Biomaterial Database

Regulation of a thyrotropin-releasing hormone-degrading enzyme in GH3 cells: induction of pyroglutamyl peptidase I by 3,5,3'-triiodothyronine. 1987

C S Suen, and S Wilk

The effect of exposure of GH3 cells to T3 on the TRH-degrading enzymes pyroglutamyl peptidase I (EC 3.4.19.3) and prolyl endopeptidase (EC 3.4.21.26) was studied. T3 produced a dose-dependent increase in the specific activity of pyroglutamyl peptidase I after 3 days of exposure. The EC50 for T3 was 5 X 10(-10) M. The specific activity of prolyl endopeptidase was unaffected by exposure to T3. The increase in pyroglutamyl peptidase I activity was dependent upon the time of exposure of the cells to this hormone. A maximal effect occurred at 72 h. The stimulation of pyroglutamyl peptidase I by T3 was totally blocked by cycloheximide, indicating that this enzyme is induced in GH3 cells by T3. The effect of T3 on the two TRH-degrading enzymes was also studied in the ACTH-secreting cell line AtT20. T3 had no effect on these enzymes in the AtT20 cell, suggesting that the effect of T3 on pyroglutamyl peptidase I may be cell specific. These studies indicate that the induction of pyroglutamyl peptidase I by T3 may contribute to the negative feedback regulation of T3 levels.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D010450	Endopeptidases	A subclass of PEPTIDE HYDROLASES that catalyze the internal cleavage of PEPTIDES or PROTEINS.	Endopeptidase,Peptide Peptidohydrolases
D010911	Pituitary Neoplasms	Neoplasms which arise from or metastasize to the PITUITARY GLAND. The majority of pituitary neoplasms are adenomas, which are divided into non-secreting and secreting forms. Hormone producing forms are further classified by the type of hormone they secrete. Pituitary adenomas may also be characterized by their staining properties (see ADENOMA, BASOPHIL; ADENOMA, ACIDOPHIL; and ADENOMA, CHROMOPHOBE). Pituitary tumors may compress adjacent structures, including the HYPOTHALAMUS, several CRANIAL NERVES, and the OPTIC CHIASM. Chiasmal compression may result in bitemporal HEMIANOPSIA.	Pituitary Cancer,Cancer of Pituitary,Cancer of the Pituitary,Pituitary Adenoma,Pituitary Carcinoma,Pituitary Tumors,Adenoma, Pituitary,Adenomas, Pituitary,Cancer, Pituitary,Cancers, Pituitary,Carcinoma, Pituitary,Carcinomas, Pituitary,Neoplasm, Pituitary,Neoplasms, Pituitary,Pituitary Adenomas,Pituitary Cancers,Pituitary Carcinomas,Pituitary Neoplasm,Pituitary Tumor,Tumor, Pituitary,Tumors, Pituitary
D011751	Pyroglutamyl-Peptidase I	An enzyme that catalyzes the release of a N-terminal pyroglutamyl group from a polypeptide provided the next residue is not proline. It is inhibited by thiol-blocking reagents and occurs in mammalian tissues, microorganisms, and plants. (From Enzyme Nomenclature, 1992) EC 3.4.19.3.	5-Oxoprolyl-Peptidase,Pyroglutamate Aminopeptidase,Pyrrolidonecarboxylate Peptidase,Pyrrolidonyl Peptidase,Pyroglutamyl-Peptide Hydrolase,5 Oxoprolyl Peptidase,Aminopeptidase, Pyroglutamate,Peptidase, Pyrrolidonecarboxylate,Peptidase, Pyrrolidonyl,Pyroglutamyl Peptidase I,Pyroglutamyl Peptide Hydrolase
D011761	Pyrrolidonecarboxylic Acid	A cyclized derivative of L-GLUTAMIC ACID. Elevated blood levels may be associated with problems of GLUTAMINE or GLUTATHIONE metabolism.	5-Oxoproline,Pidolic Acid,Pyroglutamic Acid,5-Ketoproline,5-Oxopyrrolidine-2-Carboxylic Acid,Magnesium Pidolate,Pyroglutamate,Pidolate, Magnesium
D002460	Cell Line	Established cell cultures that have the potential to propagate indefinitely.	Cell Lines,Line, Cell,Lines, Cell
D003513	Cycloheximide	Antibiotic substance isolated from streptomycin-producing strains of Streptomyces griseus. It acts by inhibiting elongation during protein synthesis.	Actidione,Cicloheximide
D004790	Enzyme Induction	An increase in the rate of synthesis of an enzyme due to the presence of an inducer which acts to derepress the gene responsible for enzyme synthesis.	Induction, Enzyme
D006868	Hydrolysis	The process of cleaving a chemical compound by the addition of a molecule of water.
D000085822	Prolyl Oligopeptidases	A family of serine proteases with specificity for proline-specific cleavage of peptides that are not longer than 30 amino acids. In humans it is broadly distributed in all tissues with higher activity found in the brain.	Post-Proline Cleaving Enzyme,Post-Proline Endopeptidase,Proline Endopeptidase,Proline Specific Endopeptidase,Prolyl Endopeptidase,Prolyl Endopeptidase (Thiol-dependent),Prolyl Endopeptidase I,Prolyl Oligopeptidase,Endopeptidase I, Prolyl,Endopeptidase, Post-Proline,Endopeptidase, Proline Specific,Oligopeptidases, Prolyl,Post Proline Cleaving Enzyme,Post Proline Endopeptidase