1
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Priya A, Antoine-Bally S, Macé AS, Monteiro P, Sabatet V, Remy D, Dingli F, Loew D, Demetriades C, Gautreau AM, Chavrier P. Codependencies of mTORC1 signaling and endolysosomal actin structures. Sci Adv 2023; 9:eadd9084. [PMID: 37703363 PMCID: PMC10881074 DOI: 10.1126/sciadv.add9084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 08/11/2023] [Indexed: 09/15/2023]
Abstract
The mechanistic target of rapamycin complex 1 (mTORC1) is part of the amino acid sensing machinery that becomes activated on the endolysosomal surface in response to nutrient cues. Branched actin generated by WASH and Arp2/3 complexes defines endolysosomal microdomains. Here, we find mTORC1 components in close proximity to endolysosomal actin microdomains. We investigated for interactors of the mTORC1 lysosomal tether, RAGC, by proteomics and identified multiple actin filament capping proteins and their modulators. Perturbation of RAGC function affected the size of endolysosomal actin, consistent with a regulation of actin filament capping by RAGC. Reciprocally, the pharmacological inhibition of actin polymerization or alteration of endolysosomal actin obtained upon silencing of WASH or Arp2/3 complexes impaired mTORC1 activity. Mechanistically, we show that actin is required for proper association of RAGC and mTOR with endolysosomes. This study reveals an unprecedented interplay between actin and mTORC1 signaling on the endolysosomal system.
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Affiliation(s)
- Amulya Priya
- Institut Curie, CNRS UMR144, PSL Research University, Research Center, Actin and Membrane Dynamics Laboratory, 26 rue d’Ulm, Paris 75248 Cedex 05, France
| | - Sandra Antoine-Bally
- Institut Curie, CNRS UMR144, PSL Research University, Research Center, Actin and Membrane Dynamics Laboratory, 26 rue d’Ulm, Paris 75248 Cedex 05, France
| | - Anne-Sophie Macé
- Institut Curie, PSL Research University, Cell and Tissue Imaging Facility (PICT-IBiSA), 26 rue d’Ulm, Paris 75248 Cedex 05, France
| | - Pedro Monteiro
- Institut Curie, CNRS UMR144, PSL Research University, Research Center, Actin and Membrane Dynamics Laboratory, 26 rue d’Ulm, Paris 75248 Cedex 05, France
| | - Valentin Sabatet
- Institut Curie, PSL Research University, CurieCoreTech Mass Spectrometry Proteomics, 26 rue d’Ulm, Paris 75248 Cedex 05, France
| | - David Remy
- Institut Curie, CNRS UMR144, PSL Research University, Research Center, Actin and Membrane Dynamics Laboratory, 26 rue d’Ulm, Paris 75248 Cedex 05, France
| | - Florent Dingli
- Institut Curie, PSL Research University, CurieCoreTech Mass Spectrometry Proteomics, 26 rue d’Ulm, Paris 75248 Cedex 05, France
| | - Damarys Loew
- Institut Curie, PSL Research University, CurieCoreTech Mass Spectrometry Proteomics, 26 rue d’Ulm, Paris 75248 Cedex 05, France
| | - Constantinos Demetriades
- Max Planck Institute for Biology of Ageing (MPI-AGE), Cologne, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Alexis M. Gautreau
- Laboratoire de Biologie Structurale de la Cellule, CNRS, École Polytechnique, Institut Polytechnique de Paris, Palaiseau, France
| | - Philippe Chavrier
- Institut Curie, CNRS UMR144, PSL Research University, Research Center, Actin and Membrane Dynamics Laboratory, 26 rue d’Ulm, Paris 75248 Cedex 05, France
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2
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Nicastro R, Brohée L, Alba J, Nüchel J, Figlia G, Kipschull S, Gollwitzer P, Romero-Pozuelo J, Fernandes SA, Lamprakis A, Vanni S, Teleman AA, De Virgilio C, Demetriades C. Malonyl-CoA is a conserved endogenous ATP-competitive mTORC1 inhibitor. Nat Cell Biol 2023; 25:1303-1318. [PMID: 37563253 PMCID: PMC10495264 DOI: 10.1038/s41556-023-01198-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Accepted: 06/29/2023] [Indexed: 08/12/2023]
Abstract
Cell growth is regulated by the mammalian/mechanistic target of rapamycin complex 1 (mTORC1), which functions both as a nutrient sensor and a master controller of virtually all biosynthetic pathways. This ensures that cells are metabolically active only when conditions are optimal for growth. Notably, although mTORC1 is known to regulate fatty acid biosynthesis, how and whether the cellular lipid biosynthetic capacity signals back to fine-tune mTORC1 activity remains poorly understood. Here we show that mTORC1 senses the capacity of a cell to synthesise fatty acids by detecting the levels of malonyl-CoA, an intermediate of this biosynthetic pathway. We find that, in both yeast and mammalian cells, this regulation is direct, with malonyl-CoA binding to the mTOR catalytic pocket and acting as a specific ATP-competitive inhibitor. When fatty acid synthase (FASN) is downregulated/inhibited, elevated malonyl-CoA levels are channelled to proximal mTOR molecules that form direct protein-protein interactions with acetyl-CoA carboxylase 1 (ACC1) and FASN. Our findings represent a conserved and unique homeostatic mechanism whereby impaired fatty acid biogenesis leads to reduced mTORC1 activity to coordinately link this metabolic pathway to the overall cellular biosynthetic output. Moreover, they reveal the existence of a physiological metabolite that directly inhibits the activity of a signalling kinase in mammalian cells by competing with ATP for binding.
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Affiliation(s)
- Raffaele Nicastro
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Laura Brohée
- Max Planck Institute for Biology of Ageing (MPI-AGE), Cologne, Germany
| | - Josephine Alba
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Julian Nüchel
- Max Planck Institute for Biology of Ageing (MPI-AGE), Cologne, Germany
| | - Gianluca Figlia
- German Cancer Research Center (DKFZ), Heidelberg, Germany
- Heidelberg University, Heidelberg, Germany
| | | | - Peter Gollwitzer
- Max Planck Institute for Biology of Ageing (MPI-AGE), Cologne, Germany
| | - Jesus Romero-Pozuelo
- German Cancer Research Center (DKFZ), Heidelberg, Germany
- Heidelberg University, Heidelberg, Germany
- Unidad de Investigación Biomedica, Universidad Alfonso X El Sabio (UAX), Madrid, Spain
| | | | - Andreas Lamprakis
- Max Planck Institute for Biology of Ageing (MPI-AGE), Cologne, Germany
| | - Stefano Vanni
- Department of Biology, University of Fribourg, Fribourg, Switzerland.
| | - Aurelio A Teleman
- German Cancer Research Center (DKFZ), Heidelberg, Germany.
- Heidelberg University, Heidelberg, Germany.
| | | | - Constantinos Demetriades
- Max Planck Institute for Biology of Ageing (MPI-AGE), Cologne, Germany.
