A rapid and sensitive assay for tyrosine-3-monooxygenase based upon the release of 3H2O and adsorption of [3H]-tyrosine by charcoal

Reinhard, John F.; Smith, Gary K.; Nichol, Charles A.

doi:10.1016/0024-3205(86)90395-4

Cited by 204 publications

(105 citation statements)

References 13 publications

Supporting

Mentioning

104

Contrasting

Order By: Relevance

“…The TH activity was measured essentially as described by Reinhard et al (1986). Briefly, the TH preparation was incubated for 5 min at 30°C in an incubation mixture consisting of 100 mM Na-HEPES (pH 7.0), 50 lg/mL catalase, 25 lM [ 3 H]-tyrosine and 100 lM FeSO 4 (total volume 100 lL).…”

Section: Th Activitymentioning

confidence: 99%

Regulation of tyrosine hydroxylase by stress‐activated protein kinases

Toska

Kleppe

Armstrong

et al. 2002

Journal of Neurochemistry

110

View full text Add to dashboard Cite

Recombinant human tyrosine hydroxylase (hTH1) was found to be phosphorylated by mitogen and stress-activated protein kinase 1 (MSK1) at Ser40 and by p38 regulated/activated kinase (PRAK) on Ser19. Phosphorylation by MSK1 induced an increase in V max and a decrease in K m for 6-(R)-5,6,7,8-tetrahydrobiopterin (BH 4 ), while these kinetic parameters were unaffected as a result of phosphorylation by PRAK. Phosphorylation of both Ser40 and Ser19 induced a high-affinity binding of 14-3-3 proteins, but only the interaction of 14-3-3 with Ser19 increased the hTH1 activity. The 14-3-3 proteins also inhibited the rate of dephosphorylation of Ser19 and Ser40 by 82 and 36%, respectively. The phosphorylation of hTH1 on Ser19 caused a threefold increase in the rate of phosphorylation of Ser40. These studies provide new insights into the possible roles of stress-activated protein kinases in the regulation of catecholamine biosynthesis.

show abstract

Section: Th Activitymentioning

confidence: 99%

Regulation of tyrosine hydroxylase by stress‐activated protein kinases

Toska

Kleppe

Armstrong

et al. 2002

Journal of Neurochemistry

110

View full text Add to dashboard Cite

show abstract

“…TH activity from striatal and nigral tissues was measured according to a modification of a previously published procedure (Reinhard et al, 1986). In brief, tissue of interest was …”

Section: In Vitro Th Activitymentioning

confidence: 99%

Lipopolysaccharide Intranigral Injection Induces Inflammatory Reaction and Damage in Nigrostriatal Dopaminergic System

Castaño

Herrera

Cano

et al. 1998

Journal of Neurochemistry

367

270

View full text Add to dashboard Cite

Abstract:The pathogenesis of Parkinson's disease is still poorly understood. To address the hypothesis that immunemediated events, such as microglial activation, may be involved in the dopaminergic neurodegeneration, we have studied the effect that intranigral injection of the immunostimulant lipopolysaccharide has on monoaminergic neurotransmitters in rats. Activation of microglial cells, visualized by immunohistochemistry with a specific monoclonal antibody, was already obvious 2 days after injection. In relation to the biochemical parameters studied, we found a significant decrease of dopamine levels in both the substantia nigra and striatum up to at least 21 days after intranigral injection of lipopolysaccharide. This result was supported by the decrease in tyrosine hydroxylase activity and the loss of tyrosine hydroxylase-positive neuronal bodies, shown by immunohistochemistry. These alterations of the dopaminergic system did not reverse during the interval studied (21 days); conversely, the serotoninergic system suffered only transient damage. In addition, we found that the neurotoxic effect of lipopolysaccharide was not mediated by nitric oxide. Based on our results we suggest that the nigrostriatal dopaminergic system is susceptible to damage by inf lammatory events and that these may be implicated in neurodegeneration processes such as Parkinson's disease.

show abstract

“…PP2A was assayed with phosphorylase as substrate [27] and one unit of activity was that amount which catalysed the release of 1 pmol phosphate from this substrate/min. TH was assayed [38] using an incubation mixture containing 100 mM Hepes, pH 7.0, 10 pM (6R)-tetrahydrobiopterin, 0.5 mg/ml catalase, 1 .O mg/ ml ovalbumin and the concentrations of [3,5-3H]tyrosine and FeSO, specified under Results.…”

Section: Enzyme Assaysmentioning

confidence: 99%

Phosphorylation and activation of human tyrosine hydroxylase in vitro by mitogen‐activated protein (MAP) kinase and MAP‐kinase‐activated kinases 1 and 2

Sutherland

Alterio

Campbell

et al. 1993

European Journal of Biochemistry

176

205

View full text Add to dashboard Cite

Mitogen-activated protein-kinase (MAP) kinase-activated protein kinases 3 and 2 (MAPKAP kinase-1, MAPKAP kinase-2), were found to phosphorylate bacterially expressed human tyrosine hydroxylase in v i m at comparable rates to other proteins thought to be physiological substrates of these protein kinases. The phosphorylation of all four alternatively spliced forms of human tyrosine hydroxylase by MAPKAP kinases-1 and -2 reached plateau values at 1 moVmol subunit and 2 mol/ mol subunit, respectively; the sites of phosphorylation were identified as Ser40 (MAPKAP kinase-3 ) and Serl9 and Ser40 (MAPKAP kinase-2). In contrast to calmodulin-dependent protein kinase-11, which phosphorylates Serl9 faster than Ser40, MAPKAP kinase-2 phosphorylated Ser4O about twice as fast as Serl9. The maximal activation of tyrosine hydroxylase by MAPKAP kinase-1 or-2 was about 3-fold, and activation by MAPKAP kinases-1 and -2 or calmodulin-dependent protein kinase-I1 correlated with the extent of phosphorylation of Ser40. The four alternatively spliced forms of human tyrosine hydroxylase were phosphorylated at Ser31 by MAP kinase, but at markedly different rates (3=4 > 1 + 2). Forms 3 and 4 were phosphorylated rapidly and stoichiometrically by MAP kinase doubling the activity, while phosphorylation of form 1 by MAP kinase to 0.4 mol/ mol subunit increased activity by 40%. The effect on activity of phosphorylating both Ser31 and Ser40 was not additive. The possible roles of MAPKAP kinase-1, MAPKAP kinase-2 and MAP kinase in the regulation of tyrosine hydroxylase in vivo are discussed.Tyrosine hydroxylase (TH) is a homotetrameric enzyme which catalyses the rate-limiting step in catecholamine synthesis. It is found predominantly in the adrenal medulla and central and sympathetic nervous systems, where its activity is increased by agonists that stimulate catecholamine secretion, providing a mechanism for replenishing the stores of catecholamine hormones and neurotransmitters that have been lost via secretion.

show abstract

A rapid and sensitive assay for tyrosine-3-monooxygenase based upon the release of 3H2O and adsorption of [3H]-tyrosine by charcoal

Cited by 204 publications

References 13 publications

Regulation of tyrosine hydroxylase by stress‐activated protein kinases

Regulation of tyrosine hydroxylase by stress‐activated protein kinases

Lipopolysaccharide Intranigral Injection Induces Inflammatory Reaction and Damage in Nigrostriatal Dopaminergic System

Phosphorylation and activation of human tyrosine hydroxylase in vitro by mitogen‐activated protein (MAP) kinase and MAP‐kinase‐activated kinases 1 and 2

Contact Info

Product

Resources

About