Abstract
DNA topoisomerase (topo) IIalpha, an essential enzyme for cell proliferation, is targeted to a proteasome-dependent degradation pathway when human tumor cells are glucose-starved. Here we show that the topo IIalpha destabilization depends on the newly identified domain, GRDD (glucose-regulated destruction domain), which was mapped to the N-terminal 70-170 amino acid sequence. Indeed, the deletion of GRDD conferred a stable feature on topo IIalpha, whereas the fusion of GRDD rendered green fluorescent protein unstable under glucose starvation conditions. Nuclear localization was a prerequisite for GRDD function, because the inhibition of nuclear translocation resulted in the suppression of GRDD-mediated topo IIalpha degradation. Further, GRDD was identified as an interactive domain for Jab1/CSN5, which promoted the degradation of topo IIalpha in a manner dependent on the MPN (Mpr1p/Prd1p N terminus) domain. Depleting Jab1/CSN5 by antisense oligonucleotide and treating cells with the CSN-associated kinase inhibitor, curcumin, inhibited topo IIalpha degradation induced by glucose starvation. These findings demonstrate that GRDD can act as a stress-activated degron for regulating topo IIalpha stability, possibly through interaction with the MPN domain of Jab1/CSN5.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Adenosine Triphosphatases / chemistry
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Adenosine Triphosphatases / genetics
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Adenosine Triphosphatases / metabolism
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Antigens, Neoplasm
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Base Sequence
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COP9 Signalosome Complex
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Cell Line, Tumor
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DNA Topoisomerases, Type II / chemistry*
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DNA Topoisomerases, Type II / genetics
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DNA Topoisomerases, Type II / 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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Glucose / metabolism
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Humans
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In Vitro Techniques
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Intracellular Signaling Peptides and Proteins
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Mutagenesis
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Nuclear Localization Signals
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Oligodeoxyribonucleotides, Antisense / genetics
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Peptide Hydrolases
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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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Transcription Factors / chemistry*
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Transcription Factors / genetics
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Transcription Factors / metabolism*
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Transfection
Substances
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Antigens, Neoplasm
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DNA-Binding Proteins
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Intracellular Signaling Peptides and Proteins
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Nuclear Localization Signals
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Oligodeoxyribonucleotides, Antisense
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Recombinant Fusion Proteins
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Transcription Factors
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Peptide Hydrolases
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COPS5 protein, human
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COP9 Signalosome Complex
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Adenosine Triphosphatases
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DNA Topoisomerases, Type II
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Glucose