reveal the identity of calcium-dependent afterhyperpolarization currents. (naver.com)
  • Analysis of Single Nucleotide Polymorphisms (SNPs) of the small-conductance calcium activated potassium channel (SK3) gene as genetic modifier of t. (cdc.gov)
  • It is a multisystemic disorder with major cardiac involvement most commonly represented by first-degree atrioventricular heart block (AVB), followed by different degrees of bundle-branch and intraventricular blocks In search for candidate genes, modifiers of the AVB phenotype in DM1, the expression of the small-conductance calcium activated potassium channel (SK3) gene was analysed in muscle biopsies from DM1 patients. (cdc.gov)
  • A detailed investigation of mRNA and protein expression of K Ca channels of intermediate (SK4) and small conductance (SK1-3) was performed by Tamarina et al. (diabetesjournals.org)
  • Then in 1970, Meech was the first to observe that intracellular calcium could trigger potassium currents. (wikipedia.org)
  • In any muscle cell, increased intracellular calcium causes contraction. (wikipedia.org)
  • In smooth muscle cells the elevated levels of intracellular calcium cause the opening of BK channels which in turn allow potassium ions to flow out of the cell. (wikipedia.org)
  • Forms a voltage-independent potassium channel activated by intracellular calcium. (rcsb.org)
  • Aim Endothelial cell (EC) KCa2.3 and KCa3.1, calcium-activated potassium channels, play a crucial role in NO- and EDHF-mediated regulation of vascular tone by controlling membrane potential and intracellular calcium levels. (ahajournals.org)
  • however, reducing channel activity with intracellular calcium destabilized inactivation. (dundee.ac.uk)
  • Electrical signals and resulting intracellular calcium transients, in vertebrates, control contraction of muscle, secretion of hormones, sensation of the environment, processing of information in the brain, and output from the brain to peripheral tissues. (sciencemag.org)
  • The levels of endogenous NO and intracellular calcium in the CA1 region of the hippocampal slices were measured respectively by electrochemical microsensors and spectrofluorometry. (naver.com)
  • Also, the level of protein expression of neuronal NO synthase was markedly lessened in the IH neurons with decreased intracellular calcium response to hypoxia. (naver.com)
  • TLQP-21 and JMV5656 induced a sharp, dose-dependent increment in intracellular calcium. (frontiersin.org)
  • The calcium binding domain may be contained in the α subunit sequence, as in KCa1, or may be through an additional calcium binding protein such as calmodulin. (wikipedia.org)
  • The alpha subunit is a tetramer which forms the pore, the voltage sensor, and the calcium sensing region. (wikipedia.org)
  • This subunit of the channel is made up of seven trans-membrane units, and a large intracellular region. (wikipedia.org)
  • The beta subunit of the channel is thought to be a regulatory subunit of the channel. (wikipedia.org)
  • BK channels in hair cells are encoded by the alternatively spliced slo gene and may include an accessory β subunit. (jneurosci.org)
  • Addition of the β subunit increased steady-state calcium affinity, raised the Hill coefficient for calcium binding, and slowed channel deactivation rates, resulting in eight functionally distinct channels. (jneurosci.org)
  • We investigated the functional role of BK channels in the corpus cavernosum utilizing a knock-out mouse lacking the Slo gene (Slo-/-) responsible for the pore-forming subunit of the BK channel. (nih.gov)
  • In molecular biology, the calcium-activated potassium channel beta subunit is a family of proteins comprising the beta subunits of calcium-activated potassium channels. (wikipedia.org)
  • The beta subunit (which is thought to possess 2 transmembrane domains) increases the calcium sensitivity of the BK channel. (wikipedia.org)
  • The complex is composed of 4 channel subunits each of which binds to a calmodulin subunit which regulates the channel activity through calcium-binding. (rcsb.org)
  • Regulatory subunit of the calcium activated potassium KCNMA1 (maxiK) channel. (uniprot.org)
  • The second group of Ca 2+ activated K + channels include Large conductance KCa channels ( KCa1.1 , also known as BK channel, Slo or Slo1), a voltage-sensitive channel that binds calcium independently of calmodulin but mediated by at least three divalent cation binding sites in the cytoplasmic carboxyl domain of each channel subunit. (axonmedchem.com)
  • To further investigate this notion, we performed a sequence analysis of the alpha-subunit of cloned slowpoke KCa channels from Drosophila and mammals. (rupress.org)
  • While regulation of expression of the BK channel gene can account for part of the diurnal difference in excitability of SCN neurons, we hypothesized that daily regulation of BK current properties in the SCN via β-subunit association, alternative splicing, and control of Ca2+ sources limits a role for BK currents in setting firing frequency during the day. (umaryland.edu)
  • Expression of the α subunit of the Maxi-K channel was significantly decreased ~40% while the expression of the β1 subunit was increased ~2-fold at the mRNA level. (elsevier.com)
  • Increased expression of the β1 subunit points to a compensatory reaction to decreased Maxi-K channel activity. (elsevier.com)
  • The C subunit colocalized with the L-type Ca 2+ channel in transverse tubules in wild-type skeletal muscle and retained this localization in knockout muscle. (pnas.org)
  • In addition to binding to the RII subunit of PKA, AKAP 79 interacts with the calcium and calmodulin-dependent protein phosphatase 2B (calcineurin) and protein kinase C through sites distinct from the RII binding site ( 7 , 8 ). (pnas.org)
  • MaxiK channels can be formed by 2 subunits: the pore-forming alpha subunit and the modulatory beta subunit. (genecards.org)
  • The protein encoded by this gene is an auxiliary beta subunit which slows activation kinetics, leads to steeper calcium sensitivity, and shifts the voltage range of current activation to more negative potentials than does the beta 1 subunit. (genecards.org)
  • KCNMB4 (Potassium Calcium-Activated Channel Subfamily M Regulatory Beta Subunit 4) is a Protein Coding gene. (genecards.org)
  • Modulation of BK channel gating is well characterized, regulated by accessory subunit interactions, intracellular signaling pathways, and membrane potential. (frontiersin.org)
  • HEK293 cells expressing the alpha subunit of BK channel were incubated with R for 4 hours after which the cells were washed and then treated with higher concentrations of KBS (50mM / 80mM) or NS1619 (0.003 - 100µM) for 10 minutes. (acseusa.org)
  • Large conductance Ca2+-activated K+ channel (BKCa) activating properties of a series of novel N-arylbenzamides: Channel subunit dependent effects. (acseusa.org)
  • Channels underlying neuronal calcium-activated potassium currents. (nih.gov)
  • In many cell types rises in cytosolic calcium, either due to influx from the extracellular space, or by release from an intracellular store activates calcium dependent potassium currents on the plasmalemma. (nih.gov)
  • In neurons, these currents are largely activated following calcium influx via voltage gated calcium channels active during the action potentials. (nih.gov)
  • Activation of these potassium currents modulates action potential time course and the repetitive firing properties of neurons. (nih.gov)
  • In this review, we discuss the properties of the different types of calcium-activated potassium channels and the relationship between these channels and the macroscopic currents present in neurons. (nih.gov)
  • Iberiotoxin-sensitive voltage- and [Ca2+]-activated K+ currents, the latter activated by local transient calcium releases (calcium sparks), were present in Slo+/+ CCSM cells, but absent in Slo-/- cells. (nih.gov)
  • While they do not seem to play an important role in healthy hearts - their associated current, IKCa, is smaller than other potassium currents -, there is increasing evidence that they may become relevant under pathological conditions. (upc.edu)
  • 1. Isolated native endothelial cells, obtained by treatment, of rabbit aortic endothelium with papain and dithiothreitol, were voltage clamped, and single channel (unitary) and spontaneous transient outward currents (STOCs) were recorded from both whole cells and excised membrane patches. (edu.au)
  • 2. In inside-out patches, the reversal potential of unitary currents was dependent on the extracellular K+ concentration and had a single-channel slope conductance of 220 pS in symmetrical 140 mM-K+ solutions. (edu.au)
