Tyrosine Hydroxylase Phosphorylation in Digitonin‐Permeabilized Bovine Adrenal Chromaffin Cells: The Effect of Protein Kinase and Phosphatase Inhibitors on Ser<sup>19</sup> and Ser<sup>40</sup> Phosphorylation

Gonçalves, Carlos‐Alberto; Hall, Amanda L.; Sim, Alistair T.R.; Bunn, Stephen J.; Marley, Philip D.; Cheah, Tat Beng; Dunkley, Peter R.

doi:10.1046/j.1471-4159.1997.69062387.x

Cited by 16 publications

(19 citation statements)

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“…1997). However, we also found that the rate of Ser40 dephosphorylation by PP2A was substantially decreased if Ser19 was also phosphorylated (Gonçalves et al . 1997).…”

Section: Discussionmentioning

confidence: 67%

“…2001) it is possible that the presence of phosphate at one site could also modulate the dephosphorylation of TH at another site. We showed that TH could be dephosphorylated at Ser40 by PP2A in permeabilized BACC (Gonçalves et al . 1997).…”

Section: Discussionmentioning

confidence: 99%

“…1997). There are many possible explanations for this result, but one explanation suggested at the time was that there is ‘an interaction between the phosphorylation and dephosphorylation of Ser19 and Ser40’ (Gonçalves et al . 1997).…”

Section: Discussionmentioning

confidence: 99%

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Role of protein phosphatase 2C from bovine adrenal chromaffin cells in the dephosphorylation of phospho‐serine 40 tyrosine hydroxylase

Bevilaqua

Cammarota

Dickson

et al. 2003

Journal of Neurochemistry

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Tyrosine hydroxylase (TH) is the rate-limiting enzyme in the synthesis of catecholamines. It is dephosphorylated by protein phosphatase (PP) 2A and PP2C. In this study we used a fixed amount of bacterially expressed rat TH (5 lM), phosphorylated only at serine 40 (pSer40TH), to determine the PP activities against this site that are present in extracts from the bovine adrenal cortex, adrenal medulla, adrenal chromaffin cells and rat striatum. We found that PP2C was the main TH phosphatase activity in extracts from the adrenal medulla and adrenal chromaffin cells. In adrenal cortex extracts PP2C and PP2A activities toward pSer40TH did not differ significantly.PP2A was the main TH phosphatase activity in extracts from rat striatum. Kinetic studies with extracts from adrenal chromaffin cells showed that when higher concentrations of pSer40TH (> 5 lM) were used the activity of PP2C increased more than the activity of PP2A. PP2C was maximally activated by 1. Tyrosine hydroxylase (TH; EC 1.14.16.2) catalyzes the initial and rate-limiting step in catecholamine biosynthesis (Levitt et al. 1965;Fitzpatrick 1999). The activity of TH is highly regulated by end-product feedback inhibition, protein phosphorylation and gene expression (Kumer and Vrana 1996). Tyrosine hydroxylase can be phosphorylated at four serine residues that are all present in the N-terminus of the protein: Ser8, Ser19, Ser31 and Ser40 (Campbell et al. 1986;Haycock 1990Haycock , 1993. Modulation of the phosphorylation of Ser8 only occurs in dividing cells and is not involved in the regulation of TH activity (Hall et al. 1991). The other phosphorylation sites regulate TH activity and are involved with the control of catecholamine synthesis. Phosphorylation of Ser40 promotes a major increase (up to 10-fold) in the activity of TH by abolishing the feedback inhibition of the catecholamines (Joh et al. 1978;Waymire et al. 1991;Sutherland et al. 1993). Phosphorylation of Ser31 (see Haycock 1990) promotes only a modest increase (twofold) in TH activity . Phosphorylation of Ser19 produces no increase in TH activity (Haycock et al. 1998) unless 14-3-3 is present (Ichimura et al. 1987;Toska et al. 2002). Interaction of TH and 14-3-3 occurs in intact cells (Itagaki et al. 1999). However, we showed that phosphorylation of Ser19 increases the rate of phosphorylation of Ser40 ) and this was recently confirmed using an entirely different approach (Toska et al. 2002). This suggests that Ser19 phosphorylation is likely to have a role in TH activation, even though it seems to be an indirect role

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“…1997). However, we also found that the rate of Ser40 dephosphorylation by PP2A was substantially decreased if Ser19 was also phosphorylated (Gonçalves et al . 1997).…”

Section: Discussionmentioning

confidence: 67%

Section: Discussionmentioning

confidence: 99%

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Role of protein phosphatase 2C from bovine adrenal chromaffin cells in the dephosphorylation of phospho‐serine 40 tyrosine hydroxylase

Bevilaqua

Cammarota

Dickson

et al. 2003

Journal of Neurochemistry

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“…1998). Increasing the concentration of cAMP increased the phosphorylation of TH only at Ser40 in permeabilized bovine adrenal chromaffin cells (Goncalves et al . 1997).…”

Section: Protein Kinases and Protein Phosphatases That Act On Tyrosinmentioning

confidence: 99%

“…Haycock (1993b) suggested that the Ser40 response to depolarizing agents may be due to activation of other pathways leading to Ser40 phosphorylation by kinases other than CaMPKII. In the permeabilized bovine adrenal chromaffin cells CaMPKII did not phosphorylate TH at Ser40 when calcium levels were increased even though Ser19 was able to be phosphorylated (Goncalves et al . 1997).…”

