The Mechanism of Cysteine Oxygenation by Cysteine Dioxygenase Enzymes

2007 ◽  
Vol 129 (48) ◽  
pp. 14846-14847 ◽  
Author(s):  
Swathi Aluri ◽  
Sam P. de Visser
Keyword(s):  
Cysteine Dioxygenase ◽  
Dioxygenase Enzymes

Hepatic localisation of rat cysteine dioxygenase

1998 ◽  
Vol 29 (4) ◽  
pp. 595-602 ◽  
Author(s):  
Richard B. Parsons ◽  
David B. Ramsden ◽  
Rosemary H. Waring ◽  
Peter C. Barber ◽  
Adrian C. Williams
Keyword(s):  
Cysteine Dioxygenase

scholarly journals Mechanism of S-Oxygenation by a Cysteine Dioxygenase Model Complex

2011 ◽  
Vol 116 (1) ◽  
pp. 582-591 ◽  
Author(s):  
Devesh Kumar ◽  
G. Narahari Sastry ◽  
David P. Goldberg ◽  
Sam P. de Visser
Keyword(s):  
Cysteine Dioxygenase ◽  
Model Complex

Overexpression of cysteine dioxygenase reduces intracellular cysteine and glutathione pools in HepG2/C3A cells

2007 ◽  
Vol 293 (1) ◽  
pp. E62-E69 ◽  
Author(s):  
John E. Dominy ◽  
Jesse Hwang ◽  
Martha H. Stipanuk
Keyword(s):  
Steady State ◽  
Experimental Evidence ◽  
Cysteine Dioxygenase ◽  
Wild Type ◽  
Hepatic Expression ◽  
Direct Experimental Evidence ◽  
Homeostatic Response ◽  
Catabolic Enzyme ◽  
In Cells

Cysteine levels are carefully regulated in mammals to balance metabolic needs against the potential for cytotoxicity. It has been postulated that one of the major regulators of intracellular cysteine levels in mammals is cysteine dioxygenase (CDO). Hepatic expression of this catabolic enzyme increases dramatically in response to increased cysteine availability and may therefore be part of a homeostatic response to shunt excess toxic cysteine to more benign metabolites such as sulfate or taurine. Direct experimental evidence, however, is lacking to support the hypothesis that CDO is capable of altering steady-state intracellular cysteine levels. In this study, we expressed either the wild-type (WT) or a catalytically inactivated mutant (H86A) isoform of CDO in HepG2/C3A cells (which do not express endogenous CDO protein) and cultured them in different concentrations of extracellular cysteine. WT CDO, but not H86A CDO, was capable of reducing intracellular cysteine levels in cells incubated in physiologically relevant concentrations of cysteine. WT CDO also decreased the glutathione pool and potentiated the toxicity of CdCl2. These results demonstrate that CDO is capable of altering intracellular cysteine levels as well as glutathione levels.

Effects of nonsulfur and sulfur amino acids on the regulation of hepatic enzymes of cysteine metabolism

1999 ◽  
Vol 277 (1) ◽  
pp. E144-E153 ◽  
Author(s):  
Deborah L. Bella ◽  
Christine Hahn ◽  
Martha H. Stipanuk
Keyword(s):  
Amino Acids ◽  
Specific Activity ◽  
Mrna Level ◽  
Basal Diet ◽  
Cysteine Dioxygenase ◽  
Sulfur Amino Acids ◽  
Subunit Mrna ◽  
Cysteine Metabolism ◽  
Glutamylcysteine Synthetase

To determine the role of nonsulfur vs. sulfur amino acids in regulation of cysteine metabolism, rats were fed a basal diet or diets supplemented with a mixture of nonsulfur amino acids (AA), sulfur amino acids (SAA), or both for 3 wk. Hepatic cysteine-sulfinate decarboxylase (CSDC), cysteine dioxygenase (CDO), and γ-glutamylcysteine synthetase (GCS) activity, concentration, and mRNA abundance were measured. Supplementation with AA alone had no effect on any of these measures. Supplementation of the basal diet with SAA, with or without AA, resulted in a higher CDO concentration (32–45 times basal), a lower CSDC mRNA level (49–64% of basal), and a lower GCS-heavy subunit mRNA level (70–76%). The presence of excess SAA and AA together resulted in an additional type of regulation: a lower specific activity of all three enzymes was observed in rats fed diets with an excess of AA and SAA. Both SAA and AA played a role in regulation of these three enzymes of cysteine metabolism, but SAA had the dominant effects, and effects of AA were not observed in the absence of SAA.

scholarly journals Dietary cysteine and ubiquitination regulate cysteine dioxygenase levels

2006 ◽  
Vol 20 (5) ◽  
Author(s):  
John E Dominy ◽  
Lawrence L Hirschberger ◽  
Relicardo M Coloso ◽  
Martha H Stipanuk
Keyword(s):  
Cysteine Dioxygenase
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