Tumor necrosis factor (TNF)-induced germinal center kinase-related (GCKR) and stress-activated protein kinase (SAPK) activation depends upon the E2/E3 complex Ubc13-Uev1A/TNF receptor-associated factor 2 (TRAF2).
Tumor necrosis factor (TNF)-induced activation of apoptosis signal-regulating kinase 1 (ASK1) and germinal center kinases (GCKs) and the subsequent activation of stress-activated protein kinases (SAPKs and c-Jun NH(2)-terminal kinases) requires TNF receptor-associated factor 2 (TRAF2). Although the TRAF2 TRAF domain binds ASK1, GCK, and the highly related kinase GCKR, the RING finger domain is needed for their activation. Here, we report that TNF activates GCKR and the SAPK pathway in a manner that depends upon TRAF2 and Ubc13, a member along with Uev1A of a dimeric ubiquitin-conjugating enzyme complex. Interference with Ubc13 function or expression inhibits both TNF- and TRAF2-mediated GCKR and SAPK activation, but has a minimal effect on ASK1 activation. TNF signaling leads to TRAF2 polyubiquitination and oligomerization and to the oligomerization, ubiquitination, and activation of GCKR, all of which are sensitive to the disruption of Ubc13 function. These results indicate that the assembly of a TRAF2 lysine 63-linked polyubiquitin chain by Ubc13/Uev1A is required for TNF-mediated GCKR and SAPK activation, but may not be required for ASK1 activation.
Shi
Chong-Shan
CS
B Cell Molecular Immunology Section, Laboratory of Immunoregulation, NIAID, National Institutes of Health, Bethesda, Maryland 20892, USA.
Kehrl
John H
JH
D004789:Enzyme Activation / Q000187:drug effects; D006801:Humans; D008025:Ligases / Q000502:physiology*; D048848:MAP Kinase Kinase Kinase 5; D020930:MAP Kinase Kinase Kinases / Q000378:metabolism; D048055:Mitogen-Activated Protein Kinase 8; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D011506:Proteins / Q000502:physiology*; D018124:Receptors, Tumor Necrosis Factor; D015398:Signal Transduction; D047992:TNF Receptor-Associated Factor 2; D014157:Transcription Factors; D014407:Tumor Cells, Cultured; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*; D025801:Ubiquitin / Q000378:metabolism; D044763:Ubiquitin-Conjugating Enzymes
D011506:Proteins; D018124:Receptors, Tumor Necrosis Factor; D047992:TNF Receptor-Associated Factor 2; D014157:Transcription Factors; D014409:Tumor Necrosis Factor-alpha; D025801:Ubiquitin; C471624:UBE2V1 protein, human; D044763:Ubiquitin-Conjugating Enzymes; C404144:MAP4K5 protein, human; D017346:Protein Serine-Threonine Kinases; D048055:Mitogen-Activated Protein Kinase 8; D020928:Mitogen-Activated Protein Kinases; D048848:MAP Kinase Kinase Kinase 5; D020930:MAP Kinase Kinase Kinases; C482858:MAP3K5 protein, human; D008025:Ligases