Related Experiment Videos
Effects of mutant Ran/TC4 proteins on cell cycle progression
M Ren1, E Coutavas, P D'Eustachio
1Department of Cell Biology, NYU Medical Center, New York 10016.
Molecular and Cellular Biology
|June 1, 1994
Summary
The Ran/TC4 protein regulates cell cycle progression. A mutant lacking GTP hydrolysis capability arrests cells in G1 and G2 phases, highlighting the GTPase cycle
Area of Science:
- Cell Biology
- Molecular Biology
- Genetics
Background:
- Ran/TC4, a RAS superfamily member, is a nuclear protein involved in GTP binding and hydrolysis.
- Previous studies suggested a role for Ran/TC4 in cell cycle regulation based on DNA replication inhibition by a GTP hydrolysis-deficient mutant.
Purpose of the Study:
- To investigate the role of Ran/TC4 in cell cycle progression.
- To analyze the cellular phenotypes associated with mutant and wild-type Ran/TC4 expression.
Main Methods:
- Utilized an efficient transfection system introducing cDNAs into 293/Tag cells.
- Analyzed cell cycle progression (G1 and G2 phases) following expression of wild-type and mutant Ran/TC4 proteins.
- Investigated the effect of deleting a carboxy-terminal hexapeptide from the Ran/TC4 mutant.
Main Results:
- Expression of a GTP hydrolysis-deficient Ran/TC4 mutant inhibited cell proliferation, causing arrest predominantly in G2 and also in G1 phases.
- Nuclear localization of the Ran/TC4 mutant was unaffected by the deletion of its carboxy-terminal hexapeptide.
- Deletion of the carboxy-terminal hexapeptide abolished the inhibitory effect of the Ran/TC4 mutant on cell cycle progression.
Conclusions:
- Normal cell cycle progression is coupled to the Ran/TC4 GTPase cycle.
- The carboxy-terminal hexapeptide of Ran/TC4 is crucial for its function in cell cycle regulation.
- Nuclear regulators like RCC1 and MPF likely mediate the coupling between the Ran/TC4 GTPase cycle and cell cycle progression.