  • Whole-cell outward K+ currents evoked by depolarizing voltage ramps had amplitudes often corresponding to the simultaneous opening of more than five single Ca2+-activated K+ channels. (edu.au)
  • Ca2+-activated K+ currents were blocked completely by 5 mM-TEA, whereas 3,4-diaminopyridine (1 mM), Ba2+ (10 mM) and apamin (0.1-1 μM) did not abolish these K+ currents. (edu.au)
  • Whole-cell recordings of membrane currents through KCa channels in RNase-treated cells demonstrated a biphasic pattern: initially their activity in cell population increased, peaked at 24h, and then gradually decreased. (ox.ac.uk)
  • Resveratrol concentration-dependently increased the current amplitude and the opening activity of BK Ca channels, but suppressed the amplitude of voltage-gated sodium currents. (biomedcentral.com)
  • Our data demonstrated that resveratrol activated BK Ca channels, but inhibited voltage-gated sodium currents. (biomedcentral.com)
  • BK currents undergo multi-level regulation by genetic and posttranslational mechanisms as well as functional coupling to Ca2+ channels. (umaryland.edu)
  • Though the BK channel is encoded via a single gene, Kcnma1, currents produced by this channel exhibit a large degree of phenotypic variability across different cell types, indicating regulation of the BK channel can influence BK current properties. (umaryland.edu)
  • Using patch-clamp electrophysiolgy we demonstrate that BK current properties in the SCN are diurnally regulated, with smaller BK currents during the day found to be due to BK channel inactivation, Ca2+ source regulation and alternative splicing, rather than simply a decrease in BK channel expression. (umaryland.edu)
  • Those more "typical" potassium channels preferentially carry outward (rather than inward) potassium currents at depolarized membrane potentials, and may be thought of as "outwardly rectifying. (wikipedia.org)
  • When first discovered, inward rectification was named "anomalous rectification" to distinguish it from outward potassium currents. (wikipedia.org)
  • Inward rectifiers also differ from tandem pore domain potassium channels , which are largely responsible for "leak" K + currents. (wikipedia.org)
  • Other inwardly rectifying channels, termed "strong inward rectifiers," carry very little outward current at all, and are mainly active at voltages negative to the K + reversal potential, where they carry inward current (the much larger currents below the 0 nA line in figure 1). (wikipedia.org)
  • The phenomenon of inward rectification of K ir channels is the result of high-affinity block by endogenous polyamines , namely spermine , as well as magnesium ions, that plug the channel pore at positive potentials, resulting in a decrease in outward currents. (wikipedia.org)
  • Unexpectedly, these channels have inactivating currents and are clustered near the apex of the cell away from synaptic sites near the base. (elsevier.com)
  • We found that the SNPs C495G and R800W had the largest effects on BK currents, affecting the conductance-voltage relationship across multiple Ca2+ conditions in the context of two BK channel splice variants. (umaryland.edu)
  • Neither application of alkaline phosphatase to patches, which results in increased BK channel activity attributed to channel dephosphorylation, nor bidirectional redox modulations completely abrogated SNP effects on BK currents. (umaryland.edu)
  • SK channels underlying calcium-activated potassium currents in various tissues. (youscribe.com)
  • However, when I expressed rSK1 in HEK-293 cells no potassium currents above background were observed, although immunofluorescence experiments using a specific antibody against the rSK1 protein showed expression of the channel. (youscribe.com)
  • Patients orOther Participants: Myometrial biopsies were obtained at elective cesarean delivery.Intervention: No intervention was applied.Main Outcome Measures: Open state probability of single channel recordings, whole cell currents, and myometrial contractile activity were measured.Results: Single-channel recordings identified the BKCa channel as a target of BRL37344. (nuigalway.ie)
  • In 77% of cells, JMV5656 also caused an increase in the total outward currents, which was blunted by TEA (tetraethyl ammonium chloride), a non-selective blocker of voltage-dependent and Ca 2+ -activated potassium (K + ) channels. (frontiersin.org)
  • Additionally, inhibition of JMV5656-stimulated outward currents by NS6180 (4-[[3-(trifluoromethyl)phenyl]methyl]-2H-1,4 benzothiazin-3(4H)-one) and TRAM-34 (triarylmethane-34), indicated that K Ca 3.1 channels are involved in this JMV5656 mechanisms of action. (frontiersin.org)
  • An increase in K + currents and concomitant membrane hyperpolarization could be evoked in WT β-cells by the SK4 channel opener DCEBIO (100 μmol/l). (diabetesjournals.org)
  • Accordingly, the SK4 channel blocker TRAM-34 (1 μmol/l) partly inhibited K Ca currents and induced electrical activity at a threshold glucose concentration. (diabetesjournals.org)
  • In this paper, we summarize a variety of accumulated evidence which suggests that BPTI binds to a site on the KCa channel protein that structurally resembles a serine proteinase. (rupress.org)
  • This diurnal change in firing rate is due in part to an increase in BK channel protein found in the SCN at night. (umaryland.edu)
  • The protein encoded by this gene is activated before membrane hyperpolarization and is thought to regulate neuronal excitability by contributing to the slow component of synaptic AHP. (nih.gov)
  • The encoded protein is an integral membrane protein that forms a voltage-independent calcium-activated channel with three other calmodulin-binding subunits. (nih.gov)
  • Sixteen antibodies raised against human or rat SK/IK channel peptide epitopes were tested for their ability to stain cells expressing channel protein. (ucl.ac.uk)
  • Following the hormonal elevation of cAMP, phosphorylation of protein substrates by cAMP-dependent protein kinase (PKA) influences many physiological processes, including cellular differentiation, metabolism, and ion channel activity. (pnas.org)
  • Internal application of Mg-ATP, but not Mg-5'-adenylylamidodiphosphate, retarded recovery of channel activity from inactivation, whereas internal application of protein phosphatase-1a enhanced recovery from inactivation. (dundee.ac.uk)
  • The protein encoded by this gene is activated before membrane hyp. (genecards.org)
  • KCNN1 (Potassium Calcium-Activated Channel Subfamily N Member 1) is a Protein Coding gene. (genecards.org)
  • Gene Ontology (GO) annotations related to this gene include protein heterodimerization activity and calcium-activated potassium channel activity . (genecards.org)
  • All of these physiological processes are mediated in part by members of the voltage-gated ion channel protein superfamily. (sciencemag.org)
  • This article identifies all of the members of this protein superfamily in the human genome, reviews the molecular and evolutionary relations among these ion channels, and describes their functional roles in cell physiology. (sciencemag.org)
  • Also covered are fluorescent and radioligand assays, exciting new visualization methods employing green fluorescent protein (GFP), and novel assays based on the functional properties of ion channels and receptors, as well as rapidly developing atomic force microscopy methodologies. (springer.com)
  • One pathway in particular showed multiple proteins upregulated significantly, the mitogen activated protein kinase (MAPK) pathway which is involved in many cellular processes including regulation of transcription and translation. (lakeforest.edu)
  • 2,4 Whether an increase in vascular calcium-activated potassium (K Ca ) channel activity after NO synthesis inhibition could contribute to the maintenance of basal conduit artery diameter and mechanics has never been investigated in vivo in humans. (ahajournals.org)
  • 16-19 Thus, the present study was designed to assess in vivo, at the level of the radial artery, the effect of the acute vascular K Ca channel blockade in the regulation of basal conduit artery diameter and mechanical properties before and after inhibition of NO synthesis. (ahajournals.org)
  • IK channels have shown a strong connection to calcification in vasculature, as inhibition of the channel causes a decrease in vascular calcification. (wikipedia.org)
  • In the heart, K Ca 2.X channels are functionally more important in atria compared to ventricles, and pharmacological inhibition of the channel confers atrial selective prolongation of the cardiac action potential and converts AF to sinus rhythm in animal models of AF. (sophion.com)
