Abstract
Dsk2p from Saccharomyces cerevisiae belongs to the class of proteins that contain a ubiquitin-like (UbL) domain at the N terminus together with a ubiquitin-associated (UBA) domain at the C terminus. We show here that the C-terminal UBA domain of Dsk2p binds to K48-linked polyubiquitin chains, and the N-terminal UbL domain of Dsk2p interacts with the proteasome. Overexpression of Dsk2p caused the accumulation of large amounts of polyubiquitin, and extragenic suppressors of the Dsk2p-mediated lethality proved to be temperature-sensitive mutations in two proteasome subunits, rpn1 and pre2. K48-linked ubiquitin-dependent degradation was impaired by disruption of the DSK2 gene. These results indicate that Dsk2p is K48-linked polyubiquitin-binding protein and also interacts with the proteasome. We discuss a possible role of adaptor function of Dsk2p via its UbL and UBA domains in the ubiquitin-proteasome pathway.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Binding Sites
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Cell Cycle Proteins*
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Cysteine Endopeptidases / chemistry
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Cysteine Endopeptidases / genetics
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Cysteine Endopeptidases / metabolism*
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DNA-Binding Proteins / chemistry
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DNA-Binding Proteins / genetics
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DNA-Binding Proteins / metabolism
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Fungal Proteins / chemistry
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Fungal Proteins / genetics
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Fungal Proteins / metabolism*
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Genes, Fungal
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Genes, Suppressor
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Multienzyme Complexes / chemistry
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Multienzyme Complexes / genetics
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Multienzyme Complexes / metabolism*
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Mutation
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Proteasome Endopeptidase Complex
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Protein Structure, Tertiary
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Protein Subunits
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Proteins / chemistry
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Proteins / genetics
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Proteins / metabolism
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Recombinant Proteins / chemistry
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Recombinant Proteins / genetics
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Recombinant Proteins / metabolism
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Saccharomyces cerevisiae Proteins / chemistry
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Saccharomyces cerevisiae Proteins / genetics
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Saccharomyces cerevisiae Proteins / metabolism*
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Temperature
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Two-Hybrid System Techniques
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Ubiquitins / chemistry
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Ubiquitins / genetics
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Ubiquitins / metabolism*
Substances
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Cell Cycle Proteins
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DNA-Binding Proteins
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DSK2 protein, S cerevisiae
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Fungal Proteins
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Multienzyme Complexes
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Protein Subunits
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Proteins
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RAD23 protein, S cerevisiae
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RPN1 protein, S cerevisiae
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Recombinant Proteins
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Saccharomyces cerevisiae Proteins
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Ubiquitins
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Cysteine Endopeptidases
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PRE2 protein, S cerevisiae
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Proteasome Endopeptidase Complex