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Published on: March 9, 2016
Feedback control of mitosis in budding yeast
1Program in Cell Biology, University of California, San Francisco 94143-0444.
Cell
|August 9, 1991
Summary
Researchers identified key cell cycle controls by studying budding yeast mutants. These mitotic arrest-deficient (MAD) mutants reveal crucial feedback mechanisms that prevent premature cell division, ensuring accurate chromosome segregation.
Area of Science:
- Cell Biology
- Genetics
- Molecular Biology
Background:
- Cell cycle progression is tightly regulated to ensure accurate duplication and segregation of genetic material.
- A critical checkpoint prevents cells from exiting mitosis until all chromosomes are properly aligned and attached to the spindle.
Purpose of the Study:
- To investigate the feedback control mechanisms that arrest cells in mitosis when spindle assembly is incomplete.
- To identify and characterize mutants defective in this mitotic arrest process.
Main Methods:
- Isolation of budding yeast mutants sensitive to the anti-microtubule drug benomyl.
- Characterization of mitotic arrest-deficient (mad) mutants, focusing on their response to benomyl and cell cycle progression.
- Cloning of the MAD2 gene and analysis of its function.
Main Results:
- Identified mitotic arrest-deficient (mad) mutants that prematurely exit mitosis and die when treated with benomyl.
- Demonstrated that these mutants are defective in feedback control over mitotic exit.
- Cloned MAD2, a gene essential for viability, encoding a putative calcium-binding protein.
Conclusions:
- The MAD2 gene product plays a critical role in the feedback control that governs exit from mitosis.
- Defects in this control lead to mitotic catastrophe and cell death.
- Feedback mechanisms are essential for coordinating cell cycle events and maintaining genomic stability.
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