1
|
Depta L, Bryce-Rogers HP, Dekker NJ, Bønke AW, Camporese N, Qian M, Xu Y, Covey DF, Laraia L. Endogenous and fluorescent sterols reveal the molecular basis for ligand selectivity of human sterol transporters. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.22.604041. [PMID: 39091845 PMCID: PMC11291047 DOI: 10.1101/2024.07.22.604041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/04/2024]
Abstract
Sterol transport proteins (STPs) play a pivotal role in cholesterol homeostasis and therefore are essential for healthy human physiology. Despite recent advances in dissecting functions of STPs in the human cell, there is still a significant knowledge gap regarding their specific biological functions and a lack of suitable selective probes for their study. Here, we profile fluorescent steroid-based probes across ten STPs, uncovering substantial differences in their selectivity, aiding the retrospective and prospective interpretation of biological results generated with those probes. These results guided the establishment of an STP screening panel combining diverse biophysical assays, enabling the evaluation of 41 steroid-based natural products and derivatives. Combining this with a thorough structural analysis revealed the molecular basis for STP specific selectivity profiles, leading to the uncovering of several new potent and selective Aster-B inhibitors, and supporting the role of this protein in steroidogenesis.
Collapse
Affiliation(s)
- Laura Depta
- Department of Chemistry, Technical University of Denmark Kemitorvet 207, 2800 Kongens Lyngby, Denmark
| | - Hogan P. Bryce-Rogers
- Department of Chemistry, Technical University of Denmark Kemitorvet 207, 2800 Kongens Lyngby, Denmark
| | - Nienke J. Dekker
- Department of Chemistry, Technical University of Denmark Kemitorvet 207, 2800 Kongens Lyngby, Denmark
| | - Anna Wiehl Bønke
- Department of Chemistry, Technical University of Denmark Kemitorvet 207, 2800 Kongens Lyngby, Denmark
| | - Nicolo’ Camporese
- Department of Chemistry, Technical University of Denmark Kemitorvet 207, 2800 Kongens Lyngby, Denmark
| | - Mingxing Qian
- Department of Developmental Biology, Washington University in St. Louis, School of Medicine, St. Louis, MO 63110
- Taylor Family Institute for Innovative Psychiatric Research, Washington University in St. Louis, School of Medicine, St. Louis, MO 63110
| | - Yuanjian Xu
- Department of Developmental Biology, Washington University in St. Louis, School of Medicine, St. Louis, MO 63110
- Taylor Family Institute for Innovative Psychiatric Research, Washington University in St. Louis, School of Medicine, St. Louis, MO 63110
| | - Douglas F. Covey
- Department of Developmental Biology, Washington University in St. Louis, School of Medicine, St. Louis, MO 63110
- Taylor Family Institute for Innovative Psychiatric Research, Washington University in St. Louis, School of Medicine, St. Louis, MO 63110
| | - Luca Laraia
- Department of Chemistry, Technical University of Denmark Kemitorvet 207, 2800 Kongens Lyngby, Denmark
| |
Collapse
|
2
|
Banerjee R, Hohe RC, Cao S, Jung BM, Horak AJ, Ramachandiran I, Massey WJ, Varadharajan V, Zajczenko NI, Burrows AC, Dutta S, Goudarzi M, Mahen K, Carter A, Helsley RN, Gordon SM, Morton RE, Strauch C, Willard B, Gogonea CB, Gogonea V, Pedrelli M, Parini P, Brown JM. The nonvesicular sterol transporter Aster-C plays a minor role in whole body cholesterol balance. Front Physiol 2024; 15:1371096. [PMID: 38694206 PMCID: PMC11061533 DOI: 10.3389/fphys.2024.1371096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2024] [Accepted: 03/19/2024] [Indexed: 05/04/2024] Open
Abstract
Introduction The Aster-C protein (encoded by the Gramd1c gene) is an endoplasmic reticulum (ER) resident protein that has been reported to transport cholesterol from the plasma membrane to the ER. Although there is a clear role for the closely-related Aster-B protein in cholesterol transport and downstream esterification in the adrenal gland, the specific role for Aster-C in cholesterol homeostasis is not well understood. Here, we have examined whole body cholesterol balance in mice globally lacking Aster-C under low or high dietary cholesterol conditions. Method Age-matched Gramd1c +/+ and Gramd1c -/- mice were fed either low (0.02%, wt/wt) or high (0.2%, wt/wt) dietarycholesterol and levels of sterol-derived metabolites were assessed in the feces, liver, and plasma. Results Compared to wild type controls (Gramd1c +/+) mice, mice lackingGramd1c (Gramd1c -/-) have no significant alterations in fecal, liver, or plasma cholesterol. Given the potential role for Aster C in modulating cholesterol metabolism in diverse tissues, we quantified levels of cholesterol metabolites such as bile acids, oxysterols, and steroid hormones. Compared to Gramd1c +/+ controls, Gramd1c -/- mice had modestly reduced levels of select bile acid species and elevated cortisol levels, only under low dietary cholesterol conditions. However, the vast majority of bile acids, oxysterols, and steroid hormones were unaltered in Gramd1c -/- mice. Bulk RNA sequencing in the liver showed that Gramd1c -/- mice did not exhibit alterations in sterol-sensitive genes, but instead showed altered expression of genes in major urinary protein and cytochrome P450 (CYP) families only under low dietary cholesterol conditions. Discussion Collectively, these data indicate nominal effects of Aster-C on whole body cholesterol transport and metabolism under divergent dietary cholesterol conditions. These results strongly suggest that Aster-C alone is not sufficient to control whole body cholesterol balance, but can modestly impact circulating cortisol and bile acid levels when dietary cholesterol is limited.
