Biomaterial Database

Properties of triiodothyronine binding sites in cerebral cortical cytosol. 1981

S E Geel, and L Gonzales, and P S Timiras

Some properties of brain cytosol components that specifically bind L-triiodothyronine (T3) were examined in order to resolve their relevance and relationship to nuclear receptors. A marked variation in T3 binding activity was apparent among different brain areas. Binding exhibited temperature dependence and was maximal at 0 degrees C. The binding component was shown to be a protein that migrated as a single included peak on Sephadex G-100 columns at a position corresponding to a Stokes radium of 30A degrees and a M.W. of 54,000. On a linear glycerol gradient the T3-macromolecular complex was estimated to have a sedimentation constant of .4.2S. By combining sedimentation and gel filtration data the calculated M.W. was 53,000. With DEAE-cellulose chromatography the T3 complex eluted as a single peak at 115mM KH2PO4. The results indicate that the properties of the cytosol thyronine-binding protein are similar in many respects to those reported for nuclear receptors. In addition, the regional and developmental binding parameters parallel those for nuclei. We conclude that cytosolic recognition sites may function in the modulation of nuclear receptors and in addition serve to distinguish target from non-target tissue.

UI	MeSH Term	Description	Entries
D010447	Peptide Hydrolases	Hydrolases that specifically cleave the peptide bonds found in PROTEINS and PEPTIDES. Examples of sub-subclasses for this group include EXOPEPTIDASES and ENDOPEPTIDASES.	Peptidase,Peptidases,Peptide Hydrolase,Protease,Proteases,Proteinase,Proteinases,Proteolytic Enzyme,Proteolytic Enzymes,Esteroproteases,Enzyme, Proteolytic,Hydrolase, Peptide
D011956	Receptors, Cell Surface	Cell surface proteins that bind signalling molecules external to the cell with high affinity and convert this extracellular event into one or more intracellular signals that alter the behavior of the target cell (From Alberts, Molecular Biology of the Cell, 2nd ed, pp693-5). Cell surface receptors, unlike enzymes, do not chemically alter their ligands.	Cell Surface Receptor,Cell Surface Receptors,Hormone Receptors, Cell Surface,Receptors, Endogenous Substances,Cell Surface Hormone Receptors,Endogenous Substances Receptors,Receptor, Cell Surface,Surface Receptor, Cell
D011988	Receptors, Thyroid Hormone	Specific high affinity binding proteins for THYROID HORMONES in target cells. They are usually found in the nucleus and regulate DNA transcription. These receptors are activated by hormones that leads to transcription, cell differentiation, and growth suppression. Thyroid hormone receptors are encoded by two genes (GENES, ERBA): erbA-alpha and erbA-beta for alpha and beta thyroid hormone receptors, respectively.	Diiodotyrosine Receptors,Receptors, Diiodotyrosine,Receptors, Thyroxine,Receptors, Triiodothyronine,T3 Receptors,T4 Receptors,Thyroid Hormone Receptors,Thyroxine Receptors,Triiodothyronine Receptors,DIT Receptors,Diiodotyrosine Receptor,MIT Receptors,Monoiodotyrosine Receptors,Receptors, DIT,Receptors, MIT,Receptors, Monoiodotyrosine,Receptors, T3,Receptors, T4,T3 Receptor,T4 Receptor,Thyroid Hormone Receptor,Thyroxine Receptor
D002540	Cerebral Cortex	The thin layer of GRAY MATTER on the surface of the CEREBRAL HEMISPHERES that develops from the TELENCEPHALON and folds into gyri and sulci. It reaches its highest development in humans and is responsible for intellectual faculties and higher mental functions.	Allocortex,Archipallium,Cortex Cerebri,Cortical Plate,Paleocortex,Periallocortex,Allocortices,Archipalliums,Cerebral Cortices,Cortex Cerebrus,Cortex, Cerebral,Cortical Plates,Paleocortices,Periallocortices,Plate, Cortical
D002918	Chymotrypsin	A serine endopeptidase secreted by the pancreas as its zymogen, CHYMOTRYPSINOGEN and carried in the pancreatic juice to the duodenum where it is activated by TRYPSIN. It selectively cleaves aromatic amino acids on the carboxyl side.	Alpha-Chymotrypsin Choay,Alphacutanée,Avazyme
D003600	Cytosol	Intracellular fluid from the cytoplasm after removal of ORGANELLES and other insoluble cytoplasmic components.	Cytosols
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
D001665	Binding Sites	The parts of a macromolecule that directly participate in its specific combination with another molecule.	Combining Site,Binding Site,Combining Sites,Site, Binding,Site, Combining,Sites, Binding,Sites, Combining
D013696	Temperature	The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.	Temperatures
D014284	Triiodothyronine	A T3 thyroid hormone normally synthesized and secreted by the thyroid gland in much smaller quantities than thyroxine (T4). Most T3 is derived from peripheral monodeiodination of T4 at the 5' position of the outer ring of the iodothyronine nucleus. The hormone finally delivered and used by the tissues is mainly T3.	Liothyronine,T3 Thyroid Hormone,3,3',5-Triiodothyronine,Cytomel,Liothyronine Sodium,Thyroid Hormone, T3