Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Galectins control mTOR in response to endomembrane damage

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 Gal8 with mTOR apparatus on the lysosome. Gal8 inhibits mTOR activity through its Ragulator-Rag signaling machinery. Thus, a novel galectin-based signal-transduction apparatus, termed here GALTOR, controls mTOR in response to lysosomal damage.

INSTRUMENT(S): Q Exactive

ORGANISM(S): Homo Sapiens (ncbitaxon:9606)

SUBMITTER: Vojo Deretic

PROVIDER: MSV000081788 | MassIVE | Thu Dec 07 09:49:00 GMT 2017

SECONDARY ACCESSION(S): PXD008390

REPOSITORIES: MassIVE

ACCESS DATA

Json Xml

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Similar Datasets

Atg8ylation coordinates stress granule formation and mTOR inactivation in response to lysosomal damage

Project description:Stress granule formation is a part of cellular homeostatic responses, with prototypical inducers being viral infections, heat shock and oxidative damage. Here we show that lysosomal damage is a previously unappreciated robust inducer of stress granule formation interlinked with mTOR inactivation during lysosomal damage. We find the two processes to be coordinated by a non-autophagy function of mammalian Atg8 proteins (mAtg8s). Stress granules were induced in response to biochemical damage and diverse lysosome damaging biological agents including SARS-CoV-2 ORF3a, Mycobacterium tuberculosis and protopathic tau. Proteomic analyses of purified lysosomes subjected to biochemical damage revealed recruitment to lysosomes of a network of stress granule proteins, including G3BP1 and NUFIP2. G3BP1 and NUFIP2 contributed to inactivation of mTOR during lysosomal damage via the Ragulator-RagA/B system. Lysosomal damage recruited a subset of mAtg8s commonly related to autophagy but also known to associate with other stressed or remodeling membranes. The GABARAP subset of mAtg8s interacted with G3BP1 and NUFIP2 and were required for NUFIP2 and G3BP1 recruitment to the damaged lysosomes. GABARAPs acted as a switch between the utilization of G3BP1 and NUFIP2 in stress granule formation vs. their role in mTOR inactivation. We furthermore found that mAtg8s lipidation, referred herein as Atg8ylation to distinguish it from its conventional implication in autophagy, but not the canonical autophagy factors ATG13, FIP200, and ATG9A, favored mTOR inactivation during lysosomal damage vs. the stress granule formation. Thus, cells utilize Atg8ylation as a response to membrane stress for specific outcomes beyond the process of autophagy, which include the coordinated stress granule formation and mTOR inactivation during lysosomal damage

| MSV000088152 | MassIVE

Membrane atg8ylation coordinates stress granule formation and mTOR inactivation in response to lysosomal damage

Project description:We report that lysosomal damage is a hitherto unknown inducer of stress granule (SG) formation and that the process termed membrane atg8ylation coordinates SG formation with mTOR inactivation during lysosomal stress. SGs were induced by lysosome-damaging agents including SARS-CoV-2ORF3a, Mycobacterium tuberculosis, and proteopathic tau. During damage, mammalian ATG8s directly interacted with the core SG proteins NUFIP2 and G3BP1. Atg8ylation was needed for their recruitment to damaged lysosomes independently of SG condensates whereupon NUFIP2 contributed to mTOR inactivation via the Ragulator-RagA/B complex. Thus, cells employ membrane atg8ylation to control and coordinate SG and mTOR responses to lysosomal damage.

2022-06-09 | MSV000089622 | MassIVE

Intracellular Galectin-3 Is a Sensor of Lipopolysaccharide that Promotes Glycolysis through Activating mTORC1

Project description:Galectin-3 is a carbohydrate binding protein implicated in cell-cell interaction and cell growth. Interestingly, recent studies suggest that galectin-3 is involved in cell metabolism and linked to diabetes and cancer. How galectin-3 might act as a diabetogenic and tumorogenic factor remains to be investigated. Here we report that intracellular galectin-3 is physically associated with Rag GTPases and Ragulator of the mTORC1 signaling machinery on lysosomes. We show that galectin-3 senses lipopolysaccharide (LPS) to facilitate the interaction of Rag GTPases and Ragulator, leading to activation of Rag GTPases thus lysosomal loading of mTOR and activation of mTORC1. Integrative genomics and transcriptomics analyses reveal that the LPS/galectin-3-Rag GTPases/Ragulator-mTORC1 axis regulates a cohort of genes including GLUT1 (glucose transporter member 1) that functions in glucose uptake and glycolysis and HK2 (hexokinase 2) and PKM2 (pyruvate kinase M2) that catalyze the first and last step of glycolysis, respectively. Indeed, galectin-3 deficiency severely compromises LPS-promoted glycolysis. Importantly, in diabetes patients, the expression of HK2 was significantly reduced, and in hepatocellular carcinoma (HCC), thyroid cancer, and prostate cancer, galectin-3 is highly expressed, and its level of expression is positively correlated with that of HK2 and PKM2 and negatively correlated with the prognosis of HCC patients. Our study unravels that galectin-3 is a sensor of LPS, an important modulator of the mTORC1 signaling, and a critical regulator of glucose metabolism, adding to the understanding of diabetogenesis and tumorigenesis.

