title: The E3 ubiquitin ligase ZNRF2 is a substrate of mTORC1 and regulates its activation by amino acids.
abstract: The mechanistic Target of Rapamycin complex 1 (mTORC1) senses intracellular amino acid levels through an intricate machinery, which includes the Rag GTPases, Ragulator and vacuolar ATPase (V-ATPase). The membrane-associated E3 ubiquitin ligase ZNRF2 is released into the cytosol upon its phosphorylation by Akt. In this study, we show that ZNRF2 interacts with mTOR on membranes, promoting the amino acid-stimulated translocation of mTORC1 to lysosomes and its activation in human cells. ZNRF2 also interacts with the V-ATPase and preserves lysosomal acidity. Moreover, knockdown of ZNRF2 decreases cell size and cell proliferation. Upon growth factor and amino acid stimulation, mTORC1 phosphorylates ZNRF2 on Ser145, and this phosphosite is dephosphorylated by protein phosphatase 6. Ser145 phosphorylation stimulates vesicle-to-cytosol translocation of ZNRF2 and forms a novel negative feedback on mTORC1. Our findings uncover ZNRF2 as a component of the amino acid sensing machinery that acts upstream of Rag-GTPases and the V-ATPase to activate mTORC1.
authors.affiliation: MRC Protein Phosphorylation Unit, School of Life Sciences, University of Dundee, Dundee, United Kingdom.|Department of Genetics and Complex Diseases, Harvard T.H. Chan School of Public Health, Boston, United States.
authors.forename: Gerta
authors.identifier: 0000-0001-6179-3583
authors.initials: G
authors.lastname: Hoxhaj
authors.affiliation: MRC Protein Phosphorylation Unit, School of Life Sciences, University of Dundee, Dundee, United Kingdom.
authors.forename: Edward
authors.initials: E
authors.lastname: Caddye
authors.affiliation: MRC Protein Phosphorylation Unit, School of Life Sciences, University of Dundee, Dundee, United Kingdom.
authors.forename: Ayaz
authors.initials: A
authors.lastname: Najafov
authors.affiliation: MRC Protein Phosphorylation Unit, School of Life Sciences, University of Dundee, Dundee, United Kingdom.
authors.forename: Vanessa P
authors.initials: VP
authors.lastname: Houde
authors.affiliation: MRC Protein Phosphorylation Unit, School of Life Sciences, University of Dundee, Dundee, United Kingdom.
authors.forename: Catherine
authors.initials: C
authors.lastname: Johnson
authors.affiliation: MRC Protein Phosphorylation Unit, School of Life Sciences, University of Dundee, Dundee, United Kingdom.|Cell and Developmental Biology Division, School of Life Sciences, University of Dundee, Dundee, United Kingdom.
authors.forename: Kumara
authors.initials: K
authors.lastname: Dissanayake
authors.affiliation: MRC Protein Phosphorylation Unit, School of Life Sciences, University of Dundee, Dundee, United Kingdom.
authors.forename: Rachel
authors.initials: R
authors.lastname: Toth
authors.affiliation: MRC Protein Phosphorylation Unit, School of Life Sciences, University of Dundee, Dundee, United Kingdom.
authors.forename: David G
authors.initials: DG
authors.lastname: Campbell
authors.affiliation: Cell Signalling and Immunology Division, School of Life Sciences, University of Dundee, Dundee, United Kingdom.
authors.forename: Alan R
authors.initials: AR
authors.lastname: Prescott
authors.affiliation: MRC Protein Phosphorylation Unit, School of Life Sciences, University of Dundee, Dundee, United Kingdom.|Cell and Developmental Biology Division, School of Life Sciences, University of Dundee, Dundee, United Kingdom.
authors.forename: Carol
authors.identifier: 0000-0001-9166-589X
authors.initials: C
authors.lastname: MacKintosh
mesh_terms: D000596:Amino Acids / Q000378:metabolism*; D020558:GTP Phosphohydrolases / Q000378:metabolism; D015971:Gene Expression Regulation, Enzymologic; D055785:Gene Knockdown Techniques; D006801:Humans; D000076222:Mechanistic Target of Rapamycin Complex 1; D046912:Multiprotein Complexes / Q000378:metabolism*; D025941:Protein Interaction Mapping; D058570:TOR Serine-Threonine Kinases / Q000378:metabolism*; D044767:Ubiquitin-Protein Ligases / Q000235:genetics / Q000378:metabolism*; D025262:Vacuolar Proton-Translocating ATPases / Q000378:metabolism
chemical_list: D000596:Amino Acids; D046912:Multiprotein Complexes; D044767:Ubiquitin-Protein Ligases; C580704:ZNRF2 protein, human; D000076222:Mechanistic Target of Rapamycin Complex 1; D058570:TOR Serine-Threonine Kinases; D020558:GTP Phosphohydrolases; D025262:Vacuolar Proton-Translocating ATPases
keywords: PP6; Ragulator; V-ATPase; ZNRF2; amino acid sensing; biochemistry; cell biology; human; mTORC1; mouse