Collapse
Affiliation(s)
- Rakhee Banerjee
- Department of Cancer Biology, Lerner Research Institute of the Cleveland Clinic, Cleveland, OH, United States
- Center for Microbiome and Human Health, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States
| | - Rachel C. Hohe
- Department of Cancer Biology, Lerner Research Institute of the Cleveland Clinic, Cleveland, OH, United States
- Center for Microbiome and Human Health, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States
| | - Shijie Cao
- Department of Cancer Biology, Lerner Research Institute of the Cleveland Clinic, Cleveland, OH, United States
- Center for Microbiome and Human Health, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States
| | - Bryan M. Jung
- Department of Cancer Biology, Lerner Research Institute of the Cleveland Clinic, Cleveland, OH, United States
- Center for Microbiome and Human Health, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States
| | - Anthony J. Horak
- Center for Microbiome and Human Health, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States
| | - Iyappan Ramachandiran
- Center for Microbiome and Human Health, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland, OH, United States
| | - William J. Massey
- Department of Cancer Biology, Lerner Research Institute of the Cleveland Clinic, Cleveland, OH, United States
- Center for Microbiome and Human Health, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States
| | - Venkateshwari Varadharajan
- Department of Cancer Biology, Lerner Research Institute of the Cleveland Clinic, Cleveland, OH, United States
- Center for Microbiome and Human Health, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States
| | - Natalie I. Zajczenko
- Department of Cancer Biology, Lerner Research Institute of the Cleveland Clinic, Cleveland, OH, United States
- Center for Microbiome and Human Health, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States
| | - Amy C. Burrows
- Department of Cancer Biology, Lerner Research Institute of the Cleveland Clinic, Cleveland, OH, United States
- Center for Microbiome and Human Health, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States
| | - Sumita Dutta
- Department of Cancer Biology, Lerner Research Institute of the Cleveland Clinic, Cleveland, OH, United States
- Center for Microbiome and Human Health, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States
| | - Maryam Goudarzi
- Department of Cancer Biology, Lerner Research Institute of the Cleveland Clinic, Cleveland, OH, United States
- Center for Microbiome and Human Health, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States
| | - Kala Mahen
- Department of Cancer Biology, Lerner Research Institute of the Cleveland Clinic, Cleveland, OH, United States
- Center for Microbiome and Human Health, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States
| | - Abigail Carter
- Department of Physiology and the Saha Cardiovascular Research Center, University of Kentucky College of Medicine, Lexington, KY, United States
| | - Robert N. Helsley
- Department of Physiology and the Saha Cardiovascular Research Center, University of Kentucky College of Medicine, Lexington, KY, United States
- Department of Internal Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Kentucky College of Medicine, Lexington, KY, United States
| | - Scott M. Gordon
- Department of Physiology and the Saha Cardiovascular Research Center, University of Kentucky College of Medicine, Lexington, KY, United States
| | - Richard E. Morton
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland, OH, United States
| | - Christopher Strauch
- Proteomics and Metabolomics Core, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States
| | - Belinda Willard
- Proteomics and Metabolomics Core, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States
| | | | - Valentin Gogonea
- Department of Chemistry, Cleveland State University, Cleveland, OH, United States
| | - Matteo Pedrelli
- Department of Laboratory Medicine, Karolinska Institute, Huddinge, Sweden
| | - Paolo Parini
- Department of Laboratory Medicine, Karolinska Institute, Huddinge, Sweden
| | - J. Mark Brown
- Department of Cancer Biology, Lerner Research Institute of the Cleveland Clinic, Cleveland, OH, United States
- Center for Microbiome and Human Health, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States
| |
Collapse
|
3
|
He N, Depta L, Sievers S, Laraia L. Fluorescent probes and degraders of the sterol transport protein Aster-A. Bioorg Med Chem 2024; 103:117673. [PMID: 38518734 DOI: 10.1016/j.bmc.2024.117673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Revised: 02/26/2024] [Accepted: 03/01/2024] [Indexed: 03/24/2024]
Abstract
Our understanding of sterol transport proteins (STPs) has increased exponentially in the last decades with advances in the cellular and structural biology of these important proteins. However, small molecule probes have only recently been developed for a few selected STPs. Here we describe the synthesis and evaluation of potential proteolysis-targeting chimeras (PROTACs) based on inhibitors of the STP Aster-A. Based on the reported Aster-A inhibitor autogramin-2, ten PROTACs were synthesized. Pomalidomide-based PROTACs functioned as fluorescent probes due to the intrinsic fluorescent properties of the aminophthalimide core, which in some cases was significantly enhanced upon Aster-A binding. Most PROTACs maintained excellent binary affinity to Aster-A, and one compound, NGF3, showed promising Aster-A degradation in cells. The tools developed here lay the foundation for optimizing Aster-A fluorescent probes and degraders and studying its activity and function in vitro and in cells.
Collapse
Affiliation(s)
- Nianzhe He
- Department of Chemistry, Technical University of Denmark, Kemitorvet 207, 2800 Kgs. Lyngby, Denmark
| | - Laura Depta
- Department of Chemistry, Technical University of Denmark, Kemitorvet 207, 2800 Kgs. Lyngby, Denmark
| | - Sonja Sievers
- Max Planck Institute of molecular physiology, Otto-Hahn-Strasse 11, Dortmund, Germany
| | - Luca Laraia
- Department of Chemistry, Technical University of Denmark, Kemitorvet 207, 2800 Kgs. Lyngby, Denmark.
