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.
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.
Potassium channels whose activation is dependent on intracellular calcium concentrations.
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.
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.
A shaker subfamily that is prominently expressed in NEURONS and are necessary for high-frequency, repetitive firing of ACTION POTENTIALS.
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.
A delayed rectifier subtype of shaker potassium channels that is commonly mutated in human episodic ATAXIA and MYOKYMIA.
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.
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.
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.
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.
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 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 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.
Ion channels that specifically allow the passage of SODIUM ions. A variety of specific sodium channel subtypes are involved in serving specialized functions such as neuronal signaling, CARDIAC MUSCLE contraction, and KIDNEY function.
A very slow opening and closing voltage-gated potassium channel that is expressed in NEURONS and is commonly mutated in BENIGN FAMILIAL NEONATAL CONVULSIONS.
Cell membrane glycoproteins that form channels to selectively pass chloride ions. Nonselective blockers include FENAMATES; ETHACRYNIC ACID; and TAMOXIFEN.
Aquaporin 1 forms a water-specific channel that is constitutively expressed at the PLASMA MEMBRANE of ERYTHROCYTES and KIDNEY TUBULES, PROXIMAL. It provides these cells with a high permeability to WATER. In humans polymorphisms of this protein result in the Colton blood group antigen.
A delayed rectifier subtype of shaker potassium channels that is selectively inhibited by a variety of SCORPION VENOMS.
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.
Potassium channels where the flow of K+ ions into the cell is greater than the outward flow.