Abstract
Insulin-stimulated glucose transport and GLUT4 translocation require regulated interactions between the v-SNARE, VAMP2, and the t-SNARE, syntaxin 4. We have isolated a novel syntaxin 4-binding protein, Synip, which specifically interacts with syntaxin 4. Insulin induces a dissociation of the Synip:syntaxin 4 complex due to an apparent decrease in the binding affinity of Synip for syntaxin 4. In contrast, the carboxyterminal domain of Synip does not dissociate from syntaxin 4 in response to insulin stimulation but inhibits glucose transport and GLUT4 translocation. These data implicate Synip as an insulin-regulated syntaxin 4-binding protein directly involved in the control of glucose transport and GLUT4 vesicle translocation.
MeSH terms
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Adipocytes / drug effects
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Adipocytes / metabolism*
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Amino Acid Sequence
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Animals
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Binding, Competitive
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Biological Transport / drug effects
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Carrier Proteins / metabolism*
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Cell Line
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Cloning, Molecular
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Cricetinae
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Genes, Dominant
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Glucose / metabolism
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Glucose Transporter Type 4
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Humans
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Insulin / pharmacology*
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Membrane Proteins / metabolism*
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Mice
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Molecular Sequence Data
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Monosaccharide Transport Proteins / metabolism*
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Muscle Proteins*
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Mutation
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Organelles / metabolism
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Protein Binding / drug effects
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Qa-SNARE Proteins
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Qb-SNARE Proteins
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Qc-SNARE Proteins
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R-SNARE Proteins
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RNA, Messenger / analysis
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RNA, Messenger / genetics
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RNA, Messenger / metabolism
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Vesicular Transport Proteins*
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Yeasts / genetics
Substances
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Carrier Proteins
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Glucose Transporter Type 4
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Insulin
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Membrane Proteins
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Monosaccharide Transport Proteins
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Muscle Proteins
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Qa-SNARE Proteins
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Qb-SNARE Proteins
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Qc-SNARE Proteins
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R-SNARE Proteins
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RNA, Messenger
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SLC2A4 protein, human
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SNAP23 protein, human
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STXBP4 protein, human
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Slc2a4 protein, mouse
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Snap23 protein, mouse
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Stxbp4 protein, mouse
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Vesicular Transport Proteins
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Glucose