Abstract
We have investigated the feedback control that prevents cells with incompletely assembled spindles from leaving mitosis. We isolated budding yeast mutants sensitive to the anti-microtubule drug benomyl. Mitotic arrest-deficient (mad) mutants are the subclass of benomyl-sensitive mutants in which the completion of mitosis is not delayed in the presence of benomyl and that die as a consequence of their premature exit from mitosis. A number of properties of the mad mutants indicate that they are defective in the feedback control over the exit from mitosis: their killing by benomyl requires passage through mitosis; their benomyl sensitivity can be suppressed by an independent method for delaying the exit from mitosis; they have normal microtubules; and they have increased frequencies of chromosome loss. We cloned MAD2, which encodes a putative calcium-binding protein whose disruption is lethal. We discuss the role of feedback controls in coordinating events in the cell cycle.
Publication types
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Research Support, Non-U.S. Gov't
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Amino Acid Sequence
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Base Sequence
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Benomyl / pharmacology
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Calcium-Binding Proteins / genetics*
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Carrier Proteins*
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Cell Cycle
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Cell Cycle Proteins
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Cell Nucleus / physiology
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Chromosomes, Fungal / metabolism
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Cloning, Molecular
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Cytoskeleton / physiology
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DNA Mutational Analysis
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DNA, Fungal / genetics
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Feedback
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Fungal Proteins / genetics*
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Genes, Fungal
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Mad2 Proteins
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Microtubules / physiology*
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Mitosis*
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Molecular Sequence Data
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Mutation
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Nuclear Proteins
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Protamine Kinase / metabolism
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Saccharomyces cerevisiae / cytology*
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Saccharomyces cerevisiae Proteins
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Spindle Apparatus / drug effects
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Spindle Apparatus / physiology*
Substances
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Calcium-Binding Proteins
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Carrier Proteins
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Cell Cycle Proteins
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DNA, Fungal
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Fungal Proteins
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MAD2 protein, S cerevisiae
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Mad2 Proteins
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Nuclear Proteins
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Saccharomyces cerevisiae Proteins
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Protamine Kinase
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Benomyl
Associated data
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GENBANK/M60962
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GENBANK/M64383
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GENBANK/M64384
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GENBANK/M64707
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GENBANK/M73821
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GENBANK/S44812
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GENBANK/S44816
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GENBANK/S44821
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GENBANK/S56137
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GENBANK/S56139
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GENBANK/U14132