A LCMT1-PME-1 methylation equilibrium controls mitotic spindle size
Xiaoyu Xia1, Ankur Gholkar, Silvia Senese
1a Department of Chemistry and Biochemistry; University of California ; Los Angeles , CA , USA.
Cell Cycle (Georgetown, Tex.)
|April 4, 2015
Summary
Maintaining the balance between Leucine carboxyl methyltransferase-1 (LCMT1) and protein phosphatase methylesterase-1 (PME-1) is crucial for controlling mitotic spindle size and ensuring proper cell division.
Area of Science:
- Cell Biology
- Molecular Biology
- Biochemistry
Background:
- Leucine carboxyl methyltransferase-1 (LCMT1) and protein phosphatase methylesterase-1 (PME-1) are key enzymes involved in the post-translational modification of protein phosphatase 2A catalytic subunit (PP2AC).
- While their roles in cell growth and proliferation are recognized, the precise mechanisms, particularly concerning cell division, remain unclear.
Purpose of the Study:
- To investigate the role of the LCMT1-PME-1 methylation equilibrium in regulating mitotic spindle size.
- To elucidate the downstream effects of disrupting this methylation balance on cell division processes.
Main Methods:
- Experimental manipulation of LCMT1 and PME-1 levels (depletion/overexpression).
- Pharmacological inhibition of PME-1.
- Microscopic analysis of mitotic spindle morphology.
- Assessment of cell cycle progression, apoptosis, and cell viability.
Main Results:
- Altered LCMT1-PME-1 balance significantly impacts mitotic spindle length, with LCMT1 depletion or PME-1 overexpression causing elongation, and PME-1 depletion or LCMT1 overexpression causing shortening.
- Disruption of the LCMT1-PME-1 equilibrium results in mitotic arrest, activation of the spindle assembly checkpoint, and impaired cell division.
- Perturbation leads to increased apoptosis and reduced overall cell viability.
Conclusions:
- The LCMT1-PME-1 methylation equilibrium is a critical regulator of mitotic spindle size.
- This balance is essential for accurate cell division, and its disruption has severe consequences for cell viability.
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