| nicotinic acetylcholine receptor | Integral membrane protein of the postsynaptic membrane to which acetylcholine binds. The receptor contains an integral ion channel, as a result of binding of acetylcholine, ion channels in the subsynaptic membrane are opened. at the neuromuscular junction, the nicotinic acetylcholine receptor initiates muscle contraction. Currently the best characterised ion channel protein: made of a hetero pentamer of related subunits, although a homo pentamer is functional in insects. Structural studies show that the acetylcholine binding site and the ionic channel are part of the same macromolecular unit. The nAChR mediates rapid transduction events (1ms) whereas receptors activating G-protein coupled channels operate on slower time scales (millisecond to second range). (18 Nov 1997) |
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| nicotinic cholinergic receptor | A class of receptors responsive to acetylcholine that also are activated by nicotine; ganglionic (including the adrenal medulla) and neuromuscular receptors. Two classes exist: nicotinic-neuronal and nicotinic-muscular. (05 Mar 2000) |
| NMDA receptor | A type of glutamate receptor that participates in excitatory neurotransmission and also binds N-methyl-d-aspartate; may be particularly involved in the cell damage observed in individuals with Huntington's disease. (05 Mar 2000) |
| N methyl D aspartate receptor | <physiology> Glutamate receptor sub type (see excitatory amino acids). N methyl D aspartate receptor channels seem to be potentiated by intracellular arachidonic acid. Acronym: NMDA (26 Mar 1998) |
| quisqualate receptor | <cell biology> Glutamate operated ion channel. See: excitatory amino acid receptor channels. (05 Feb 1998) |
| insulin receptor | Areas on the outer part of a cell that allow the cell to join or bind with insulin that is in the blood. When the cell and insulin bind together, the cell can take glucose (sugar) from the blood and use it for energy. (09 Oct 1997) |
| insulin receptor protein-tyrosine kinase | <enzyme> A catalytic protein-tyrosine kinase domain found on the cytoplasmic beta-portion of the insulin receptor. Registry number: EC 2.7.1.- (12 Dec 1998) |
| insulin receptor substrate-1 protein | <chemical> Amino acid sequence given in first source; a 180 kD protein that contains multiple phosphorylated tyrosine residues after insulin stimulation; human and rat forms (hirs-1 and irs-1) are homologous Synonym: insulin receptor substrate-1-like protein, irs-1 protein, irs-1 gene product, hirs-1 protein, hirs-1 gene product, insulin receptor substrate 1, insulin receptor substrate-1 (05 Dec 1998) |
| oestrogen receptor | <cell biology> Cytoplasmic proteins that bind oestrogens and migrate to the nucleus where they regulate DNA transcription. Evaluation of the state of oestrogen receptors in breast cancer patients has become clinically important and determines the likelihood of response to anti-oestrogen therapy with tamoxifen. (17 Jul 2002) |
| olfactory receptor cells | Very slender nerve cell's, with large nuclei and surmounted by six to eight long, sensitive cilia in the olfactory epithelium at the roof of the nose; they are the receptors for smell. Synonym: olfactory cells, Schultze's cells. (05 Mar 2000) |
| olfactory receptor neurons | Neurons in the olfactory epithelium with proteins (receptors, odourant) that bind, and thus detect, odourants. Olfactory receptor neurons are bipolar. They send to the surface of the epithelium apical dendrites with non-motile cilia from which project odourant receptor molecules. Their unmyelinated axons synapse in the olfactory bulb of the brain. Unlike other neurons, they can be generated from precursor cells in adults. (12 Dec 1998) |
| opiate receptor | <pharmacology> Opiate-binding sites found throughout primary afferents and the neuraxis. (16 Dec 1997) |
| opioid receptor | <pharmacology> A membrane protein, widely distributed in animal cells, but especially in the brain (enkephalin receptors) and gut. The natural ligands are the opiate peptide neurotransmitters, but the name is given because opiates are potent agonists that occupy the receptors and mimic the action of the natural transmitters. (18 Nov 1997) |
| T-cell receptor | <immunology> The antigen recognising receptor on the surface of T-cells. Heterodimeric (disulphide linked), one of the immunoglobulin superfamily of proteins, binds antigen in association with the major histocompatibility complex (MHC), leading to the activation of the cell. There are two subunits (_ and _, 42-44 kD in mouse, 50-40 kD in humans), each with variable and constant regions, that are associated noncovalently with T3 (20-30 kD). A second heterodimer on CD3 cells with _ (35 kD in mice, 55 kD in humans) and _ (45 kD in mice, 40 kD in humans) chains is a second T-cell antigen receptor that is not MHC restricted. The __ T-cell receptors (TCRs) are formed on very early T-cells in the thymus. (18 Nov 1997) |
| TCK receptor-tyrosine kinase | <enzyme> A member of the eph receptor tyrosine kinase subfamily; expressed during xenopus development; shows 79% amino acid identity to hek2; genbank l43621 Registry number: EC 2.7.1.- Synonym: tck protein (26 Jun 1999) |