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Voltage-gated Potassium Channel
Voltage-gated potassium channels (VGKCs) are potassium channel, transmembrane channels specific for potassium and Voltage-gated ion channel, sensitive to voltage changes in the cell's membrane potential. During action potentials, they play a crucial role in returning the depolarized cell to a resting state. Classification Alpha subunits Alpha subunits form the actual conductance pore. Based on sequence homology of the hydrophobic transmembrane cores, the alpha subunits of voltage-gated potassium channels are grouped into 12 classes. These are labeled Kvα1-12. The following is a list of the 40 known human voltage-gated potassium channel alpha subunits grouped first according to function and then subgrouped according to the Kv sequence homology classification scheme: Delayed rectifier slowly inactivating or non-inactivating *Kvα1.x - shaker superfamily of potassium channels, Shaker-related: Kv1.1 (KCNA1), Kv1.2 (KCNA2), Kv1.3 (KCNA3), Kv1.5 (KCNA5), Kv1.6 (KCNA6), Kv1.7 (KCN ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lipid Bilayer
The lipid bilayer (or phospholipid bilayer) is a thin polar membrane made of two layers of lipid molecules. These membranes form a continuous barrier around all cell (biology), cells. The cell membranes of almost all organisms and many viruses are made of a lipid bilayer, as are the nuclear envelope, nuclear membrane surrounding the cell nucleus, and biological membrane, membranes of the membrane-bound organelles in the cell. The lipid bilayer is the barrier that keeps ions, proteins and other molecules where they are needed and prevents them from diffusing into areas where they should not be. Lipid bilayers are ideally suited to this role, even though they are only a few nanometers in width, because they are impermeable to most water-soluble (hydrophilic) molecules. Bilayers are particularly impermeable to ions, which allows cells to regulate salt concentrations and pH by transporting ions across their membranes using proteins called Ion transporter, ion pumps. Biological bilaye ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
KCNQ1
Kv7.1 (KvLQT1) is a potassium channel protein whose primary subunit in humans is encoded by the ''KCNQ1'' gene. Its mutation causes Long QT syndrome, Kv7.1 is a voltage and lipid-gated potassium channel present in the cell membranes of cardiac tissue and in inner ear neurons among other tissues. In the cardiac cells, Kv7.1 mediates the IKs (or slow delayed rectifying K+) current that contributes to the repolarization of the cell, terminating the cardiac action potential and thereby the heart's contraction. It is a member of the KCNQ family of potassium channels. Structure KvLQT1 is made of six membrane-spanning domains S1-S6, two intracellular domains, and a pore loop. The KvLQT1 channel is made of four KCNQ1 subunits, which form the actual ion channel. Function This gene encodes a protein for a voltage-gated potassium channel required for the repolarization phase of the cardiac action potential. The gene product can form heteromultimers with two other potassium ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
KCNH2
hERG (the human '' Ether-à-go-go''-Related Gene) is a gene () that codes for a protein known as Kv11.1, the alpha subunit of a potassium ion channel. This ion channel (sometimes simply denoted as 'hERG') is best known for its contribution to the electrical activity of the heart: the hERG channel mediates the repolarizing ''I''Kr current in the cardiac action potential, which helps coordinate the heart's beating. When this channel's ability to conduct electrical current across the cell membrane is inhibited or compromised, either by application of drugs or by rare mutations in some families, it can result in a potentially fatal disorder called long QT syndrome. Conversely, genetic mutations that increase the current through these channels can lead to the related inherited heart rhythm disorder short QT syndrome. A number of clinically successful drugs in the market have had the tendency to inhibit hERG, lengthening the QT and potentially leading to a fatal irregularity o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
KCNH5
Potassium voltage-gated channel, subfamily H (eag-related), member 5, also known as KCNH5, is a human gene encoding the Kv10.2 protein. Voltage-gated potassium (Kv) channels represent the most complex class of voltage-gated ion channels from both functional and structural standpoints. Their diverse functions include regulating neurotransmitter release, heart rate, insulin secretion, neuronal excitability, epithelial electrolyte transport, smooth muscle contraction, and cell volume. This gene encodes a member of the potassium channel, voltage-gated, subfamily H. This member is a pore-forming (alpha) subunit of a voltage-gated non-inactivating delayed rectifier potassium channel. This gene is not expressed in differentiating myoblasts. Alternative splicing results in three transcript variants encoding distinct isoforms. Mutations in this gene have been linked to cases of early onset Epilepsy Epilepsy is a group of Non-communicable disease, non-communicable Neurological disorde ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
KCND3
Potassium voltage-gated channel subfamily D member 3 also known as Kv4.3 is a protein that in humans is encoded by the ''KCND3'' gene. It contributes to the cardiac transient outward potassium current (Ito1), the main contributing current to the repolarizing phase 1 of the cardiac action potential. Function Voltage-gated potassium ( Kv) channels represent the most complex class of voltage-gated ion channels from both functional and structural standpoints. Their diverse functions include regulating neurotransmitter release, heart rate, insulin secretion, neuronal excitability, epithelial electrolyte transport, smooth muscle contraction, and cell volume. Four sequence-related potassium channel genes – shaker, shaw, shab, and shal – have been identified in Drosophila, and each has been shown to have human homolog(s). Kv4.3 is a member of the potassium channel, voltage-gated, shal-related subfamily, members of which form voltage-activated A-type potassium ion channels and ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