| |
Collapse
|
4
|
Delafontaine S, Iannuzzo A, Bigley TM, Mylemans B, Rana R, Baatsen P, Poli MC, Rymen D, Jansen K, Mekahli D, Casteels I, Cassiman C, Demaerel P, Lepelley A, Frémond ML, Schrijvers R, Bossuyt X, Vints K, Huybrechts W, Tacine R, Willekens K, Corveleyn A, Boeckx B, Baggio M, Ehlers L, Munck S, Lambrechts D, Voet A, Moens L, Bucciol G, Cooper MA, Davis CM, Delon J, Meyts I. Heterozygous mutations in the C-terminal domain of COPA underlie a complex autoinflammatory syndrome. J Clin Invest 2024; 134:e163604. [PMID: 38175705 PMCID: PMC10866661 DOI: 10.1172/jci163604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Accepted: 12/20/2023] [Indexed: 01/05/2024] Open
Abstract
Mutations in the N-terminal WD40 domain of coatomer protein complex subunit α (COPA) cause a type I interferonopathy, typically characterized by alveolar hemorrhage, arthritis, and nephritis. We described 3 heterozygous mutations in the C-terminal domain (CTD) of COPA (p.C1013S, p.R1058C, and p.R1142X) in 6 children from 3 unrelated families with a similar syndrome of autoinflammation and autoimmunity. We showed that these CTD COPA mutations disrupt the integrity and the function of coat protein complex I (COPI). In COPAR1142X and COPAR1058C fibroblasts, we demonstrated that COPI dysfunction causes both an anterograde ER-to-Golgi and a retrograde Golgi-to-ER trafficking defect. The disturbed intracellular trafficking resulted in a cGAS/STING-dependent upregulation of the type I IFN signaling in patients and patient-derived cell lines, albeit through a distinct molecular mechanism in comparison with mutations in the WD40 domain of COPA. We showed that CTD COPA mutations induce an activation of ER stress and NF-κB signaling in patient-derived primary cell lines. These results demonstrate the importance of the integrity of the CTD of COPA for COPI function and homeostatic intracellular trafficking, essential to ER homeostasis. CTD COPA mutations result in disease by increased ER stress, disturbed intracellular transport, and increased proinflammatory signaling.
Collapse
Affiliation(s)
- Selket Delafontaine
- Laboratory for Inborn Errors of Immunity, Department of Microbiology, Immunology and Transplantation, KU Leuven, Leuven, Belgium
- Department of Pediatrics, University Hospitals Leuven, Leuven, Belgium
| | - Alberto Iannuzzo
- Université Paris Cité, CNRS, INSERM, Institut Cochin, Paris, France
| | - Tarin M. Bigley
- Department of Pediatrics, Division of Rheumatology/Immunology, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Bram Mylemans
- Laboratory of Biomolecular Modelling and Design, Department of Chemistry, KU Leuven, Leuven, Belgium
| | - Ruchit Rana
- Division of Immunology, Allergy and Retrovirology, Baylor College of Medicine, Texas Children’s Hospital, Houston, Texas, USA
| | - Pieter Baatsen
- Electron Microscopy Platform of VIB Bio Imaging Core, KU Leuven, Leuven, Belgium
| | - Maria Cecilia Poli
- Department of Pediatrics, Clínica Alemana de Santiago, Universidad del Desarollo, Santiago, Chile
- Immunology and Rheumatology Unit, Hospital de Niños Dr. Roberto del Rio, Santiago, Chile
| | - Daisy Rymen
- Department of Pediatrics, University Hospitals Leuven, Leuven, Belgium
| | - Katrien Jansen
- Department of Pediatrics, University Hospitals Leuven, Leuven, Belgium
| | - Djalila Mekahli
- PKD Research Group, Laboratory of Ion Channel Research, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
- Department of Pediatric Nephrology
| | | | | | - Philippe Demaerel
- Department of Radiology, University Hospitals Leuven, Leuven, Belgium
| | - Alice Lepelley
- Université Paris Cité, Imagine Institute, Laboratory of Neurogenetics and Neuroinflammation, INSERM UMR 1163, Paris, France
| | - Marie-Louise Frémond
- Université Paris Cité, Imagine Institute, Laboratory of Neurogenetics and Neuroinflammation, INSERM UMR 1163, Paris, France
- Paediatric Haematology-Immunology and Rheumatology Unit, Necker Hospital, AP-HP.Centre - Université Paris Cité, Paris, France
| | - Rik Schrijvers
- Allergy and Clinical Immunology Research Group, Department of Microbiology, Immunology and Transplantation, and
| | - Xavier Bossuyt
- Clinical and Diagnostic Immunology, Department of Microbiology, Immunology and Transplantation, KU Leuven, Leuven, Belgium
| | - Katlijn Vints
- Electron Microscopy Platform of VIB Bio Imaging Core, KU Leuven, Leuven, Belgium
| | - Wim Huybrechts
- Center for Human Genetics, Leuven University Hospitals, Leuven, Belgium
| | - Rachida Tacine
- Université Paris Cité, CNRS, INSERM, Institut Cochin, Paris, France
| | - Karen Willekens
- Center for Human Genetics, Leuven University Hospitals, Leuven, Belgium
| | - Anniek Corveleyn
- Center for Human Genetics, Leuven University Hospitals, Leuven, Belgium
| | - Bram Boeckx
- Laboratory for Translational Genetics, Department of Human Genetics, KU Leuven, Leuven, Belgium
- VIB Center for Cancer Biology, Leuven, Belgium
| | - Marco Baggio
- Laboratory for Inborn Errors of Immunity, Department of Microbiology, Immunology and Transplantation, KU Leuven, Leuven, Belgium
| | - Lisa Ehlers
- Laboratory for Inborn Errors of Immunity, Department of Microbiology, Immunology and Transplantation, KU Leuven, Leuven, Belgium
| | - Sebastian Munck
- VIB Bio Imaging Core and VIB–KU Leuven Center for Brain & Disease Research, KU Leuven Department of Neurosciences, Leuven, Belgium
| | - Diether Lambrechts
- Laboratory for Translational Genetics, Department of Human Genetics, KU Leuven, Leuven, Belgium
- VIB Center for Cancer Biology, Leuven, Belgium
| | - Arnout Voet
- Laboratory of Biomolecular Modelling and Design, Department of Chemistry, KU Leuven, Leuven, Belgium
| | - Leen Moens
- Laboratory for Inborn Errors of Immunity, Department of Microbiology, Immunology and Transplantation, KU Leuven, Leuven, Belgium
| | - Giorgia Bucciol
- Laboratory for Inborn Errors of Immunity, Department of Microbiology, Immunology and Transplantation, KU Leuven, Leuven, Belgium
- Department of Pediatrics, University Hospitals Leuven, Leuven, Belgium
| | - Megan A. Cooper
- Department of Pediatrics, Division of Rheumatology/Immunology, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Carla M. Davis