- University of Cologne, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Cologne, Germany.
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3
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Artoni F, Grützmacher N, Demetriades C. Unbiased evaluation of rapamycin's specificity as an mTOR inhibitor. Aging Cell 2023; 22:e13888. [PMID: 37222020 PMCID: PMC10410055 DOI: 10.1111/acel.13888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 05/02/2023] [Accepted: 05/07/2023] [Indexed: 05/25/2023] Open
Abstract
Rapamycin is a macrolide antibiotic that functions as an immunosuppressive and anti-cancer agent, and displays robust anti-ageing effects in multiple organisms including humans. Importantly, rapamycin analogues (rapalogs) are of clinical importance against certain cancer types and neurodevelopmental diseases. Although rapamycin is widely perceived as an allosteric inhibitor of mTOR (mechanistic target of rapamycin), the master regulator of cellular and organismal physiology, its specificity has not been thoroughly evaluated so far. In fact, previous studies in cells and in mice hinted that rapamycin may be also acting independently from mTOR to influence various cellular processes. Here, we generated a gene-edited cell line that expresses a rapamycin-resistant mTOR mutant (mTORRR ) and assessed the effects of rapamycin treatment on the transcriptome and proteome of control or mTORRR -expressing cells. Our data reveal a striking specificity of rapamycin towards mTOR, demonstrated by virtually no changes in mRNA or protein levels in rapamycin-treated mTORRR cells, even following prolonged drug treatment. Overall, this study provides the first unbiased and conclusive assessment of rapamycin's specificity, with potential implications for ageing research and human therapeutics.
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Affiliation(s)
- Filippo Artoni
- Max Planck Institute for Biology of Ageing (MPI‐AGE)CologneGermany
- Cologne Graduate School of Ageing Research (CGA)CologneGermany
| | - Nina Grützmacher
- Max Planck Institute for Biology of Ageing (MPI‐AGE)CologneGermany
| | - Constantinos Demetriades
- Max Planck Institute for Biology of Ageing (MPI‐AGE)CologneGermany
- Cologne Graduate School of Ageing Research (CGA)CologneGermany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging‐Associated Diseases (CECAD)University of CologneCologneGermany
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4
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Suzuki T, Chéret J, Scala FD, Akhundlu A, Gherardini J, Demetrius DL, O'Sullivan JDB, Kuka Epstein G, Bauman AJ, Demetriades C, Paus R. mTORC1 activity negatively regulates human hair follicle growth and pigmentation. EMBO Rep 2023:e56574. [PMID: 37212043 DOI: 10.15252/embr.202256574] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 04/11/2023] [Accepted: 04/24/2023] [Indexed: 05/23/2023] Open
Abstract
Dysregulation of the activity of the mechanistic target of rapamycin complex 1 (mTORC1) is commonly linked to aging, cancer, and genetic disorders such as tuberous sclerosis (TS), a rare neurodevelopmental multisystemic disease characterized by benign tumors, seizures, and intellectual disability. Although patches of white hair on the scalp (poliosis) are considered as early signs of TS, the underlying molecular mechanisms and potential involvement of mTORC1 in hair depigmentation remain unclear. Here, we have used healthy, organ-cultured human scalp hair follicles (HFs) to interrogate the role of mTORC1 in a prototypic human (mini-)organ. Gray/white HFs exhibit high mTORC1 activity, while mTORC1 inhibition by rapamycin stimulated HF growth and pigmentation, even in gray/white HFs that still contained some surviving melanocytes. Mechanistically, this occurred via increased intrafollicular production of the melanotropic hormone, α-MSH. In contrast, knockdown of intrafollicular TSC2, a negative regulator of mTORC1, significantly reduced HF pigmentation. Our findings introduce mTORC1 activity as an important negative regulator of human HF growth and pigmentation and suggest that pharmacological mTORC1 inhibition could become a novel strategy in the management of hair loss and depigmentation disorders.
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Affiliation(s)
- Takahiro Suzuki
- Dr Phillip Frost Department of Dermatology & Cutaneous Surgery, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Jérémy Chéret
- Dr Phillip Frost Department of Dermatology & Cutaneous Surgery, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Fernanda Dinelli Scala
- Dr Phillip Frost Department of Dermatology & Cutaneous Surgery, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Aysun Akhundlu
- Dr Phillip Frost Department of Dermatology & Cutaneous Surgery, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Jennifer Gherardini
- Dr Phillip Frost Department of Dermatology & Cutaneous Surgery, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Dana-Lee Demetrius
- Dr Phillip Frost Department of Dermatology & Cutaneous Surgery, University of Miami Miller School of Medicine, Miami, FL, USA
| | - James D B O'Sullivan
- Dr Phillip Frost Department of Dermatology & Cutaneous Surgery, University of Miami Miller School of Medicine, Miami, FL, USA
| | | | | | - Constantinos Demetriades
- Max Planck Institute for Biology of Ageing, Cologne, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Ralf Paus
- Dr Phillip Frost Department of Dermatology & Cutaneous Surgery, University of Miami Miller School of Medicine, Miami, FL, USA
- Monasterium Laboratory, Muenster, Germany
- CUTANEON, Hamburg, Germany
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5
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Gollwitzer P, Grützmacher N, Wilhelm S, Kümmel D, Demetriades C. Author Correction: A Rag GTPase dimer code defines the regulation of mTORC1 by amino acids. Nat Cell Biol 2023; 25:366. [PMID: 36536178 PMCID: PMC9928581 DOI: 10.1038/s41556-022-01073-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Peter Gollwitzer
- grid.419502.b0000 0004 0373 6590Max Planck Institute for Biology of Ageing (MPI-AGE), Cologne, Germany
| | - Nina Grützmacher
- grid.419502.b0000 0004 0373 6590Max Planck Institute for Biology of Ageing (MPI-AGE), Cologne, Germany
| | - Sabine Wilhelm
- grid.419502.b0000 0004 0373 6590Max Planck Institute for Biology of Ageing (MPI-AGE), Cologne, Germany
| | - Daniel Kümmel
- grid.5949.10000 0001 2172 9288Institute of Biochemistry, University of Münster, Münster, Germany
| | - Constantinos Demetriades
- Max Planck Institute for Biology of Ageing (MPI-AGE), Cologne, Germany. .,Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany.
