Related Experiment Video
Updated: Feb 5, 2026

High-resolution Imaging and Analysis of Individual Astral Microtubule Dynamics in Budding Yeast
Published on: April 20, 2017
Microtubule dynamics regulation reconstituted in budding yeast lysates
Zane J Bergman1, Jonathan Wong1, David G Drubin1
1Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA.
Abstract:
Microtubules (MTs) are important for cellular structure, transport of cargoes and segregation of chromosomes and organelles during mitosis. The stochastic growth and shrinkage of MTs, known as dynamic instability, is necessary for these functions. Previous studies to determine how individual MT-associated proteins (MAPs) affect MT dynamics have been performed either through in vivo studies, which provide limited opportunity for observation of individual MTs or manipulation of conditions, or in vitro studies, which focus either on purified proteins, and therefore lack cellular complexity, or on cell extracts made from genetically intractable organisms. In order to investigate the ensemble activities of all MAPs on MT dynamics using lysates made from a genetically tractable organism, we developed a cell-free assay for budding yeast lysates using total internal reflection fluorescence (TIRF) microscopy. Lysates were prepared from yeast strains expressing GFP-tubulin. MT polymerization from pre-assembled MT seeds adhered to a coverslip was observed in real time. Through use of cell division cycle (cdc) and MT depolymerase mutants, we found that MT polymerization and dynamic instability are dependent on the cell cycle state and the activities of specific MAPs.
Insights
Microtubule dynamics are crucial for cell division. This study developed a new cell-free assay in yeast to observe how microtubule-associated proteins collectively influence microtubule growth and instability during the cell cycle.
Area of Science:
- Cell Biology
- Biophysics
Background:
- Microtubules (MTs) are essential cytoskeletal components involved in cell structure, intracellular transport, and chromosome segregation during mitosis.
- The dynamic instability of MTs, characterized by stochastic growth and shrinkage, is critical for their diverse cellular functions.
- Previous research on microtubule-associated proteins (MAPs) faced limitations due to either the complexity of in vivo studies or the lack of cellular context in in vitro assays using purified proteins or extracts from non-tractable organisms.
Purpose of the Study:
- To develop and validate a novel cell-free assay using budding yeast lysates to investigate the collective effects of all MAPs on MT dynamics.
- To examine the real-time polymerization and dynamic instability of microtubules in a cellular context without genetic manipulation of individual MAPs.
- To determine the influence of cell cycle state and specific MAP activities on MT polymerization and dynamic instability.
Main Methods:
- Development of a cell-free assay utilizing total internal reflection fluorescence (TIRF) microscopy with lysates from yeast strains expressing GFP-tubulin.
- Observation of MT polymerization from pre-assembled MT seeds adhered to a coverslip in real time.
- Utilized cell division cycle (cdc) and MT depolymerase mutants to perturb cellular states and analyze their effects on MT dynamics.
Main Results:
- Successfully established a functional cell-free system for observing MT dynamics in budding yeast lysates.
- Demonstrated that MT polymerization and dynamic instability are significantly influenced by the cell cycle stage.
- Identified the dependence of MT dynamics on the collective activities of MAPs present in the yeast lysate.
Conclusions:
- The developed cell-free assay provides a powerful tool to study the ensemble activities of MAPs on MT dynamics in a genetically tractable organism.
- MT polymerization and dynamic instability are regulated by the cell cycle and the integrated functions of various MAPs.
- This approach overcomes limitations of previous methods, enabling a more comprehensive understanding of MT regulation within a cellular context.
Related Concept Videos
Microtubules
Microtubules
Microtubules have two structurally similar globular protein subunits: α and β tubulins. In the cytosol, the α and β tubulins form a heterodimer....
Yeast Signaling
The Tongue and Taste Buds
Taste Buds and Receptors
Microtubule Instability

