hsp70-DnaJ chaperone pairs prevent nitric oxide-mediated apoptosis in RAW 264.7 macrophages.
Excess nitric oxide (NO) induces apoptosis in some cell types, including macrophages. Heat shock protein of 70 kDa (hsp70) has been reported to protect cells from various stresses, including apoptosis-inducing stimuli. Several mammalian cytosolic DnaJ homologs, partner chaperones of hsp70 family members, have been identified. We asked if a DnaJ homolog is required to prevent NO-mediated apoptosis. When mouse macrophage-like RAW 264.7 cells were treated with an NO donor, SNAP, apoptosis occurred. This apoptosis could be prevented by pretreatment of the cells with heat or a low dose of SNAP. Under these conditions, levels of hsc70 (an hsp70 member) remained unchanged, whereas hsp70 was markedly induced. Of the DnaJ homologs dj1 (hsp40/hdj-1) was strongly induced and dj2 (HSDJ/hdj-2) was moderately induced. In transfection experiments, hsp70, hsc70, dj1 or dj2 alone was ineffective in preventing NO-mediated apoptosis. In contrast, both dj1 and dj2, in combination with hsc70 or hsp70, prevented the cells from apoptosis. The hsp70-DnaJ chaperone pairs exerted their anti-apoptotic effects upstream of caspase 3 activation, and apparently upstream of cytochrome c release from mitochondria.
Gotoh
T
T
Department of Molecular Genetics, Kumamoto University School of Medicine, Honjo 2-2-1, Kumamoto 860-0811, Japan.
Terada
K
K
Mori
M
M
D000818:Animals; D017209:Apoptosis; D002352:Carrier Proteins / Q000235:genetics / Q000502:physiology*; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism; D002460:Cell Line; D003574:Cytochrome c Group / Q000378:metabolism; D050956:HSP40 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics / Q000502:physiology*; D006360:Heat-Shock Proteins / Q000235:genetics / Q000502:physiology*; D018869:Heat-Shock Response; D008264:Macrophages / Q000166:cytology* / Q000378:metabolism; D051379:Mice; D008856:Microscopy, Fluorescence; D008928:Mitochondria / Q000378:metabolism; D009569:Nitric Oxide / Q000037:antagonists & inhibitors*; D020030:Nitric Oxide Donors / Q000494:pharmacology; D010396:Penicillamine / Q000031:analogs & derivatives* / Q000494:pharmacology; D014162:Transfection
D002352:Carrier Proteins; D003574:Cytochrome c Group; C107481:DNAJA1 protein, human; D050956:HSP40 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins; D006360:Heat-Shock Proteins; D020030:Nitric Oxide Donors; C110881:S-nitro-N-acetylpenicillamine; D009569:Nitric Oxide; C505407:CASP3 protein, human; C505409:Casp3 protein, mouse; D053148:Caspase 3; D020169:Caspases; D010396:Penicillamine