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6
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Suzuki T, Chéret J, Scala F, Gherardini J, O’Sullivan J, Epstein-Kuka G, Bauman A, Demetriades C, Paus R. 518 Nutrient and stress sensing as novel physiological regulator of human hair pigmentation and greying: Role of mTORC1 activity. J Invest Dermatol 2022. [DOI: 10.1016/j.jid.2022.09.533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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7
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Huang W, Kew C, Fernandes SDA, Löhrke A, Han L, Demetriades C, Antebi A. Decreased spliceosome fidelity and egl-8 intron retention inhibit mTORC1 signaling to promote longevity. Nat Aging 2022; 2:796-808. [PMID: 37118503 PMCID: PMC10154236 DOI: 10.1038/s43587-022-00275-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Accepted: 07/28/2022] [Indexed: 11/09/2022]
Abstract
AbstractChanges in splicing fidelity are associated with loss of homeostasis and aging, yet only a handful of splicing factors have been shown to be causally required to promote longevity, and the underlying mechanisms and downstream targets in these paradigms remain elusive. Surprisingly, we found a hypomorphic mutation within ribonucleoprotein RNP-6/poly(U)-binding factor 60 kDa (PUF60), a spliceosome component promoting weak 3′-splice site recognition, which causes aberrant splicing, elevates stress responses and enhances longevity in Caenorhabditis elegans. Through genetic suppressor screens, we identify a gain-of-function mutation within rbm-39, an RNP-6-interacting splicing factor, which increases nuclear speckle formation, alleviates splicing defects and curtails longevity caused by rnp-6 mutation. By leveraging the splicing changes induced by RNP-6/RBM-39 activities, we uncover intron retention in egl-8/phospholipase C β4 (PLCB4) as a key splicing target prolonging life. Genetic and biochemical evidence show that neuronal RNP-6/EGL-8 downregulates mammalian target of rapamycin complex 1 (mTORC1) signaling to control organismal lifespan. In mammalian cells, PUF60 downregulation also potently and specifically inhibits mTORC1 signaling. Altogether, our results reveal that splicing fidelity modulates lifespan through mTOR signaling.
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8
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Suzuki T, Chéret J, Scala F, Gherardini J, O'Sullivan J, Epstein-Kuka G, Bauman A, Demetriades C, Paus R. 650 Controlling mTORC1 activity as a novel therapeutic strategy for managing human hair growth and pigmentation. J Invest Dermatol 2022. [DOI: 10.1016/j.jid.2022.05.661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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9
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Demetriades C, Nuüchel J, Plomann M. GRASPing the unconventional secretory machinery to bridge cellular stress signaling to the extracellular proteome. Cell Stress 2021; 5:173-175. [PMID: 34782889 PMCID: PMC8561302 DOI: 10.15698/cst2021.11.259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 10/07/2021] [Indexed: 11/13/2022] Open
Abstract
Cellular adaptation to stress is a crucial homeostatic process for survival, metabolism, physiology, and disease. Cells respond to stress stimuli (e.g., nutrient starvation, growth factor deprivation, hypoxia, low energy, etc.) by changing the activity of signaling pathways, and interact with their environment by qualitatively and quantitatively modifying their intracellular, surface, and extracellular proteomes. How this delicate communication takes place is a hot topic in cell biological research, and has important implications for human disease.
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Affiliation(s)
- Constantinos Demetriades
- Max Planck Institute for Biology of Ageing (MPI-AGE), 50931 Cologne, Germany.,University of Cologne, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), 50931 Cologne, Germany
| | - Julian Nuüchel
- Max Planck Institute for Biology of Ageing (MPI-AGE), 50931 Cologne, Germany
| | - Markus Plomann
- University of Cologne, Faculty of Medicine and University Hospital Cologne, Center for Biochemistry, 50931 Cologne, Germany
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10
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Fernandes SA, Demetriades C. The Multifaceted Role of Nutrient Sensing and mTORC1 Signaling in Physiology and Aging. Front Aging 2021; 2:707372. [PMID: 35822019 PMCID: PMC9261424 DOI: 10.3389/fragi.2021.707372] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/09/2021] [Accepted: 08/12/2021] [Indexed: 01/10/2023]
Abstract
The mechanistic Target of Rapamycin (mTOR) is a growth-related kinase that, in the context of the mTOR complex 1 (mTORC1), touches upon most fundamental cellular processes. Consequently, its activity is a critical determinant for cellular and organismal physiology, while its dysregulation is commonly linked to human aging and age-related disease. Presumably the most important stimulus that regulates mTORC1 activity is nutrient sufficiency, whereby amino acids play a predominant role. In fact, mTORC1 functions as a molecular sensor for amino acids, linking the cellular demand to the nutritional supply. Notably, dietary restriction (DR), a nutritional regimen that has been shown to extend lifespan and improve healthspan in a broad spectrum of organisms, works via limiting nutrient uptake and changes in mTORC1 activity. Furthermore, pharmacological inhibition of mTORC1, using rapamycin or its analogs (rapalogs), can mimic the pro-longevity effects of DR. Conversely, nutritional amino acid overload has been tightly linked to aging and diseases, such as cancer, type 2 diabetes and obesity. Similar effects can also be recapitulated by mutations in upstream mTORC1 regulators, thus establishing a tight connection between mTORC1 signaling and aging. Although the role of growth factor signaling upstream of mTORC1 in aging has been investigated extensively, the involvement of signaling components participating in the nutrient sensing branch is less well understood. In this review, we provide a comprehensive overview of the molecular and cellular mechanisms that signal nutrient availability to mTORC1, and summarize the role that nutrients, nutrient sensors, and other components of the nutrient sensing machinery play in cellular and organismal aging.
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Affiliation(s)
- Stephanie A. Fernandes
- Max Planck Institute for Biology of Ageing (MPI-AGE), Cologne, Germany
- Cologne Graduate School for Ageing Research (CGA), Cologne, Germany
| | - Constantinos Demetriades
- Max Planck Institute for Biology of Ageing (MPI-AGE), Cologne, Germany
- Cologne Graduate School for Ageing Research (CGA), Cologne, Germany
- University of Cologne, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Cologne, Germany
- *Correspondence: Constantinos Demetriades,
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11
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Nüchel J, Tauber M, Nolte JL, Mörgelin M, Türk C, Eckes B, Demetriades C, Plomann M. An mTORC1-GRASP55 signaling axis controls unconventional secretion to reshape the extracellular proteome upon stress. Mol Cell 2021; 81:3275-3293.e12. [PMID: 34245671 PMCID: PMC8382303 DOI: 10.1016/j.molcel.2021.06.017] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 04/21/2021] [Accepted: 06/14/2021] [Indexed: 01/13/2023]
Abstract
Cells communicate with their environment via surface proteins and secreted factors. Unconventional protein secretion (UPS) is an evolutionarily conserved process, via which distinct cargo proteins are secreted upon stress. Most UPS types depend upon the Golgi-associated GRASP55 protein. However, its regulation and biological role remain poorly understood. Here, we show that the mechanistic target of rapamycin complex 1 (mTORC1) directly phosphorylates GRASP55 to maintain its Golgi localization, thus revealing a physiological role for mTORC1 at this organelle. Stimuli that inhibit mTORC1 cause GRASP55 dephosphorylation and relocalization to UPS compartments. Through multiple, unbiased, proteomic analyses, we identify numerous cargoes that follow this unconventional secretory route to reshape the cellular secretome and surfactome. Using MMP2 secretion as a proxy for UPS, we provide important insights on its regulation and physiological role. Collectively, our findings reveal the mTORC1-GRASP55 signaling hub as the integration point in stress signaling upstream of UPS and as a key coordinator of the cellular adaptation to stress. mTORC1 phosphorylates GRASP55 directly at the Golgi in non-stressed cells mTORC1 inactivation by stress leads to GRASP55 dephosphorylation and relocalization GRASP55 relocalization to autophagosomes and MVBs drives UPS of selected cargo mTORC1-GRASP55 link cellular stress to changes in the extracellular proteome via UPS
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Affiliation(s)
- Julian Nüchel
- Max Planck Institute for Biology of Ageing (MPI-AGE), 50931 Cologne, Germany; University of Cologne, Faculty of Medicine and University Hospital Cologne, Center for Biochemistry, 50931 Cologne, Germany
| | - Marina Tauber
- University of Cologne, Faculty of Medicine and University Hospital Cologne, Center for Biochemistry, 50931 Cologne, Germany
| | - Janica L Nolte
- University of Cologne, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), 50931 Cologne, Germany
| | | | - Clara Türk
- University of Cologne, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), 50931 Cologne, Germany
| | - Beate Eckes
- University of Cologne, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), 50931 Cologne, Germany; University of Cologne, Faculty of Medicine and University Hospital Cologne, Translational Matrix Biology, 50931 Cologne, Germany
| | - Constantinos Demetriades
- Max Planck Institute for Biology of Ageing (MPI-AGE), 50931 Cologne, Germany; University of Cologne, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), 50931 Cologne, Germany.
