title: Activation of stress-activated protein kinase/c-Jun N-terminal kinase, but not NF-kappaB, by the tumor necrosis factor (TNF) receptor 1 through a TNF receptor-associated factor 2- and germinal center kinase related-dependent pathway.
abstract: A key step by which tumor necrosis factor (TNF) signals the activation of nuclear factor-kappaB (NF-kappaB) and the stress-activated protein kinase (SAPK, also called c-Jun N-terminal kinase or JNK) is the recruitment to the TNF receptor of TNF receptor-associated factor 2 (TRAF2). However, the subsequent steps in TRAF2-induced SAPK and NF-kappaB activation remain unresolved. Here we report the identification of a TNF-responsive serine/threonine protein kinase termed GCK related (GCKR) that likely signals via mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) kinase kinase 1 (MEKK1) to activate the SAPK pathway. TNF, TRAF2, and ultraviolet (UV) light, which in part uses the TNF receptor signaling pathway, all increased GCKR activity. A TRAF2 mutant, which inhibits both TRAF2-induced NF-kappaB and SAPK activation, blocked TNF-induced GCKR activation. Finally, interference with GCKR expression impeded TRAF2- and TNF-induced SAPK activation but not that of NF-kappaB. This suggests a divergence in the TNF signaling pathway that leads to SAPK and NF-kappaB activation, which is located downstream of TRAF2 but upstream of GCKR.
authors.affiliation: B Cell Molecular Immunology Section, Laboratory of Immunoregulation, NIAID, National Institutes of Health, Bethesda, Maryland 20892-1876, USA.
authors.forename: C S
authors.initials: CS
authors.lastname: Shi
authors.forename: J H
authors.initials: JH
authors.lastname: Kehrl
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D015703:Antigens, CD / Q000378:metabolism*; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism*; D002460:Cell Line; D004789:Enzyme Activation; D004790:Enzyme Induction; D000081410:Germinal Center Kinases; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases; D008969:Molecular Sequence Data; D016328:NF-kappa B / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism*; D011506:Proteins / Q000378:metabolism*; D018124:Receptors, Tumor Necrosis Factor / Q000378:metabolism*; D047888:Receptors, Tumor Necrosis Factor, Type I; D017386:Sequence Homology, Amino Acid; D047990:TNF Receptor-Associated Factor 1
chemical_list: D015703:Antigens, CD; D000081410:Germinal Center Kinases; D016328:NF-kappa B; D011506:Proteins; D018124:Receptors, Tumor Necrosis Factor; D047888:Receptors, Tumor Necrosis Factor, Type I; D047990:TNF Receptor-Associated Factor 1; D017346:Protein Serine-Threonine Kinases; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases