Related Experiment Video

Updated: Aug 15, 2026

Intracellular Phosphoflow Cytometry of Acute Myeloid Leukemia Patient-Derived Xenotransplants
07:38

Intracellular Phosphoflow Cytometry of Acute Myeloid Leukemia Patient-Derived Xenotransplants

Published on: June 6, 2025

Growing roles for the mTOR pathway

Dos D Sarbassov1, Siraj M Ali, David M Sabatini

  • 1Whitehead Institute, MIT Department of Biology, 9 Cambridge Center, Cambridge, Massachussetts 02142, USA.

Current Opinion in Cell Biology
|October 18, 2005
PubMed

Insights

The mammalian target of rapamycin (mTOR) pathway regulates cell growth and is implicated in diseases like cancer. New research clarifies how mTOR senses signals through distinct complexes and upstream regulators.

Area of Science:

  • Cellular Biology
  • Molecular Biology
  • Biochemistry

Background:

  • The mammalian target of rapamycin (mTOR) pathway is crucial for regulating cell growth, proliferation, and metabolism.
  • Deregulation of the mTOR pathway is increasingly linked to human diseases, notably cancer and diabetes.
  • The pathway integrates diverse signals including nutrients, energy levels, and growth factors.

Purpose of the Study:

  • To elucidate the mechanisms by which the mTOR pathway senses and integrates various cellular signals.
  • To understand the roles of distinct mTOR-containing complexes and their upstream regulators.
  • To provide insights into how mTOR orchestrates cellular processes like autophagy, ribosome biogenesis, and metabolism.

Main Methods:

  • Investigated the structure and function of mTOR-containing multiprotein complexes.
  • Characterized the roles of upstream regulators such as TSC1/2, rheb, and AMPK.
  • Analyzed the integration of nutrient, energy, and growth factor signals by the mTOR pathway.

Main Results:

  • Identified two distinct mTOR-containing complexes with unique structures and functions.
  • Elucidated the regulatory roles of TSC1/2, rheb, and AMPK as upstream modulators of mTOR.
  • Demonstrated how these components enable mTOR to sense diverse environmental cues.

Conclusions:

  • The mTOR pathway's ability to sense diverse signals and generate varied responses is mediated by distinct complexes and upstream regulators.
  • This intricate regulatory network is fundamental to cellular homeostasis and disease pathogenesis.
  • Further understanding of the mTOR pathway offers potential therapeutic targets for diseases like cancer and diabetes.

More Related Videos

Isolation of Primary Mouse Hepatocytes for Nascent Protein Synthesis Analysis by Non-radioactive L-azidohomoalanine Labeling Method08:04

Isolation of Primary Mouse Hepatocytes for Nascent Protein Synthesis Analysis by Non-radioactive L-azidohomoalanine Labeling Method

Published on: October 23, 2018

A RANKL-based Osteoclast Culture Assay of Mouse Bone Marrow to Investigate the Role of mTORC1 in Osteoclast Formation09:37

A RANKL-based Osteoclast Culture Assay of Mouse Bone Marrow to Investigate the Role of mTORC1 in Osteoclast Formation

Published on: March 15, 2018

Related Concept Videos

mTOR Signaling and Cancer Progression03:03

mTOR Signaling and Cancer Progression

The mammalian target of rapamycin or mTOR protein was discovered in 1994 due to its direct interaction with rapamycin. The protein gets its name from a yeast homolog called TOR. The mTOR protein complex in mammalian cells plays a major role in balancing anabolic processes such as the synthesis of proteins, lipids, and nucleotides and catabolic processes, such as autophagy in response to environmental cues, such as availability of nutrients and growth factors.
The mTOR pathway or the...
mTOR Signaling and Cancer Progression03:03

mTOR Signaling and Cancer Progression

The mammalian target of rapamycin or mTOR protein was discovered in 1994 due to its direct interaction with rapamycin. The protein gets its name from a yeast homolog called TOR. The mTOR protein complex in mammalian cells plays a major role in balancing anabolic processes such as the synthesis of proteins, lipids, and nucleotides and catabolic processes, such as autophagy in response to environmental cues, such as availability of nutrients and growth factors.
The mTOR pathway or the...
PI3K/mTOR/AKT Signaling Pathway01:22

PI3K/mTOR/AKT Signaling Pathway

The mammalian target of rapamycin  (mTOR) is a serine/threonine kinase that regulates growth, proliferation, and cell survival in response to hormones, growth factors, or nutrient availability. This kinase exists in two structurally and functionally distinct forms: mTOR complex 1  (mTORC1) and mTOR complex 2  (mTORC2). The first form (mTORC1) is composed of a rapamycin-sensitive Raptor and proline-rich Akt substrate, PRAS40. In contrast,  mTORC2 consists of a rapamycin-insensitive companion...
Interactions Between Signaling Pathways01:19

Interactions Between Signaling Pathways

Signaling cascades usually lack linearity. Multiple pathways interact and regulate one another, allowing cells to integrate and respond to diverse environmental stimuli.
Convergence and divergence, and cross-talk between signaling pathways
Two distinct signaling pathways can converge on a single functional unit, which may either be a single protein or a complex of proteins. The response is either functionally distinct or synergistic between the two pathways but different from the response...
MAPK Signaling Cascades01:07

MAPK Signaling Cascades

Mitogen-activated protein kinase, or MAPK pathway, activates three sequential kinases to regulate cellular responses such as proliferation, differentiation, survival, and apoptosis. The canonical MAPK pathway starts with a mitogen or growth factor binding to an RTK. The activated RTKs stimulate Ras, which recruits Raf or MAP3 Kinase (MAPKKK), the first kinase of the MAPK signaling cascade. Raf further phosphorylates and activates MEK or MAP2 Kinases (MAPKK), which in turn phosphorylates MAP...
Mitogens and the Cell Cycle02:38

Mitogens and the Cell Cycle

Mitogens and their receptors play a crucial role in controlling the progression of the cell cycle. However, the loss of mitogenic control over cell division leads to tumor formation. Therefore, mitogens and mitogen receptors play an important role in cancer research. For instance, the epidermal growth factor (EGF) - a type of mitogen and its transmembrane receptor (EGFR), decides the fate of the cell's proliferation. When EGF binds to EGFR, a member of the ErbB family of tyrosine kinase...