  • Methods and Results: We have applied the SKCa-activator EBIO on embryonic stem cells and identified this particular ion channel family as a new critical target involved in the generation of cardiac pacemaker-like cells: SKCa-activation led to rapid remodeling of the actin cytoskeleton, inhibition of proliferation, induction of differentiation and diminished teratoma formation. (datamed.org)
  • NO donors, SNP or DETA/NO, significantly restored the activity of BK channels in the IH neurons, which was prevented by blockade of S-nitrosylation with NEM or MTSES but not by inhibition of the cGMP pathway with ODQ or 8-bromo-cGMP. (naver.com)
  • Subtypes of BK Channels KCa1.1 (BK, Slo1, Maxi-K, KCNMA1) Beta subunits: β1, β2, β3, β4 Intermediate conductance channels seem to be the least studied of all of the channels. (wikipedia.org)
  • Modulates the calcium sensitivity and gating kinetics of KCNMA1, thereby contributing to KCNMA1 channel diversity. (uniprot.org)
  • Increases the apparent Ca 2+ /voltage sensitivity of the KCNMA1 channel. (uniprot.org)
  • It also modifies KCNMA1 channel kinetics and alters its pharmacological properties. (uniprot.org)
  • Acts as a negative regulator of smooth muscle contraction by enhancing the calcium sensitivity to KCNMA1. (uniprot.org)
  • Its presence is also a requirement for internal binding of the KCNMA1 channel opener dehydrosoyasaponin I (DHS-1) triterpene glycoside and for external binding of the agonist hormone 17-beta-estradiol (E2). (uniprot.org)
  • Methods: We selected a total of 35 genes covering KCa channels KCNN1-4, KCNMA1 and their subunits KCNMB1-4, endoplasmic reticulum (ER) calcium sensors STIM1 and STIM2, Ca 2+ channels ORAI1-3 and the family of cation channels TRP (TRPC1-7, TRPA1, TRPV1/2,4-6 and TRPM1-8). (inserm.fr)
  • BK channel-null mice (Kcnma1 -/- ) have increased SFRs in SCN neurons selectively at night and weak circadian amplitudes in multiple behaviors timed by the SCN. (elsevier.com)
  • Kcnma1 -/- mice show normal expression of clock genes such as Arntl (Bmal1), indicating a role for BK channels in SCN pacemaker output, rather than in intrinsic time-keeping. (elsevier.com)
  • Here, we studied the expression of another potassium channel, namely, the calcium-activated potassium channel KCa1.1 (KCNMA1) in cervical cancer models. (global-summit.com)
  • Decreases the gating kinetics and calcium sensitivity of the KCNMA1 channel, but with fast deactivation kinetics. (genecards.org)
  • May decrease KCNMA1 channel openings at low calcium concentrations but increases channel openings at high calcium concentrations. (genecards.org)
  • Makes KCNMA1 channel resistant to 100 nM charybdotoxin (CTX) toxin concentrations. (genecards.org)
  • 2. The channel had a conductance of 210 pS in a 150 mM:150 mM K+ gradient, was highly selective for K+ over Na+, and was sensitive to block by external charybdotoxin or tetraethylammonium (TEA) and by internal Ba2+. (nih.gov)
  • Using human intermediate-conductance calcium-activated potassium (hIKCa1) channels as a model we aimed to characterize structural differences between maurotoxin (MTX) and charybdotoxin (CTX) and to gain new insights into the molecular determinants that define the interaction of these pore-blocking peptides with hIKCa1 channel. (ovid.com)
  • The BK channel was inhibited reversibly by external tetraethylammonium (TEA) ions, charybdotoxin, and quinine and was resistant to block by 4-aminopyridine and apamin. (edu.au)
  • Moreover, the effects of ion channel blockers charybdotoxin and iberiotoxin, suggested that multiple calcium-activated K + channel types drove the outward current stimulated by JMV5656. (frontiersin.org)
  • The properties of single Ca2+-activated K+ (BK) channels in neonatal rat intracardiac neurons were investigated using the patch-clamp recording technique. (edu.au)
  • They also suggest that medullary neurons which contribute to respiratory pattern may be characterized by SK3 channels while those responsible for rhythm may not. (biomedcentral.com)
  • However, relatively little is known about whether resveratrol modulates the ion channels in cortical neurons. (biomedcentral.com)
  • The large-conductance calcium-activated potassium channels (BK Ca ) and voltage-gated sodium channels were expressed in cortical neurons and play important roles in regulation of neuronal excitability. (biomedcentral.com)
  • As BK Ca channels and sodium channels are critical molecular determinants for seizure generation, our findings suggest that regulation of these two channels in cortical neurons probably makes a considerable contribution to the antiseizure activity of resveratrol. (biomedcentral.com)
  • Voltage-gated sodium channels in cardiomyocytes [ 47 ] and rat dorsal root ganglion neurons [ 21 ] are also blocked by resveratrol. (biomedcentral.com)
  • Despite this, the effects of resveratrol on the membrane properties and the ion channels of neurons have not yet been fully determined. (biomedcentral.com)
  • Large-conductance Ca2+-activated K+ (BK) channels have a major role in driving the diurnal patterns of spontaneous firing in SCN neurons. (umaryland.edu)
  • Lastly, this investigated a potential mechanism by which LTCCs contribute to firing rate in SCN neurons by examining their ability to activate BK channels under controlled conditions. (umaryland.edu)
  • Furthermore, regulation of current properties, as opposed to changing expression of the channel, may act as a mechanism through which excitability can be modulated in various neurons. (umaryland.edu)
  • Differentiated dopaminergic neurons expressed low levels of SK2 channels and high levels of SK1 and SK3 channels. (nih.gov)
  • Inside-out patch recordings from rat acutely dissociated cerebral cortical neurons revealed time and voltage-dependent activity of a large-conductance calcium-activated potassium channel. (dundee.ac.uk)
  • We found that the open probability of BK channels remarkably decreased in the CA1 pyramidal neurons in a time-dependent manner with the IH treatment, without changes in the unitary conductance and reversal potential. (naver.com)
  • For enteric neurons, SK4 channels seem to mediate the late after-hyperpolarization ( 8 ). (diabetesjournals.org)
  • To examine this hypothesis, we have studied whether K(+)-channel blockers inhibit the effects of neuromodulators of sensory nerves in guinea pig bronchi by using selective K(+)-channel blockers. (pnas.org)
  • The sustained increase in NP(o) of the Ca2+-activated K+ channel was attenuated upon the removal of external Ca2+ (Mg2+ replacement) or in the presence of the Ca2+ entry blocker, Ni2+, and the potassium channel blockers tetrabutylammonium (TBA) or tetraethylammonium (TEA). (edu.au)
  • Factors altering the activity of BK channels, such as gene mutations, polymorphism, channel openers or blockers that lead to loss- or gain-of-function, have all been linked to epilepsy onset. (eurekaselect.com)
  • In addition, the enhancing effects of BK Ca channel blockers tetraethylammonium (TEA) and paxilline on action potential firing were sensitive to resveratrol. (biomedcentral.com)
  • Moreover, the action potential firing rates evoked by the depolarizing current and BK Ca channel blockers were remarkably decreased by application of resveratrol. (biomedcentral.com)
  • Attempts to block medium duration AHPs in DRG cells using IK and calcium channel blockers, also failed in most cases, suggesting that some other potassium conductances) are responsible. (ucl.ac.uk)
  • 3. In the presence of indomethacin, relaxation to ACh in the endothelium-intact RMCA precontracted with histamine was unaffected by either glibenclamide (10 μM), an ATP-sensitive K + channel (K(ATP)) blocker, 4-aminopyridine (4-AP, 1 mM) or dendrotoxin (DTX, 0.1 μM), delayed rectifier K + channel (K(v)) blockers. (elsevier.com)
  • It is known that IK channels are modulated by calmodulin, whereas BK channels are not. (wikipedia.org)
  • Since laminar shear stress (LS) is a major determinant of EC function in a calcium-dependent manner, we hypothesized that LS upregulates KCa2.3 and KCa3.1 via activating calcium/calmodulin (CaM) kinase cascade. (ahajournals.org)
  • This rank-order potency is different from their potency as calmodulin inhibitors, which suggests that neuroleptics bind to the channel rather than a calmodulin-channel complex. (centerforfacialappearances.com)
  • Unless they do not bind calcium directly they detect it by virtue of calmodulin , which is constitutively bound to the C-terminal region. (axonmedchem.com)
