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Identification of Cyclin-dependent Kinase 1 Specific Phosphorylation Sites by an In Vitro Kinase Assay
Published on: May 3, 2018
The MRN-CtIP pathway is required for metaphase chromosome alignment
Lorene Rozier1, Yige Guo, Shaun Peterson
1Department of Pathology and Cell Biology, Columbia University College of Physicians and Surgeons, 630 W. 168(th) Street, New York, NY 10032, USA.
Molecular Cell
|February 26, 2013
Summary
The MRN-CtIP complex is crucial for accurate chromosome segregation during cell division. This pathway ensures proper spindle assembly by regulating protein association with chromosomes.
Area of Science:
- Cell Biology
- Genomics
- Molecular Biology
Background:
- Accurate genome duplication and segregation are vital for maintaining genomic integrity.
- Proteins involved in DNA transactions are increasingly recognized for their role in chromosome stability.
Purpose of the Study:
- To investigate the role of the MRN (Mre11, Rad50, and Nbs1) complex and CtIP in accurate chromosome segregation.
- To elucidate the mechanism by which the MRN-CtIP pathway influences mitotic processes.
Main Methods:
- Depletion of Mre11 or CtIP in Xenopus egg extracts.
- Inhibition of Mre11 or the MRN complex using antibodies or the small molecule mirin.
- Analysis of chromosome alignment, spindle assembly, and RanGTP gradient in egg extracts and mammalian cells.
Main Results:
- Depletion or inhibition of Mre11/CtIP/MRN caused chromosome alignment defects and impaired spindle assembly in Xenopus egg extracts.
- Loss of MRN function in mammalian cells led to metaphase delay and disrupted the RanGTP gradient.
- Inhibition of MRN function reduced RCC1 association with mitotic chromosomes in both systems.
Conclusions:
- The MRN-CtIP pathway is essential for accurate chromosome segregation.
- This pathway contributes to Ran-dependent mitotic spindle assembly by modulating RCC1 chromosome association.
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