Glutaredoxin protects cerebellar granule neurons from dopamine-induced apoptosis by activating NF-kappa B via Ref-1.
The neurotransmitter dopamine (DA) induces apoptosis via its oxidative metabolites. This study shows that glutaredoxin 2 (Grx2) from Escherichia coli and human glutaredoxin could protect cerebellar granule neurons from DA-induced apoptosis. E. coli Grx2, which catalyzes glutathione-disulfide oxidoreduction via its -Cys-Pro-Tyr-Cys- active site, penetrates into cerebellar granule neurons and exerts its activity via NF-kappaB activation. Analysis of single and double cysteine to serine substitutions in the active site of Grx2 showed that both cysteine residues were essential for activity. Although DA significantly reduced NF-kappaB binding activity, Grx2 could stimulate the binding of NF-kappaB to DNA by: (i) translocating NF-kappaB from the cytoplasm to the nucleus after promoting the phosphorylation and degradation of I-kappaBalpha, and (ii) activating the binding of pre existing nuclear NF-kappaB. The DNA binding activity of NF-kappaB itself was essential for neuronal survival. Overexpression of I-kappaB dominant negative gene (I-kappaB-DeltaN) in granule neurons significantly reduced their viability, irrespective of the presence of Grx2. Ref-1 expression was down-regulated by DA but up-regulated by Grx2, while treatment of neurons with Ref-1 antisense oligonucleotide reduced the ability of Grx2 to activate NF-kappaB binding activity. These results show that Grx2 exerts its anti apoptotic activity through the activation of Ref-1, which then activates NF-kappaB.
Daily
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Department of Neurobiochemistry, George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv 69978 Israel.
Vlamis-Gardikas
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Offen
D
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Mittelman
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Melamed
E
E
Holmgren
A
A
Barzilai
A
A
D019943:Amino Acid Substitution; D000818:Animals; D000831:Animals, Newborn; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology*; D001426:Bacterial Proteins / Q000494:pharmacology; D019757:Carbon-Oxygen Lyases / Q000378:metabolism*; D002478:Cells, Cultured; D002531:Cerebellum / Q000166:cytology*; D004260:DNA Repair; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase; D004298:Dopamine / Q000494:pharmacology*; D004706:Endodeoxyribonucleases / Q000378:metabolism; D004926:Escherichia coli; D054477:Glutaredoxins; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D016297:Mutagenesis, Site-Directed; D016328:NF-kappa B / Q000378:metabolism*; D009474:Neurons / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D010088:Oxidoreductases; D021381:Protein Transport / Q000187:drug effects; D011506:Proteins / Q000737:chemistry / Q000235:genetics / Q000494:pharmacology*; D011994:Recombinant Proteins / Q000494:pharmacology
D001426:Bacterial Proteins; C516008:GLRX2 protein, human; C516009:Glrx2 protein, mouse; D054477:Glutaredoxins; D016328:NF-kappa B; D011506:Proteins; D011994:Recombinant Proteins; D010088:Oxidoreductases; D004706:Endodeoxyribonucleases; D019757:Carbon-Oxygen Lyases; C085108:APEX1 protein, human; C486216:Apex1 protein, mouse; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase; D004298:Dopamine