TUMOR-NECROSIS-FACTOR RECEPTOR-ASSOCIATED FACTOR (TRAF)-1, TRAF-2, AND TRAF-3 INTERACT IN-VIVO WITH THE CD30 CYTOPLASMIC DOMAIN - TRAF-2 MEDIATES CD30-INDUCED NUCLEAR-FACTOR-KAPPA-B ACTIVATION

CD30 is a member of the tumor necrosis factor receptor superfamily, wh ich can transduce signals for proliferation, death, or nuclear factor kappa B (NF-kappa B) activation. Investigation of CD30 signaling pathw ays using a yeast two-hybrid interaction system trapped a cDNA encodin g the tumor necrosis factor receptor-associated factor (TRAF)-2 TRAF h omology domain. TRAF-1 and TRAF-3 also interacted with CD30, and >90% of in vitro-translated TRAF-1 or -2, or 50% of TRAF-3, bound to the CD 30 cytoplasmic domain. TRAF-1, -2, and -3 bound mostly, but not exclus ively, to the carboxyl-terminal 36 residues of CD30. The binding was s trongly inhibited by a CD30 oligopeptide centered around a PXQXT (wher e X is any amino acid) motif shared with CD40 and the Epstein-Barr vir us transforming protein LMP1, indicating that this motif in CD30 is an important determinant of TRAF-1, -2 or -3 interaction. At least 15% o f TRAF-1, -2, or -3 associated with CD30 when coexpressed in 293 cells . The association was not affected by CD30 cross-linking. However, cro ss-linking of CD30 activated NF-kappa B. NF-kappa B activation was dep endent on the carboxyl-terminal 36 amino acids of CD30 that mediate TR AF association. TRAF-2 has been previously shown to have a unique role in TRAF-mediated NF-kappa B activation, and NF-kappa B activation fol lowing CD30 cross-linking was blocked by a dominant negative TRAF-2 mu tant. These data indicate that CD30 cross-linking-induced NF-kappa B a ctivation is predominantly TRAF-2-mediated.