Regulation of cellular growth by the Drosophila target of rapamycin dTOR
What this study shows
The authors showed that fly TOR (dTOR) is needed inside each cell for normal growth and proliferation during larval development. dTOR was also needed for the extra cell growth caused by activating PI3K signalling. As in mammalian cells, dTOR kinase activity was needed for growth factor-dependent phosphorylation of S6 kinase in vitro, and overexpressing S6 kinase rescued dTOR mutant flies to viability. dTOR loss also produced signs of amino acid starvation, such as smaller nucleoli and lipid droplet clumping in the fat body, plus a cell-type-specific cell cycle arrest that cyclin E could bypass. The authors proposed that dTOR links growth factor signalling to nutrient availability during development. Boundary: Drosophila larvae and in vitro kinase assays; rescue relied on overexpression of S6 kinase, and results are not shown in mammals here.
At a glance
| Evidence type | M Molecular — cells, biochemistry, structure Marked M because it is molecular or in-vitro work (model: Drosophila melanogaster dTOR mutants and mosaic clones; PI3K activation in vivo; in vitro dTOR kinase assays on p70S6K; S6K and cyclin E overexpression rescue) rather than a whole-organism health-outcome study. That is often exactly where causal biology gets established -- the code says which system the finding was shown in, and nothing about how good the work is. |
| Study type | 5 - Mechanistic / In Vitro |
| Model system | Drosophila melanogaster dTOR mutants and mosaic clones; PI3K activation in vivo; in vitro dTOR kinase assays on p70S6K; S6K and cyclin E overexpression rescue |
| Journal | Genes & Development |
| Year | 2000 |
| Peer reviewed | Yes |
| Record last updated | 2026-10-01 |
| Source | DOI 10.1101/gad.835000 · PMID 11069888 · Free full text (PMC317034) |
Extracted findings
These fields were extracted from the paper with AI assistance and have not been checked against the source. Read them as a pointer into the paper, not as curated claims; where they disagree with the curated summary above, the curated summary stands.
| Intervention | dTOR loss-of-function; PI3K activation; p70S6K overexpression |
| Target | Cell growth and proliferation; p70S6K phosphorylation; viability |
| Model | Drosophila melanogaster; in vitro |
| Effect | dTOR required for normal and PI3K-driven growth; S6K overexpression rescues dTOR mutant viability |
In the Atlas
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