2022-10-25 | GSE211784 | GEO

Spatial Coupling of mTOR and Autophagy Augments Secretory Phenotypes

Project description:Protein synthesis and autophagic degradation are regulated in an opposite manner by mammalian target of rapamycin (mTOR), whereas under certain conditions it would be beneficial if they occured in unison to handle rapid protein turnover. We observed a distinct cellular compartment at the trans-side of the Golgi apparatus, the ‘TOR-autophagy spatial coupling compartment’ (TASCC), where (auto)lysosomes and mTOR accumulated during Ras-induced senescence. mTOR recruitment to the TASCC was amino acid- and Rag guanosine triphosphatase (GTPase)-dependent, and disruption of mTOR localization to the TASCC suppressed interleukin-6/8 synthesis. TASCC-formation was observed during macrophage differentiation and in glomerular podocytes; both displayed increased protein secretion. The spatial coupling of cells’ catabolic and anabolic machinery could augment their respective functions and facilitate the mass synthesis of secretory proteins. To compare gene expression profile between growing and oncogenic Ras induced senescence, 4OHT inducible ER:H-RasV12 was stably expressed in IMR90 human diploid fibroblasts. Total RNA was isolated from day 0 and day 4 after 4OHT addition. There were 3 biological replicates for each of day0 and day 4 timepoints.

2011-05-04 | E-GEOD-28464 | biostudies-arrayexpress

Spatial Coupling of mTOR and Autophagy Augments Secretory Phenotypes

2011-05-05 | GSE28464 | GEO

Cathepsin B modulates lysosomal biogenesis and host defense against Francisella novicida infection

Project description:Lysosomal cathepsins regulate an exquisite range of biological functions, and their deregulation is associated with inflammatory, metabolic and degenerative disease in humans. Here, we identified a key cell-intrinsic role for cathepsin B as a negative feedback regulator of lysosomal biogenesis and autophagy. Mice and macrophages lacking cathepsin B activity had increased resistance to the cytosolic bacterial pathogen Francisella novicida. Genetic deletion or pharmacological inhibition of cathepsin B downregulated mTOR activity and prevented cleavage of the lysosomal calcium channel TRPML1. These events drove transcription of lysosomal and autophagy genes via the transcription factor TFEB, which increased lysosomal biogenesis and activation of autophagy-initiation kinase ULK1 for clearance of the bacteria. Our results identified a fundamental biological function of cathepsin B in providing a checkpoint for homeostatic maintenance of lysosome population and basic recycling functions in the cell. We used microarrays to explore the gene expression profiles differentially expressed in bone marrow-derived macrophages (BMDM) isolated from cathepsin B-/- and wild-type mice.

2016-08-04 | E-GEOD-79508 | biostudies-arrayexpress

Autophagy and lysosomal dysfunction in Tay Sachs disease are restored by mTOR modulation

Project description:Autophagy and lysosomal dysfunction in Tay Sachs disease are restored by mTOR modulation

| PRJNA767011 | ENA

Autophagy and lysosomal dysfunction in Tay Sachs disease are restored by mTOR modulation

Project description:Tay-Sachs disease (TSD) is a inherited lysosomal storage disease resulting from mutations in the α-subunits of the lysosomal enzyme, β-hexosaminidase A, and leads to excessive accumulation of GM2 ganglioside. This disease can be presented in infantil, juvenil and adult forms with rapid, progressive neurodegeneration. Although the link between mTOR and autophagy in Taysachs diseases has not been previously examined, it is reasonably to infer that reduced activity of HexA and the consequent intracellular accumulation of undegraded ganglyosides could lead accumulation of lysosomes, other substrates or dysfunctional organelles, similar to other defects detected in other LSD. In the present study, we show that skin fibroblasts derived from PLS patients presented increased p62/SQSTM1 expression levels and autophagosome accumulation suggesting an impaired autophagic flux.

2021-09-30 | GSE184906 | GEO

mTOR

Project description:mTOR

| PRJEB9498 | ENA

mTOR inhibitors synergistically induce regression, reversal of gene expression and autophagy in hepatocellular carcinoma

Project description:The mTOR-allosteric inhibitor, RAD001, in combination with a PI3K/mTOR ATP-site competitive inhibitor, BEZ235, causes gene reprogramming, autophagy and tumor regression, in a mouse model approximating human HCC with poor prognosis, leading to an investigator Phase 1B-2 clinical trial. Comparative study of total RNA obtained from normal and tumor liver tissue under RAD001, BEZ235, or RAD001 + BEZ235.

2012-07-11 | E-GEOD-37129 | biostudies-arrayexpress

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data