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Activation of Tyrosine Hydroxylase in PC12 Cells by the Cyclic GMP and Cyclic AMP Second Messenger Systems
Author(s) -
Roskoski Robert,
Roskoski Laura M.
Publication year - 1987
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1987.tb13153.x
Subject(s) - tyrosine hydroxylase , adenylate kinase , tyrosine 3 monooxygenase , activator (genetics) , forskolin , second messenger system , chemistry , tyrosine , cyclase , tyrosine kinase , protein kinase a , protein tyrosine phosphatase , sodium nitroprusside , medicine , endocrinology , biochemistry , biology , kinase , signal transduction , enzyme , in vitro , receptor , nitric oxide
Tyrosine hydroxylase, the rate‐limiting enzyme in catecholamine biosynthesis, is subject to regulation by a variety of agents. Previous workers have found that cyclic AMP‐dependent protein kinase and calcium‐stimulated protein kinases activate tyrosine hydroxylase. We wanted to determine whether cyclic GMP might also be involved in the regulation of tyrosine hydroxylase activity. We found that treatment of rat PC12 cells with sodium nitroprusside (an activator of guanylate cyclase), 8‐bromocyclic GMP, forskolin (an activator of adenylate cyclase), and 8‐bromocyclic AMP all produced an increase in tyrosine hydroxylase activity measured in vitro or an increased conversion of [ 14 C]tyrosine to labeled catecholamine in situ. Sodium nitroprusside also increased the relative synthesis of cyclic GMP in these cells. In the presence of MgATP, both cyclic GMP and cyclic AMP increased tyrosine hydroxylase activity in PC12 cell extracts. The heat‐stable cyclic AMP‐dependent protein kinase inhibitor failed to attenuate the activation produced in the presence of cyclic GMP. It eliminated the activation produced in the presence of cyclic AMP. Sodium nitroprusside also increased tyrosine hydroxylase activity in vitro in rat corpus striatal synaptosomes and bovine adrenal chromaffin cells. In all cases, the cyclic AMP‐dependent activation of tyrosine hydroxylase was greater than that of the cyclic GMP‐dependent second messenger system. These results indicate that both cyclic GMP and cyclic AMP and their cognate protein kinases activate tyrosine hydroxylase activity in PC12 cells.