A KIR receptor that has specificity for HLA-C ANTIGENS. It is an inhibitory receptor that contains D1 and D2 extracellular immunoglobulin-like domains and a long cytoplasmic tail. It is similar in structure and function to the KIR2DL1 RECEPTORS and the KIR2DL3 RECEPTORS.

An activating KIR receptor that contains D0, D1, and D2 extracellular immunoglobulin-like domains and a short cytoplasmic tail.

A KIR receptor that has specificity for HLA-A3 ANTIGEN. It is an inhibitory receptor that contains D0, D1, and D2 extracellular immunoglobulin-like domains and a long cytoplasmic tail.

A KIR receptor that has specificity for HLA-B ANTIGENS. It is an inhibitory receptor that contains D0, D1, and D2 extracellular immunoglobulin-like domains and a long cytoplasmic tail.

A KIR receptor that has specificity for HLA-G antigen. It contains D0 and D2 extracellular immunoglobulin-like domains and a long cytoplasmic tail.

A KIR receptor that has specificity for HLA-C ANTIGENS. It is an inhibitory receptor that contains D1 and D2 extracellular immunoglobulin-like domains and a long cytoplasmic tail. It is similar in structure and function to the KIR2DL2 RECEPTOR and the KIR2DL3 RECEPTORS.

Class I human histocompatibility (HLA) antigens encoded by a small cluster of structural genes at the C locus on chromosome 6. They have significantly lower immunogenicity than the HLA-A and -B determinants and are therefore of minor importance in donor/recipient crossmatching. Their primary role is their high-risk association with certain disease manifestations (e.g., spondylarthritis, psoriasis, multiple myeloma).

Bone marrow-derived lymphocytes that possess cytotoxic properties, classically directed against transformed and virus-infected cells. Unlike T CELLS; and B CELLS; NK CELLS are not antigen specific. The cytotoxicity of natural killer cells is determined by the collective signaling of an array of inhibitory and stimulatory CELL SURFACE RECEPTORS. A subset of T-LYMPHOCYTES referred to as NATURAL KILLER T CELLS shares some of the properties of this cell type.

Cell surface molecules on cells of the immune system that specifically bind surface molecules or messenger molecules and trigger changes in the behavior of cells. Although these receptors were first identified in the immune system, many have important functions elsewhere.

A family of receptors found on NK CELLS that have specificity for a variety of HLA ANTIGENS. KIR receptors contain up to three different extracellular immunoglobulin-like domains referred to as D0, D1, and D2 and play an important role in blocking NK cell activation against cells expressing the appropriate HLA antigens thus preventing cell lysis. Although they are often referred to as being inhibitory receptors, a subset of KIR receptors may also play an activating role in NK cells.

A KIR receptor that has specificity for HLA-C ANTIGEN. It is an inhibitory receptor that contains D1 and D2 extracellular immunoglobulin-like domains and a long cytoplasmic tail. It is similar in structure and function to the KIR2DL2 RECEPTORS and the KIR2DL3 RECEPTORS.

Potassium channels where the flow of K+ ions into the cell is greater than the outward flow.

An inhibitory KIR receptor that contains D0 and D1 extracellular immunoglobulin-like domains and a long cytoplasmic tail.

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.

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.

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.

A chromosome disorder associated either with an extra chromosome 21 or an effective trisomy for chromosome 21. Clinical manifestations include hypotonia, short stature, brachycephaly, upslanting palpebral fissures, epicanthus, Brushfield spots on the iris, protruding tongue, small ears, short, broad hands, fifth finger clinodactyly, Simian crease, and moderate to severe INTELLECTUAL DISABILITY. Cardiac and gastrointestinal malformations, a marked increase in the incidence of LEUKEMIA, and the early onset of ALZHEIMER DISEASE are also associated with this condition. Pathologic features include the development of NEUROFIBRILLARY TANGLES in neurons and the deposition of AMYLOID BETA-PROTEIN, similar to the pathology of ALZHEIMER DISEASE. (Menkes, Textbook of Child Neurology, 5th ed, p213)

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.

Class I human histocompatibility (HLA) surface antigens encoded by more than 30 detectable alleles on locus B of the HLA complex, the most polymorphic of all the HLA specificities. Several of these antigens (e.g., HLA-B27, -B7, -B8) are strongly associated with predisposition to rheumatoid and other autoimmune disorders. Like other class I HLA determinants, they are involved in the cellular immune reactivity of cytolytic T lymphocytes.

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 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 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 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.

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).

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).

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.

A subclass of NK cell lectin-like receptors that associates with members of NK CELL LECTIN-LIKE RECEPTOR SUBFAMILY D to form heterodimeric receptors for HLA-E antigen.

Sulfonylurea compounds are a class of medications used in the treatment of diabetes mellitus type 2 that promote insulin secretion from pancreatic beta-cells by closing ATP-sensitive potassium channels in their membranes.

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 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.