Related Experiment Video

Updated: Aug 19, 2026

Light-mediated Reversible Modulation of the Mitogen-activated Protein Kinase Pathway during Cell Differentiation and Xenopus Embryonic Development
09:32

Light-mediated Reversible Modulation of the Mitogen-activated Protein Kinase Pathway during Cell Differentiation and Xenopus Embryonic Development

Published on: June 15, 2017

TOR signaling: an odyssey from cellular stress to the cell growth machinery

Robert T Abraham1

  • 1Signal Transduction Program, The Burnham Institute, 10901 North Torrey Pines Road, La Jolla, California 92037, USA. abraham@burnham.org

Current Biology : CB
|February 23, 2005
PubMed

Insights

Hypoxic stress, which occurs when cells lack oxygen, reduces target of rapamycin (TOR) signaling. This finding reveals a key mechanism controlling cell growth and proliferation under stress.

Area of Science:

  • Cellular biology
  • Molecular signaling
  • Stress response

Background:

  • The target of rapamycin (TOR) protein kinase regulates cell growth and proliferation in response to nutrients and growth factors.
  • Understanding how cells adapt to environmental stress is crucial for comprehending development and disease.

Purpose of the Study:

  • To elucidate the mechanism by which hypoxic stress impacts TOR signaling in metazoan cells.
  • To identify how cellular stress influences fundamental processes like cell growth.

Main Methods:

  • Investigated the effects of hypoxia on TOR signaling pathways.
  • Utilized molecular biology techniques to analyze cellular responses to low oxygen conditions.

Main Results:

  • Demonstrated that hypoxic stress significantly dampens TOR signaling in metazoan cells.
  • Identified a specific mechanism linking oxygen availability to the regulation of cell growth pathways.

Conclusions:

  • Hypoxic stress actively suppresses TOR signaling, providing a critical link between oxygen levels and cell growth control.
  • This mechanism is essential for metazoan cells to adapt their growth and proliferation strategies under conditions of oxygen deprivation.

More Related Videos

Identification of Intracellular Signaling Events Induced in Viable Cells by Interaction with Neighboring Cells Undergoing Apoptotic Cell Death09:18

Identification of Intracellular Signaling Events Induced in Viable Cells by Interaction with Neighboring Cells Undergoing Apoptotic Cell Death

Published on: December 27, 2016

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...
Diversity in Cell Signaling Responses01:22

Diversity in Cell Signaling Responses

The physiological function of a cell and cellular communication are outcomes of a range of extrinsic signals, intracellular signaling pathways, and cellular responses. No two cell types express the same repertoire of signaling components. Receptors are highly selective for their cognate ligands, but once activated, they can alter multiple cellular processes such as DNA transcription, protein synthesis, and metabolic activity. 
Graded and Abrupt Responses
Some signaling systems generate...
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...
Overview of Cell Signaling01:23

Overview of Cell Signaling

Despite the protective membrane that separates a cell from the environment, cells need the ability to detect and respond to environmental changes. Additionally, cells often need to communicate with one another. Unicellular and multicellular organisms use a variety of cell signaling mechanisms to communicate with the environment.
Cells respond to many types of information, often through receptor proteins positioned on the membrane. For example, skin cells respond to and transmit touch...