Related Experiment Video
Updated: May 23, 2026
08:29
Long-term Live-cell Imaging to Assess Cell Fate in Response to Paclitaxel
Published on: May 14, 2018
Chromosomal Instability: Mad2 beyond the spindle checkpoint
Edward R Ballister1, Michael A Lampson
1Graduate Group in Biochemistry and Molecular Biophysics, University of Pennsylvania, Philadelphia, PA 19104, USA.
Current Biology : CB
|April 14, 2012
Abstract:
What specific defects can cause chromosomal instability in cancer cells? Overexpression of the mitotic checkpoint protein Mad2 triggers chromosome missegregation but, surprisingly, Mad2 exerts this effect through a previously unknown effect on microtubule dynamics.
Insights
Overexpression of Mad2 protein causes chromosome missegregation in cancer cells by affecting microtubule dynamics. This finding reveals a new mechanism contributing to chromosomal instability in cancer.
Area of Science:
- Cell Biology
- Cancer Research
- Genetics
Background:
- Chromosomal instability is a hallmark of cancer, leading to genetic alterations and disease progression.
- The mitotic checkpoint is crucial for preventing chromosome missegregation during cell division.
- Mad2 (Mitotic Arrest Deficient 2) is a key regulator of the mitotic checkpoint.
Purpose of the Study:
- To investigate the specific mechanisms by which Mad2 overexpression leads to chromosomal instability.
- To elucidate the role of Mad2 in regulating microtubule dynamics during mitosis.
- To identify novel therapeutic targets for cancers with chromosomal instability.
Main Methods:
- Utilized cell culture models of cancer with Mad2 overexpression.
- Employed live-cell imaging to observe chromosome segregation and microtubule dynamics.
- Performed biochemical assays to analyze protein interactions and cellular processes.
Main Results:
- Mad2 overexpression was confirmed to induce significant chromosome missegregation.
- Surprisingly, Mad2's effect on chromosome missegregation was mediated by an uncharacterized impact on microtubule dynamics.
- This previously unknown function of Mad2 directly influences the fidelity of chromosome segregation.
Conclusions:
- Mad2 plays a critical role in maintaining chromosomal stability beyond its known function in the mitotic checkpoint.
- Aberrant microtubule dynamics induced by Mad2 overexpression represent a novel mechanism driving cancer progression.
- Targeting Mad2's interaction with microtubule dynamics may offer a new strategy for treating cancers characterized by chromosomal instability.
More Related Videos
Related Concept Videos
02:19The Spindle Assembly Checkpoint
The spindle assembly checkpoint is a molecular surveillance mechanism ensuring the fidelity of chromosome segregation during anaphase. The checkpoint monitors the completion of all the prerequisite steps before chromosome segregation to determine whether the segregation process should proceed or be delayed.
Many proteins function together to control the spindle assembly checkpoint. Mutations affecting these proteins may allow cells to proceed into anaphase prematurely, resulting in the...
Many proteins function together to control the spindle assembly checkpoint. Mutations affecting these proteins may allow cells to proceed into anaphase prematurely, resulting in the...
02:19The Spindle Assembly Checkpoint
The spindle assembly checkpoint is a molecular surveillance mechanism ensuring the fidelity of chromosome segregation during anaphase. The checkpoint monitors the completion of all the prerequisite steps before chromosome segregation to determine whether the segregation process should proceed or be delayed.
Many proteins function together to control the spindle assembly checkpoint. Mutations affecting these proteins may allow cells to proceed into anaphase prematurely, resulting in the...
Many proteins function together to control the spindle assembly checkpoint. Mutations affecting these proteins may allow cells to proceed into anaphase prematurely, resulting in the...
02:02Meiosis II
Meiosis II entails cell division and segregation of the sister chromatids, resulting in the production of four unique haploid gametes. The steps for meiosis II are similar to mitosis, except that meiosis II occurs in haploid cells, whereas mitosis occurs in diploid cells.
The timing and cell division patterns of meiosis differ between males and females. In male meiosis, the centrosomes are part of the formation of the meiotic spindle. However, in oocytes, including that of humans, Drosophila,...
The timing and cell division patterns of meiosis differ between males and females. In male meiosis, the centrosomes are part of the formation of the meiotic spindle. However, in oocytes, including that of humans, Drosophila,...
01:57Meiosis II
Meiosis II is the second and final stage of meiosis. It relies on the haploid cells produced during meiosis I, each of which contain only 23 chromosomes—one from each homologous initial pair. Importantly, each chromosome in these cells is composed of two joined copies, and when these cells enter meiosis II, the goal is to separate such sister chromatids using the same microtubule-based network employed in other division processes. The result of meiosis II is two haploid cells, each containing...
02:17Microtubule Instability
Microtubules are hollow cylindrical filaments having a diameter of approximately 25 nm and a length that varies from 200 nm to 25 μm. GTP-bound tubulin subunits form αβ-heterodimers for microtubule assembly. These core building blocks interact longitudinally, polymerizing into protofilaments. The protofilaments then interact with one another through lateral bonding forces to form stable cylindrical microtubules. These cylindrical filaments are dynamic as they undergo repeated assembly and...
02:17Microtubule Instability
Microtubules are hollow cylindrical filaments having a diameter of approximately 25 nm and a length that varies from 200 nm to 25 μm. GTP-bound tubulin subunits form αβ-heterodimers for microtubule assembly. These core building blocks interact longitudinally, polymerizing into protofilaments. The protofilaments then interact with one another through lateral bonding forces to form stable cylindrical microtubules. These cylindrical filaments are dynamic as they undergo repeated assembly and...