Galectins Control mTOR in Response to Endomembrane Damage.


FULLTEXT
Published:
04.07.2018
|
Last Revised:
01.07.2019
PMID:
29625033
Molecular cell
Journal Article,Research Support, Non-U.S. Gov't,Research Support, N.I.H., Extramural

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.
Molecular Cancer Research Group, Institute of Medical Biology, University of Tromsø-The Arctic University of Norway, 9037 Tromsø, Norway.
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.
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.
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.
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.
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.
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.
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.
Proteomics Core Facility, UC Davis Genome Center, University of California, Davis, CA 95616, USA.
Proteomics Core Facility, UC Davis Genome Center, University of California, Davis, CA 95616, USA.
Molecular Cancer Research Group, Institute of Medical Biology, University of Tromsø-The Arctic University of Norway, 9037 Tromsø, Norway.
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: vderetic@salud.unm.edu.

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.

GrantID: P20 GM121176, Acronym: GM, Agency: NIGMS NIH HHS, Country: United States | GrantID: R01 AI031139, Acronym: AI, Agency: NIAID NIH HHS, Country: United States | GrantID: R01 AI042999, Acronym: AI, Agency: NIAID NIH HHS, Country: United States | GrantID: R01 AI111935, Acronym: AI, Agency: NIAID NIH HHS, Country: United States