ADP Ribosylation and G Protein Regulation in the Thyroid
Although most of the metabolic effects of TSH on the thyroid reflect its activation of the adenylate cyclase-cAMP system (1), other signalling systems mediate the effect of other agonists such as acetylcholine (2) and phorbol esters (3). Furthermore effects of TSH on desensitization (4) and 32P incorportation into phospholipids (1) are not mediated by cAMP. The phosphatidylinositol 4,5-bisphosphate cascade which increases intracellular Ca2+ and activates protein kinase C is present in the thyroid and may be important for the regulation of several metabolic effects (5–9). ADP ribosylation of various proteins is another possible signalling system for cell regulation (10–13). Although this process may involve either poly ADP ribosylation or mono ADP ribosylation, the present discussion will be limited to the latter process.
KeywordsCholera Toxin Pertussis Toxin Thyroid Cell Bovine Thyroid Arginine Methyl Ester
Unable to display preview. Download preview PDF.
- 1.J. B. Field, “Mechanism of action of TSH, in the Thyroid,” Harper and Row, New York, (1978).Google Scholar
- 6.J. B. Field, P. A. Ealey, N. J. Marshall, and S. Cockcroft, Thyroid stimulating hormone stimulates increases in inositol phosphates as well as cyclic AMP in the FRTL-5 rat thyroid cell line, Biochem. J. 247: 519 (1987).Google Scholar
- 13.M. J. S. DeWolf, P. Vitti, F. S. Ambesi-Impiombaba, and L. D. Kohn, Thyroid membrane ADP ribosyltransferase activity. J. Biol. Chem. 256: 12287, (1981).Google Scholar
- 15.F. Ribeiro-Neto, L. Birnbaumer, and J. B. Field, Incubation of bovine thyroid slices with thyrotropin is associated with a decrease in the ability of pertussis toxin to adenosine diphosphate-ribosylate guanine nucleotide regulatory component(s), Mol. Endocrinol. 1: 482, (1987).Google Scholar
- 16.F. Ribeiro-Neto, R. Mattera, D. Grenet, R. D. Sekura, L. Birnbaumer, and J. B. Field, Adenosine diphosphate ribosylation of G proteins by pertussis and cholerat toxin in isolated membranes. Different requirements for and effects of guanine nucleotides and Mgt+, Mol. Endocrinol. 1: 472, (1981).Google Scholar
- 24.I. Pastan, B. Herring, P. Johnson, and J. B. Field, In vitro stimulation of glucose oxidation in thyroid by acetylcholine, J. Biol. Chem. 236:340, (1961).Google Scholar
- 28.D. Corda, and L. D. Kohn, Role of pertussis toxin sensitive G proteins in the alpha]. adrenergic receptor but not in the thyrotropin receptor mediated activation of membrane phospholipases and iodide fluxes in FRTL-5 thyroid cells, Biochem. and Biphys. Res. Commun. 141: 1000, (1986).Google Scholar