Dos D. Sarbassov
Discovered rictor and defined mTOR Complex 2
Postdoc, Whitehead Institute/MIT (Sabatini lab) · Dept. of Molecular & Cellular Oncology, MD Anderson Cancer Center · now Professor of Biology, Nazarbayev University, Kazakhstan
Faculty profile, Nazarbayev University ↗
Dos Sarbassov trained as a postdoc in David Sabatini's lab, where he identified rictor (rapamycin-insensitive companion of mTOR), the protein that defines mTOR Complex 2 — a second mTOR machine, distinct from mTORC1, that is largely insensitive to short-term rapamycin treatment and instead controls the actin cytoskeleton.
Sarbassov then showed that mTORC2 directly phosphorylates Akt/PKB on serine 473, identifying mTORC2 as a missing kinase in the insulin-signalling pathway with direct relevance to cancer and metabolic disease. He continued this line of work as a faculty member in the Department of Molecular and Cellular Oncology at MD Anderson Cancer Center.
The timeline below follows Sarbassov's contributions gathered in this Atlas.
Milestones in the Atlas
| Year | Evidence | Study |
|---|---|---|
| 2002 | M | mTOR interacts with raptor to form a nutrient-sensitive complex that signals to the cell growth machinery KIM2002 Discovery of Raptor as the defining partner of mTOR in mTORC1. This is the paper that gives mTORC1 its identity: Raptor is the scaffold that lets mTOR find and phosphorylate its targets (S6K1), and the complex is stabilized under starvation. Companion paper to Hara 2002. |
| 2003 | M | GbetaL, a positive regulator of the rapamycin-sensitive pathway required for the nutrient-sensitive interaction between raptor and mTOR KIM2003 Discovered mLST8 (GbetaL), the third core subunit that clamps onto mTOR's kinase domain and stabilizes the complex. It fine-tunes how tightly Raptor holds mTOR in response to nutrients - a small but essential cog that later turned out to be especially critical for the mTORC2 complex. |
| 2004 | M | Rictor, a novel binding partner of mTOR, defines a rapamycin-insensitive and raptor-independent pathway that regulates the cytoskeleton SAR2004 Discovers rictor and defines mTOR Complex 2, a rapamycin-insensitive mTOR machine distinct from mTORC1. |
| 2005 | M | Phosphorylation and regulation of Akt/PKB by the rictor-mTOR complex SAR2005 Shows mTORC2 directly phosphorylates and activates Akt/PKB, wiring mTOR into insulin signalling. |
| 2006 | M | Prolonged rapamycin treatment inhibits mTORC2 assembly and Akt/PKB SAR2006 Shows prolonged rapamycin treatment can also disassemble mTORC2, explaining some of the drug's off-target effects. |