Abstract
The tumor suppressor CYLD antagonizes NF-kappaB and JNK signaling by disassembly of Lys63-linked ubiquitin chains synthesized in response to cytokine stimulation. Here we describe the crystal structure of the CYLD USP domain, revealing a distinctive architecture that provides molecular insights into its specificity toward Lys63-linked polyubiquitin. We identify regions of the USP domain responsible for this specificity and demonstrate endodeubiquitinase activity toward such chains. Pathogenic truncations of the CYLD C terminus, associated with the hypertrophic skin tumor cylindromatosis, disrupt the USP domain, accounting for loss of CYLD catalytic activity. A small zinc-binding B box domain, similar in structure to other crossbrace Zn-binding folds--including the RING domain found in E3 ubiquitin ligases--is inserted within the globular core of the USP domain. Biochemical and functional characterization of the B box suggests a role as a protein-interaction module that contributes to determining the subcellular localization of CYLD.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Amino Acid Sequence
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Binding Sites
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Cell Line
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Crystallography, X-Ray
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Deubiquitinating Enzyme CYLD
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Genes, Tumor Suppressor
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Humans
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JNK Mitogen-Activated Protein Kinases / antagonists & inhibitors
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JNK Mitogen-Activated Protein Kinases / metabolism
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Lysine / metabolism*
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Models, Molecular
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Molecular Sequence Data
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Mutation
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NF-kappa B / metabolism
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Neoplasms / genetics
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Polyubiquitin / chemistry
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Polyubiquitin / genetics
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Polyubiquitin / metabolism*
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Protein Structure, Tertiary*
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Recombinant Fusion Proteins / chemistry
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Recombinant Fusion Proteins / genetics
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Recombinant Fusion Proteins / metabolism
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Sequence Alignment
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Signal Transduction / physiology
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Substrate Specificity
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Tumor Suppressor Proteins / chemistry*
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Tumor Suppressor Proteins / classification
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Tumor Suppressor Proteins / genetics
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Tumor Suppressor Proteins / metabolism*
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Ubiquitin Thiolesterase / chemistry
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Ubiquitin Thiolesterase / genetics
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Ubiquitin-Specific Peptidase 7
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Zinc / metabolism
Substances
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NF-kappa B
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Recombinant Fusion Proteins
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Tumor Suppressor Proteins
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Polyubiquitin
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JNK Mitogen-Activated Protein Kinases
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CYLD protein, human
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Deubiquitinating Enzyme CYLD
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USP7 protein, human
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Ubiquitin Thiolesterase
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Ubiquitin-Specific Peptidase 7
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Zinc
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Lysine