Abstract
The proinflammatory cytokine interleukin-17 (IL-17) is important for the immune response to pathogens and also contributes to the pathogenesis of various inflammatory diseases. To avoid persistent inflammation, signaling by the IL-17 receptor (IL-17R), which involves the adaptor protein Act1, must be tightly controlled. Here, we report that persistent stimulation of HeLa cells with IL-17 resulted in degradation of Act1 and desensitization of IL-17R signaling. IL-17 stimulated the Lys48-linked polyubiquitination and degradation of Act1, which was phosphorylation-dependent, similar to the IL-17-dependent degradation of inhibitor of nuclear factor κB α. Act1 was recruited to SCF (Skp1-cullin-1-F-box)-type E3 ubiquitin ligase complexes containing β-transducin repeat-containing protein 1 (β-TrCP1) or β-TrCP2 in a phosphorylation-dependent manner upon stimulation of cells with IL-17. Dominant-negative β-TrCP or knockdown of β-TrCP1 and β-TrCP2 markedly reduced IL-17-induced, phosphorylation-dependent ubiquitination and degradation of Act1. Thus, our studies identify a previously uncharacterized desensitization mechanism, involving the SCFβ-TrCP-mediated degradation of Act1, that occurs during persistent stimulation with IL-17.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Adaptor Proteins, Signal Transducing
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Animals
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Blotting, Western
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Cell Line, Tumor
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Cells, Cultured
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Fibroblasts / cytology
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Fibroblasts / drug effects
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Fibroblasts / metabolism
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HEK293 Cells
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HeLa Cells
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Humans
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Interleukin-17 / pharmacology*
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Mice
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Mice, Inbred C57BL
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Mice, Knockout
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Phosphorylation / drug effects
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Protein Binding / drug effects
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Proteolysis / drug effects
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RNA Interference
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Receptors, Interleukin-17 / genetics
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Receptors, Interleukin-17 / metabolism
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Signal Transduction / drug effects
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Tumor Necrosis Factor Receptor-Associated Peptides and Proteins / genetics
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Tumor Necrosis Factor Receptor-Associated Peptides and Proteins / metabolism*
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Ubiquitin-Protein Ligases / genetics
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Ubiquitin-Protein Ligases / metabolism*
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Ubiquitination / drug effects
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beta-Transducin Repeat-Containing Proteins / genetics
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beta-Transducin Repeat-Containing Proteins / metabolism*
Substances
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Adaptor Proteins, Signal Transducing
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BTRC protein, human
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FBXW11 protein, human
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IL17RA protein, human
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Interleukin-17
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Receptors, Interleukin-17
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TRAF3IP2 protein, human
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Tumor Necrosis Factor Receptor-Associated Peptides and Proteins
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beta-Transducin Repeat-Containing Proteins
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Ubiquitin-Protein Ligases