Gamma-tubulin regulates the anaphase-promoting complex/cyclosome during interphase
Tania Nayak1, Heather Edgerton-Morgan, Tetsuya Horio
1Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210, USA.
The Journal of Cell Biology
|August 4, 2010
Summary
A mutation in gamma-tubulin disrupts cell cycle regulation by preventing key proteins from accumulating in some nuclei. This leads to noncycling nuclei and inhibited growth, revealing gamma-tubulin
Area of Science:
- Cell Biology
- Molecular Biology
- Genetics
Background:
- Gamma-tubulin is essential for microtubule nucleation.
- Cell cycle regulation involves precise protein accumulation and degradation.
- The anaphase-promoting complex/cyclosome (APC/C) controls cell cycle progression.
Purpose of the Study:
- To investigate the function of a cold-sensitive gamma-tubulin allele (mipAD159) in Aspergillus nidulans.
- To determine the effects of mipAD159 on mitotic and cell cycle regulation.
- To elucidate the mechanism by which gamma-tubulin influences cell cycle control.
Main Methods:
- Time-lapse microscopy of fluorescently tagged proteins.
- Analysis of mitotic and cell cycle regulatory proteins (cyclin B, CDK1, Ancdc14).
- Assessment of nuclear cell cycle progression in a multinucleate system.
Main Results:
- The mipAD159 allele caused defects in mitotic and cell cycle regulation at restrictive temperatures.
- Key cell cycle proteins failed to accumulate in a subset of nuclei.
- These nuclei were permanently removed from the cell cycle in a microtubule-independent manner.
- A failure in APC/C inactivation was identified as the cause of noncycling nuclei.
Conclusions:
- Gamma-tubulin plays a critical role in regulating the anaphase-promoting complex/cyclosome.
- Gamma-tubulin's function in cell cycle regulation is independent of its role in microtubule nucleation.
- Dysregulation of gamma-tubulin can lead to cell cycle arrest and growth inhibition.
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