- Division of Immunology, Allergy and Retrovirology, Baylor College of Medicine, Texas Children’s Hospital, Houston, Texas, USA
| | - Jérôme Delon
- Université Paris Cité, CNRS, INSERM, Institut Cochin, Paris, France
| | - Isabelle Meyts
- Laboratory for Inborn Errors of Immunity, Department of Microbiology, Immunology and Transplantation, KU Leuven, Leuven, Belgium
- Department of Pediatrics, University Hospitals Leuven, Leuven, Belgium
| |
Collapse
|
5
|
Naito T, Yang H, Koh DHZ, Mahajan D, Lu L, Saheki Y. Regulation of cellular cholesterol distribution via non-vesicular lipid transport at ER-Golgi contact sites. Nat Commun 2023; 14:5867. [PMID: 37735529 PMCID: PMC10514280 DOI: 10.1038/s41467-023-41213-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Accepted: 08/28/2023] [Indexed: 09/23/2023] Open
Abstract
Abnormal distribution of cellular cholesterol is associated with numerous diseases, including cardiovascular and neurodegenerative diseases. Regulated transport of cholesterol is critical for maintaining its proper distribution in the cell, yet the underlying mechanisms remain unclear. Here, we show that lipid transfer proteins, namely ORP9, OSBP, and GRAMD1s/Asters (GRAMD1a/GRAMD1b/GRAMD1c), control non-vesicular cholesterol transport at points of contact between the ER and the trans-Golgi network (TGN), thereby maintaining cellular cholesterol distribution. ORP9 localizes to the TGN via interaction between its tandem α-helices and ORP10/ORP11. ORP9 extracts PI4P from the TGN to prevent its overaccumulation and suppresses OSBP-mediated PI4P-driven cholesterol transport to the Golgi. By contrast, GRAMD1s transport excess cholesterol from the Golgi to the ER, thereby preventing its build-up. Cells lacking ORP9 exhibit accumulation of cholesterol at the Golgi, which is further enhanced by additional depletion of GRAMD1s with major accumulation in the plasma membrane. This is accompanied by chronic activation of the SREBP-2 signalling pathway. Our findings reveal the importance of regulated lipid transport at ER-Golgi contacts for maintaining cellular cholesterol distribution and homeostasis.
Collapse
Affiliation(s)
- Tomoki Naito
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, 308232, Singapore
| | - Haoning Yang
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, 308232, Singapore
| | - Dylan Hong Zheng Koh
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, 308232, Singapore
| | - Divyanshu Mahajan
- School of Biological Sciences, Nanyang Technological University, Singapore, 637551, Singapore
| | - Lei Lu
- School of Biological Sciences, Nanyang Technological University, Singapore, 637551, Singapore
| | - Yasunori Saheki
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, 308232, Singapore.
- Institute of Resource Development and Analysis, Kumamoto University, Kumamoto, 860-0811, Japan.
| |
Collapse
|
6
|
The role of CaMKK2 in Golgi-associated vesicle trafficking. Biochem Soc Trans 2023; 51:331-342. [PMID: 36815702 PMCID: PMC9987998 DOI: 10.1042/bst20220833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2022] [Revised: 02/03/2023] [Accepted: 02/07/2023] [Indexed: 02/24/2023]
Abstract
Calcium/calmodulin-dependent protein kinase kinase 2 (CaMKK2) is a serine/threonine-protein kinase, that is involved in maintaining various physiological and cellular processes within the cell that regulate energy homeostasis and cell growth. CaMKK2 regulates glucose metabolism by the activation of downstream kinases, AMP-activated protein kinase (AMPK) and other calcium/calmodulin-dependent protein kinases. Consequently, its deregulation has a role in multiple human metabolic diseases including obesity and cancer. Despite the importance of CaMKK2, its signalling pathways and pathological mechanisms are not completely understood. Recent work has been aimed at broadening our understanding of the biological functions of CaMKK2. These studies have uncovered new interaction partners that have led to the description of new functions that include lipogenesis and Golgi vesicle trafficking. Here, we review recent insights into the role of CaMKK2 in membrane trafficking mechanisms and discuss the functional implications in a cellular context and for disease.
Collapse
|
7
|
Frappaolo A, Karimpour-Ghahnavieh A, Cesare G, Sechi S, Fraschini R, Vaccari T, Giansanti MG. GOLPH3 protein controls organ growth by interacting with TOR signaling proteins in Drosophila. Cell Death Dis 2022; 13:1003. [PMID: 36435842 PMCID: PMC9701223 DOI: 10.1038/s41419-022-05438-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 11/11/2022] [Accepted: 11/14/2022] [Indexed: 11/28/2022]
Abstract
The oncoprotein GOLPH3 (Golgi phosphoprotein 3) is an evolutionarily conserved phosphatidylinositol 4-phosphate effector, mainly localized to the Golgi apparatus, where it supports organelle architecture and vesicular trafficking. Overexpression of human GOLPH3 correlates with poor prognosis in several cancer types and is associated with enhanced signaling downstream of mTOR (mechanistic target of rapamycin). However, the molecular link between GOLPH3 and mTOR remains elusive. Studies in Drosophila melanogaster have shown that Translationally controlled tumor protein (Tctp) and 14-3-3 proteins are required for organ growth by supporting the function of the small GTPase Ras homolog enriched in the brain (Rheb) during mTORC1 (mTOR complex 1) signaling. Here we demonstrate that Drosophila GOLPH3 (dGOLPH3) physically interacts with Tctp and 14-3-3ζ. RNAi-mediated knockdown of dGOLPH3 reduces wing and eye size and enhances the phenotypes of Tctp RNAi. This phenotype is partially rescued by overexpression of Tctp, 14-3-3ζ, or Rheb. We also show that the Golgi localization of Rheb in Drosophila cells depends on dGOLPH3. Consistent with dGOLPH3 involvement in Rheb-mediated mTORC1 activation, depletion of dGOLPH3 also reduces levels of phosphorylated ribosomal S6 kinase, a downstream target of mTORC1. Finally, the autophagy flux and the expression of autophagic transcription factors of the TFEB family, which anti correlates with mTOR signaling, are compromised upon reduction of dGOLPH3. Overall, our data provide the first in vivo demonstration that GOLPH3 regulates organ growth by directly associating with mTOR signaling proteins.