  • Binding of calcium to this calmodulin results in conformational changes that are in turn responsible for channel gating. (axonmedchem.com)
  • K Ca 3.1 is voltage-independent and is activated by Ca 2+ binding to the calmodulin that is always present at the channel's C terminus. (guidetopharmacology.org)
  • The intermediate conductance calcium-activated potassium channel KCa3.1 (also known as KCNN4 and IKCa), a member of the calcium-activated potassium channel (KCa) 4 family, tightly binds the Ca 2+ sensor calmodulin near its C-terminal domain. (pubmedcentralcanada.ca)
  • KCa3.1 is opened by a small rise in free cytosolic Ca 2+ ([Ca 2+ ] i ) due to Ca 2+ -calmodulin-mediated cross-linking in the subunits of the channel tetramer ( 1 ). (pubmedcentralcanada.ca)
  • The resonant frequency is determined in large part by the number and kinetics of large conductance, calcium-activated potassium (BK) channels. (jneurosci.org)
  • Deactivation kinetics were used to predict tuning frequencies and thus tonotopic location if hair cells were endowed with each of the expressed channels. (jneurosci.org)
  • Alternative splicing of the slo -α channel message provides intrinsic variability in gating kinetics that is expanded to a wider range of tuning by modulation with β subunits. (jneurosci.org)
  • Electrical tuning frequencies vary systematically (tonotopically) along the turtle's basilar papilla ( Crawford and Fettiplace, 1980 ), leading to the remarkable conclusion that the molecular determinants of BK channel kinetics must be tonotopically distributed as well. (jneurosci.org)
  • It slows down the activation and the deactivation kinetics of the channel. (uniprot.org)
  • This allows us to evaluate changes in the action potential under different parameters affecting the kinetics of these channels. (upc.edu)
  • Although higher calcium affinities might be found in other splice variants, these inconsistencies imply that native hair cell BK channels may contain other components that combine with and modify the slo-α gene product. (jneurosci.org)
  • We estimate the tuning frequencies for eight varieties of BK channel and predict the corresponding position of each gene product along the tonotopically organized basilar papilla of the chick. (jneurosci.org)
  • Ghanshani S, Coleman M, Gustavsson P, Wu AC, Gargus JJ, Gutman GA, Dahl N, Mohrenweiser H, Chandy KG: Human calcium-activated potassium channel gene KCNN4 maps to chromosome 19q13.2 in the region deleted in diamond-blackfan anemia. (hmdb.ca)
  • This gene is a member of the KCNN family of potassium channel genes. (nih.gov)
  • Maxi-K channel openers or gene therapy may therefore provide therapeutic benefit for the overactive bladder. (elsevier.com)
  • SK4 channels are Ca 2+ -activated K + channels of intermediate conductance (synonymous with IK1 and KCa3.1) encoded by the KCNN4 gene. (diabetesjournals.org)
  • 1. A high-conductance calcium-activated potassium channel (BK KCa) was characterized at a cholinergic presynaptic nerve terminal using the calyx synapse isolated from the chick ciliary ganglion. (nih.gov)
  • Because calcium-activated potassium (BKCa) channels are essential for vascular smooth muscle cell (VSMC) relaxation, we hypothesized that aldosterone alters their expression and/or function in VSMCs. (ahajournals.org)
  • BKCa channels may therefore be useful therapeutic targets in cardiovascular diseases. (ahajournals.org)
  • This was identified as the major neuronal form of the big conductance, calcium-activated potassium (BKCa ) channel. (qmul.ac.uk)
  • Drug-induced opening of neuronal BKCa channels induced membrane hyperpolarization, limiting excessive neural-excitability and controlling spasticity. (qmul.ac.uk)
  • CONCLUSIONS AND IMPLICATIONS: We identified the neuronal form of the BKCa channel as the target for VSN16R and demonstrated that its activation alleviates neuronal excitability and spasticity in an experimental model of MS, revealing a novel mechanism to control spasticity. (qmul.ac.uk)
  • To examine the effect of partial urethral obstruction (PUO) on bladder smooth muscle outward potassium current and the contribution of the large-conductance calcium-activated potassium (Maxi-K, BKCa) channel to this activity in smooth muscle cells isolated from bladders of sham-operated and PUO male rats using whole-cell patch clamp recording techniques. (elsevier.com)
  • Maxi-K+ channels (BKCa) play a significant role in modulating cell membrane potential and excitability.Objective: This study was designed to investigate the potential involvement of BKCa channel function in the response of human myometrium to beta(3)-adrenoceptor activation.Design: Single and whole-cell electrophysiological BKCa channel recordings from freshly dispersed myocytes were obtained in the presence and absence of BRL37344, a specific beta(3)-adrenoreceptor agonist. (nuigalway.ie)
  • The in vitro effects of BRL37344 on isolated myometrial contractions, in the presence and absence of the specific BKCa channel blocker, iberiotoxin ( IbTX), were investigated.Setting: The study was carried out at the Clinical Science Institute. (nuigalway.ie)
  • 0.05), and preincubation of these strips with IbTX attenuated this effect on both spontaneous and oxytocin- induced contractions (44.44 and 57.84% at 10(-5) M, respectively).Conclusions: These findings outline that activation of the BKCa channel may explain the potent uterorelaxant effect of beta(3)-adrenoreceptor agonists. (nuigalway.ie)
  • 1] Calcium-Activated Potassium Channels: Multiple Contributions to Neuronal Function. (axonmedchem.com)
  • BK channels can be activated by the increase of the intracellular Ca2+ concentration, a consequence of neuronal excitation, and then terminate the action potential with the outward K+ flux. (eurekaselect.com)
  • These effects are likely associated with the alterations in neuronal cell membrane ion channel activities. (biomedcentral.com)
  • MaxiK channels are large conductance, voltage and calcium-sensitive potassium channels which are fundamental to the control of smooth muscle tone and neuronal excitability. (genecards.org)
  • BK channels are critical regulators of neuronal activity, controlling firing, neurotransmitter release, cerebellar function, and BK channel mutations have been linked to seizure disorders. (frontiersin.org)
  • Future studies could apply this line to ex vivo neuronal cultures to study live-cell channel trafficking. (frontiersin.org)
  • Collectively, the results suggest that the IH-induced NO deficit mediated by a down-regulation of the expression of neuronal NO synthase plays a causative role in the impaired activity of BK channels, which could account for the hippocampal injury in patients with sleep apnea. (naver.com)
  • The International Union of Pharmacology has put the Ca 2+ activated K + channels into one large family which can be subdivided into two functionally but genetically unrelated groups. (axonmedchem.com)
  • Detailed reviews of the structure, function and pharmacology of BK channels have recently been provided (Salkoff et al. (soton.ac.uk)
  • Next, to determine which Ca2+ channels are involved in Ca2+i rhythms, this study tested the effects of the same Ca2+ channel pharmacology on the circadian parameters of Ca2+i measured from SCN slice cultures transfected with a fluorescent Ca2+ sensor. (umaryland.edu)
  • In vivo experiments (done by Dr Rie Suzuki, Department of Pharmacology, UCL) using UCL 1848 and l-ethyl-2- benzimidazolinone (1-EBIO an SK channel opener) showed that SK channels are likely to be active at these terminals where they have a functional role in mediating innocuous mechanical and nociceptive responses. (ucl.ac.uk)
  • Members of a previously unidentified family of potassium channel subunits were cloned from rat and human brain. (sciencemag.org)
  • Voltage-gated potassium channels (KV) belong to the 6-TM family of potassium channel that also comprises the Ca2+-activated Slo (actually 7-TM) and the Ca2+-activated SK subfamilies. (genecards.org)
  • They were first discovered in 1958 by Gardos who saw that Calcium levels inside of a cell could affect the permeability of potassium through that cell membrane. (wikipedia.org)
  • One important target of PKGI in smooth muscle is the large-conductance, calcium-activated potassium (BK) channel, which upon activation hyperpolarizes the smooth muscle cell membrane, causing relaxation. (nih.gov)
  • Whole-cell current recordings of K ir 2 inwardly-rectifying potassium channels expressed in an HEK293 cell . (wikipedia.org)
