Ras1 promotes cellular growth in the Drosophila wing.
The Ras GTPase links extracellular mitogens to intracellular mechanisms that control cell proliferation. To understand how Ras regulates proliferation in vivo, we activated or inactivated Ras in cell clones in the developing Drosophila wing. Cells lacking Ras were smaller, had reduced growth rates, accumulated in G1, and underwent apoptosis due to cell competition. Conversely, activation of Ras increased cell size and growth rates and promoted G1/S transitions. Ras upregulated the growth driver dMyc, and both Ras and dMyc increased levels of cyclin E posttranscriptionally. We propose that Ras primarily promotes growth and that growth is coupled to G1/S progression via cyclin E. Interestingly, upregulation of growth by Ras did not deregulate G2/M progression or a developmentally regulated cell cycle exit.
Prober
D A
DA
Molecular and Cellular Biology Program, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109, USA.
Edgar
B A
BA
D000818:Animals; D030801:Animals, Genetically Modified; D017209:Apoptosis; D002454:Cell Differentiation; D002455:Cell Division; D002470:Cell Survival; D019927:Cyclin E / Q000378:metabolism; D004268:DNA-Binding Proteins; D004330:Drosophila / Q000254:growth & development*; D029721:Drosophila Proteins; D016193:G1 Phase; D019476:Insect Proteins / Q000378:metabolism; D016196:S Phase; D013997:Time Factors; D014157:Transcription Factors / Q000378:metabolism; D015854:Up-Regulation; D014921:Wings, Animal / Q000254:growth & development; D018631:ras Proteins / Q000235:genetics / Q000502:physiology*
D019927:Cyclin E; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D019476:Insect Proteins; C102284:Myc protein, Drosophila; D014157:Transcription Factors; D018631:ras Proteins