Abstract
By phosphorylating Thr3 of histone H3, Haspin promotes centromeric recruitment of the chromosome passenger complex (CPC) during mitosis. Aurora B kinase, a CPC subunit, sustains chromosome bi-orientation and the spindle assembly checkpoint (SAC). Here, we characterize the small molecule 5-iodotubercidin (5-ITu) as a potent Haspin inhibitor. In vitro, 5-ITu potently inhibited Haspin but not Aurora B. Consistently, 5-ITu counteracted the centromeric localization of the CPC without affecting the bulk of Aurora B activity in HeLa cells. Mislocalization of Aurora B correlated with dephosphorylation of CENP-A and Hec1 and SAC override at high nocodazole concentrations. 5-ITu also impaired kinetochore recruitment of Bub1 and BubR1 kinases, and this effect was reversed by concomitant inhibition of phosphatase activity. Forcing localization of Aurora B to centromeres in 5-ITu also restored Bub1 and BubR1 localization but failed to rescue the SAC override. This result suggests that a target of 5-ITu, possibly Haspin itself, may further contribute to SAC signaling downstream of Aurora B.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Aurora Kinase B
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Aurora Kinases
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Autoantigens / metabolism
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Cell Cycle Proteins / genetics
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Cell Cycle Proteins / metabolism
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Cell Line, Tumor
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Centromere Protein A
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Chromosomal Proteins, Non-Histone / metabolism
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Chromosome Segregation
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Cytoskeletal Proteins
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HeLa Cells
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Humans
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Intracellular Signaling Peptides and Proteins / antagonists & inhibitors*
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Kinetochores / metabolism*
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M Phase Cell Cycle Checkpoints / drug effects*
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Nocodazole / pharmacology
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Nuclear Proteins / metabolism
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Phosphorylation
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Protein Serine-Threonine Kinases / antagonists & inhibitors*
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Protein Serine-Threonine Kinases / metabolism*
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Signal Transduction
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Tubercidin / analogs & derivatives*
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Tubercidin / pharmacology
Substances
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Autoantigens
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CENPA protein, human
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Cell Cycle Proteins
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Centromere Protein A
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Chromosomal Proteins, Non-Histone
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Cytoskeletal Proteins
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Intracellular Signaling Peptides and Proteins
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NDC80 protein, human
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Nuclear Proteins
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5-iodotubercidin
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AURKB protein, human
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Aurora Kinase B
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Aurora Kinases
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BUB1 protein, human
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Bub1 spindle checkpoint protein
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HASPIN protein, human
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Protein Serine-Threonine Kinases
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Tubercidin
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Nocodazole