Biomaterial Database

Rat beta 3 subunits expressed in human embryonic kidney 293 cells form high affinity [35S]t-butylbicyclophosphorothionate binding sites modulated by several allosteric ligands of gamma-aminobutyric acid type A receptors. 1995

A Slany, and J Zezula, and V Tretter, and W Sieghart

Department of Biochemical Psychiatry, University Clinic for Psychiatry, Vienna, Austria.

Human embryonic kidney 293 cells transiently transfected with beta 3 subunits of gamma-aminobutyric acid type A receptors from the rat exhibited a specific high affinity binding for [35S]t-butylbicyclophosphorothionate (TBPS) that could be inhibited by pentobarbital, etazolate, (+)-etomidate, alphaxalone, propofol, chlormethiazole, and Ro 5-4864. The potency of these compounds for inhibition of [35S]TBPS binding was similar in membranes from beta 3 subunit-transfected human embryonic kidney 293 cells and in cerebellar membranes. In contrast to maximally inhibiting concentrations of unlabeled TBPS or picrotoxin, which caused a monophasic and rather slow dissociation of [35S]TBPS, maximally inhibiting concentrations of pentobarbital, etazolate, alphaxalone, propofol, chlormethiazole, and Ro 5-4864 accelerated the dissociation of [35S]TBPS from beta 3 subunit-containing membranes. Immunoaffinity chromatography and Western blot analysis with subunit-specific antibodies indicated that other endogenous subunits possibly present in these cells were not associated with beta 3 subunits. These results appear to indicate that most of the allosteric binding sites present on gamma-aminobutyric acid type A receptors can be formed by the beta subunit of these receptors. Homo-oligomeric beta 3 receptors therefore are an excellent model system for the structural investigation of gamma-aminobutyric acid type A receptors.

UI	MeSH Term	Description	Entries
D007668	Kidney	Body organ that filters blood for the secretion of URINE and that regulates ion concentrations.	Kidneys
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008024	Ligands	A molecule that binds to another molecule, used especially to refer to a small molecule that binds specifically to a larger molecule, e.g., an antigen binding to an antibody, a hormone or neurotransmitter binding to a receptor, or a substrate or allosteric effector binding to an enzyme. Ligands are also molecules that donate or accept a pair of electrons to form a coordinate covalent bond with the central metal atom of a coordination complex. (From Dorland, 27th ed)	Ligand
D011963	Receptors, GABA-A	Cell surface proteins which bind GAMMA-AMINOBUTYRIC ACID and contain an integral membrane chloride channel. Each receptor is assembled as a pentamer from a pool of at least 19 different possible subunits. The receptors belong to a superfamily that share a common CYSTEINE loop.	Benzodiazepine-Gaba Receptors,GABA-A Receptors,Receptors, Benzodiazepine,Receptors, Benzodiazepine-GABA,Receptors, Diazepam,Receptors, GABA-Benzodiazepine,Receptors, Muscimol,Benzodiazepine Receptor,Benzodiazepine Receptors,Benzodiazepine-GABA Receptor,Diazepam Receptor,Diazepam Receptors,GABA(A) Receptor,GABA-A Receptor,GABA-A Receptor alpha Subunit,GABA-A Receptor beta Subunit,GABA-A Receptor delta Subunit,GABA-A Receptor epsilon Subunit,GABA-A Receptor gamma Subunit,GABA-A Receptor rho Subunit,GABA-Benzodiazepine Receptor,GABA-Benzodiazepine Receptors,Muscimol Receptor,Muscimol Receptors,delta Subunit, GABA-A Receptor,epsilon Subunit, GABA-A Receptor,gamma-Aminobutyric Acid Subtype A Receptors,Benzodiazepine GABA Receptor,Benzodiazepine Gaba Receptors,GABA A Receptor,GABA A Receptor alpha Subunit,GABA A Receptor beta Subunit,GABA A Receptor delta Subunit,GABA A Receptor epsilon Subunit,GABA A Receptor gamma Subunit,GABA A Receptor rho Subunit,GABA A Receptors,GABA Benzodiazepine Receptor,GABA Benzodiazepine Receptors,Receptor, Benzodiazepine,Receptor, Benzodiazepine-GABA,Receptor, Diazepam,Receptor, GABA-A,Receptor, GABA-Benzodiazepine,Receptor, Muscimol,Receptors, Benzodiazepine GABA,Receptors, GABA A,Receptors, GABA Benzodiazepine,delta Subunit, GABA A Receptor,epsilon Subunit, GABA A Receptor,gamma Aminobutyric Acid Subtype A Receptors
D002478	Cells, Cultured	Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.	Cultured Cells,Cell, Cultured,Cultured Cell
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000495	Allosteric Site	A site on an enzyme which upon binding of a modulator, causes the enzyme to undergo a conformational change that may alter its catalytic or binding properties.	Allosteric Sites,Site, Allosteric,Sites, Allosteric
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013462	Sulfur Radioisotopes	Unstable isotopes of sulfur that decay or disintegrate spontaneously emitting radiation. S 29-31, 35, 37, and 38 are radioactive sulfur isotopes.	Radioisotopes, Sulfur
D014162	Transfection	The uptake of naked or purified DNA by CELLS, usually meaning the process as it occurs in eukaryotic cells. It is analogous to bacterial transformation (TRANSFORMATION, BACTERIAL) and both are routinely employed in GENE TRANSFER TECHNIQUES.	Transfections