Liron Bar-Peled
Showed as a Sabatini-lab graduate student that Ragulator switches the Rag GTPases on, acting as their GEF. He also discovered GATOR1 and GATOR2; GATOR1 switches the Rags off and its genes are mutated in some cancers
Rullo Family Endowed Chair in Cancer Research, Massachusetts General Hospital & Harvard Medical School · PhD, Sabatini lab, Whitehead Institute/MIT
Bar-Peled Lab, MGH & Harvard (Boston, Massachusetts, USA) ↗ Lab lineagetrained under David M. Sabatini → Bluesky@liron1bar-peled.bsky.social ↗
As a graduate student in David Sabatini's lab, Liron Bar-Peled showed that the Ragulator complex acts as a GEF (guanine nucleotide exchange factor) that switches the Rag GTPases on, and then identified GATOR1 as the GAP (GTPase-activating protein) complex that switches them back off — together defining the molecular on/off switch that gates amino-acid signalling to mTORC1.
Bar-Peled now leads his own lab at Massachusetts General Hospital and Harvard Medical School, where his research has broadened to how cancer cells manage metabolic and oxidative stress.
The timeline below follows Bar-Peled's contributions gathered in this Atlas.
Milestones in the Atlas
A selection, not a full bibliography: only papers that meet the Atlas inclusion criteria.
| Year | Evidence | Study |
|---|---|---|
| 2008 | M | The Rag GTPases bind raptor and mediate amino acid signaling to mTORC1 SAN2008 Identifies the Rag GTPase family as the missing link that lets mTORC1 sense amino acids by controlling whether mTOR is positioned near its activator Rheb. |
| 2010 | M | Ragulator-Rag complex targets mTORC1 to the lysosomal surface and is necessary for its activation by amino acids SAN2010 Established WHERE mTORC1 gets switched on: the lysosome surface. Identified Ragulator as the lysosomal dock that recruits the Rag GTPases and drags mTORC1 to the membrane where its activator Rheb lives. Amino acids work by controlling this translocation. |
| 2011 | M | mTORC1 senses lysosomal amino acids through an inside-out mechanism that requires the vacuolar H(+)-ATPase ZON2011 Showed amino acid sensing starts INSIDE the lysosome: amino acids accumulate in the lumen and the v-ATPase relays that signal outward ('inside-out') to Ragulator-Rag. A surprising twist on where the cell measures its nutrient status. |
| 2012 | M | Ragulator is a GEF for the rag GTPases that signal amino acid levels to mTORC1 BAR2012 Shows Ragulator is a GEF for the Rag GTPases, switching them on to signal amino-acid sufficiency to mTORC1. |
| 2013 | M | The folliculin tumor suppressor is a GAP for the RagC/D GTPases that signal amino acid levels to mTORC1 TSU2013 FLCN-FNIP is a GAP for RagC/D; GDP-bound RagC/D is required for the Rag heterodimer to bind mTORC1, promoting its lysosomal recruitment and activation by amino acids. |
| 2013 | M | A Tumor suppressor complex with GAP activity for the Rag GTPases that signal amino acid sufficiency to mTORC1 BAR2013 Identifies GATOR1 as a tumor-suppressor GAP complex that switches the Rag GTPases off in the absence of amino acids. |
| 2014 | M | The Sestrins interact with GATOR2 to negatively regulate the amino-acid-sensing pathway upstream of mTORC1 CHA2014 Sestrins bind GATOR2 to negatively regulate amino-acid signalling upstream of mTORC1. |
| 2015 | M | Metabolism. Lysosomal amino acid transporter SLC38A9 signals arginine sufficiency to mTORC1 WAN2015 The lysosomal transporter SLC38A9 signals arginine sufficiency to mTORC1. |
Co-authors in the Atlas 25
People with a profile here who share at least one study with Liron Bar-Peled.
