γ-Glutamylcysteine synthetase from erythrocytes

Seelig, G F; Meister, Alton

doi:10.1016/0003-2697(84)90079-4

Cited by 55 publications

(42 citation statements)

References 15 publications

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“…The activity of glutamylcysteine ligase (GCL) in the pancreas was assessed by monitoring the oxidation of NADH at 340 nm in reaction mixtures containing 140 mM Tris-HCl (pH 8.2), 10 units/mL lactate dehydrogenase, 10 units/mL pyruvate kinase, 75 mM KCl, 25 mM MgCl 2 , 10 mM ATP, 5 mM L-glutamate, 10 mM α-amino-L-butyrate, 0.2 mM NADH, 0.2 mM EDTA, and 1 mM phosphoenolpyruvate (18). Glutathione peroxidase (GPx) activity was measured by monitoring NADPH oxidation at 340 nm in reaction mixtures containing 50 mM potassium phosphate (pH 7.4), 1 mM EDTA, 1 mM NaN 3 , 0.2 mM NADPH, 1 unit/mL glutathione reductase (GRd), 1 mM GSH, and 0.25 mM H 2 O 2 .…”

Section: Enzyme Assaysmentioning

confidence: 99%

Prevention of Alloxan-induced Diabetes by Se-Methylselenocysteine Pretreatment in Rats: The Effect on Antioxidant System in Pancreas

Nam¹,

Park²,

Choi

2009

JFN

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In this study, we assessed the effects of Se-methylselenocysteine (MSC) pretreatment on the antioxidant system in the pancreas and the development of alloxan-induced diabetes in rats. The rats were treated with MSC at a dose of 0.75 mg/rat/day for 2 weeks. The MSC-treated rats evidenced significantly increased glutathione content, GSH/GSSG ratio, and glutathione peroxidase (GPx) and glutathione reductase (GRd) activities in the pancreas. Diabetes was induced via alloxan injection. The alloxan-diabetic rats evidenced significantly reduced glutathione content and glucose 6-phosphate dehydrogenase (G6PD) activity and increased catalase activity in the pancreas, when measured 3 days after the alloxan injection. 2-week MSC pretreatment was shown to prevent the alloxan-induced hyperglycemia as well as changes in glutathione content, G6PD activity, and catalase activity. The results of this study indicate that the prevention of alloxan-diabetes by MSC pretreatment is associated with its effects on antioxidants in the pancreas, namely, the increase in cellular content and the reduction of glutathione by the facilitation of glutathione recycling induced via increased GPx, GRd, and G6PD activities.

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Section: Enzyme Assaysmentioning

confidence: 99%

Prevention of Alloxan-induced Diabetes by Se-Methylselenocysteine Pretreatment in Rats: The Effect on Antioxidant System in Pancreas

Nam¹,

Park²,

Choi

2009

JFN

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“…MTT assay (mitochondrial activity) showed that g-GCS-transfected cells are completely protected from the cytotoxic e ects of TNF ( Figure 7a, upper panel). One hallmark of apoptosis is the activation of caspase-3 activity, which leads to cleavage of PARP substrate from 116 kDa to 85 kDa (Seelig et al, 1984). TNF induced cleavage of PARP within 1 h in control cells (Figure 7, lower panel) whereas g-GCS-transfected cells were resistant to PARP cleavage even with 1000 pM TNF treatment.…”

Section: G-gcs Blocks Tnf-mediated Cytotoxicity and Activation Of Casmentioning

confidence: 99%

“…g-GCS consists of a light chain and a heavy chain. The catalytic activity resides in the heavy chain whereas the light chain has regulatory function (Gipp et al, 1992;Huang et al, 1993a,b;Seelig et al, 1984). The promoter region of the gene for heavy chain has been shown to possess binding sites for AP-1, AP-2, antioxidant response elements (ARE), metal response regulatory elements (MRE), and NF-kB.…”

