Abstract
We have identified a novel mammalian protein, MIR1, with microtubule-binding activity. MIR1 is a relative of MID1/midin, the protein implicated in Opitz G/BBB syndrome. In tissue culture cells, MIR1 is enriched at the centrosome. MIR1 dissociates from centrosomes at the G2/M transition and is recruited back to spindle poles during anaphase. When overexpressed during interphase, MIR1 binds along microtubule filaments, which become stabilized, bundled and detached from the centrosome. In mitosis, overexpressed MIR1 dissociates from microtubules but still affects the normally focused localization of gamma-tubulin in spindle poles. Tight binding to microtubules in interphase appears to require an oligomeric state of MIR1, and phosphorylation in mitosis at predicted cyclin-dependent kinase (cdk) sites weakens the interaction.
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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Animals
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Antineoplastic Agents / metabolism
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Cell Cycle / physiology
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Cell Line
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Centrosome / metabolism*
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Cyclin-Dependent Kinase 5
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Cyclin-Dependent Kinases / metabolism
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Humans
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Microtubule-Associated Proteins / genetics
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Microtubule-Associated Proteins / metabolism*
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Microtubules / metabolism*
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Molecular Sequence Data
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Nerve Tissue Proteins
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Nocodazole / metabolism
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Nuclear Proteins / genetics
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Nuclear Proteins / metabolism*
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Protein Binding
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Recombinant Fusion Proteins / genetics
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Recombinant Fusion Proteins / metabolism
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Spindle Apparatus / metabolism
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Tissue Distribution
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Tubulin / metabolism
Substances
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Antineoplastic Agents
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FSD1 protein, human
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Microtubule-Associated Proteins
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Nerve Tissue Proteins
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Nuclear Proteins
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Recombinant Fusion Proteins
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Tubulin
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Cyclin-Dependent Kinase 5
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CDK5 protein, human
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Cyclin-Dependent Kinases
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Nocodazole