A survivin-ran complex regulates spindle formation in tumor cells
Fang Xia1, Pedro M Canovas, Thomas M Guadagno
1Department of Cancer Biology, LRB428, University of Massachusetts Medical School, 364 Plantation Street, Worcester, MA 01605, USA.
Molecular and Cellular Biology
|July 2, 2008
Summary
Survivin, a key mitosis regulator, binds to the small GTPase Ran. This interaction is crucial for proper mitotic spindle formation, especially in cancer cells, revealing a novel cancer-specific pathway.
Area of Science:
- Molecular Biology
- Cell Biology
- Cancer Research
Background:
- Aberrant cell division is a hallmark of cancer.
- The molecular mechanisms governing cell division in tumors are not fully understood.
- Survivin is an essential mitosis regulator overexpressed in various cancers.
Purpose of the Study:
- To identify novel molecular partners of survivin using high-throughput proteomics.
- To investigate the functional significance of survivin-interacting proteins in cancer cell division.
- To elucidate the role of survivin in Ran signaling pathways.
Main Methods:
- High-throughput proteomics screening to identify survivin-binding proteins.
- Biochemical assays to characterize the survivin-Ran interaction.
- Cellular experiments to assess the impact of disrupting the survivin-Ran complex on mitosis.
Main Results:
- Survivin was found to associate with the small GTPase Ran in a conserved manner.
- This interaction is cell-cycle regulated, dependent on Ran-GTP, and involves a specific binding site on survivin.
- Disruption of the survivin-Ran complex impaired TPX2 delivery to microtubules, leading to aberrant spindle formation and chromosome missegregation in tumor cells.
Conclusions:
- Survivin acts as a novel effector of Ran signaling.
- The survivin-Ran pathway is preferentially utilized for mitotic spindle assembly in tumor cells.
- Targeting this pathway could offer a strategy for cancer therapy.
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