Activation and nuclear translocation of protein kinase during transsynaptic induction of tyrosine 3-monooxygenase.

Abstract

The tyrosine-3-monooxygenase activity [Ltyrosine, tetrahydropteridine:oxygen oxidoreductase (3-hydroxylating); EC 1.14.16.2] of rat adrenal medulla is induced 20-24 hr after the injection of reserpine (16 tmol/kg intraperitoneally). This and other inducing stimuli increase the 3':5'-cyclic AMP (cAMP) content in the medulla for longer than 60 min and activate the cAMP-dependent protein kinase (ATP:protein phosphotransferase; EC 2.7.1.37) for several hours. Corticotropin (ACTH), dopamine, and propranolol do not induce the monooxygenase, but elicit an increase in the cAMP content of the medulla which fails to activate protein kinase and lasts less than 1 hr. A high-and low-molecular-weight protein kinase are separated by gel filtration from the 20,000 X g pellet extract of adrenal medulla homogenate. The activity of the low-molecular-weight enzyme 'is expressed as its ability to phosphorylate histone. The protein kinase activity of the pellet is increased between 3 and 17 hr after reserpine injection. Our evidence indicates that this increase is due to a translocation from cytosol to subcellular structures of a kinase that utilizes lysine-rich histone as phosphate acceptor. The protein kinase activity that is extracted from a purified nuclear fraction prepared from the adrenal medulla of rats injected 7 hr previously with reserpine is greater than that extracted from medulla of saline-treated rats.In neural tissue, intracellular communication is mediated by hormones and neurotransmitters. The latter not only regulate the polarity of the neuronal membranes, but they also influence the expression of the metabolic code in postsynaptic cells (1). In the rat adrenal medulla, the biosynthesis of tyrosine-3-monooxygenase [EC 1.14.16.2; L-tyrosine, tetrahydropteridine:oxygen oxidoreductase (3-hydroxylating)] is regulated transsynaptically (2)(3)(4). In chromaffin cells that are presistently (1 hr or more) stimulated by the acetylcholine released by nerve impulses from presynaptic terminals, the monooxygenase is induced 18-24 hr later (2-7). We have adopted this transsynaptic induction of tyrosine monooxygenase as a model to study the molecular mechanisms whereby the release of acetylcholine regulates the expression of the metabolic code in postsynaptic cells. The first event in this induction is an increase in the 3':5'-cyclic AMP (cAMP) content, presumably by the activation of adenylate cyclase (4,7,8). When the synthesis rate of cAMP is enhanced, the number of cytosol protein kinase (EC 2.7.1.37; ATP:protein phosphotransferase) molecules that are activated is also increased (3). In the present paper, we report that in the adrenal medulla the transsynaptic regulation of the expression of the metabolic code is critically dependent on the translocation from cytosol into the nucleus of a low-molecular-weight catalytic subunit of protein kinase. Moreover, we show that this translocation, which begins a few hours after the increase in the release of acetylcholine elicited by reserpine, Abbreviation: cAMP, 3':5'-cyclic...

Time‐dependent translocation of protein kinase in liver of glucagon‐treated rats

“…Thus, regulation of hepatic protein synthesis by glucagon [10] may well proceed via translocation of protein kinase. Comparable results were obtained with cAMP mediated stimulation of adrenal medulla [11], and of porcine ovaries [12].…”

Specific nuclear binding of adenosine 3',5'-monophosphate-binding protein complex with subsequent poly(A) RNA synthesis in embryonic chick cartilage.

“…The nuclear pellet was vortexed with 2 ml ice cold STKM, and centrifuged again. The nuclear pellet was solubilized with 10 ,ul 10% SDS and 10 ,lp of 0.1 mM dithiothreitol and heated at 900C for 10 min. Polyacrylamide gel electrophoresis and autoradiography were performed as described above.…”

“…8C). When cyclic AMP 10 ,uM was incubated with 1 The film was overexposed to the gel since fewer counts per min were placed in B than C. With overexposure many bands of radioactivity are seen in DEAE peak cytosol protein but the major bands are at 41,000, 51,000, and 55,000 dalton.…”

“…Jungman et al (8,9) have demonstrated that nuclear protein kinase II of porcine ovary, which is cyclic AMP dependent, is identical to the cytosol cyclic AMP-dependent protein kinase and postulated the translocation of cytosol protein kinase to the nucleus. Costa et al (10), using beef adrenal medulla, and Walsh et al (11,12), using rat liver cells, have reported the translocation of the catalytic subunit ofcytosol cyclic AMP protein kinase to the nucleus. Little is known of the nature of the proposed cyclic AMP receptor-genome interactions.…”

“…Klein-smith (16) reported that cyclic AMP enhanced RNA transcription even though it decreased phosphorylation of RNA polymerase and Varrone et al (19) demonstrated that cyclic AMP increases RNA synthesis in the absence of phosphorylation of nucleoproteins in a cell free system. In addition, many investigators have found that the net chromatin-bound histone kinase activity is cyclic AMP independent (9,10,20).…”