Zinc ions prevent processing of caspase-3 during apoptosis induced by geranylgeraniol in HL-60 cells.
Geranylgeraniol (GGO) at 50 microM induces apoptosis in HL-60 cells. We examined the effects of Zn2+ ions on this process. Treatment of HL-60 cells with Zn2+ ions inhibited subsequent GGO-induced fragmentation of DNA. In a cell-free system that consisted of a specific substrate for caspase-3 and a lysate of HL-60 cells that had been treated with 50 microM GGO, Zn2+ ions at concentrations above 0.1 mM inhibited the activity of caspase-3. The effect of Zn2+ ions on the processing of caspase-3 during GGO-induced apoptosis was investigated by Western blotting, which revealed that an inactive 32-kDa precursor of caspase-3 was cleaved, in response to GGO, to yield an activated 17-kDa enzyme. Treatment of HL-60 cells with Zn2+ ions inhibited the cleavage of the precursor by a protease that was induced by treatment with GGO, and inhibition of this processing was well correlated with the inhibition by Zn2+ ions of caspase-3 activity in the cell-free system. In cell-extracted cytosols, Zn2+ ions inhibited the cleavage of the 32-kDa precursor by caspase-9 (Aapf-3) that was activated by addition of cytochrome c and dATP. These results indicate that inhibition of GGO-induced apoptosis in HL-60 cells by Zn2+ ions might be due to inhibition by Zn2+ ions of the processing of a precursor to caspase-3.
Laboratory of Biological Chemistry, School of Pharmaceutical Sciences, Showa University, Shinagawa-ku, Tokyo, 142-8555, Japan. aiu@pharm.showa-u.ac.jp
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Aiuchi
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Mihara
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Nakaya
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Masuda
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Nakajo
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Nakaya
D017209:Apoptosis / Q000502:physiology*; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism*; D002712:Chlorides / Q000494:pharmacology*; D003574:Cytochrome c Group / Q000187:drug effects / Q000378:metabolism; D053938:DNA Fragmentation / Q000187:drug effects; D004224:Diterpenes / Q000494:pharmacology*; D004792:Enzyme Precursors / Q000187:drug effects / Q000378:metabolism; D004794:Enzyme Repression; D018922:HL-60 Cells; D006801:Humans; D011499:Protein Processing, Post-Translational; D017967:Zinc Compounds / Q000494:pharmacology*
D002712:Chlorides; D003574:Cytochrome c Group; D004224:Diterpenes; D004792:Enzyme Precursors; D017967:Zinc Compounds; C016837:zinc chloride; C017338:geranylgeraniol; C505407:CASP3 protein, human; D053148:Caspase 3; D020169:Caspases