  • This suggests that ChTX-sensitive K(+)-channel activation may be a common mechanism for the prejunctional modulation of sensory nerves in airways. (pnas.org)
  • Structurally they are thought to be very similar to BK channels with the main differences being conductance, and the methods of modulation. (wikipedia.org)
  • In the present study, we examine β modulation of several slo splice variants over a wide range of voltage and calcium concentrations. (jneurosci.org)
  • Besides membrane potential modulation, SK channels have been found to be involved in cardiac pacemaker cell development from ES cells and morphological shaping of neural stem cells. (hindawi.com)
  • SK2 channels, therefore, may represent a target for pharmacologic modulation of bile flow. (nih.gov)
  • These channels are targets for modulation because they have been thought to influence neurological and psychiatric disorders. (slideserve.com)
  • This interaction is thought to depend on binding of the type II regulatory (RII) subunits to AKAPs and is essential for PKA-dependent modulation of the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid/kainate receptor, the L-type Ca 2+ channel, and the K Ca channel. (pnas.org)
  • Our findings implicate BK channels as important regulators of the SFR and suggest that the SCN pacemaker governs the expression of circadian behavioral rhythms through SFR modulation. (elsevier.com)
  • Therefore, pharmacologic modulation of these channels might provide an interesting approach for the development of novel insulinotropic drugs. (diabetesjournals.org)
  • In the search for compensatory mechanisms, modulation of insulin release by other K + channels gains particular interest. (diabetesjournals.org)
  • The electrophysiologic and anti-AF effects of the relative selective SK channel inhibitor NS8593 (5 mg/kg IV) were evaluated in anesthetized horses, focusing on the potential of NS8593 to terminate acute pacing-induced AF, drug-induced changes in atrial effective refractory period, AF duration and vulnerability, and ventricular depolarization and repolarization times. (ku.dk)
  • These channels were potassium selective and the open channel probability (Po) was always about 1 percent for displacemtne of potential from the resting value in the range of -20 to +60 mV. (bvsalud.org)
  • Reversal potential measurements on excised inside-out patches demonstrated that the channels were highly potassium selective with unitary conductance of about 206.8 + or - 6.36 pS(mean + or - SEM of 6 measurements ), and an estimated permeability of 3.6 x 10-13 + or - 0.2 x 10--13 cm3/s (mean + or - SEM for 6 measurements ), in symmetrical 140 mM KCl. (bvsalud.org)
  • Selective activation of Ca2+-dependent K+ channels by novel benzimidazolone. (acseusa.org)
  • The channels that formed from the various subunits displayed differential sensitivity to apamin and tubocurare. (sciencemag.org)
  • The channel is blocked by apamin. (rcsb.org)
  • These channels are sensitive to block by apamin (100 pM-10 nM), which distinguishes them from all other KCa channels. (axonmedchem.com)
  • Medium AHP Apamin blocks SK Channels which causes a reduction in the medium AHP. (slideserve.com)
  • In order to determine the expression of the different SK channel subtypes, pharmacological tools such as apamin and d-tubocurarine have been widely used. (youscribe.com)
  • Our experiments show that this toxin is more potent in blocking SK2 channels than apamin. (youscribe.com)
  • hSK1 subunits form functional potassium channels that are blocked by apamin and d-tubocurarine. (youscribe.com)
  • The functional diversity of potassium channels can arise through homo- or hetero-associations of alpha subunits or association with auxiliary cytoplasmic beta subunits. (wikipedia.org)
  • The functional role of these channels in cardiac electrophysiology is still under intense debate. (upc.edu)
  • Present study directly defines the functional roles of SK2 channels in transgenic mice using a genetically engineered model, and provides a possible link between abnormalities in cardiac SK2 channels and cardiac arrhythmias. (nih.gov)
  • To investigate possible functional roles for SK/IK channels sensory neurones, action potential afterhyperpolarisations (AHPs) were recorded from cultured DRG and nodose cells. (ucl.ac.uk)
  • OBJECTIVE: The purpose of this study was to investigate the existence and functional role of SK channels in the equine heart. (ku.dk)
  • We are interested in the study of structural and functional properties of ion channels and their role in cell physiology. (javeriana.edu.co)
  • The third section of Ion Channel Localization: Methods and Protocols utilizes the functional properties of the channels for localization. (springer.com)
  • Large-conductance, calcium-activated potassium channels: structural and functional implications. (acseusa.org)
  • A medium-throughput functional assay of KCNQ2 potassium channels using rubidium efflux and atomic absorption spectrometry. (acseusa.org)
  • Fingerprint Dive into the research topics of 'Large-conductance calcium-activated potassium channel activity, as determined by whole-cell patch clamp recording, is decreased in urinary bladder smooth muscle cells from male rats with partial urethral obstruction. (elsevier.com)
  • Dive into the research topics of 'Stretch-activated chloride, potassium, and calcium channels coexisting in plasma membranes of guard cells of Vicia faba L.'. Together they form a unique fingerprint. (elsevier.com)
  • The different modes of activation in these channels are thought to be independent of one another. (wikipedia.org)
  • 5. The properties of the presynaptic BK channel are well suited for rapid activation during the presynaptic depolarization and Ca2+ influx that are associated with transmitter release. (nih.gov)
  • Conclusions LS upregulates KCa2.3 and KCa3.1 expressions via CREB phosphorylation through activation of CaMKK and AMPK, a downstream kinase of CaMKK, whereas TNF- α suppresses both channel expressions. (ahajournals.org)
  • The increased K+ permeability via activation of these channels would effectively clamp the endothelial cell at negative membrane potentials and provide an electrochemical gradient for sustained Ca2+ entry. (edu.au)
  • Activation is followed by membrane hyperpolarization which promotes calcium influx. (hmdb.ca)
  • The intermediate conductance calcium-activated potassium channel KCa3.1 contributes to a variety of cell activation processes in pathologies such as inflammation, carcinogenesis, and vascular remodeling. (pubmedcentralcanada.ca)
  • Channel activation induces membrane hyperpolarization, which promotes Ca 2+ influx. (pubmedcentralcanada.ca)
  • Activation of endothelial cell small- (S) and intermediate- (I) conductance calcium-activated potassium channels (K(Ca)) and current or molecular transfer via myoendothelial gap junctions underlies endothelium-derived hyperpolarization leading to vasodilation. (semanticscholar.org)
  • We hypothesize that this COOH-terminal domain of the slowpoke KCa channel adopts the characteristic double-barrel fold of serine proteinases, is involved in Ca(2+)-activation of the channel, and may also bind other intracellular components that regulate KCa channel activity. (rupress.org)
  • Intracellular Ca2+ (Ca2+i) is required for BK channel activation and previous studies have shown BK current is predominantly coupled to two types of Ca2+ sources in the SCN: L-type Ca2+ channels (LTCCs), and ryanodine receptors (RyRs). (umaryland.edu)
  • Results suggest that SK2-channel activation may largely contribute to the sustained Ca2+ influx in the G0/G1 phase in comparison of that in the G2/M phase in Jurkat T-lymphocytes. (nih.gov)
  • Activation of skeletal muscle Ca 2+ channels is enhanced by activation of PKA, and potentiation of Ca 2+ channel activity by single 50-200 ms depolarizations or trains of 3 ms depolarizations requires phosphorylation by PKA ( 10 ). (pnas.org)
  • The intermediate-conductance calcium-activated potassium channel KCa3.1 is expressed in multiple cell types implicated in atherogenesis, and pharmacological blockade of this channel inhibits VSMC and lymphocyte activation in rats and mice. (elsevier.com)
  • Our aim was to investigate whether JMV5656 (RRRHFHHALPPAR), a novel short analogue of TLQP-21, stimulates intracellular Ca 2+ in the N9 microglia cells, and whether this Ca 2+ elevation is coupled with the activation Ca 2+ -sensitive K + channels. (frontiersin.org)
  • Channel activation requires Ca 2+ increase and determines the cell volume of T-cells and erythrocytes by elevating K + efflux. (diabetesjournals.org)
