| receptors, ampa | Cell surface proteins that bind glutamate and directly gate ion channels in cell membranes. Ampa receptors were originally discriminated from other glutamate receptors by their affinity for the agonist ampa (alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid). They are probably the most common mediators of fast excitatory synaptic transmission in the central nervous system. Several subtypes have been cloned, and for some types the traditional distinction from kainate receptors may not apply. (12 Dec 1998) |
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| receptors, androgen | Proteins, generally found in the cytoplasm, that specifically bind androgens and mediate their cellular actions. The complex of the androgen and receptor migrates to the nucleus where it induces transcription of specific segments of DNA. (12 Dec 1998) |
| receptors, angiotensin | Cell surface proteins that bind angiotensins and trigger intracellular changes influencing the behaviour of cells. (12 Dec 1998) |
| receptors, antigen | Molecules on the surface of b- and T-lymphocytes that recognise and combine with specific antigens. (12 Dec 1998) |
| receptors, antigen, B-cell | Immunoglobulin molecules on the surface of B-lymphocytes that recognise and bind antigen. (12 Dec 1998) |
| receptors, antigen, T-cell | Molecules on the surface of T-lymphocytes that recognise and combine with antigens. The receptors are non-covalently associated with a complex of several polypeptides collectively called CD3 antigens (antigens, CD3). Recognition of foreign antigen and the major histocompatibility complex is accomplished by a single heterodimeric antigen-receptor structure, composed of either alpha-beta (receptors, antigen, T-cell, alpha-beta) or gamma-delta (receptors, antigen, T-cell, gamma-delta) chains. (12 Dec 1998) |
| receptors, antigen, T-cell, alpha-beta | T-cell receptors composed of CD3-associated alpha and beta polypeptide chains and expressed primarily in CD4+ or CD8+ T-cells. Unlike immunoglobulins, the alpha-beta T-cell receptors recognise antigens only when presented in association with major histocompatibility (MHC) molecules. (12 Dec 1998) |
| receptors, antigen, T-cell, gamma-delta | T-cell receptors composed of CD3-associated gamma and delta polypeptide chains and expressed primarily in CD4-/CD8- T-cells. The receptors appear to be preferentially located in epithelial sites and probably play a role in the recognition of bacterial antigens. The T-cell receptor gamma/delta chains are separate and not related to the gamma and delta chains which are subunits of CD3 (see antigens, CD3). (12 Dec 1998) |
| receptors, aryl hydrocarbon | Cytoplasmic proteins that bind certain aryl hydrocarbons, translocate to the nucleus, and activate transcription of particular DNA segments. Ah receptors are identified by their high-affinity binding to several carcinogenic or teratogenic environmental chemicals including polycyclic aromatic hydrocarbons found in cigarette smoke and smog, heterocyclic amines found in cooked foods, and halogenated hydrocarbons including dioxins and polychlorinated biphenyls. No endogenous ligand has been identified, but an unknown natural messenger with a role in cell differentiation and development is suspected. (12 Dec 1998) |
| receptors, biogenic amine | Cell surface proteins that bind biogenic amines with high affinity and regulate intracellular signals which influence the behaviour of cells. Biogenic amine is a chemically imprecise term which, by convention, includes the catecholamines epinephrine, norepinephrine, and dopamine, the indoleamine serotonin, the imidazolamine histamine, and compounds closely related to each of these. (12 Dec 1998) |
| receptors, bombesin | Cell surface proteins that bind bombesin or closely related peptides with high affinity and trigger intracellular changes influencing the behaviour of cells. Gastrin- releasing peptide (grp), grp 18-27 (neuromedin c), and neuromedin b are endogenous ligands of bombesin receptors in mammals. (12 Dec 1998) |
| receptors, bradykinin | Cell surface receptors that bind bradykinin and related kinins with high affinity and trigger intracellular changes which influence the behaviour of cells. The identified receptor types (b-1 and b-2, or bk-1 and bk-2) recognise the endogenous kallidins, t-kinins, and certain bradykinin fragments as well as bradykinin itself. (12 Dec 1998) |
| receptors, calcitonin | Cell surface proteins that bind calcitonin and trigger intracellular changes which influence the behaviour of cells. Calcitonin receptors outside the nervous system mediate the role of calcitonin in calcium homeostasis. The role of calcitonin receptors in the brain is not well understood. (12 Dec 1998) |
| receptors, calcitonin gene-related peptide | Cell surface proteins that bind calcitonin gene-related peptide (cgrp) with high affinity and trigger intracellular changes which influence the behaviour of cells. Cgrp receptors are present in both the central nervous system and the periphery and are not the same as calcitonin receptors. (12 Dec 1998) |
| receptors, calcitriol | Proteins, usually found in the cytoplasm, that specifically bind calcitriol, migrate to the nucleus, and regulate transcription of specific segments of DNA. Vitamin d is converted in the liver and kidney to calcitriol and ultimately acts through these receptors. (12 Dec 1998) |