J Biol Chem. 2003 Jul 11;278(28):25534-41. Epub 2003 Apr 29.

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.External

Harper, N., Hughes, M., MacFarlane, M., Cohen, G. M.,
--- - Medical Research Council Toxicology Unit, Hodgkin Building, University of Leicester, P.O. Box 138, Lancaster Road, Leicester, LE1 9HN, United Kingdom.
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.
PMID: 12721308External
Arrow2 In vitro interaction Arrow2 In vivo interaction Arrow2 Characterization Arrow2 Functional role Arrow2 top
In vitro interaction
  DD1 DD2 Reference
Family DD1 DD2 Method Species Region Expression Species Region Expression
DD DR5 Link FADD GST fusion protein pull-down Not specified 191-411 E.coli Jurkat lysate 12721308
DD FADD Link Fas GST fusion protein pull-down Jurkat lysate Not specified 191-335 E.coli 12721308
DD RIP Link TNFR1 GST fusion protein pull-down Jurkat lysate Not specified 237-455 E.coli 12721308
DD TNFR1 Link TRADD GST fusion protein pull-down Not specified 237-455 E.coli Jurkat lysate 12721308
(Link: click this icon to show interactions only between the two corresponding DDs)