Section: Introductionmentioning

confidence: 99%

Overexpression of γ-glutamylcysteine synthetase suppresses tumor necrosis factor-induced apoptosis and activation of nuclear transcription factor-kappa B and activator protein-1

1999

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Tumor necrosis factor (TNF) is a highly pleiotropic cytokine whose activity is at least partially regulated by the redox status of the cell. The cellular redox status is controlled primarily by glutathione, a major cellular antioxidant, whose synthesis is regulated by the ratelimiting enzyme g-glutamylcysteine synthetase (g-GCS).In the present report we investigated the e ect of g-GCS overexpression on the TNF-induced activation of nuclear transcription factors NF-kB and AP-1, stress-activated protein kinase/c-Jun amino-terminal kinase (JNK) and apoptosis. Transfection of cells with g-GCS cDNA blocked TNF-induced NF-kB activation, cytoplasmic IkBa degradation, nuclear translocation of p65, and NF-kB-dependent gene transcription. g-GCS overexpression also completely suppressed NF-kB activation induced by phorbol ester and okadaic acid, whereas that induced by H 2 O 2 , ceramide, and lipopolysaccharide was minimally a ected. g-GCS also abolished the activation of AP-1 induced by TNF and inhibited TNF-induced activation of JNK and mitogen-activated protein kinase kinase. TNF-mediated cytotoxicity and activation of caspase-3 were both abrogated in g-GCS-overexpressing cells. Overall, our results indicate that most of the pleiotropic actions of TNF are regulated by the glutathione-controlled redox status of the cell.

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“…For the GSSG assay, acid extract was treated with 2-vinylpyridine and triethanolamine as previously described [16], and the treated supernatant was used in the assay [15]. 7GCS activity was measured by the method described by Seelig and Meister [17].…”

Section: Gsh Gssg and ?Gcs Activity Assaysmentioning

confidence: 99%

“…Glutathione is synthesised from its constituent amino acids ~n two sequential, ATP-dependent enzymatic reactions cataysed by y-glutamylcysteine synthetase (~3CS) and GSH ,ynthase [7]. ~GCS is the rate-limiting step in de novo GSH ynthesis and is inhibited by a feedback mechanism.…”

Section: ! Introductionmentioning

confidence: 99%

Induction of γ‐glutamylcysteine synthetase by cigarette smoke is associated with AP‐1 in human alveolar epithelial cells

Rahman¹,

Smith

Lawson³

et al. 1996

FEBS Letters

152

117

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Increased levels of glutathione (GSH) occur in the epithelial lining fluid (ELF) of chronic cigarette smokers. Therefore we investigated the effect of cigarette smoke condensate solution (CSC) on GSH synthesis and the regulation of T-glutamylcysteine synthetase (~CS) in human type II alveolar epithelial cells (A549). CSC exposure increased GSH levels, TGCS activity and ~CS heavy subunit (HS) mRNA, as well as increasing DNA binding of the activator protein-1 (AP-1) and the human antioxidant response element (hARE). Transfection of deletion constructs of the ~GCS-HS promoter in a chloramphenicol acetyl transferase (CAT) reporter system revealed that an hARE, present within promoter, is not required tot the CSC mediated induction. We conclude that CSC induction of ~GCS-HS expression is associated with AP-1/AP-I-like responsive elements.

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γ-Glutamylcysteine synthetase from erythrocytes

Cited by 55 publications

References 15 publications

Prevention of Alloxan-induced Diabetes by Se-Methylselenocysteine Pretreatment in Rats: The Effect on Antioxidant System in Pancreas

Prevention of Alloxan-induced Diabetes by Se-Methylselenocysteine Pretreatment in Rats: The Effect on Antioxidant System in Pancreas

Overexpression of γ-glutamylcysteine synthetase suppresses tumor necrosis factor-induced apoptosis and activation of nuclear transcription factor-kappa B and activator protein-1

Induction of γ‐glutamylcysteine synthetase by cigarette smoke is associated with AP‐1 in human alveolar epithelial cells

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