S-Glutathionylation Impairs Signal Transducer and Activator of Transcription 3 Activation and Signaling
Open Access
- 6 November 2008
- journal article
- other
- Published by The Endocrine Society in Endocrinology
- Vol. 150 (3), 1122-1131
- https://doi.org/10.1210/en.2008-1241
Abstract
S-glutathionylation is a physiological, reversible protein modification of cysteine residues with glutathione in response to mild oxidative stress. Because the key cell growth regulator signal transducer and activator of transcription (STAT) 3 is particularly susceptible to redox regulation, we hypothesized that oxidative modification of cysteine residues of STAT3 by S-glutathionylation may occur. Herein, we show that the cysteine residues of STAT3 are modified by a thiol-alkylating agent and are the targets of S-glutathionylation. STAT3 protein thiol reactivity was reversibly attenuated with concomitant increase in the S-glutathionylation of STAT3 upon treatment of human HepG2 hepatoma cells with pyrrolidine dithiocarbamate, glutathione disulfide, or diamide. Under these conditions there was a marked reduction in IL-6-dependent STAT3 signaling, including decreased STAT3 tyrosine phosphorylation, loss in nuclear accumulation of STAT3, and impaired expression of target genes, such as fibrinogen-γ. In a cell-free system, diamide induced glutathionylation of STAT3, which was decreased upon addition of glutaredoxin (GRX)-1, a deglutathionylation enzyme, or the reducing agent, dithiothreitol. Glutathionylated STAT3 was a poor Janus protein tyrosine kinase 2 substrate in vitro, and it exhibited low DNA-binding activity. Cellular GRX-1 activity was inhibited by diamide and pyrrolidine dithiocarbamate treatment; however, ectopic expression of GRX-1 was accompanied by a modest increase in phosphorylation, nuclear translocation, and DNA-binding ability of STAT3 in response to IL-6. These results are the first to show S-glutathionylation of STAT3, a modification that may exert regulatory function in STAT3 signaling. Reversible S-glutathionylation of STAT3 regulates its activity as transcription factor.Keywords
This publication has 60 references indexed in Scilit:
- Determination of free and protein-bound glutathione in HepG2 cells using capillary electrophoresis with laser-induced fluorescence detectionJournal of Chromatography A, 2008
- NOV-002, a Glutathione Disulfide Mimetic, as a Modulator of Cellular Redox BalanceCancer Research, 2008
- Crif1 is a novel transcriptional coactivator of STAT3The EMBO Journal, 2008
- Targeted disruption of the glutaredoxin 1 gene does not sensitize adult mice to tissue injury induced by ischemia/reperfusion and hyperoxiaFree Radical Biology & Medicine, 2007
- Mechanisms of reversible protein glutathionylation in redox signaling and oxidative stressCurrent Opinion in Pharmacology, 2007
- Human p53 Is Inhibited by Glutathionylation of Cysteines Present in the Proximal DNA-Binding Domain during Oxidative Stress,Biochemistry, 2007
- Selective chemical probe inhibitor of Stat3, identified through structure-based virtual screening, induces antitumor activityProceedings of the National Academy of Sciences of the United States of America, 2007
- Glutathionylation of beta-actin via a cysteinyl sulfenic acid intermediaryBMC Biochemistry, 2007
- Dynamic redox control of NF-κB through glutaredoxin-regulated S-glutathionylation of inhibitory κB kinase βProceedings of the National Academy of Sciences of the United States of America, 2006
- The 20S proteasome processes NF-κB1 p105 into p50 in a translation-independent mannerThe EMBO Journal, 2006