| | - Markus Plomann
- University of Cologne, Faculty of Medicine and University Hospital Cologne, Center for Biochemistry, 50931 Cologne, Germany.
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12
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Cheret J, Suzuki T, Scala F, O'Sullivan J, Nicu C, Gherardini J, Epstein-Kuka G, Bauman A, Demetriades C, Paus R. 602 mTORC1 activity controls human scalp hair follicle pigmentation and growth. J Invest Dermatol 2021. [DOI: 10.1016/j.jid.2021.02.630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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13
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Prentzell MT, Rehbein U, Cadena Sandoval M, De Meulemeester AS, Baumeister R, Brohée L, Berdel B, Bockwoldt M, Carroll B, Chowdhury SR, von Deimling A, Demetriades C, Figlia G, de Araujo MEG, Heberle AM, Heiland I, Holzwarth B, Huber LA, Jaworski J, Kedra M, Kern K, Kopach A, Korolchuk VI, van 't Land-Kuper I, Macias M, Nellist M, Palm W, Pusch S, Ramos Pittol JM, Reil M, Reintjes A, Reuter F, Sampson JR, Scheldeman C, Siekierska A, Stefan E, Teleman AA, Thomas LE, Torres-Quesada O, Trump S, West HD, de Witte P, Woltering S, Yordanov TE, Zmorzynska J, Opitz CA, Thedieck K. G3BPs tether the TSC complex to lysosomes and suppress mTORC1 signaling. Cell 2021; 184:655-674.e27. [PMID: 33497611 PMCID: PMC7868890 DOI: 10.1016/j.cell.2020.12.024] [Citation(s) in RCA: 58] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 11/03/2020] [Accepted: 12/14/2020] [Indexed: 12/22/2022]
Abstract
Ras GTPase-activating protein-binding proteins 1 and 2 (G3BP1 and G3BP2, respectively) are widely recognized as core components of stress granules (SGs). We report that G3BPs reside at the cytoplasmic surface of lysosomes. They act in a non-redundant manner to anchor the tuberous sclerosis complex (TSC) protein complex to lysosomes and suppress activation of the metabolic master regulator mechanistic target of rapamycin complex 1 (mTORC1) by amino acids and insulin. Like the TSC complex, G3BP1 deficiency elicits phenotypes related to mTORC1 hyperactivity. In the context of tumors, low G3BP1 levels enhance mTORC1-driven breast cancer cell motility and correlate with adverse outcomes in patients. Furthermore, G3bp1 inhibition in zebrafish disturbs neuronal development and function, leading to white matter heterotopia and neuronal hyperactivity. Thus, G3BPs are not only core components of SGs but also a key element of lysosomal TSC-mTORC1 signaling.
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Affiliation(s)
- Mirja Tamara Prentzell
- Brain Cancer Metabolism Group, German Consortium of Translational Cancer Research (DKTK) & German Cancer Research Center (DKFZ), Heidelberg 69120, Germany; Department of Pediatrics, Section Systems Medicine of Metabolism and Signaling, University of Groningen, University Medical Center Groningen, Groningen 9700 RB, The Netherlands; Department of Bioinformatics and Molecular Genetics (Faculty of Biology), University of Freiburg, Freiburg 79104, Germany; Spemann Graduate School of Biology and Medicine (SGBM), University of Freiburg, Freiburg 79104, Germany
| | - Ulrike Rehbein
- Department of Pediatrics, Section Systems Medicine of Metabolism and Signaling, University of Groningen, University Medical Center Groningen, Groningen 9700 RB, The Netherlands; Department for Neuroscience, School of Medicine and Health Sciences, Carl von Ossietzky University Oldenburg, Oldenburg 26129, Germany; Institute of Biochemistry and Center for Molecular Biosciences Innsbruck, University of Innsbruck, Innsbruck 6020, Austria
| | - Marti Cadena Sandoval
- Department of Pediatrics, Section Systems Medicine of Metabolism and Signaling, University of Groningen, University Medical Center Groningen, Groningen 9700 RB, The Netherlands; Institute of Biochemistry and Center for Molecular Biosciences Innsbruck, University of Innsbruck, Innsbruck 6020, Austria
| | - Ann-Sofie De Meulemeester
- Laboratory for Molecular Biodiscovery, Department of Pharmaceutical and Pharmacological Sciences, University of Leuven, Leuven BE-3000, Belgium
| | - Ralf Baumeister
- Department of Bioinformatics and Molecular Genetics (Faculty of Biology), University of Freiburg, Freiburg 79104, Germany; Spemann Graduate School of Biology and Medicine (SGBM), University of Freiburg, Freiburg 79104, Germany; Signalling Research Centres BIOSS and CIBSS & ZBMZ Center for Biochemistry and Molecular Cell Research (Faculty of Medicine), University of Freiburg, Freiburg 79104, Germany
| | - Laura Brohée
- Cell Growth Control in Health and Age-Related Disease Group, Max Planck Institute for Biology of Ageing (MPI-AGE), Cologne 50931, Germany
| | - Bianca Berdel
- Brain Cancer Metabolism Group, German Consortium of Translational Cancer Research (DKTK) & German Cancer Research Center (DKFZ), Heidelberg 69120, Germany
| | - Mathias Bockwoldt
- Department of Arctic and Marine Biology, UiT The Arctic University of Norway, Tromsø 9037, Norway
| | - Bernadette Carroll
- School of Biochemistry, Biomedical Sciences Building, University Walk, Bristol BS8 1TD, UK
| | - Suvagata Roy Chowdhury
- Cell Signaling and Metabolism Group, German Cancer Research Center (DKFZ), Heidelberg 69120, Germany
| | - Andreas von Deimling
- German Consortium of Translational Cancer Research (DKTK), Clinical Cooperation Unit Neuropathology, German Cancer Research Center (DKFZ), Heidelberg 69120, Germany; Department of Neuropathology, Institute of Pathology, Heidelberg University, Heidelberg 69120, Germany
| | - Constantinos Demetriades
- Cell Growth Control in Health and Age-Related Disease Group, Max Planck Institute for Biology of Ageing (MPI-AGE), Cologne 50931, Germany; CECAD Cluster of Excellence, University of Cologne, Cologne 50931, Germany
| | - Gianluca Figlia
- Signal Transduction in Cancer and Metabolism, German Cancer Research Center (DKFZ), Heidelberg 69120, Germany; Heidelberg University, Heidelberg 69120, Germany
| | | | - Alexander M Heberle