KCND2
Potassium voltage-gated channel subfamily D member 2 is a protein that in humans is encoded by the ''KCND2'' gene. It contributes to the cardiac transient outward potassium current (Ito1), the main contributing current to the repolarizing phase 1 of the cardiac action potential. Description Voltage-gated potassium (Kv) channels represent the most complex class of voltage-gated ion channels from both functional and structural standpoints. Their diverse functions include regulating neurotransmitter release, heart rate, insulin secretion, neuronal excitability, epithelial electrolyte transport, smooth muscle contraction, and cell volume. Four sequence-related potassium channel genes - shaker, shaw, shab, and shal - have been identified in Drosophila, and each has been shown to have human homolog(s). This gene encodes a member of the potassium channel, voltage-gated, shal-related subfamily, members of which form voltage-activated A-type potassium ion channels and are prominent in th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
KCND1
Potassium voltage-gated channel, Shal-related subfamily, member 1 (KCND1), also known as Kv4.1, is a human gene. Voltage-gated potassium (Kv) channels represent the most complex class of voltage-gated ion channels from both functional and structural standpoints. Their diverse functions include regulating neurotransmitter release, heart rate, insulin secretion, neuronal excitability, epithelial electrolyte transport, smooth muscle contraction, and cell volume. Four sequence-related potassium channel genes - shaker, shaw, shab, and shal - have been identified in Drosophila, and each has been shown to have human homolog(s). This gene encodes a member of the potassium channel, voltage-gated, shal-related subfamily, members of which form voltage-activated A-type potassium ion channels and are prominent in the repolarization phase of the action potential. This gene is expressed at moderate levels in all tissues analyzed, with lower levels in skeletal muscle. See also * Voltage-gated pot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
KCNA4
Potassium voltage-gated channel subfamily A member 4 also known as Kv1.4 is a protein that in humans is encoded by the ''KCNA4'' gene. It contributes to the cardiac transient outward potassium current (Ito1), the main contributing current to the repolarizing phase 1 of the cardiac action potential. Description Potassium channels represent the most complex class of voltage-gated ion channels from both functional and structural standpoints. Their diverse functions include regulating neurotransmitter release, heart rate, insulin secretion, neuronal excitability, epithelial electrolyte transport, smooth muscle contraction, and cell volume. Four sequence-related potassium channel genes - shaker, shaw, shab, and shal - have been identified in Drosophila, and each has been shown to have human homolog(s). This gene encodes a member of the potassium channel, voltage-gated, shaker-related subfamily. This member contains six membrane-spanning domains with a shaker-type repeat in the fourt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
KCNH1
Potassium voltage-gated channel subfamily H member 1 (KV10.1, EAG1) is a protein that in humans is encoded by the ''KCNH1'' gene. Mutations in ''KCNH1'' cause genetic epilepsy and developmental encephalopathies, and aberant expression is associated with tumor progression. Function Expression of KCNH1 is predominantly restricted to the adult central nervous system. The ''KCNH1'' gene encodes a homotetrameric highly-conserved voltage-gated potassium channel (KV10.1) thought to be responsible for reestablishing the membrane potential of excitatory neurons in response to high frequency firing. KV10.1 is a non-inactivating delayed rectifier potassium channel. Like other voltage-gated potassium ion channels, opening of the KV10.1 channel pore is triggered by membrane depolarisation, which results in an outward flow of potassium ions to rectify the baseline membrane potential. KV10.1 is slow to open when triggered and does not undergo an inactivation state after closing. Structural ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
KCNQ5
Potassium voltage-gated channel subfamily KQT member 5 is a protein that in humans is encoded by the ''KCNQ5'' gene. This gene is a member of the KCNQ potassium channel gene family that is differentially expressed in subregions of the brain and in skeletal muscle. The protein encoded by this gene yields currents that activate slowly with depolarization and can form heteromeric channels with the protein encoded by the KCNQ3 gene. Currents expressed from this protein have voltage dependences and inhibitor sensitivities in common with M-currents. They are also inhibited by M1 muscarinic receptor activation. Three alternatively spliced transcript variants encoding distinct isoforms have been found for this gene, but the full-length nature of only one has been determined. Interactions KCNQ5 has been shown to interact with KvLQT3. See also * Voltage-gated potassium channel Voltage-gated potassium channels (VGKCs) are potassium channel, transmembrane channels specific for potas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
KCNQ4
Potassium voltage-gated channel subfamily KQT member 4, also known as voltage-gated potassium channel subunit Kv7.4, is a protein that in humans is encoded by the ''KCNQ4'' gene. Function The protein encoded by this gene forms a potassium channel that is thought to play a critical role in the regulation of neuronal excitability, particularly in sensory cells of the cochlea. The encoded protein can form a homomultimeric potassium channel or possibly a heteromultimeric channel in association with the protein encoded by the KCNQ3 gene. Clinical significance The current generated by this channel is inhibited by muscarinic acetylcholine receptor M1 and activated by retigabine, a novel anti-convulsant drug. Defects in this gene are a cause of nonsyndromic sensorineural deafness type 2 (DFNA2), an autosomal dominant form of progressive hearing loss. Two transcript variants encoding different isoforms have been found for this gene. Ligands * ML213: KCNQ2/Q4 channel opener. S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
