title: Disruption of hsp90 function results in degradation of the death domain kinase, receptor-interacting protein (RIP), and blockage of tumor necrosis factor-induced nuclear factor-kappaB activation.
abstract: The death domain kinase, receptor interacting protein (RIP), is one of the major components of the tumor necrosis factor receptor 1 (TNFR1) complex and plays an essential role in tumor necrosis factor (TNF)-mediated nuclear factor kappaB (NF-kappaB) activation. The activation of NF-kappaB protects cells against TNF-induced apoptosis. Heat-shock proteins (Hsps) are chaperone molecules that confer protein stability and help to restore protein native folding following heat shock and other stresses. The most abundant Hsp, Hsp90, is also involved in regulating the stability and function of a number of cell-signaling molecules. Here we report that RIP is a novel Hsp90-associated kinase and that disruption of Hsp90 function by its specific inhibitor, geldanamycin (GA), selectively causes RIP degradation and the subsequent inhibition of TNF-mediated IkappaB kinase and NF-kappaB activation. MG-132, a specific proteasome inhibitor, abrogated GA-induced degradation of RIP but failed to restore the activation of IkappaB kinase by TNF, perhaps because, in the presence of GA and MG-132, RIP accumulated in a detergent-insoluble subcellular fraction. Most importantly, the degradation of RIP sensitizes cells to TNF-induced apoptosis. These data indicate that Hsp90 plays an important role in TNF-mediated NF-kappaB activation by modulating the stability and solubility of RIP. Thus, inhibition of NF-kappaB activation by GA may be a critical component of the anti-tumor activity of this drug.
authors.affiliation: Department of Cell and Cancer Biology, Medicine Branch, Division of Clinical Sciences, NCI, National Institutes of Health, Bethesda, Maryland 20892, USA.
authors.forename: J
authors.initials: J
authors.lastname: Lewis
authors.forename: A
authors.initials: A
authors.lastname: Devin
authors.forename: A
authors.initials: A
authors.lastname: Miller
authors.forename: Y
authors.initials: Y
authors.lastname: Lin
authors.forename: Y
authors.initials: Y
authors.lastname: Rodriguez
authors.forename: L
authors.initials: L
authors.lastname: Neckers
authors.forename: Z G
authors.initials: ZG
authors.lastname: Liu
mesh_terms: D017209:Apoptosis / Q000187:drug effects / Q000502:physiology*; D016227:Benzoquinones; D002470:Cell Survival / Q000187:drug effects; D003513:Cycloheximide / Q000494:pharmacology; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D017930:Genes, Reporter; D018841:HSP90 Heat-Shock Proteins / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D051550:I-kappa B Kinase; D007700:Kinetics; D047029:Lactams, Macrocyclic; D007976:Leupeptins / Q000494:pharmacology; D008156:Luciferases / Q000032:analysis / Q000235:genetics; D016328:NF-kappa B / Q000037:antagonists & inhibitors / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D011506:Proteins / Q000378:metabolism*; D011809:Quinones / Q000494:pharmacology; D053422:Receptor-Interacting Protein Serine-Threonine Kinases; D011994:Recombinant Proteins / Q000378:metabolism; D014162:Transfection; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
chemical_list: D016227:Benzoquinones; D015853:Cysteine Proteinase Inhibitors; D004791:Enzyme Inhibitors; D018841:HSP90 Heat-Shock Proteins; D047029:Lactams, Macrocyclic; D007976:Leupeptins; D016328:NF-kappa B; D011506:Proteins; D011809:Quinones; D011994:Recombinant Proteins; D014409:Tumor Necrosis Factor-alpha; D003513:Cycloheximide; D008156:Luciferases; D017346:Protein Serine-Threonine Kinases; C506249:RIPK1 protein, human; D053422:Receptor-Interacting Protein Serine-Threonine Kinases; C496559:CHUK protein, human; D051550:I-kappa B Kinase; C496560:IKBKB protein, human; C496565:IKBKE protein, human; C072553:benzyloxycarbonylleucyl-leucyl-leucine aldehyde; C001277:geldanamycin