  • SK4 channels are suggested to be involved in mast cell stimulation ( 5 ), and channel upregulation is important for lymphocyte activation and cell proliferation ( 6 , 7 ). (diabetesjournals.org)
  • Several studies indicate that K v channel activation plays a role in action potential (AP) repolarization ( 20 - 22 ). (diabetesjournals.org)
  • The KCa channel α subunits have six or seven transmembrane segments, similar to the KV channels but occasionally with an additional N-terminal transmembrane helix. (wikipedia.org)
  • The voltage sensor is made by the S4 transmembrane region, which has several Arginine residues which act to 'sense' the changes in charge and move in a very similar way to other voltage gated potassium channels. (wikipedia.org)
  • Below is a list of the 8 known human calcium-activated potassium channel grouped according to sequence homology of transmembrane hydrophobic cores: Though not implied in the name, but implied by the structure these channels can also be activated by voltage. (wikipedia.org)
  • 7. The large conductance, Ca2+-activated K+ (maxi-K+) channel in rabbit aortic endothelial cells is postulated to play a significant role in controlling transmembrane Ca2+ influx at rest and during agonist stimulation. (edu.au)
  • [4] IRK channels possess a pore domain, homologous to that of voltage-gated ion channels , and flanking transmembrane segments (TMSs). (wikipedia.org)
  • Na+ ions were not measurably permeant through the open channel. (edu.au)
  • At membrane potentials negative to potassium's reversal potential , inwardly rectifying K + channels support the flow of positively charged K + ions into the cell, pushing the membrane potential back to the resting potential. (wikipedia.org)
  • Calcium (Ca2+) -activated potassium channels (KCa) are a group of 6/7-TM ion channels that selectively transport K+ ions across biological membranes. (genecards.org)
  • Conclusion: The aim of this review is to summarize existing knowledge and recent findings on the molecular properties, signaling complex and channel dysfunction of the BK channels with a particular attention to the possible relevance to the pathophysiology of epilepsy. (eurekaselect.com)
  • We used electrophysiological, molecular and cellular techniques to the study of ion channel activity. (javeriana.edu.co)
  • 4. In cell-attached patch recordings BK channel opening was enhanced by a prepulse permissive for calcium influx through the patch, suggesting that the channel can be activated by calcium ion influx through neighbouring calcium channels. (nih.gov)
  • Moreover, after-hyperpolarization induced by BK channels closes Cav channels and thus precludes excessive Ca2+ influx. (eurekaselect.com)
  • Spatial separation of endothelial small- and intermediate-conductance calcium-activated potassium channels (K(Ca)) and connexins: possible relationship to vasodilator function? (semanticscholar.org)
  • A study of small and intermediate conductance calcium-activated potassium channels in sensory neurones. (ucl.ac.uk)
  • The role of small and intermediate conductance calcium-activated potassium channels (SK and IK channels) in dorsal root ganglion (DRG) neurones was examined. (ucl.ac.uk)
  • They are broadly classified into three subtypes: SK, IK and BK channels (small, intermediate and big conductance). (genecards.org)
  • Earlier work identified Ca2+-activated potassium channels of small and intermediate conductance (SKCas) as important regulators of neural stem cell fate. (datamed.org)
  • Here, we examined the role of intermediate-conductance calcium-activated potassium channel (KCa3.1) and chloride channel (CLC3) in lymphatic chemokine-induced migration of DCs. (elsevier.com)
  • Shao, Z, Gaurav, R & Agrawal, DK 2015, ' Intermediate-conductance calcium-activated potassium channel KCa3.1 and chloride channel modulate chemokine ligand (CCL19/CCL21)-induced migration of dendritic cells ', Translational Research , vol. 166, no. 1, pp. 89-102. (elsevier.com)
  • Agrawal, Devendra K. / Intermediate-conductance calcium-activated potassium channel KCa3.1 and chloride channel modulate chemokine ligand (CCL19/CCL21)-induced migration of dendritic cells . (elsevier.com)
  • In this study, we investigated whether the Ca 2+ -activated K + channel of intermediate conductance SK4 (KCa3.1, IK1) plays a physiological role in pancreatic β-cell function. (diabetesjournals.org)
  • This finding has sparked further exploration surrounding these channels and researchers have found that IK channels regulate the cell cycle in cancer cells, B and T lymphocytes, and stem cells. (wikipedia.org)
  • In fact, resveratrol has been reported to regulate ion channel activities in a variety of cells. (biomedcentral.com)
  • Healthy cerebrovascular myocytes express members of several different ion channel families which regulate resting membrane potential, vascular diameter, and vascular tone and are involved in cerebral autoregulation. (hindawi.com)
  • MaxiK channels are activated by either membrane depolarization or an increase in intracellular Ca(2+). (curehunter.com)
  • The large conductance Ca2+- and voltage-activated potassium (BK) channel is activated via two important cellular signaling mechanisms: increases in intracellular Ca2+ and membrane depolarization. (umaryland.edu)
  • They are primarily expressed in cells of the hematopoietic system, where they represent the Gardos channel ( 1 ). (diabetesjournals.org)
  • The abolition of channel inactivation by alkaline phosphatase was prevented by prior internal tetraethylammonium treatment, indicating that the alkaline phosphatase site is closely associated with the channel pore. (dundee.ac.uk)
  • By Meech and Strumwasser - they described an ionic current activated by a rise in cytosolic calcium. (slideserve.com)
  • Indeed, endothelium-derived hyperpolarizing factor (EDHF) is described as the non-NO and non-PGI 2 factor leading to smooth muscle cell hyperpolarization and relaxation by the opening of vascular K Ca channels. (ahajournals.org)
  • This causes further hyperpolarization and closing of voltage gated calcium channels, relaxation can then occur. (wikipedia.org)
  • TRP channel Ca(2+) sparklets: fundamental signals underlying endothelium-dependent hyperpolarization. (semanticscholar.org)
  • Channel activity inactivated within minutes following a depolarizing voltage step, and was recovered from inactivation by membrane hyperpolarization. (dundee.ac.uk)
  • A major class of calcium activated potassium channels whose members are voltage-dependent. (curehunter.com)
  • We report here that the block of MTX, but not of CTX on current through hIKCa1 channels is pH0 dependent. (ovid.com)
  • Both IK and SK channels play roles in processes involving calcium-dependent signaling in both electrically excitable and nonexcitable cells. (axonmedchem.com)
  • Ca 2+-dependent channels are now considered key regulators of tumor progression. (inserm.fr)
  • In this study, we aimed to investigate the association of non-voltage gated Ca 2+ channels and Ca 2+-dependent potassium channels (KCa) with CRC using the transcriptional profile of their genes. (inserm.fr)
  • GTP-dependent regulation of myometrial KCa channels incorporated into lipid bilayers. (rupress.org)
  • Functions of SK2 channels in atrial myocytes are critically dependent on the normal expression of Ca(v)1.3 Ca(2+) channels. (nih.gov)
  • Surprisingly, the anchored PKA-dependent potentiation of the L-type Ca 2+ channel in RIIα knockout skeletal muscle was unchanged compared with wild type although it was more sensitive to inhibitors of PKA-AKAP interactions. (pnas.org)
  • Ht31 peptide blocked the voltage-dependent potentiation of the skeletal muscle L-type Ca 2+ channel, suggesting that close proximity between PKA and the L-type Ca 2+ channel is necessary for the rapid phosphorylation of this channel during trains of brief depolarizations ( 11 ). (pnas.org)
  • Specifically, the subtypes of potassium channels involved in the effects of endothelium-derived relaxing factors (EDRFs) in acetylcholine (ACh)-induced endothelium-dependent vasorelaxation in this vessel were systematically compared. (elsevier.com)
  • Kv4 potassium channel subunits control action potential repolarization and frequency-dependent broadening in rat hippocampal CA1 pyramidal neurones. (naver.com)
  • Membrane potential of cerebrovascular smooth muscle cells and thus dilation and constriction of cerebral arteries are directly dependent on potassium conductance [ 5 , 6 ]. (hindawi.com)
  • OBJECTIVE Ca 2+ -regulated K + channels are involved in numerous Ca 2+ -dependent signaling pathways. (diabetesjournals.org)
  • Several reports provide evidence that efficient blood glucose regulation and even glucose-dependent insulin secretion ( 15 - 17 ) is possible despite K ATP channel ablation. (diabetesjournals.org)
  • The excitatory beta subunits affect the alpha subunits in such a way that the channel seldom inactivates. (wikipedia.org)
  • A cysteine-rich motif confers hypoxia sensitivity to mammalian large conductance voltage- and Ca-activated K (BK) channel alpha-subunits. (naver.com)
  • The family of calcium-activated potassium channels consists of four members with varying biological functions and conductances. (hindawi.com)
  • These findings indicate that BK channels are involved in the relaxation of smooth muscle cells. (wikipedia.org)
  • Distinct SK channel subtype expression in ES cells might elucidate their precise impact during cardiac development. (hindawi.com)
  • We examined the effect of neuroleptics on Ca-activated K channels from dog airway smooth muscle cells. (centerforfacialappearances.com)
  • Calcium-activated potassium channels in native endothelial cells from " by J Rusko, Franco Tanzi et al. (edu.au)
  • The ionic selectivity and Ca2+ sensitivity indicate that a large conductance, Ca2+-activated K+ channel is present in freshly dissociated rabbit aortic endothelial cells. (edu.au)
  • In activated T cells, K Ca 3.1 and K V 1.3 localise to the immunological synapse, where interactions with regulatory kinases occurs. (guidetopharmacology.org)
  • In particular, this channel plays a critical role in the proliferation of smooth muscle cells ( 3 , 4 ), endothelial cells ( 5 ), lymphocytes including B- and T-cells ( 6 , 7 ), fibroblasts ( 8 ), stem cells ( 9 ), and several cancer cells ( 10 ). (pubmedcentralcanada.ca)
  • We conclude that EDPs potently dilate coronary microvessels and are the most potent fatty epoxides known to activate BK Ca channels in coronary smooth muscle cells. (elsevier.com)
  • The connection between the action of microbial RNases and Ca2+-activated K+ (KCa) channels was investigated in human embryo kidney cells HEKhSK4 artificially expressing the channels. (ox.ac.uk)
  • These channels protected HEKhSK4 cells from apoptosis induced by binase and 5K charge reversal mutant of RNase Sa. (ox.ac.uk)
  • Large-conductance calcium-activated potassium channel activity, as determined by whole-cell patch clamp recording, is decreased in urinary bladder smooth muscle cells from male rats with partial urethral obstruction. (elsevier.com)
  • Our findings show that obstruction of the rat bladder is associated with decreased Maxi-K channel activity of bladder smooth muscle cells, determined via direct current measurement. (elsevier.com)
  • Auditory hair cells from nonmammalian vertebrates are electrically tuned to specific sound frequencies primarily by the interactions of voltage-gated calcium channels and calcium-activated potassium (BK) channels colocalized at synaptic active zones. (elsevier.com)
  • Mammalian inner hair cells are not electrically tuned and, yet, BK channels are also thought to reside at active zones. (elsevier.com)
  • Using patch-clamp recordings and immunofluorescence, we characterized BK channel expression in mouse inner hair cells. (elsevier.com)
  • These results indicate a novel function of BK channels in mammalian inner hair cells and provide a framework for future research. (elsevier.com)
  • Dr. Paola Pedarzani (University College London, United Kingdom) M űndliche Pr űfung am 13 June 2005 SummaryIon channels are integral membrane proteins present in all cells. (youscribe.com)
  • Ion channels are integral membrane proteins present in all cells. (youscribe.com)
  • Background: Ion channels are key determinants for the function of excitable cells but little is known about their role and involvement during cardiac development. (datamed.org)
  • Stretch-activated chloride, potassium, and calcium channels coexisting in plasma membranes of guard cells of Vicia faba L. (elsevier.com)
  • The patch-clamp technique was used to investigate the involvement of ion channels in the response of Leydig cells to gonadotropic hormones (viz.hCG). (bvsalud.org)
  • Treatment of the cells with hCG (2 ng/ml) led to a large increase in the frequency of openings, concomitant with a reduction in the mean closed time and there was essentially no effect on the mean open time of the channels. (bvsalud.org)
  • In contrast, the role of intracellular trafficking mechanisms in controlling BK channel function, especially in live cells, has been less studied. (frontiersin.org)
  • Although there are many useful books on virtually every aspect of ion channel structure and function, work on channel localization-determining the specific sites of ion channels and their receptors on cells-has long been neglected. (springer.com)
  • Comprehensive and rich in practical detail, Ion Channel Localization: Methods and Protocols brings together in a single volume detailed reviews of all the major techniques-both currently in use and in development-for localizing ion channels and receptors in cells, tissues, and organisms. (springer.com)
  • The role of ion channels is largely unknown in chemokine-induced migration in nonexcitable cells such as dendritic cells (DCs). (elsevier.com)
  • In microglial cells, TLQP-21 stimulates increases of intracellular Ca 2+ that may activate functions, including proliferation, migration, phagocytosis and production of inflammatory molecules. (frontiersin.org)
  • In summary, we demonstrate that, in N9 microglia cells, the interaction of JMV5656 with the TLQP-21 receptors induced an increase in intracellular Ca 2+ , and, following extracellular Ca 2+ entry, the opening of K Ca 3.1 channels. (frontiersin.org)
  • Because vasospastic smooth muscle cells are known to be depolarized compared to controls [ 3 , 4 ], the expression and function of ion channels in these cells after SAH are of great interest. (hindawi.com)
  • Besides K Ca channels, pancreatic β-cells express K + channels exclusively regulated by voltage (K v channels) ( 10 , 18 , 19 ). (diabetesjournals.org)
  • Channel activity increased with the cytoplasmic free Ca2+ concentration ([Ca2+]i) with a Hill plot giving a half-saturating [Ca2+] (K0.5) of 1.35 μM and slope of ≅3. (edu.au)
  • Ionomycin (1-10 μM) increased BK channel activity in the cell-attached recording configuration. (edu.au)
  • The purpose of this review is to discuss how SLO-1 channels might function as regulators of neural transmission and network activity. (soton.ac.uk)
  • Therefore, one may reasonably suppose that membrane excitability would increase when the BK channel activity decreases. (eurekaselect.com)
  • The activity of KCa channels could be restored by removing RNases from the media. (ox.ac.uk)
  • First, to determine which Ca2+ channels are involved in AP rhythms, this study measured the impact of Ca2+ channel agonists and antagonists on the circadian parameters of spontaneous AP activity from organotypic SCN slice cultures grown on multi-electrode arrays. (umaryland.edu)
  • Another potential mechanism for modulating BK channel activity is genetic variation due to single nucleotide polymorphisms (SNPs). (umaryland.edu)
  • However, the variation in BK channel activity due to SNPs is not well studied. (umaryland.edu)
  • Together, these results implicate naturally occurring human genetic variation as a potential modifier of BK channel activity across a variety of conditions. (umaryland.edu)
  • Application of alkaline phosphatase to the internal aspect of the patch membrane increased channel activity and abolished channel inactivation, without affecting its voltage and calcium dependence. (dundee.ac.uk)
  • The slow time-course of channel inactivation may have some pathophysiological significance in maintenance of epileptiform activity. (dundee.ac.uk)
  • The activity of the channel in excised paches was very sensitive to the free- calcium concentration on the intracellular surface of the free- calcium concentration on the intracellular surface of the channel. (bvsalud.org)
  • We examined the hypothesis that hippocampal NO deficit impairs the activity of large conductance calcium-activated potassium (BK) channels in rats with chronic IH, mimicking conditions in patients with sleep apnea. (naver.com)
  • Rubidium efflux assay using flame atomic absorption spectrometry is employed in analyzing potassium channel activity. (acseusa.org)
  • Ibrahim, Z. G. (2015) Rubidium efflux assay using flame atomic absorption spectrometry as a measure for BK channel activity. (acseusa.org)