Section: Protein Kinases and Protein Phosphatases That Act On Tyrosinmentioning

confidence: 99%

Tyrosine hydroxylase phosphorylation: regulation and consequences

Dunkley¹,

Bobrovskaya²,

Graham

et al. 2004

Journal of Neurochemistry

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550

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The rate-limiting enzyme in catecholamine synthesis is tyrosine hydroxylase. It is phosphorylated at serine (Ser) residues Ser8, Ser19, Ser31 and Ser40 in vitro, in situ and in vivo. A range of protein kinases and protein phosphatases are able to phosphorylate or dephosphorylate these sites in vitro. Some of these enzymes are able to regulate tyrosine hydroxylase phosphorylation in situ and in vivo but the identity of the kinases and phosphatases is incomplete, especially for physiologically relevant stimuli. The stoichiometry of tyrosine hydroxylase phosphorylation in situ and in vivo is low. The phosphorylation of tyrosine hydroxylase at Ser40 increases the enzyme's activity in vitro, in situ and in vivo. Phosphorylation at Ser31 also increases the activity but to a much lesser extent than for Ser40 phosphorylation. The phosphorylation of tyrosine hydroxylase at Ser19 or Ser8 has no direct effect on tyrosine hydroxylase activity. Hierarchical phosphorylation of tyrosine hydroxylase occurs both in vitro and in situ, whereby the phosphorylation at Ser19 increases the rate of Ser40 phosphorylation leading to an increase in enzyme activity. Hierarchical phosphorylation depends on the state of the substrate providing a novel form of control of tyrosine hydroxylase activation. Keywords: activity, catecholamine synthesis, phosphorylation, protein kinases, protein phosphatases, tyrosine hydroxylase. The catecholamines (CAs) dopamine (DA), noradrenaline and adrenaline are physiologically important neurotransmitters and hormones. It has been established that when the CAs are secreted there is generally no decrease in their levels within tissues (Zigmond et al. 1989). This is because there is a concomitant increase in the rate of CA synthesis that is closely coupled to secretion. Tyrosine hydroxylase (TH; tyrosine 3-monooxygenase; E.C. 1.14.16.2) is the first and rate-limiting enzyme in CA synthesis and it catalyses the hydroxylation of L-tyrosine to DOPA. The activity of TH can be modulated by two mechanisms: medium-to long-term regulation of gene expression (enzyme stability, transcriptional regulation, RNA stability, alternative RNA splicing and translational regulation) and short-term regulation of enzyme activity (feedback inhibition, allosteric regulation and phosphorylation) (Kumer and Vrana 1996). TH activation by phosphorylation is the primary mechanism responsible for the maintenance of CA levels in tissues after CA secretion. TH can be phosphorylated at serine residues (Ser) 8, 19, 31 and 40 by a variety of protein kinases. The regulation of the phosphorylation of these sites and the consequences in terms of TH activity in vitro have been extensively investigated. In situ and in vivo it is less clear which protein kinase(s), and/or phosphatase(s), modulates TH phosphorylation and which mechanism(s) leads to the activation of TH and CA synthesis. The major focus of this review is therefore the regulation and consequences of the (Kaufman 1995;Nagatsu 1995;Kappock and Caradonna 1996;Kumer and Vrana 1996;...

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Complex molecular regulation of tyrosine hydroxylase

Roskoski²,

et al. 2014

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Tyrosine hydroxylase, the rate-limiting enzyme in catecholamine biosynthesis, is strictly controlled by several interrelated regulatory mechanisms. Enzyme synthesis is controlled by epigenetic factors, transcription factors, and mRNA levels. Enzyme activity is regulated by end-product feedback inhibition. Phosphorylation of the enzyme is catalyzed by several protein kinases and dephosphorylation is mediated by two protein phosphatases that establish a sensitive process for regulating enzyme activity on a minute-to-minute basis. Interactions between tyrosine hydroxylase and other proteins introduce additional layers to the already tightly controlled production of catecholamines. Tyrosine hydroxylase degradation by the ubiquitin-proteasome coupled pathway represents yet another mechanism of regulation. Here, we revisit the myriad mechanisms that regulate tyrosine hydroxylase expression and activity and highlight their physiological importance in the control of catecholamine biosynthesis.

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Tyrosine Hydroxylase Phosphorylation in Digitonin‐Permeabilized Bovine Adrenal Chromaffin Cells: The Effect of Protein Kinase and Phosphatase Inhibitors on Ser¹⁹ and Ser⁴⁰ Phosphorylation

Cited by 16 publications

References 28 publications

Role of protein phosphatase 2C from bovine adrenal chromaffin cells in the dephosphorylation of phospho‐serine 40 tyrosine hydroxylase

Role of protein phosphatase 2C from bovine adrenal chromaffin cells in the dephosphorylation of phospho‐serine 40 tyrosine hydroxylase

Tyrosine hydroxylase phosphorylation: regulation and consequences

Complex molecular regulation of tyrosine hydroxylase

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Tyrosine Hydroxylase Phosphorylation in Digitonin‐Permeabilized Bovine Adrenal Chromaffin Cells: The Effect of Protein Kinase and Phosphatase Inhibitors on Ser19 and Ser40 Phosphorylation

Cited by 16 publications

References 28 publications

Role of protein phosphatase 2C from bovine adrenal chromaffin cells in the dephosphorylation of phospho‐serine 40 tyrosine hydroxylase

Role of protein phosphatase 2C from bovine adrenal chromaffin cells in the dephosphorylation of phospho‐serine 40 tyrosine hydroxylase

Tyrosine hydroxylase phosphorylation: regulation and consequences

Complex molecular regulation of tyrosine hydroxylase

Contact Info

Product

Resources

About

Tyrosine Hydroxylase Phosphorylation in Digitonin‐Permeabilized Bovine Adrenal Chromaffin Cells: The Effect of Protein Kinase and Phosphatase Inhibitors on Ser¹⁹ and Ser⁴⁰ Phosphorylation