Collapse
Affiliation(s)
- Anna Frappaolo
- grid.7841.aIstituto di Biologia e Patologia Molecolari del CNR, c/o Dipartimento di Biologia e Biotecnologie, Sapienza Università di Roma, 00185 Roma, Italy
| | - Angela Karimpour-Ghahnavieh
- grid.7841.aIstituto di Biologia e Patologia Molecolari del CNR, c/o Dipartimento di Biologia e Biotecnologie, Sapienza Università di Roma, 00185 Roma, Italy
| | - Giuliana Cesare
- grid.4708.b0000 0004 1757 2822Dipartimento di Bioscienze, Università degli Studi di Milano, 20133 Milano, Italy
| | - Stefano Sechi
- grid.7841.aIstituto di Biologia e Patologia Molecolari del CNR, c/o Dipartimento di Biologia e Biotecnologie, Sapienza Università di Roma, 00185 Roma, Italy
| | - Roberta Fraschini
- grid.7563.70000 0001 2174 1754Dipartimento di Biotecnologie e Bioscienze, Università degli studi di Milano Bicocca, 20126 Milano, Italy
| | - Thomas Vaccari
- grid.4708.b0000 0004 1757 2822Dipartimento di Bioscienze, Università degli Studi di Milano, 20133 Milano, Italy
| | - Maria Grazia Giansanti
- grid.7841.aIstituto di Biologia e Patologia Molecolari del CNR, c/o Dipartimento di Biologia e Biotecnologie, Sapienza Università di Roma, 00185 Roma, Italy
| |
Collapse
|
8
|
Ng MYW, Charsou C, Lapao A, Singh S, Trachsel-Moncho L, Schultz SW, Nakken S, Munson MJ, Simonsen A. The cholesterol transport protein GRAMD1C regulates autophagy initiation and mitochondrial bioenergetics. Nat Commun 2022; 13:6283. [PMID: 36270994 PMCID: PMC9586981 DOI: 10.1038/s41467-022-33933-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 10/05/2022] [Indexed: 12/25/2022] Open
Abstract
During autophagy, cytosolic cargo is sequestered into double-membrane vesicles called autophagosomes. The contributions of specific lipids, such as cholesterol, to the membranes that form the autophagosome, remain to be fully characterized. Here, we demonstrate that short term cholesterol depletion leads to a rapid induction of autophagy and a corresponding increase in autophagy initiation events. We further show that the ER-localized cholesterol transport protein GRAMD1C functions as a negative regulator of starvation-induced autophagy and that both its cholesterol transport VASt domain and membrane binding GRAM domain are required for GRAMD1C-mediated suppression of autophagy initiation. Similar to its yeast orthologue, GRAMD1C associates with mitochondria through its GRAM domain. Cells lacking GRAMD1C or its VASt domain show increased mitochondrial cholesterol levels and mitochondrial oxidative phosphorylation, suggesting that GRAMD1C may facilitate cholesterol transfer at ER-mitochondria contact sites. Finally, we demonstrate that expression of GRAMD family proteins is linked to clear cell renal carcinoma survival, highlighting the pathophysiological relevance of cholesterol transport proteins.