- Department of Pediatrics, Section Systems Medicine of Metabolism and Signaling, University of Groningen, University Medical Center Groningen, Groningen 9700 RB, The Netherlands; Institute of Biochemistry and Center for Molecular Biosciences Innsbruck, University of Innsbruck, Innsbruck 6020, Austria
| | - Ines Heiland
- Department of Arctic and Marine Biology, UiT The Arctic University of Norway, Tromsø 9037, Norway
| | - Birgit Holzwarth
- Department of Bioinformatics and Molecular Genetics (Faculty of Biology), University of Freiburg, Freiburg 79104, Germany
| | - Lukas A Huber
- Institute of Cell Biology, Biocenter, Medical University of Innsbruck, Innsbruck 6020, Austria; Austrian Drug Screening Institute (ADSI), Innsbruck 6020, Austria
| | - Jacek Jaworski
- Laboratory of Molecular and Cellular Neurobiology, International Institute of Molecular and Cell Biology in Warsaw, Warsaw 02-109, Poland
| | - Magdalena Kedra
- Laboratory of Molecular and Cellular Neurobiology, International Institute of Molecular and Cell Biology in Warsaw, Warsaw 02-109, Poland
| | - Katharina Kern
- Brain Cancer Metabolism Group, German Consortium of Translational Cancer Research (DKTK) & German Cancer Research Center (DKFZ), Heidelberg 69120, Germany
| | - Andrii Kopach
- Laboratory of Molecular and Cellular Neurobiology, International Institute of Molecular and Cell Biology in Warsaw, Warsaw 02-109, Poland
| | - Viktor I Korolchuk
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Ineke van 't Land-Kuper
- Department of Pediatrics, Section Systems Medicine of Metabolism and Signaling, University of Groningen, University Medical Center Groningen, Groningen 9700 RB, The Netherlands; Department for Neuroscience, School of Medicine and Health Sciences, Carl von Ossietzky University Oldenburg, Oldenburg 26129, Germany
| | - Matylda Macias
- Laboratory of Molecular and Cellular Neurobiology, International Institute of Molecular and Cell Biology in Warsaw, Warsaw 02-109, Poland
| | - Mark Nellist
- Department of Clinical Genetics, Erasmus Medical Center, Rotterdam 3015 GD, The Netherlands
| | - Wilhelm Palm
- Cell Signaling and Metabolism Group, German Cancer Research Center (DKFZ), Heidelberg 69120, Germany
| | - Stefan Pusch
- German Consortium of Translational Cancer Research (DKTK), Clinical Cooperation Unit Neuropathology, German Cancer Research Center (DKFZ), Heidelberg 69120, Germany; Department of Neuropathology, Institute of Pathology, Heidelberg University, Heidelberg 69120, Germany
| | - Jose Miguel Ramos Pittol
- Institute of Biochemistry and Center for Molecular Biosciences Innsbruck, University of Innsbruck, Innsbruck 6020, Austria
| | - Michèle Reil
- Brain Cancer Metabolism Group, German Consortium of Translational Cancer Research (DKTK) & German Cancer Research Center (DKFZ), Heidelberg 69120, Germany
| | - Anja Reintjes
- Institute of Biochemistry and Center for Molecular Biosciences Innsbruck, University of Innsbruck, Innsbruck 6020, Austria
| | - Friederike Reuter
- Brain Cancer Metabolism Group, German Consortium of Translational Cancer Research (DKTK) & German Cancer Research Center (DKFZ), Heidelberg 69120, Germany
| | - Julian R Sampson
- Institute of Medical Genetics, Division of Cancer and Genetics, Cardiff University Medical School, Cardiff CF14 4AY, UK
| | - Chloë Scheldeman
- Laboratory for Molecular Biodiscovery, Department of Pharmaceutical and Pharmacological Sciences, University of Leuven, Leuven BE-3000, Belgium; Neurogenetics Research Group, VUB, Brussels 1090, Belgium
| | - Aleksandra Siekierska
- Laboratory for Molecular Biodiscovery, Department of Pharmaceutical and Pharmacological Sciences, University of Leuven, Leuven BE-3000, Belgium
| | - Eduard Stefan
- Institute of Biochemistry and Center for Molecular Biosciences Innsbruck, University of Innsbruck, Innsbruck 6020, Austria
| | - Aurelio A Teleman
- Signal Transduction in Cancer and Metabolism, German Cancer Research Center (DKFZ), Heidelberg 69120, Germany; Heidelberg University, Heidelberg 69120, Germany
| | - Laura E Thomas
- Institute of Life Science, Swansea University, Swansea SA2 8PP, UK
| | - Omar Torres-Quesada
- Institute of Biochemistry and Center for Molecular Biosciences Innsbruck, University of Innsbruck, Innsbruck 6020, Austria
| | - Saskia Trump
- Molecular Epidemiology Unit, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health (BIH), Berlin 13353, Germany
| | - Hannah D West
- Institute of Medical Genetics, Division of Cancer and Genetics, Cardiff University Medical School, Cardiff CF14 4AY, UK
| | - Peter de Witte
- Laboratory for Molecular Biodiscovery, Department of Pharmaceutical and Pharmacological Sciences, University of Leuven, Leuven BE-3000, Belgium
| | - Sandra Woltering
- Brain Cancer Metabolism Group, German Consortium of Translational Cancer Research (DKTK) & German Cancer Research Center (DKFZ), Heidelberg 69120, Germany
| | - Teodor E Yordanov
- Institute of Cell Biology, Biocenter, Medical University of Innsbruck, Innsbruck 6020, Austria; Division of Cell and Developmental Biology, Institute for Molecular Bioscience, University of Queensland, St Lucia QLD 4072, Australia
| | - Justyna Zmorzynska
- Laboratory of Molecular and Cellular Neurobiology, International Institute of Molecular and Cell Biology in Warsaw, Warsaw 02-109, Poland
| | - Christiane A Opitz
- Brain Cancer Metabolism Group, German Consortium of Translational Cancer Research (DKTK) & German Cancer Research Center (DKFZ), Heidelberg 69120, Germany; Department of Neurology, University Hospital Heidelberg and National Center for Tumor Diseases, Heidelberg 69120, Germany.
| | - Kathrin Thedieck
- Department of Pediatrics, Section Systems Medicine of Metabolism and Signaling, University of Groningen, University Medical Center Groningen, Groningen 9700 RB, The Netherlands; Department for Neuroscience, School of Medicine and Health Sciences, Carl von Ossietzky University Oldenburg, Oldenburg 26129, Germany; Institute of Biochemistry and Center for Molecular Biosciences Innsbruck, University of Innsbruck, Innsbruck 6020, Austria.
