| receptors, interleukin-1 | Specific molecular sites or structures on cells with which interleukin-1 reacts or to which it binds to modify the function of the cells. The il-1 receptor on T-lymphocytes and fibroblasts is composed of a single polypeptide chain that binds both il-1 alpha and il-1 beta. The molecular weight of this high-affinity receptor is believed to be 80 kD. (12 Dec 1998) |
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| receptors, interleukin-2 | Receptors present on activated t- and B-cells as a complex consisting of a 55 kD peptide, which reacts with the anti-tac monoclonal antibody, and a 75 kD non-tac interleukin-2-binding peptide. The receptor is present in two forms, one with a very high affinity and the other with low affinity for il-2. The high-affinity form appears to mediate exclusively the growth-promoting response to il-2. The receptor is present in large numbers on resting HTLV-I leukaemia cells, but not on normal resting cells. (12 Dec 1998) |
| receptors, interleukin-3 | Phosphotyrosine-containing proteins, mw 140 kD. They form a stable complex with interleukin-3 with an apparent mass of 170 kD. They are found on a variety of cells and activate interleukin-3. (12 Dec 1998) |
| receptors, interleukin-4 | Receptors present on a wide variety of haematopoietic and non-haematopoietic cell types and various human tumours. Two forms of the receptor have been described, soluble and membrane-bound. Low affinity and high affinity receptors for il-4 have been reported. (12 Dec 1998) |
| receptors, interleukin-6 | <chemical> Receptors present on t cells, mitogen-activated B-cells, peripheral monocytes, and some macrophage- and B-cell-derived tumour cell types. The receptor is a strongly glycosylated protein of 80 kD and a length of 468 amino acids. Pharmacological action: growth inhibitors. (12 Dec 1998) |
| receptors, invertebrate peptide | Cell surface receptors for invertebrate peptide hormones or neuropeptides. (12 Dec 1998) |
| receptors, kainic acid | Cell surface proteins that bind glutamate and directly gate ion channels. Kainic acid receptors were originally discriminated from other glutamate receptors by their affinity for the agonist kainic acid. Activation of kainic acid receptors is generally excitatory to cells. Subtypes have been cloned, and for some the traditional distinction from ampa receptors may not apply. (12 Dec 1998) |
| receptors, laminin | Glycoprotein molecules on the surface of cells that react with or bind to laminin whose function allows the binding of epithelial cells to the basement membrane. The molecular weight of this high-affinity receptor is 67 kD. (12 Dec 1998) |
| receptors, ldl | Receptors on the plasma membrane of nonhepatic cells that specifically bind ldl. The receptors are localised in specialised regions called coated pits. Hypercholesteraemia is caused by an allelic genetic defect of three types: 1) receptors do not bind to ldl; 2) there is reduced binding of ldl; and 3) there is normal binding but no internalization of ldl. In consequence, entry of cholesterol esters into the cell is impaired and the intracellular feedback by cholesterol on 3-hydroxy-3-methylglutaryl CoA reductase is lacking. (12 Dec 1998) |
| receptors, leukocyte-adhesion | Family of proteins associated with the capacity of leukocytes, including lymphocytes, monocytes, and neutrophils, to adhere to each other and to certain substrata, e.g., the c3bi component of complement. Members of this family are the lymphocyte function-associated antigen-1 (lfa-1), the macrophage-1 antigen (mac-1), and the antigen p150,95 or p150,95 leukocyte adhesion protein. They all share a common beta-subunit which is the CD18 antigen. All three of the above antigens are absent in inherited leukocyte-adhesion deficiency syndrome, which is characterised by recurrent bacterial infections, impaired pus formation, and wound healing as well as abnormalities in a wide spectrum of adherence-dependent functions of granulocytes, monocytes, and lymphoid cells. (12 Dec 1998) |
| receptors, leukotriene | Cell-surface receptors that bind leukotrienes with high affinity and trigger intracellular changes influencing the behaviour of cells. The leukotriene receptor subtypes have been tentatively named according to their affinities for the endogenous leukotrienes ltb4, ltc4, ltd4, and lte4. (12 Dec 1998) |
| receptors, leukotriene b4 | A class of cell surface leukotriene receptors with a preference for leukotriene b4. Leukotriene b4 receptor activation influences chemotaxis, chemokinesis, adherence, enzyme release, oxidative bursts, and degranulation in polymorphonuclear leukocytes. There are at least two subtypes of these receptors. Some actions are mediated through the inositol phosphate and diacylglycerol second messenger systems. (12 Dec 1998) |
| receptors, lh | Those protein complexes or molecular sites on the surfaces and cytoplasm of gonadal cells that bind luteinizing or chorionic gonadotropic hormones and thereby cause the gonadal cells to synthesise and secrete sex steroids. The hormone-receptor complex is internalised from the plasma membrane and initiates steroid synthesis. (12 Dec 1998) |
| receptors, lhrh | Receptors with a 6-kD protein on the surfaces of cells that secrete lh or fsh, usually in the adenohypophysis. Lhrh binds to these receptors, is endocytosed with the receptor and, in the cell, triggers the release of lh or fsh by the cell. These receptors are also found in rat gonads. Inhibin prevents the binding of gnrh to its receptors. (12 Dec 1998) |
| receptors, lipoprotein | Cell surface proteins that bind lipoproteins with high affinity. Lipoprotein receptors in the liver and peripheral tissues mediate the regulation of plasma and cellular cholesterol metabolism and concentration. The receptors generally recognise the apolipoproteins of the lipoprotein complex, and binding is often a trigger for endocytosis. (12 Dec 1998) |