Collapse
Affiliation(s)
- Matthew Yoke Wui Ng
- grid.5510.10000 0004 1936 8921Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, 0372 Oslo, Norway ,grid.5510.10000 0004 1936 8921Centre for Cancer Cell Reprogramming, Institute of Clinical Medicine, University of Oslo, 0450 Oslo, Norway
| | - Chara Charsou
- grid.5510.10000 0004 1936 8921Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, 0372 Oslo, Norway ,grid.5510.10000 0004 1936 8921Centre for Cancer Cell Reprogramming, Institute of Clinical Medicine, University of Oslo, 0450 Oslo, Norway
| | - Ana Lapao
- grid.5510.10000 0004 1936 8921Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, 0372 Oslo, Norway ,grid.5510.10000 0004 1936 8921Centre for Cancer Cell Reprogramming, Institute of Clinical Medicine, University of Oslo, 0450 Oslo, Norway
| | - Sakshi Singh
- grid.5510.10000 0004 1936 8921Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, 0372 Oslo, Norway ,grid.5510.10000 0004 1936 8921Centre for Cancer Cell Reprogramming, Institute of Clinical Medicine, University of Oslo, 0450 Oslo, Norway
| | - Laura Trachsel-Moncho
- grid.5510.10000 0004 1936 8921Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, 0372 Oslo, Norway ,grid.5510.10000 0004 1936 8921Centre for Cancer Cell Reprogramming, Institute of Clinical Medicine, University of Oslo, 0450 Oslo, Norway
| | - Sebastian W. Schultz
- grid.5510.10000 0004 1936 8921Centre for Cancer Cell Reprogramming, Institute of Clinical Medicine, University of Oslo, 0450 Oslo, Norway ,grid.55325.340000 0004 0389 8485Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital Montebello, 0379 Oslo, Norway
| | - Sigve Nakken
- grid.5510.10000 0004 1936 8921Centre for Cancer Cell Reprogramming, Institute of Clinical Medicine, University of Oslo, 0450 Oslo, Norway ,grid.55325.340000 0004 0389 8485Department of Tumor Biology, Institute for Cancer Research, Oslo University Hospital Montebello, 0379 Oslo, Norway
| | - Michael J. Munson
- grid.5510.10000 0004 1936 8921Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, 0372 Oslo, Norway ,grid.5510.10000 0004 1936 8921Centre for Cancer Cell Reprogramming, Institute of Clinical Medicine, University of Oslo, 0450 Oslo, Norway ,grid.418151.80000 0001 1519 6403Present Address: Advanced Drug Delivery, Pharmaceutical Sciences, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Anne Simonsen
- grid.5510.10000 0004 1936 8921Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, 0372 Oslo, Norway ,grid.5510.10000 0004 1936 8921Centre for Cancer Cell Reprogramming, Institute of Clinical Medicine, University of Oslo, 0450 Oslo, Norway ,grid.55325.340000 0004 0389 8485Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital Montebello, 0379 Oslo, Norway
| |
Collapse
|
9
|
Murley A, Wickham K, Dillin A. Life in lockdown: Orchestrating endoplasmic reticulum and lysosome homeostasis for quiescent cells. Mol Cell 2022; 82:3526-3537. [PMID: 36044901 DOI: 10.1016/j.molcel.2022.08.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 07/06/2022] [Accepted: 08/04/2022] [Indexed: 11/25/2022]
Abstract
Cellular quiescence-reversible exit from the cell cycle-is an important feature of many cell types important for organismal health. Quiescent cells activate protective mechanisms that allow their persistence in the absence of growth and division for long periods of time. Aging and cellular dysfunction compromise the survival and re-activation of quiescent cells over time. Counteracting this decline are two interconnected organelles that lie at opposite ends of the secretory pathway: the endoplasmic reticulum and lysosomes. In this review, we highlight recent studies exploring the roles of these two organelles in quiescent cells from diverse contexts and speculate on potential other roles they may play, such as through organelle contact sites. Finally, we discuss emerging models of cellular quiescence, utilizing new cell culture systems and model organisms, that are suited to the mechanistic investigation of the functions of these organelles in quiescent cells.
Collapse
Affiliation(s)
- Andrew Murley
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA
| | - Kevin Wickham
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA
| | - Andrew Dillin
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA; Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, CA, USA.
| |
Collapse
|
10
|
Whitmarsh-Everiss T, Olsen AH, Laraia L. Identification of Inhibitors of Cholesterol Transport Proteins Through the Synthesis of a Diverse, Sterol-Inspired Compound Collection. Angew Chem Int Ed Engl 2021; 60:26755-26761. [PMID: 34626154 DOI: 10.1002/anie.202111639] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Indexed: 12/26/2022]
Abstract
Cholesterol transport proteins regulate a vast array of cellular processes including lipid metabolism, vesicular and non-vesicular trafficking, organelle contact sites, and autophagy. Despite their undoubted importance, the identification of selective modulators of this class of proteins has been challenging due to the structural similarities in the cholesterol-binding site. Herein we report a general strategy for the identification of selective inhibitors of cholesterol transport proteins via the synthesis of a diverse sterol-inspired compound collection. Fusion of a primary sterol fragment to an array of secondary privileged scaffolds led to the identification of potent and selective inhibitors of the cholesterol transport protein Aster-C, which displayed a surprising preference for the unnatural-sterol AB-ring stereochemistry and new inhibitors of Aster-A. We propose that this strategy can and should be applied to any therapeutically relevant sterol-binding protein.
Collapse
Affiliation(s)
- Thomas Whitmarsh-Everiss
- Department of Chemistry, Technical University of Denmark, Kemitorvet 207, 2800, Kongens Lyngby, Denmark
| | - Asger Hegelund Olsen
- Department of Chemistry, Technical University of Denmark, Kemitorvet 207, 2800, Kongens Lyngby, Denmark
| | - Luca Laraia
- Department of Chemistry, Technical University of Denmark, Kemitorvet 207, 2800, Kongens Lyngby, Denmark
| |
Collapse
|
11
|
Whitmarsh‐Everiss T, Olsen AH, Laraia L. Identification of Inhibitors of Cholesterol Transport Proteins Through the Synthesis of a Diverse, Sterol‐Inspired Compound Collection. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202111639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Thomas Whitmarsh‐Everiss
- Department of Chemistry Technical University of Denmark Kemitorvet 207 2800 Kongens Lyngby Denmark
| | - Asger Hegelund Olsen
- Department of Chemistry Technical University of Denmark Kemitorvet 207 2800 Kongens Lyngby Denmark
| | - Luca Laraia
- Department of Chemistry Technical University of Denmark Kemitorvet 207 2800 Kongens Lyngby Denmark
| |
Collapse
|
12
|
Loissell-Baltazar YA, Dokudovskaya S. SEA and GATOR 10 Years Later. Cells 2021; 10:cells10102689. [PMID: 34685669 PMCID: PMC8534245 DOI: 10.3390/cells10102689] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 09/30/2021] [Accepted: 10/03/2021] [Indexed: 12/17/2022] Open
Abstract
The SEA complex was described for the first time in yeast Saccharomyces cerevisiae ten years ago, and its human homologue GATOR complex two years later. During the past decade, many advances on the SEA/GATOR biology in different organisms have been made that allowed its role as an essential upstream regulator of the mTORC1 pathway to be defined. In this review, we describe these advances in relation to the identification of multiple functions of the SEA/GATOR complex in nutrient response and beyond and highlight the consequence of GATOR mutations in cancer and neurodegenerative diseases.