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- David M. Sabatini 8 shared studies Identified mTOR (as RAFT1) in 1994. His lab then mapped much of the machinery around it: raptor and rictor at the core of mTORC1 and mTORC2, the Rag–Ragulator system that docks mTORC1 on the lysosome, and the sensors that detect leucine, arginine and SAM
- Roberto Zoncu 5 shared studies Showed as a postdoc that mTORC1 senses amino acids from inside the lysosome, through the v-ATPase and Ragulator. His Berkeley lab has since mapped how the Rag GTPases and the folliculin complex switch mTORC1 on, and how lysosomal cholesterol feeds into the same system
- Lynne Chantranupong 4 shared studies Showed as a Sabatini-lab graduate student that the Sestrins act through GATOR2 to regulate amino-acid signalling to mTORC1. She then discovered the CASTOR proteins, the cell's arginine sensors for the pathway
- Yasemin Sancak 3 shared studies Showed as a Sabatini-lab graduate student, in parallel with Kun-Liang Guan's lab, that the Rag GTPases relay amino-acid signals to mTORC1, and that Ragulator anchors them to the lysosome where mTORC1 is switched on. She also identified PRAS40 as an insulin-regulated inhibitor of mTORC1
- Eric Spooner 2 shared studies Manager of the Whitehead Institute's Proteomics Core Facility, whose mass spectrometry work identified proteins in complexes for many Whitehead studies, including two on amino acid sensing upstream of mTORC1
- Choah Kim 2 shared studies Researcher in David Sabatini's lab at the Whitehead Institute who contributed to three studies on how amino acids at the lysosome are sensed by mTORC1
- Rachel L. Wolfson 2 shared studies Identified Sestrin2 as the direct leucine sensor of the mTORC1 pathway as a Sabatini-lab MD-PhD student. She also co-discovered KICSTOR, the complex that recruits GATOR1 to the lysosome
- Shuyu Wang 2 shared studies Co-discovered SLC38A9 as a Sabatini-lab MD-PhD student, a lysosomal amino-acid transporter that signals arginine sufficiency to mTORC1
- Tim Wang 2 shared studies Co-developed genome-wide CRISPR screening in human cells (reported in parallel by Feng Zhang's lab) as a graduate student with David Sabatini and Eric Lander, and contributed to studies showing that the 4E-BPs mediate mTORC1's control of translation and that CASTOR1 senses arginine
- Zhi-Yang Tsun 2 shared studies Biologist who, as first author in David Sabatini's lab, showed that the tumour suppressor folliculin is a GAP for the RagC and RagD GTPases that carry the amino acid signal to mTORC1
- Alejo Efeyan Showed that the Rag GTPases, which relay amino-acid signals to mTORC1, are a life-or-death switch for newborn mice surviving the fast before their first feeding
- Andrew L. Markhard Contributed, as a Sabatini-lab researcher, to the discovery that Ragulator docks mTORC1 on the lysosome, and now studies metabolite signals that tell the body it has eaten
- Brian C. Grabiner Catalogued cancer-associated MTOR mutations and showed that many of them hyperactivate the kinase and can predict sensitivity to rapamycin; he also contributed to the discovery of GATOR1
- Carson C. Thoreen Used Torin1, one of the first ATP-competitive mTOR inhibitors, to reveal functions of mTORC1 that rapamycin cannot block. He then showed that mTORC1 controls translation of mRNAs for the protein-making machinery mainly through the 4E-BP proteins
- Elizabeth D. Yuan Second author on the study showing that S6K1 phosphorylates BMAL1 to link mTOR signalling with circadian protein synthesis, and co-author on the follow-up in tuberous sclerosis models.
- Gregory A. Wyant Showed that the lysosomal protein SLC38A9 exports leucine and other essential amino acids out of the lysosome, letting cells grow on proteins they have taken up and broken down there
- Jose M. Orozco Researcher trained in David Sabatini's laboratory at the Whitehead Institute and MIT who showed that mTORC1 senses glucose through the glycolysis metabolite DHAP
- Kathleen Ottina Researcher in David Sabatini's lab at the Whitehead Institute and HHMI at MIT who contributed to studies of the GATOR1 amino acid off-switch, mTORC1 feedback on growth-factor signalling, and cancer drug resistance
- Kuang Shen Solved, as a Sabatini-lab postdoc, cryo-EM structures of GATOR1 and of the FLCN–FNIP2–Rag–Ragulator complex, two switches that set mTORC1 activity. His UMass Chan lab studies the structural basis of nutrient sensing
- Matthew Meyerson Cancer geneticist whose group has helped identify key genes mutated in lung cancer, and who contributed the cancer-genome analysis to the discovery that GATOR1 is a tumour suppressor acting on mTORC1
- Robert A Lindquist Researcher in David Sabatini's group at the Whitehead Institute who ran large image-based RNAi screens for regulators of TORC1 signaling and helped build the CellProfiler image-analysis software
- Robert A. Saxton Solved, as a Sabatini-lab graduate student, the structures of the leucine sensor Sestrin2 and the arginine sensor CASTOR1, showing how each one grips its amino acid. He also co-wrote a widely cited 2017 review of mTOR signalling with David Sabatini
- Sonia M. Scaria Contributed, as an MIT undergraduate in the Sabatini lab, to the discovery of CASTOR1 as the arginine sensor and SAMTOR as the SAM sensor of the mTORC1 pathway
- Steven P. Gygi Mass-spectrometry scientist whose Harvard lab builds large-scale proteomics methods, including the BioPlex human protein-interaction map, and contributed proteomics to the discoveries of the CASTOR and SAMTOR nutrient sensors
- Timothy R. Peterson Discovered DEPTOR, an inhibitor that binds mTOR in both complexes and is overexpressed in some multiple myelomas. He also showed that mTORC1 controls fat synthesis by regulating where the enzyme lipin 1 sits in the cell, and through it the SREBP pathway
Every researcher with a profile →
On the programme
Meetings in the Atlas calendar where Liron Bar-Peled is listed among the speakers or organisers.
- past Prague Metabolism and Signaling Symposium 2026 ↗ 24–27 Jun 2026 ·
Prague, Czech Republic · ★★★ - past Keystone: Mitochondria Signaling in Physiology and Disease 2026 ↗ 9–12 Feb 2026 ·
Keystone, Colorado, USA · ★
All meetings in the calendar →
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