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High-resolution Imaging and Analysis of Individual Astral Microtubule Dynamics in Budding Yeast
Published on: April 20, 2017
Microtubule interactions with the cell cortex causing nuclear movements in Saccharomyces cerevisiae
1Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
The Journal of Cell Biology
|May 17, 2000
Summary
Budding yeast nuclear movement to the bud neck relies on microtubule capture and depolymerization for initial positioning and microtubule sliding for entry. Both processes are essential for successful cell division.
Area of Science:
- Cell Biology
- Molecular Biology
- Genetics
Background:
- Nuclear positioning is crucial for cell division in budding yeast.
- Cytoplasmic microtubules interact with the cell cortex to drive nuclear movements.
- Specific mutants (EB1, Arp1) affect distinct stages of nuclear migration.
Purpose of the Study:
- To investigate the mechanisms of nuclear movement to and into the bud neck during mitosis in budding yeast.
- To elucidate the roles of microtubule dynamics, capture, depolymerization, and sliding in nuclear migration.
Main Methods:
- Live-cell video analysis of GFP-labeled microtubules.
- Examination of wild-type cells and EB1 and Arp1 mutants.
- Investigating microtubule-cortex interactions and their impact on nuclear positioning.
Main Results:
- Nuclear movement to the neck is primarily mediated by microtubule end capture at the cortex followed by depolymerization.
- Efficient capture requires long and dynamic microtubules probing the cortex.
- Spindle entry into the neck involves microtubule sliding along the bud cortex, dependent on dynein and dynactin.
- Microtubule sliding and capture/shrinkage act as complementary mechanisms for nuclear entry.
Conclusions:
- Nuclear migration to the bud neck involves distinct microtubule-dependent mechanisms: capture/depolymerization and sliding.
- These mechanisms can compensate for each other, ensuring robust nuclear positioning during mitosis.
- Understanding these processes provides insights into the regulation of organelle transport in eukaryotic cells.
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