Collapse
|
13
|
Naito T, Saheki Y. GRAMD1-mediated accessible cholesterol sensing and transport. Biochim Biophys Acta Mol Cell Biol Lipids 2021; 1866:158957. [PMID: 33932585 DOI: 10.1016/j.bbalip.2021.158957] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 04/09/2021] [Accepted: 04/19/2021] [Indexed: 01/19/2023]
Abstract
Cholesterol, an essential lipid for cell signaling and structural integrity of cellular membranes, is highly enriched in the plasma membrane (PM). However, the regulatory mechanisms that control its biosynthesis and uptake both reside in the endoplasmic reticulum (ER). Thus, the ER needs to constantly monitor the levels of PM cholesterol. This is in part mediated by regulated transport of a biochemically defined pool of cholesterol, termed "accessible" cholesterol, from the PM to the ER via evolutionarily conserved ER-anchored lipid transfer proteins, the GRAMD1s/Asters (GRAMD1a/1b/1c) (Lam/Ltc proteins in yeast). GRAMD1s possess cytosolically exposed GRAM domain and StART-like domain followed by a transmembrane ER anchor. They form homo- and hetero-meric complexes and move to the contacts formed between the ER and the PM by sensing a transient expansion of the accessible pool of cholesterol in the PM via the GRAM domain and facilitate its extraction and transport to the ER via the StART-like domain. The GRAMD1b GRAM domain possesses distinct, but synergistic sites, for recognizing accessible cholesterol and anionic lipids, including phosphatidylserine, within the PM. This property of the GRAM domain contributes to regulated tethering of the PM to ER membrane where GRAMD1s are anchored and fine-tunes StART-like domain-dependent accessible cholesterol transport. Thus, cells use GRAMD1s to sense the levels of cholesterol in the PM and regulate transport of accessible PM cholesterol to the ER in order to maintain cholesterol homeostasis.
Collapse
Affiliation(s)
- Tomoki Naito
- Lee Kong Chian School of Medicine, Nanyang Technological University, 308232, Singapore
| | - Yasunori Saheki
- Lee Kong Chian School of Medicine, Nanyang Technological University, 308232, Singapore; Institute of Resource Development and Analysis, Kumamoto University, Kumamoto 860-0811, Japan.
| |
Collapse
|
14
|
Zanco B, Mirth CK, Sgrò CM, Piper MDW. A dietary sterol trade-off determines lifespan responses to dietary restriction in Drosophila melanogaster females. eLife 2021; 10:e62335. [PMID: 33494859 PMCID: PMC7837700 DOI: 10.7554/elife.62335] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Accepted: 12/16/2020] [Indexed: 01/16/2023] Open
Abstract
Diet plays a significant role in maintaining lifelong health. In particular, lowering the dietary protein: carbohydrate ratio can improve lifespan. This has been interpreted as a direct effect of these macronutrients on physiology. Using Drosophila melanogaster, we show that the role of protein and carbohydrate on lifespan is indirect, acting by altering the partitioning of limiting amounts of dietary sterols between reproduction and lifespan. Shorter lifespans in flies fed on high protein: carbohydrate diets can be rescued by supplementing their food with cholesterol. Not only does this fundamentally alter the way we interpret the mechanisms of lifespan extension by dietary restriction, these data highlight the important principle that life histories can be affected by nutrient-dependent trade-offs that are indirect and independent of the nutrients (often macronutrients) that are the focus of study. This brings us closer to understanding the mechanistic basis of dietary restriction.
Collapse
Affiliation(s)
- Brooke Zanco
- Monash University, School of Biological SciencesClaytonAustralia
| | - Christen K Mirth
- Monash University, School of Biological SciencesClaytonAustralia
| | - Carla M Sgrò
- Monash University, School of Biological SciencesClaytonAustralia
| | - Matthew DW Piper
- Monash University, School of Biological SciencesClaytonAustralia
| |
Collapse
|
15
|
Zheng Koh DH, Saheki Y. Regulation of Plasma Membrane Sterol Homeostasis by Nonvesicular Lipid Transport. CONTACT (THOUSAND OAKS (VENTURA COUNTY, CALIF.)) 2021; 4:25152564211042451. [PMID: 37366378 PMCID: PMC10259818 DOI: 10.1177/25152564211042451] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/28/2023]
Abstract
Sterol contributes to the structural integrity of cellular membranes and plays an important role in the regulation of cell signaling in eukaryotes. It is either produced in the endoplasmic reticulum or taken up from the extracellular environment. In most eukaryotic cells, however, the majority of sterol is enriched in the plasma membrane. Thus, the transport of sterol between the plasma membrane and other organelles, including the endoplasmic reticulum, is crucial for maintaining sterol homeostasis. While vesicular transport that relies on membrane budding and fusion reactions plays an important role in bulk sterol transport, this mode of transport is slow and non-selective. Growing evidence suggests a critical role of nonvesicular transport mediated by evolutionarily conserved families of lipid transfer proteins in more rapid and selective delivery of sterol. Some lipid transfer proteins act primarily at the sites of contacts formed between the endoplasmic reticulum and other organelles or the plasma membrane without membrane fusion. In this review, we describe the similarities and differences of sterol biosynthesis and uptake in mammals and yeast and discuss the role of their lipid transfer proteins in maintaining plasma membrane sterol homeostasis.