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Romero-Pozuelo J, Demetriades C, Schroeder P, Teleman AA. CycD/Cdk4 and Discontinuities in Dpp Signaling Activate TORC1 in the Drosophila Wing Disc. Dev Cell 2017; 42:376-387.e5. [PMID: 28829945 DOI: 10.1016/j.devcel.2017.07.019] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Revised: 06/19/2017] [Accepted: 07/23/2017] [Indexed: 01/08/2023]
Abstract
The molecular mechanisms regulating animal tissue size during development are unclear. This question has been extensively studied in the Drosophila wing disc. Although cell growth is regulated by the kinase TORC1, no readout exists to visualize TORC1 activity in situ in Drosophila. Both the cell cycle and the morphogen Dpp are linked to tissue growth, but whether they regulate TORC1 activity is not known. We develop here an anti-phospho-dRpS6 antibody that detects TORC1 activity in situ. We find, unexpectedly, that TORC1 activity in the wing disc is patchy. This is caused by elevated TORC1 activity at the cell cycle G1/S transition due to CycD/Cdk4 phosphorylating TSC1/2. We find that TORC1 is also activated independently of CycD/Cdk4 when cells with different levels of Dpp signaling or Brinker protein are juxtaposed. We thereby characterize the spatial distribution of TORC1 activity in a developing organ.
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Affiliation(s)
- Jesús Romero-Pozuelo
- German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany; Heidelberg University, 69120 Heidelberg, Germany
| | - Constantinos Demetriades
- German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany; Heidelberg University, 69120 Heidelberg, Germany
| | - Phillip Schroeder
- German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany; Heidelberg University, 69120 Heidelberg, Germany
| | - Aurelio A Teleman
- German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany; Heidelberg University, 69120 Heidelberg, Germany.
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15
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Tsokanos FF, Albert MA, Demetriades C, Spirohn K, Boutros M, Teleman AA. eIF4A inactivates TORC1 in response to amino acid starvation. EMBO J 2016; 35:1058-76. [PMID: 26988032 PMCID: PMC4868951 DOI: 10.15252/embj.201593118] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Accepted: 02/19/2016] [Indexed: 12/20/2022] Open
Abstract
Amino acids regulate TOR complex 1 (TORC1) via two counteracting mechanisms, one activating and one inactivating. The presence of amino acids causes TORC1 recruitment to lysosomes where TORC1 is activated by binding Rheb. How the absence of amino acids inactivates TORC1 is less well understood. Amino acid starvation recruits the TSC1/TSC2 complex to the vicinity of TORC1 to inhibit Rheb; however, the upstream mechanisms regulating TSC2 are not known. We identify here the eIF4A-containing eIF4F translation initiation complex as an upstream regulator of TSC2 in response to amino acid withdrawal in Drosophila We find that TORC1 and translation preinitiation complexes bind each other. Cells lacking eIF4F components retain elevated TORC1 activity upon amino acid removal. This effect is specific for eIF4F and not a general consequence of blocked translation. This study identifies specific components of the translation machinery as important mediators of TORC1 inactivation upon amino acid removal.
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Affiliation(s)
- Foivos-Filippos Tsokanos
- Division of Signal Transduction in Cancer and Metabolism, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Marie-Astrid Albert
- Division of Signal Transduction in Cancer and Metabolism, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Constantinos Demetriades
- Division of Signal Transduction in Cancer and Metabolism, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Kerstin Spirohn
- Department of Cell and Molecular Biology, Medical Faculty Mannheim, German Cancer Research Center (DKFZ), Division of Signaling and Functional Genomics and Heidelberg University, Heidelberg, Germany
| | - Michael Boutros
- Department of Cell and Molecular Biology, Medical Faculty Mannheim, German Cancer Research Center (DKFZ), Division of Signaling and Functional Genomics and Heidelberg University, Heidelberg, Germany
| | - Aurelio A Teleman
- Division of Signal Transduction in Cancer and Metabolism, German Cancer Research Center (DKFZ), Heidelberg, Germany
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16
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Abstract
mTORC1 promotes cell growth and is therefore inactivated upon unfavourable growth conditions. Signalling pathways downstream of most cellular stresses converge on TSC1/2, which serves as an integration point that inhibits mTORC1. The TSC1/2 complex was shown to translocate to lysosomes to inactivate mTORC1 in response to two stresses: amino-acid starvation and growth factor removal. Whether other stresses also regulate TSC2 localization is not known. How TSC2 localization responds to combinations of stresses and other stimuli is also unknown. We show that both amino acids and growth factors are required simultaneously to maintain TSC2 cytoplasmic; when one of the two is missing, TSC2 relocalizes to lysosomes. Furthermore, multiple different stresses that inhibit mTORC1 also drive TSC2 lysosomal accumulation. Our findings indicate that lysosomal recruitment of TSC2 is a universal response to stimuli that inactivate mTORC1, and that the presence of any single stress is sufficient to cause TSC2 lysosomal localization.
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Affiliation(s)
- Constantinos Demetriades
- Division of Signal Transduction in Cancer and Metabolism, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Monika Plescher
- Division of Signal Transduction in Cancer and Metabolism, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Aurelio A. Teleman
- Division of Signal Transduction in Cancer and Metabolism, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
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17
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Plescher M, Teleman AA, Demetriades C. TSC2 mediates hyperosmotic stress-induced inactivation of mTORC1. Sci Rep 2015; 5:13828. [PMID: 26345496 PMCID: PMC4642562 DOI: 10.1038/srep13828] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Accepted: 08/06/2015] [Indexed: 02/07/2023] Open
Abstract
mTOR complex 1 (mTORC1) regulates cell growth and metabolism. mTORC1 activity is regulated via integration of positive growth-promoting stimuli and negative stress stimuli. One stress cells confront in physiological and pathophysiological contexts is hyperosmotic stress. The mechanism by which hyperosmotic stress regulates mTORC1 activity is not well understood. We show here that mild hyperosmotic stress induces a rapid and reversible inactivation of mTORC1 via a mechanism involving multiple upstream signaling pathways. We find that hyperosmotic stress causes dynamic changes in TSC2 phosphorylation by upstream kinases, such as Akt, thereby recruiting TSC2 from the cytoplasm to lysosomes where it acts on Rheb, the direct activator of mTORC1. This work puts together a signaling pathway whereby hyperosmotic stress inactivates mTORC1.