  • Initial hypoperfusion after exposure of cerebral vessels to oxyhemoglobin correlates with a suppression of voltage-gated potassium channel activity, whereas delayed cerebral vasospasm involves changes in other potassium channel and voltage-gated calcium channels expression and function. (hindawi.com)
  • The role of NO in the regulation of the mechanical properties of conduit arteries is controversial in humans, and the involvement of an endothelium-derived hyperpolarizing factor (EDHF), acting through calcium-activated potassium (K Ca ) channels, has never been investigated at this level in vivo. (ahajournals.org)
  • 6. These results indicate that: (1) in the RMCA the EDRFs released by ACh are NO and a prostanoid (presumably PGI 2 ), and there is no evidence for the release of a non-NO/PGI 2 endothelium-derived hyperpolarizing factor (EDHF), (2) K(Ca) channels are involved in NO-mediated relaxation of the RMCA but both K(Ca) and K(v) channels are involved in PGI 2 -mediated relaxation. (elsevier.com)
  • Background & Objective: The large conductance, calcium- and voltage-activated potassium channels (BK) are widely distributed channel proteins which exist in virtually every cell type of mammals and function to influence membrane excitability and Ca2+ signaling. (eurekaselect.com)
  • In terms of function, these proteins transport potassium (K + ) , with a greater tendency for K + uptake than K + export. (wikipedia.org)
  • With emphasis on techniques employing the unique properties of these proteins, the core topics of the book include all the major pharmacological tools for ion channel determination. (springer.com)
  • Thus, the second part of this book concentrates on the quantification and cellular or subcellular visualization of ion channel expression in oocytes and immortal cell lines using green fluorescent proteins (GFP). (springer.com)
  • The cassette is readily expressed under the control of doxycycline, and the overexpression of SK4 led to an increase in cardiac and pacemaker cell differentiation thereby serving as a unique tool to characterize the cell biological variances due to specific SK channel overexpression. (hindawi.com)
  • METHODS: Cardiac biopsies were analyzed to investigate the expression level of the most prominent cardiac ion channels, with special focus on SK channels, in the equine heart. (ku.dk)
  • On the premise that C. elegans is a 'model nematode' with respect to many aspects of neural function, the intention is that this might inform a broader understanding of the role of these channels in the nematodes and their potential as novel anthelmintic targets. (soton.ac.uk)
  • [3] They are the targets of multiple toxins, and malfunction of the channels has been implicated in several diseases. (wikipedia.org)
  • Mesobuthus tamulus, which targets SK channels. (youscribe.com)
  • Big Potassium (BK) ion channels in biology, disease and possible targets for cancer immunotherapy. (acseusa.org)
  • 9 μmol/min for 8 minutes), a K Ca channels inhibitor, and the combination of both on radial artery internal diameter, wall thickness (echo tracking), blood flow (Doppler), and pressure. (ahajournals.org)
  • On the interaction of bovine pancreatic trypsin inhibitor with maxi Ca(2+)-activated K+ channels. (rupress.org)
  • Moreover, the effects of resveratrol on action potential firing rate and the BK Ca channel inhibitor TEA (or paxilline)-induced hyperexcitability were also evaluated. (biomedcentral.com)
  • Furthermore, the inhibitor of L-type calcium channels nimodipine remains gold standard in treatment and prophylaxis of vasospasm after SAH. (hindawi.com)
  • Single channel studies have identified two types of calcium-activated potassium channel which can also be separated on biophysical and pharmacological grounds and have been named BK and SK channels. (nih.gov)
  • The subtype SK2 channels were up-regulated under hypoxia, shown with pharmacological tools and with mRNA analysis. (nih.gov)
  • The first part concentrates on the fluorescent and radioligand binding of channel or receptors with specific pharmacological agents or toxins. (springer.com)
  • Rubidium efflux as a tool for the pharmacological characterisation of compounds with BK channel opening properties. (acseusa.org)
  • Nerve-evoked relaxations of precontracted strips were reduced by 50%, both in strips from Slo-/- mice and by blocking BK channels with iberiotoxin in the Slo+/+ strips. (nih.gov)
  • Iberiotoxin (300 nM) sensitive Maxi-K channel current comprised about 40% of the outward whole-cell current in SHAM bladders but only about 8% in PUO bladders. (elsevier.com)
  • Furthermore, multiple members of family are both ligand and voltage activated, further complicating the description of this family. (wikipedia.org)
  • Large-conductance calcium and voltage-activated potassium channels, termed SLO-1 (or BK), are pivotal players in the regulation of cell excitability across the animal phyla. (soton.ac.uk)
  • Consequently, K ATP channel inhibitors are important drugs to augment insulin secretion in type 2 diabetic subjects. (diabetesjournals.org)
  • Of the AADs recommended for treatment of AF only dofetilide and propafenone inhibited hK Ca 2.X channels, with no subtype selectivity. (sophion.com)
  • Potassium Channels and Calcium-Activated Chloride. (hhmi.org)
  • The physiological effects of BK channels have been studied extensively using knockout mice. (wikipedia.org)
  • The generation of mice in which one member of this class of potassium channels (SK3) can be regulated by dietary doxycycline (dox) [ 1 ] has enabled its role in the ventilatory response to carbon dioxide to be examined. (biomedcentral.com)
  • This family of ion channels is, for the most part, activated by intracellular Ca2+ and contains 8 members in the human genome. (wikipedia.org)
  • In this work, we have incorporated the current through SK channels, IKCa, into an electrophysiological ionic model of human atria myocyte. (upc.edu)
  • To this end, we tested a large number of AADs on the human K Ca 2.2 and K Ca 2.3 channels to assess their effect on this new target using automated whole-cell patch clamp. (sophion.com)
  • The Ca(++)-activated potassium channel known as BK has the nucleotide sequences of its alpha and beta subunits represented in messenger RNA of cultured human lens epithelium. (scite.ai)
  • In 1997, SK4 channels were cloned from human pancreatic tissue ( 9 ). (diabetesjournals.org)
  • 10 nM), which blocks large conductance Ca(2+)-activated K(+)-channel function, completely blocked and reversed the inhibitory effects of a mu-opioid agonist, neuropeptide Y, and an alpha 2-adrenoceptor agonist on excitatory NANC responses. (pnas.org)
  • In this chapter we discuss the data obtained for a calcium-activated potassium channel of large unitary conductance. (springer.com)
  • Large conductance, calcium-activated potassium (BK) channels play a prominent role in vertebrate hair cell function. (jneurosci.org)
  • We observe a large dependence of the action potential duration with the conductance and gate dynamics of the channel. (upc.edu)
  • Large-conductance calcium-activated potassium channels in neonatal rat" by F Franciolini, Ron C. Hogg et al. (edu.au)
  • Calcium-activated potassium channels are a large family of potassium channels that are found throughout the central nervous system and in many other cell types. (axonmedchem.com)
  • We previously described an interaction of BPTI at an intracellular site that results in the production of discrete subconductance events in large conductance Ca2+ activated K+ channels (Moss, G.W.J., and E. Moczydlowski. (rupress.org)
  • Vascular endothelium contains cytochrome P-450 epoxygenases that transform the n-6 fatty acid arachidonate into epoxyeicosatrienoic acids (EETs), potent dilators of coronary arterioles and activators of large-conductance calcium-activated potassium (BK Ca ) channels. (elsevier.com)
  • Spinal cord slices stained with SK/EK channel antibodies revealed positive SK3 staining in the outer laminae of the dorsal horn, where small and large diameter DRG fibres are expected to terminate. (ucl.ac.uk)
  • We show that daily expression of the large conductance Ca 2+ -activated K + channel (BK) in the SCN is controlled by the intrinsic circadian clock. (elsevier.com)
  • These results demonstrate that cortical large-conductance calcium-activated potassium channel inactivation is probably mediated by an endogenous, trypsin-sensitive, inactivation particle. (dundee.ac.uk)
  • CONCLUSIONS SK4 channels are involved in β-cell stimulus-secretion coupling. (diabetesjournals.org)
  • Blocking these channels broadens APs and increases insulin secretion ( 23 - 25 ). (diabetesjournals.org)