Collapse
Affiliation(s)
- Dylan Hong Zheng Koh
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore 308232, Singapore
| | - Yasunori Saheki
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore 308232, Singapore
- Institute of Resource Development and
Analysis, Kumamoto University, Kumamoto 860-0811, Japan
| |
Collapse
|
16
|
Andersen JP, Zhang J, Sun H, Liu X, Liu J, Nie J, Shi Y. Aster-B coordinates with Arf1 to regulate mitochondrial cholesterol transport. Mol Metab 2020; 42:101055. [PMID: 32738348 PMCID: PMC7476871 DOI: 10.1016/j.molmet.2020.101055] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 07/17/2020] [Accepted: 07/22/2020] [Indexed: 12/21/2022] Open
Abstract
OBJECTIVE Cholesterol plays a pivotal role in mitochondrial steroidogenesis, membrane structure, and respiration. Mitochondrial membranes are intrinsically low in cholesterol content and therefore must be replenished with cholesterol from other subcellular membranes. However, the molecular mechanisms underlying mitochondrial cholesterol transport remains poorly understood. The Aster-B gene encodes a cholesterol binding protein recently implicated in cholesterol trafficking from the plasma membrane to the endoplasmic reticulum (ER). In this study, we investigated the function and underlying mechanism of Aster-B in mediating mitochondrial cholesterol transport. METHODS CRISPR/Cas9 gene editing was carried out to generate cell lines deficient in Aster-B expression. The effect of Aster-B deficiency on mitochondrial cholesterol transport was examined by both confocal imaging analysis and biochemical assays. Deletion mutational analysis was also carried out to identify the function of a putative mitochondrial targeting sequence (MTS) at the N-terminus of Aster-B for its role in targeting Aster-B to mitochondria and in mediating mitochondrial cholesterol trafficking. RESULTS Ablation of Aster-B impaired cholesterol transport from the ER to mitochondria, leading to a significant decrease in mitochondrial cholesterol content. Aster-B is also required for mitochondrial transport of fatty acids derived from hydrolysis of cholesterol esters. A putative MTS at the N-terminus of Aster-B mediates the mitochondrial cholesterol uptake. Deletion of the MTS or ablation of Arf1 GTPase which is required for mitochondrial translocation of ER proteins prevented mitochondrial cholesterol transport, leading to mitochondrial dysfunction. CONCLUSIONS We identified Aster-B as a key regulator of cholesterol transport from the ER to mitochondria. Aster-B also coordinates mitochondrial cholesterol trafficking with uptake of fatty acids derived from cholesterol esters, implicating the Aster-B protein as a novel regulator of steroidogenesis.
Collapse
Affiliation(s)
- John-Paul Andersen
- Sam and Ann Barshop Institute for Longevity and Aging Studies, Department of Pharmacology, University of Texas Health Science Center at San Antonio, Texas Research Park Campus - MC 7755, 15355 Lambda Drive, San Antonio, TX, 78245, USA
| | - Jun Zhang
- Sam and Ann Barshop Institute for Longevity and Aging Studies, Department of Pharmacology, University of Texas Health Science Center at San Antonio, Texas Research Park Campus - MC 7755, 15355 Lambda Drive, San Antonio, TX, 78245, USA
| | - Haoran Sun
- Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing, PR China
| | - Xuyun Liu
- Sam and Ann Barshop Institute for Longevity and Aging Studies, Department of Pharmacology, University of Texas Health Science Center at San Antonio, Texas Research Park Campus - MC 7755, 15355 Lambda Drive, San Antonio, TX, 78245, USA; Center for Mitochondrial Biology and Medicine, The Key Laboratory of Biomedical, Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, Shaanxi, PR China
| | - Jiankang Liu
- Center for Mitochondrial Biology and Medicine, The Key Laboratory of Biomedical, Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, Shaanxi, PR China
| | - Jia Nie
- Sam and Ann Barshop Institute for Longevity and Aging Studies, Department of Pharmacology, University of Texas Health Science Center at San Antonio, Texas Research Park Campus - MC 7755, 15355 Lambda Drive, San Antonio, TX, 78245, USA
| | - Yuguang Shi
- Sam and Ann Barshop Institute for Longevity and Aging Studies, Department of Pharmacology, University of Texas Health Science Center at San Antonio, Texas Research Park Campus - MC 7755, 15355 Lambda Drive, San Antonio, TX, 78245, USA; Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing, PR China.
| |
Collapse
|
17
|
Zhang J, Andersen JP, Sun H, Liu X, Sonenberg N, Nie J, Shi Y. Aster-C coordinates with COP I vesicles to regulate lysosomal trafficking and activation of mTORC1. EMBO Rep 2020; 21:e49898. [PMID: 32648345 DOI: 10.15252/embr.201949898] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 05/29/2020] [Accepted: 06/12/2020] [Indexed: 01/27/2023] Open
Abstract
Nutrient sensing by the mTOR complex 1 (mTORC1) requires its translocation to the lysosomal membrane. Upon amino acids removal, mTORC1 becomes cytosolic and inactive, yet its precise subcellular localization and the mechanism of inhibition remain elusive. Here, we identified Aster-C as a negative regulator of mTORC1 signaling. Aster-C earmarked a special rough ER subdomain where it sequestered mTOR together with the GATOR2 complex to prevent mTORC1 activation during nutrient starvation. Amino acids stimulated rapid disassociation of mTORC1 from Aster-C concurrently with assembly of COP I vesicles which escorted mTORC1 to the lysosomal membrane. Consequently, ablation of Aster-C led to spontaneous activation of mTORC1 and dissociation of TSC2 from lysosomes, whereas inhibition of COP I vesicle biogenesis or actin dynamics prevented mTORC1 activation. Together, these findings identified Aster-C as a missing link between lysosomal trafficking and mTORC1 activation by revealing an unexpected role of COP I vesicles in mTORC1 signaling.
Collapse
Affiliation(s)
- Jun Zhang
- Department of Pharmacology, Sam and Ann Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - John-Paul Andersen
- Department of Pharmacology, Sam and Ann Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Haoran Sun
- Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing, China
| | - Xuyun Liu
- Department of Pharmacology, Sam and Ann Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Nahum Sonenberg
- Department of Biochemistry, McGill University, Montreal, QC, Canada
| | - Jia Nie
- Department of Pharmacology, Sam and Ann Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Yuguang Shi
- Department of Pharmacology, Sam and Ann Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA.,Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing, China
| |
Collapse
|