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Affiliation(s)
- Monika Plescher
- Division of Signal Transduction in Cancer and Metabolism, German Cancer Research Center (DKFZ), 69120, Heidelberg, Germany
| | - Aurelio A Teleman
- Division of Signal Transduction in Cancer and Metabolism, German Cancer Research Center (DKFZ), 69120, Heidelberg, Germany
| | - Constantinos Demetriades
- Division of Signal Transduction in Cancer and Metabolism, German Cancer Research Center (DKFZ), 69120, Heidelberg, Germany
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18
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Demetriades C, Doumpas N, Teleman AA. Regulation of TORC1 in response to amino acid starvation via lysosomal recruitment of TSC2. Cell 2014; 156:786-99. [PMID: 24529380 DOI: 10.1016/j.cell.2014.01.024] [Citation(s) in RCA: 305] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Revised: 11/12/2013] [Accepted: 01/09/2014] [Indexed: 01/09/2023]
Abstract
TOR complex 1 (TORC1) is a potent anabolic regulator of cellular growth and metabolism. When cells have sufficient amino acids, TORC1 is active due to its lysosomal localization mediated via the Rag GTPases. Upon amino acid removal, the Rag GTPases release TORC1, causing it to become cytoplasmic and inactive. We show here that, upon amino acid removal, the Rag GTPases also recruit TSC2 to the lysosome, where it can act on Rheb. Only when both the Rag GTPases and Rheb are inactive is TORC1 fully released from the lysosome. Upon amino acid withdrawal, cells lacking TSC2 fail to completely release TORC1 from the lysosome, fail to completely inactivate TORC1, and fail to adjust physiologically to amino acid starvation. These data suggest that regulation of TSC2 subcellular localization may be a general mechanism to control its activity and place TSC2 in the amino-acid-sensing pathway to TORC1.
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Antonaki A, Demetriades C, Polyzos A, Banos A, Vatsellas G, Lavigne MD, Apostolou E, Mantouvalou E, Papadopoulou D, Mosialos G, Thanos D. Genomic analysis reveals a novel nuclear factor-κB (NF-κB)-binding site in Alu-repetitive elements. J Biol Chem 2011; 286:38768-38782. [PMID: 21896491 DOI: 10.1074/jbc.m111.234161] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The transcription factor NF-κB is a critical regulator of immune responses. To determine how NF-κB builds transcriptional control networks, we need to obtain a topographic map of the factor bound to the genome and correlate it with global gene expression. We used a ChIP cloning technique and identified novel NF-κB target genes in response to virus infection. We discovered that most of the NF-κB-bound genomic sites deviate from the consensus and are located away from conventional promoter regions. Remarkably, we identified a novel abundant NF-κB-binding site residing in specialized Alu-repetitive elements having the potential for long range transcription regulation, thus suggesting that in addition to its known role, NF-κB has a primate-specific function and a role in human evolution. By combining these data with global gene expression profiling of virus-infected cells, we found that most of the sites bound by NF-κB in the human genome do not correlate with changes in gene expression of the nearby genes and they do not appear to function in the context of synthetic promoters. These results demonstrate that repetitive elements interspersed in the human genome function as common target sites for transcription factors and may play an important role in expanding the repertoire of binding sites to engage new genes into regulatory networks.
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Affiliation(s)
- Athina Antonaki
- Institute of Molecular Biology, Genetics and Biotechnology, Biomedical Research Foundation, Academy of Athens, 4 Soranou Efesiou Street, Athens 11527, Greece
| | - Constantinos Demetriades
- Department of Biology, Aristotle University of Thessaloniki, University Campus, Thessaloniki 54124, Greece
| | - Alexander Polyzos
- Institute of Molecular Biology, Genetics and Biotechnology, Biomedical Research Foundation, Academy of Athens, 4 Soranou Efesiou Street, Athens 11527, Greece
| | - Aggelos Banos
- Institute of Molecular Biology, Genetics and Biotechnology, Biomedical Research Foundation, Academy of Athens, 4 Soranou Efesiou Street, Athens 11527, Greece
| | - Giannis Vatsellas
- Institute of Molecular Biology, Genetics and Biotechnology, Biomedical Research Foundation, Academy of Athens, 4 Soranou Efesiou Street, Athens 11527, Greece
| | - Matthieu D Lavigne
- Institute of Molecular Biology, Genetics and Biotechnology, Biomedical Research Foundation, Academy of Athens, 4 Soranou Efesiou Street, Athens 11527, Greece
| | - Effie Apostolou
- Institute of Molecular Biology, Genetics and Biotechnology, Biomedical Research Foundation, Academy of Athens, 4 Soranou Efesiou Street, Athens 11527, Greece
| | - Eva Mantouvalou
- Institute of Molecular Biology, Genetics and Biotechnology, Biomedical Research Foundation, Academy of Athens, 4 Soranou Efesiou Street, Athens 11527, Greece
| | - Deppie Papadopoulou
- Institute of Molecular Biology, Genetics and Biotechnology, Biomedical Research Foundation, Academy of Athens, 4 Soranou Efesiou Street, Athens 11527, Greece
| | - George Mosialos
- Department of Biology, Aristotle University of Thessaloniki, University Campus, Thessaloniki 54124, Greece.
| | - Dimitris Thanos
- Institute of Molecular Biology, Genetics and Biotechnology, Biomedical Research Foundation, Academy of Athens, 4 Soranou Efesiou Street, Athens 11527, Greece.
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Aggelidou E, Iordanidou P, Demetriades C, Piltsi O, Hadzopoulou-Cladaras M. Functional characterization of hepatocyte nuclear factor-4 alpha dimerization interface mutants. FEBS J 2006; 273:1948-58. [PMID: 16640558 DOI: 10.1111/j.1742-4658.2006.05208.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Hepatocyte nuclear factor-4 (HNF-4alpha), a member of the nuclear receptor superfamily, binds DNA exclusively as a homodimer. Dimerization controls important aspects of receptor function, such as DNA binding, protein stability, ligand binding and interaction with coactivators. Crystallographic data of the HNF-4alpha ligand-binding domain (LBD) demonstrated that the homodimer interface is composed of residues in helices 7, 9 and 10 with intermolecular salt bridges, hydrogen bonds and hydrophobic interactions contributing to the stability of the interface. To investigate the importance of the proposed ionic interactions for HNF-4alpha dimerization, interactions critical for formation of the LBD homodimer interface were disrupted by introducing point mutations in residues D261N (H7), E269Q (H7), Q307L (H9), D312N (H9) and Q336L (H10). Mutants were analysed for transactivation, coactivator interaction, DNA binding and dimerization. EMSA analysis showed that the mutants are able to bind DNA as dimers and coimmunoprecipitation assays confirmed dimerization in solution. Furthermore, the mutations do not compromise HNF-4alpha activity and are responsive to PPAR-gamma coactivator-1 (PGC-1). Finally, residue R324, located in the H9/H10 loop, which was suspected to be involved in dimer stabilization via an ionic interaction with residue E276, was studied. In contrast to the conservative substitution R324H the mutation R324L abolishes HNF-4alpha transcriptional activity and coactivator recruitment, revealing that the nature of substitution may play an important role in HNF-4alpha function.
