2. Academic Validation
  3. Galectins Control mTOR in Response to Endomembrane Damage

Galectins Control mTOR in Response to Endomembrane Damage

  • Mol Cell. 2018 Apr 5;70(1):120-135.e8. doi: 10.1016/j.molcel.2018.03.009.
Jingyue Jia 1,  Yakubu Princely Abudu 2,  Aurore Claude-Taupin 1,  Yuexi Gu 1,  Suresh Kumar 1,  Seong Won Choi 1,  Ryan Peters 1,  Michal H Mudd 1,  Lee Allers 1,  Michelle Salemi 3,  Brett Phinney 3,  Terje Johansen 2,  Vojo Deretic 4
Affiliations

Affiliations

  • 1 Autophagy Inflammation and Metabolism Center of Biomedical Research Excellence, University of New Mexico Health Sciences Center, 915 Camino de Salud, NE, Albuquerque, NM 87131, USA; Department of Molecular Genetics and Microbiology, University of New Mexico Health Sciences Center, 915 Camino de Salud, NE, Albuquerque, NM 87131, USA.
  • 2 Molecular Cancer Research Group, Institute of Medical Biology, University of Tromsø-The Arctic University of Norway, 9037 Tromsø, Norway.
  • 3 Proteomics Core Facility, UC Davis Genome Center, University of California, Davis, CA 95616, USA.
  • 4 Autophagy Inflammation and Metabolism Center of Biomedical Research Excellence, University of New Mexico Health Sciences Center, 915 Camino de Salud, NE, Albuquerque, NM 87131, USA; Department of Molecular Genetics and Microbiology, University of New Mexico Health Sciences Center, 915 Camino de Salud, NE, Albuquerque, NM 87131, USA. Electronic address: [email protected].
PMID: 29625033 DOI: 10.1016/j.molcel.2018.03.009
Abstract

The Ser/Thr protein kinase mTOR controls metabolic pathways, including the catabolic process of Autophagy. Autophagy plays additional, catabolism-independent roles in homeostasis of cytoplasmic endomembranes and whole organelles. How signals from endomembrane damage are transmitted to mTOR to orchestrate autophagic responses is not known. Here we show that mTOR is inhibited by lysosomal damage. Lysosomal damage, recognized by galectins, leads to association of Galectin-8 (Gal8) with the mTOR apparatus on the lysosome. Gal8 inhibits mTOR activity through its Ragulator-Rag signaling machinery, whereas Galectin-9 activates AMPK in response to lysosomal injury. Both systems converge upon downstream effectors including Autophagy and defense against Mycobacterium tuberculosis. Thus, a novel galectin-based signal-transduction system, termed here GALTOR, intersects with the known regulators of mTOR on the lysosome and controls them in response to lysosomal damage. VIDEO ABSTRACT.

Keywords

AMPK; APEX2; LC3; TAK1; TFEB; autophagy; catabolism; galectins; lysosome; mTOR.

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