Abstract
The human serine/threonine kinase Aurora-B is structurally related to the protein kinase Ipl1p from S cerevisiae and aurora from Drosophila melanogaster, which are key regulators of mitosis. The present study shows that human Aurora-B is activated by okadaic acid and forms complexes with the protein serine/threonine phosphatase type 1 (PP1) or PP2A, but not with PP5. These data identified Aurora-B associated protein phosphatases as negative regulators of kinase activation. We then used a series of substrates based on a histone H3 phosphorylation site (residues 5-15) to determine the substrate specificity of human Aurora-B. We found that this enzyme is an arginine-directed kinase that can phosphorylate histone H3 at serines 10 and 28 in vitro, suggesting that human Aurora-B is a mitotic histone H3 kinase.
Publication types
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Comparative Study
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Research Support, Non-U.S. Gov't
MeSH terms
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Animals
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Arginine / chemistry
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Aurora Kinase B
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Aurora Kinases
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COS Cells
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Chlorocebus aethiops
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Dose-Response Relationship, Drug
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Enzyme Activation / drug effects
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HeLa Cells
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Histones / metabolism*
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Humans
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Isoenzymes / metabolism
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Nuclear Proteins / physiology
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Okadaic Acid / pharmacology
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Phosphoprotein Phosphatases / physiology*
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Phosphorylation
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Phosphoserine / metabolism
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Protein Interaction Mapping
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Protein Processing, Post-Translational / physiology*
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Protein Serine-Threonine Kinases / physiology*
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Recombinant Fusion Proteins / metabolism
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Substrate Specificity
Substances
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Histones
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Isoenzymes
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Nuclear Proteins
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Recombinant Fusion Proteins
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Phosphoserine
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Okadaic Acid
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Arginine
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AURKB protein, human
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Aurora Kinase B
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Aurora Kinases
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Protein Serine-Threonine Kinases
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Phosphoprotein Phosphatases
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protein phosphatase 5