Biomaterial Database

Decrease in cAMP-dependent protein kinase activity in suspension cultures of porcine thyroid cells exposed to TSH or forskolin. 1988

M F Breton, and B Haye, and B Omri, and C Jacquemin, and M Pavlovic-Hournac

INSERM U.96, Unité de Recherche sur la Glande Thyroide et la Régulation Hormonale, Kremlin-Bicêtre, France.

Suspension cultures of porcine thyroid cells were used to study the action of TSH and forskolin (Fk) on cAMP-dependent (PKa) and Ca2+-phospholipid-dependent (PKc) protein kinase--enzymes which represent the key step in the transduction of extracellular signals. The PKa activity in cells cultured for 2 days in the presence of TSH was decreased to about 50% of control level with a TSH dose of 0.1 mU/ml. This decrease is dose dependent; only traces of PKa activity remained at very high doses of TSH (50 mU/ml). Similar results were obtained with Fk (10(-5) M), the adenylate cyclase activator. It decreased the PKa activity to the level obtained with 0.1-1.0 mU/ml TSH. The loss of the PKa activity was parallel in cytosol and particulate fractions, suggesting that there is no translocation of enzymes under the action of either TSH or Fk. Neither TSH nor Fk had any effect on PKc, which became the predominant activity in cells exposed to either of the regulators. The cAMP-dependent phosphorylation of endogenous proteins was lower in TSH- or Fk-treated cells than in controls, and was dependent, like the PKa activity, on the dose of TSH. Polyacrylamide gel electrophoresis (PAGE) revealed the specific substrates of PKa in cultured thyroid cells. Proteins of 28, 30 and 33 kDa were regularly found, while 58 kDa protein was not present in all experiments. PAGE patterns showed that the decrease in endogenous phosphorylation in TSH- and Fk-treated cells was due to decreased labelling of PKa-specific substrates. The observed down-regulation of PKa activity could have an influence on the expression of thyroid cell differentiation.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D010766	Phosphorylation	The introduction of a phosphoryl group into a compound through the formation of an ester bond between the compound and a phosphorus moiety.	Phosphorylations
D011494	Protein Kinases	A family of enzymes that catalyze the conversion of ATP and a protein to ADP and a phosphoprotein.	Protein Kinase,Kinase, Protein,Kinases, Protein
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
D005576	Colforsin	Potent activator of the adenylate cyclase system and the biosynthesis of cyclic AMP. From the plant COLEUS FORSKOHLII. Has antihypertensive, positive inotropic, platelet aggregation inhibitory, and smooth muscle relaxant activities; also lowers intraocular pressure and promotes release of hormones from the pituitary gland.	Coleonol,Forskolin,N,N-Dimethyl-beta-alanine-5-(acetyloxy)-3-ethenyldodecahydro-10,10b-dihydroxy-3,4a,7,7,10a-pentamethyl-1-oxo-1H-naphtho(2,1-b)pyran-6-yl Ester HCl,NKH 477,NKH-477,NKH477
D000242	Cyclic AMP	An adenine nucleotide containing one phosphate group which is esterified to both the 3'- and 5'-positions of the sugar moiety. It is a second messenger and a key intracellular regulator, functioning as a mediator of activity for a number of hormones, including epinephrine, glucagon, and ACTH.	Adenosine Cyclic 3',5'-Monophosphate,Adenosine Cyclic 3,5 Monophosphate,Adenosine Cyclic Monophosphate,Adenosine Cyclic-3',5'-Monophosphate,Cyclic AMP, (R)-Isomer,Cyclic AMP, Disodium Salt,Cyclic AMP, Monoammonium Salt,Cyclic AMP, Monopotassium Salt,Cyclic AMP, Monosodium Salt,Cyclic AMP, Sodium Salt,3',5'-Monophosphate, Adenosine Cyclic,AMP, Cyclic,Adenosine Cyclic 3',5' Monophosphate,Cyclic 3',5'-Monophosphate, Adenosine,Cyclic Monophosphate, Adenosine,Cyclic-3',5'-Monophosphate, Adenosine,Monophosphate, Adenosine Cyclic
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
D013552	Swine	Any of various animals that constitute the family Suidae and comprise stout-bodied, short-legged omnivorous mammals with thick skin, usually covered with coarse bristles, a rather long mobile snout, and small tail. Included are the genera Babyrousa, Phacochoerus (wart hogs), and Sus, the latter containing the domestic pig (see SUS SCROFA).	Phacochoerus,Pigs,Suidae,Warthogs,Wart Hogs,Hog, Wart,Hogs, Wart,Wart Hog
D013961	Thyroid Gland	A highly vascularized endocrine gland consisting of two lobes joined by a thin band of tissue with one lobe on each side of the TRACHEA. It secretes THYROID HORMONES from the follicular cells and CALCITONIN from the parafollicular cells thereby regulating METABOLISM and CALCIUM level in blood, respectively.	Thyroid,Gland, Thyroid,Glands, Thyroid,Thyroid Glands,Thyroids
D013972	Thyrotropin	A glycoprotein hormone secreted by the adenohypophysis (PITUITARY GLAND, ANTERIOR). Thyrotropin stimulates THYROID GLAND by increasing the iodide transport, synthesis and release of thyroid hormones (THYROXINE and TRIIODOTHYRONINE). Thyrotropin consists of two noncovalently linked subunits, alpha and beta. Within a species, the alpha subunit is common in the pituitary glycoprotein hormones (TSH; LUTEINIZING HORMONE and FSH), but the beta subunit is unique and confers its biological specificity.	Thyroid-Stimulating Hormone,TSH (Thyroid Stimulating Hormone),Thyreotropin,Thyrotrophin,Hormone, Thyroid-Stimulating,Thyroid Stimulating Hormone