Comprehensive studies on subcellular localizations and cell death-inducing activities of eight GFP-tagged apoptosis-related caspases.
By using green fluorescent protein fusion, we investigated the subcellular localization of all the caspases that have been cloned from humans and implicated in the execution of apoptosis. We divided these caspases into three groups according to subcellular localization. The first group includes caspase-1, -3, -6, -7, and -9, which are expressed mainly in the cytoplasm with various levels of nuclear localization depending on the cell type. The second group has a single member, caspase-2, which is primarily localized in the nucleus. The nuclear localization was demonstrated to be mediated by a nuclear localization signal near the NH(2)-terminus of the prodomain. The third group includes caspase-8 and -10, which have a cytoplasmic distribution. These two members have potent, rapid cell death-inducing activity and are prone to make aggregates when overexpressed. Their prodomains formed marked fibrous structures in the cytoplasm whose localization seemed distinct from organelles or cytoskeletons. None of the GFP-caspases examined in this study showed a predominant mitochondrial localization as has been reported for some caspases.
Department of Genetics, National Children's Medical Research Center, 3-35-31 Taishido, Setagaya-ku, Tokyo, 154-8509, Japan.
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Y
Shikama
M
M
U
T
T
Miyashita
M
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Yamada
D017209:Apoptosis; D020170:Caspase 1 / Q000235:genetics / Q000378:metabolism; D053455:Caspase 10; D053143:Caspase 2; D053148:Caspase 3; D053178:Caspase 6; D053179:Caspase 7; D053181:Caspase 8; D053453:Caspase 9; D020169:Caspases / Q000235:genetics / Q000378:metabolism*; D016923:Cell Death; D002460:Cell Line; D002467:Cell Nucleus / Q000201:enzymology; D003593:Cytoplasm / Q000201:enzymology; D004058:Diffusion; D004789:Enzyme Activation; D015870:Gene Expression; D049452:Green Fluorescent Proteins; D006367:HeLa Cells; D006801:Humans; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D013347:Subcellular Fractions; D014407:Tumor Cells, Cultured
D008164:Luminescent Proteins; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins; C505407:CASP3 protein, human; C505514:CASP6 protein, human; C505520:CASP7 protein, human; C505530:CASP8 protein, human; C506433:CASP9 protein, human; D053455:Caspase 10; D053143:Caspase 2; D053148:Caspase 3; D053178:Caspase 6; D053179:Caspase 7; D053181:Caspase 8; D053453:Caspase 9; D020169:Caspases; D020170:Caspase 1; C506438:CASP10 protein, human