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Overexpression of DA41 in v-Ha-ras-3Y1 cells causes growth suppression
T Ozaki1, Y Nakamura, E Hanaoka
1Division of Biochemistry, Chiba Cancer Center Research Institute, Chuoh-ku, Chiba 260-8717, Japan. tozaki@chiba-cc.pref.chiba.jp
Abstract:
We have recently found that DA41 exhibits marked homology with mouse PLIC-1, PLIC-2, frog XDRP1 and yeast DSK2. XDRP1 has been shown to be associated with cyclin A, and blocks cell division of frog embryo. In the present study, we examined the biological role(s) of DA41 in mammalian cells by overexpressing it in v-Ha-ras-transformed 3Y1 cells (ras-3Y1). Transfectants which expressed a high level of DA41 mRNA exhibited a decrease in growth rate, a reduction in saturation density, and a suppression of colony formation in soft agar medium. To clarify the molecular mechanism(s) by which DA41 affects cell growth, the effect of DA41 expression on the levels of various cell cycle-regulatory proteins was examined. The forced expression of DA41 gene resulted in a remarkable reduction in CDK2 activity, while the amount of CDK2 did not change. These observations indicate that DA41 is involved in cell cycle regulation in ras-3Y1 cells.
Insights
The DA41 gene, homologous to cell cycle regulators, was overexpressed in mammalian cells. High DA41 expression reduced cell growth and CDK2 activity, indicating its role in cell cycle regulation.
Area of Science:
- Cell Biology
- Molecular Biology
- Genetics
Background:
- DA41 shows homology to known cell cycle regulators like XDRP1, which affects embryonic cell division.
- XDRP1's association with cyclin A suggests a role in cell cycle control.
Purpose of the Study:
- To investigate the biological functions of DA41 in mammalian cells.
- To elucidate the molecular mechanisms underlying DA41's effect on cell growth and proliferation.
Main Methods:
- Overexpression of DA41 in v-Ha-ras-transformed 3Y1 cells (ras-3Y1).
- Assessment of cell growth rate, saturation density, and soft agar colony formation.
- Analysis of cell cycle-regulatory protein levels and CDK2 activity.
Main Results:
- High DA41 mRNA expression led to decreased cell growth rate and saturation density.
- Suppression of colony formation in soft agar medium was observed.
- Forced DA41 expression significantly reduced CDK2 activity without altering CDK2 protein levels.
Conclusions:
- DA41 plays a significant role in regulating the cell cycle in mammalian ras-3Y1 cells.
- DA41 impacts cell proliferation by modulating CDK2 activity, suggesting its involvement in cancer research.