Fas-associated death domain protein and caspase-8 are not recruited to the tumor necrosis factor receptor 1 signaling complex during tumor necrosis factor-induced apoptosis

J Biol Chem. 2003 Jul 11;278(28):25534-41. doi: 10.1074/jbc.M303399200. Epub 2003 Apr 29.

Abstract

Death receptors are a subfamily of the tumor necrosis factor (TNF) receptor subfamily. They are characterized by a death domain (DD) motif within their intracellular domain, which is required for the induction of apoptosis. Fas-associated death domain protein (FADD) is reported to be the universal adaptor used by death receptors to recruit and activate the initiator caspase-8. CD95, TNF-related apoptosis-inducing ligand (TRAIL-R1), and TRAIL-R2 bind FADD directly, whereas recruitment to TNF-R1 is indirect through another adaptor TNF receptor-associated death domain protein (TRADD). TRADD also binds two other adaptors receptor-interacting protein (RIP) and TNF-receptor-associated factor 2 (TRAF2), which are required for TNF-induced NF-kappaB and c-Jun N-terminal kinase activation, respectively. Analysis of the native TNF signaling complex revealed the recruitment of RIP, TRADD, and TRAF2 but not FADD or caspase-8. TNF failed to induce apoptosis in FADD- and caspase-8-deficient Jurkat cells, indicating that these apoptotic mediators were required for TNF-induced apoptosis. In an in vitro binding assay, the intracellular domain of TNF-R1 bound TRADD, RIP, and TRAF2 but did not bind FADD or caspase-8. Under the same conditions, the intracellular domain of both CD95 and TRAIL-R2 bound both FADD and caspase-8. Taken together these results suggest that apoptosis signaling by TNF is distinct from that induced by CD95 and TRAIL. Although caspase-8 and FADD are obligatory for TNF-mediated apoptosis, they are not recruited to a TNF-induced membrane-bound receptor signaling complex as occurs during CD95 or TRAIL signaling, but instead must be activated elsewhere within the cell.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Signal Transducing*
  • Annexin A5 / pharmacology
  • Antigens, CD / metabolism*
  • Apoptosis Regulatory Proteins
  • Apoptosis*
  • Blotting, Western
  • Carrier Proteins / metabolism*
  • Caspase 8
  • Caspase 9
  • Caspases / metabolism
  • Electrophoresis, Polyacrylamide Gel
  • Fas-Associated Death Domain Protein
  • Glutathione Transferase / metabolism
  • HeLa Cells
  • Humans
  • Jurkat Cells
  • Membrane Glycoproteins / metabolism
  • NF-kappa B / metabolism
  • Protein Binding
  • Protein Structure, Tertiary
  • Proteins / metabolism
  • Receptors, Tumor Necrosis Factor / metabolism*
  • Receptors, Tumor Necrosis Factor, Type I
  • Recombinant Fusion Proteins / metabolism
  • Recombinant Proteins / metabolism
  • Signal Transduction*
  • TNF Receptor-Associated Factor 1
  • TNF Receptor-Associated Factor 2
  • TNF-Related Apoptosis-Inducing Ligand
  • Time Factors
  • Tumor Necrosis Factor-alpha / metabolism
  • U937 Cells
  • fas Receptor / metabolism

Substances

  • Adaptor Proteins, Signal Transducing
  • Annexin A5
  • Antigens, CD
  • Apoptosis Regulatory Proteins
  • Carrier Proteins
  • FADD protein, human
  • Fas-Associated Death Domain Protein
  • Membrane Glycoproteins
  • NF-kappa B
  • Proteins
  • Receptors, Tumor Necrosis Factor
  • Receptors, Tumor Necrosis Factor, Type I
  • Recombinant Fusion Proteins
  • Recombinant Proteins
  • TNF Receptor-Associated Factor 1
  • TNF Receptor-Associated Factor 2
  • TNF-Related Apoptosis-Inducing Ligand
  • TNFSF10 protein, human
  • Tumor Necrosis Factor-alpha
  • fas Receptor
  • Glutathione Transferase
  • CASP8 protein, human
  • CASP9 protein, human
  • Caspase 8
  • Caspase 9
  • Caspases