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Affiliation(s)
- Eleni Aggelidou
- Department of Genetics, Development and Molecular Biology, Laboratory of Developmental Biology, School of Biology, Aristotle University of Thessaloniki, Greece
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21
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Iordanidou P, Aggelidou E, Demetriades C, Hadzopoulou-Cladaras M. Distinct amino acid residues may be involved in coactivator and ligand interactions in hepatocyte nuclear factor-4alpha. J Biol Chem 2005; 280:21810-9. [PMID: 15826954 DOI: 10.1074/jbc.m501221200] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Hepatocyte nuclear factor-4 (HNF-4) is a transcription factor of the nuclear hormone receptor superfamily that is constitutively active without the addition of exogenous ligand. Crystallographic analysis of the HNF-4alpha and HNF-4gamma ligand binding domains (LBDs) demonstrated the presence of endogenous ligands that may act as structural cofactors for HNF-4. It was also proposed by crystallographic studies that a combination of ligand and coactivator might be required to lock the receptor in its active state. We previously showed that mutations in amino acid residues Ser-181 and Met-182 in H3, Leu-219 and Leu-220 and Arg-226 in H5, Ileu-338 in H10, and Ileu-346 in H11, which line the LBD pocket in HNF-4alpha and come in contact with the ligand, impair its transactivation potential. In the present study, physical and functional interaction assays were utilized with two different coactivators, PGC-1 and SRC-3, to address the role of coactivators in HNF-4 function. We show that the integrity of the hinge (D) domain of HNF-4alpha and the activation function (AF)-2 activation domain region are critical for coactivation. Surprisingly, a different mode of coactivation is observed among the LBD point mutants that lack transcriptional activity. In particular, coactivation is maintained in mutants Ser-181, Arg-226, and Ile-346 but is abolished in mutants Met-182, Leu-219, and Ile-338. Physical interactions confirm this pattern of activation, implying that distinct amino acid residues may be involved in coactivator and ligand interactions, although some residues may be critical for both functions. Our results provide evidence and expand predictions based on the crystallographic data as to the role of coactivators in HNF-4alpha constitutive transcriptional activity.
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Affiliation(s)
- Panagiota Iordanidou
- Department of Genetics, Development and Molecular Biology, Laboratory of Developmental Biology, Aristotle University of Thessaloniki, Thessaloniki, Greece 54124
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22
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Christoforidis E, Goulimaris I, Kanellos I, Tsalis K, Demetriades C, Betsis D. Post-ERCP pancreatitis and hyperamylasemia: patient-related and operative risk factors. Endoscopy 2002; 34:286-92. [PMID: 11932783 DOI: 10.1055/s-2002-23630] [Citation(s) in RCA: 99] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND AND STUDY AIMS Previous studies on the development of post-endoscopic retrograde cholangiopancreatography (post-ERCP) hyperamylasemia and pancreatitis have focused on different risk factors, either procedure- or patient-related, and also prognostic factors, such as amylase levels together with the occurrence of pancreatic-type pain, which might be implicated. The aim of this study is to identify possible predictive risk factors and also prognostic factors in order to better organize the treatment strategy. PATIENTS AND METHODS During a 5-year period, 556 ERCP procedures were performed by the same operator. Of these, 43 procedures were excluded from the study. Data recorded from the procedures included both patient characteristics and procedure details. Patients were evaluated for pancreatic-type pain at 4 and 24 h after the procedure, and serum amylase levels were determined at 2 and 24 h after the procedure. Pancreatitis was diagnosed on the basis of both clinical and laboratory examination, while patients with hyperamylasemia were in a normal clinical condition but had high serum amylase levels. RESULTS Post-ERCP pancreatitis occurred after 17 procedures (3.3%) and hyperamylasemia after 85 procedures (16.5%). Patients who developed pancreatitis all had pancreatic-type pain together with amylase levels higher than 4-5 times the upper normal limit at 24 h after ERCP. There was a significant association between serum amylase levels and post-procedure pancreatic-type pain both at 4 h and 24 h after ERCP (P = 0.006). Age less than 50 years, history of relapsing pancreatitis, pancreatic duct opacification, and difficulty in obtaining bile duct cannulation all proved to be significant predictive risk factors for the development of either hyperamylasemia or pancreatitis. In contrast, additional procedures and sphincterotomy seemed to reduce the likelihood of both complications. CONCLUSIONS Serum amylase levels higher than 4 - 5 times the normal upper limit together with the existence of pancreatic-type pain, at 24 h after ERCP, strongly suggest the occurrence of pancreatitis. When any of the predictive risk factors coexist during a procedure it would be better either to abandon the procedure and try again later or, if the situation is urgent, to have earlier recourse to an alternative, such as precut or needle-knife papillotomy.
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Affiliation(s)
- E Christoforidis
- Fourth Surgical Department, Aristotelian University of Thessaloniki, Thessaloniki, Greece.
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23
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Demetriades C, Botsios D, Tsalis K, Manafis K, Zisiadis A, Dadoukis J. Management of large rectal wall defects with open pedicle grafts of small intestine. An experimental study. Dig Surg 2000; 15:693-6. [PMID: 9845639 DOI: 10.1159/000018680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Abstract
The aim of this study was to evaluate the possible repair of large rectal wall defects using an open pedicle ileal graft as a mucosal patch. This experiment was carried out in 14 adult mongrel dogs. By excision of a portion of the antimesenteric wall comprising 50-70% of the circumference and measuring 5-6 cm in length, a suitable full thickness defect was created in the lower part of the rectum. A segment of the distal ileum was then isolated on a mesenteric pedicle and opened from its antimesenteric border. This was sutured over the defect in two layers. The animals were observed for a period of 15 days to 12 months. All the animals survived the operation apart from 1 dog that died of fecal peritonitis. Function of the rectum generally remained normal. Barium X-ray did not show any obstruction, shrinkage of the patch, lumen dilatation or extravasation. At the time of autopsy pedicles of ileal grafts appeared intact and pulsating. On gross examination there was no evidence of focal hemorrhage, ulceration or any cicatricial thickening of the grafts. Healing was good and the ileal mucosa retained its villi and general characteristics without any major inflammatory reactions. There was an increase in the number of goblet cells which returned to normal in 6 months.
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Affiliation(s)
- C Demetriades
- 4th Surgical Department, Aristotle University of Thessaloniki, G. Papanicolaou General Hospital, Thessaloniki, Greece
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Kanellos I, Kazantzidou D, Christoforidis E, Demetriades C, Papavasiliou K, Dadoukis I. Simultaneous, combined sclerotherapy and rubber band ligation of haemorrhoids. Tech Coloproctol 1999. [DOI: 10.1007/s101510050015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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