Abstract
Kinetochores (KTs) are large multiprotein complexes that constitute the interface between centromeric chromatin and the mitotic spindle during chromosome segregation. In spite of their essential role, little is known about how centromeres and KTs are assembled and how their precise stoichiometry is regulated. In this study, we show that the nuclear pore basket component Alm1 is required to maintain both the proteasome and its anchor, Cut8, at the nuclear envelope, which in turn regulates proteostasis of certain inner KT components. Consistently, alm1-deleted cells show increased levels of KT proteins, including CENP-CCnp3, spindle assembly checkpoint activation, and chromosome segregation defects. Our data demonstrate a novel function of the nucleoporin Alm1 in proteasome localization required for KT homeostasis.
© 2017 Salas-Pino et al.
MeSH terms
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Carrier Proteins / genetics
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Carrier Proteins / metabolism
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Cell Cycle Proteins / genetics
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Cell Cycle Proteins / metabolism
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Chromosomal Proteins, Non-Histone / genetics
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Chromosomal Proteins, Non-Histone / metabolism
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Chromosome Segregation
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Chromosomes, Fungal
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Endopeptidases / genetics
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Endopeptidases / metabolism
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Genotype
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Homeostasis
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Intracellular Signaling Peptides and Proteins
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Kinetochores / metabolism*
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Mutation
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Nuclear Envelope / enzymology*
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Nuclear Envelope / genetics
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Phenotype
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Proteasome Endopeptidase Complex / metabolism*
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Proteolysis
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Schizosaccharomyces / enzymology*
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Schizosaccharomyces / genetics
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Schizosaccharomyces pombe Proteins / genetics
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Schizosaccharomyces pombe Proteins / metabolism*
Substances
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ALM1 protein, S pombe
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Carrier Proteins
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Cell Cycle Proteins
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Chromosomal Proteins, Non-Histone
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Cut8 protein, S pombe
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Intracellular Signaling Peptides and Proteins
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MTS4 protein, S pombe
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Schizosaccharomyces pombe Proteins
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centromere protein C
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Endopeptidases
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Proteasome Endopeptidase Complex
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ATP dependent 26S protease
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rpt2 protein, S pombe