Characterization of reaper- and FADD-induced apoptosis in a lepidopteran cell line.
Expression of the reaper gene (rpr) correlates with the initiation of apoptosis in Drosophila melanogaster. Transient expression of rpr in the lepidopteran SF-21 cell line induced apoptosis displaying nuclear condensation and fragmentation, oligonucleosomal ladder formation, cell surface blebbing, and apoptotic body formation. Inhibitors of ICE-family proteases p35 and crmA, as well as members of the iap class of genes, Op-iap and D-iap2, but not bcl-2 family members, blocked rpr-induced apoptosis. Mutational analysis of rpr provided no support for the proposed sequence similarity of Reaper and death domain proteins. Mutations in the N-terminal region of Reaper, which displays sequence similarity to Hid and Grim, other Drosophila gene products correlated with the initiation of apoptosis, suggested that these residues might be functionally important. The mammalian cDNA encoding FADD (Fas-associating protein with a death domain) also induced cell death in SF-21 cells, but death progressed more slowly and with features which distinguished it from rpr-induced apoptosis. Several bcl-2 family members delayed or blocked FADD-induced cellular death. Thus, apoptosis initiated by Reaper progressed by a faster path which appeared to differ from that of FADD-induced apoptosis.
Vucic
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Department of Genetics, The University of Georgia, Athens 30602, USA.
Seshagiri
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Miller
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D048868:Adaptor Proteins, Signal Transducing; D000595:Amino Acid Sequence; D000818:Animals; D015703:Antigens, CD / Q000502:physiology; D017209:Apoptosis / Q000502:physiology*; D002352:Carrier Proteins / Q000235:genetics / Q000502:physiology*; D002460:Cell Line; D015853:Cysteine Proteinase Inhibitors; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000235:genetics; D053200:Fas-Associated Death Domain Protein; D005796:Genes / Q000502:physiology; D019254:Genes, bcl-2 / Q000502:physiology; D008969:Molecular Sequence Data; D009154:Mutation; D010455:Peptides / Q000235:genetics / Q000502:physiology*; D018124:Receptors, Tumor Necrosis Factor / Q000502:physiology; D047888:Receptors, Tumor Necrosis Factor, Type I; D011993:Recombinant Fusion Proteins; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D018411:Spodoptera; D014157:Transcription Factors
D048868:Adaptor Proteins, Signal Transducing; D015703:Antigens, CD; C091732:BCL2-associated athanogene 1 protein; D002352:Carrier Proteins; D015853:Cysteine Proteinase Inhibitors; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D053200:Fas-Associated Death Domain Protein; D010455:Peptides; D018124:Receptors, Tumor Necrosis Factor; D047888:Receptors, Tumor Necrosis Factor, Type I; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; C086973:rpr protein, Drosophila