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Updated: May 30, 2026
08:35
In Situ Immunofluorescent Staining of Autophagy in Muscle Stem Cells
Published on: June 12, 2017
Spatio-temporal association between mTOR and autophagy during cellular senescence
Andrew R J Young1, Masako Narita, Masashi Narita
1Cancer Research UK, Cambridge Research Institute, Li Ka Shing Centre, Cambridge, UK.
Autophagy
|July 30, 2011
Summary
Lysosomes spatially link the mechanistic target of rapamycin (mTOR) and autophagy, forming a compartment that enhances protein synthesis and lysosome biogenesis during senescence. This TOR-autophagy spatial coupling compartment (TASCC) supports secretory functions and promotes autophagy.
Area of Science:
- Cell Biology
- Molecular Biology
- Biochemistry
Background:
- Emerging evidence links lysosomes to the mechanistic target of rapamycin (mTOR) signaling pathway.
- mTOR is recruited to lysosomal surfaces in response to amino acids, but its biological significance remains unclear.
- Lysosomes play a role in cellular senescence and are implicated in regulating mTOR activity.
Purpose of the Study:
- To investigate the spatial relationship between lysosomes, mTOR, and autophagy during oncogenic Ras-induced senescence.
- To elucidate the functional significance of the TOR-autophagy spatial coupling compartment (TASCC).
- To understand how TASCC formation influences protein synthesis, lysosome biogenesis, and autophagy.
Main Methods:
- Cellular imaging techniques to visualize lysosomes, mTOR, and autophagic structures.
- Biochemical assays to measure protein synthesis and mTOR activity.
- Genetic manipulation to study the role of Rag GTPases and Rheb in TASCC formation.
Main Results:
- Lysosomes spatially couple mTOR and autophagy, forming a TASCC near the Golgi apparatus during senescence.
- The TASCC is enriched for autolysosomes and facilitates mTOR recruitment and activation.
- mTOR recruitment to the TASCC enhances protein synthesis and reinforces lysosome and autophagy biogenesis.
- TASCC formation supports the production of secretory proteins and promotes autophagy by sequestering mTOR.
Conclusions:
- The TASCC is a novel cellular compartment that spatially integrates mTOR signaling and autophagy.
- TASCC formation is a self-enhancing process that promotes cellular functions like protein synthesis and lysosome biogenesis.
- Understanding TASCC biology offers insights into senescence, cancer, and metabolic regulation.
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