251
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Chen L, Chen XW, Huang X, Song BL, Wang Y, Wang Y. Regulation of glucose and lipid metabolism in health and disease. SCIENCE CHINA-LIFE SCIENCES 2019; 62:1420-1458. [PMID: 31686320 DOI: 10.1007/s11427-019-1563-3] [Citation(s) in RCA: 135] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Accepted: 10/15/2019] [Indexed: 02/08/2023]
Abstract
Glucose and fatty acids are the major sources of energy for human body. Cholesterol, the most abundant sterol in mammals, is a key component of cell membranes although it does not generate ATP. The metabolisms of glucose, fatty acids and cholesterol are often intertwined and regulated. For example, glucose can be converted to fatty acids and cholesterol through de novo lipid biosynthesis pathways. Excessive lipids are secreted in lipoproteins or stored in lipid droplets. The metabolites of glucose and lipids are dynamically transported intercellularly and intracellularly, and then converted to other molecules in specific compartments. The disorders of glucose and lipid metabolism result in severe diseases including cardiovascular disease, diabetes and fatty liver. This review summarizes the major metabolic aspects of glucose and lipid, and their regulations in the context of physiology and diseases.
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Affiliation(s)
- Ligong Chen
- School of Pharmaceutical Sciences, Beijing Advanced Innovation Center for Structural Biology, Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology (Ministry of Education), Tsinghua University, Beijing, 100084, China.
| | - Xiao-Wei Chen
- State Key Laboratory of Membrane Biology, Institute of Molecular Medicine, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China.
| | - Xun Huang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China.
| | - Bao-Liang Song
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, 430072, China.
| | - Yan Wang
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, 430072, China.
| | - Yiguo Wang
- MOE Key Laboratory of Bioinformatics, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, 100084, China.
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252
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Savini M, Zhao Q, Wang MC. Lysosomes: Signaling Hubs for Metabolic Sensing and Longevity. Trends Cell Biol 2019; 29:876-887. [PMID: 31611045 DOI: 10.1016/j.tcb.2019.08.008] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 08/21/2019] [Accepted: 08/23/2019] [Indexed: 12/25/2022]
Abstract
Lysosomes are sites of active metabolism in a cell. They contain various hydrolases that degrade extracellular and intracellular materials during endocytosis and autophagy, respectively. In addition to their long-recognized roles in degradation and recycling, emerging studies have revealed that lysosomes are organizing centers for signal transduction. Lysosome-derived signaling plays crucial roles in regulating nutrient sensing, metabolic adaptation, organelle crosstalk, and aging. In particular, how the degradative role of the lysosome cooperates with its signaling functions to actively modulate lifespan is beginning to be unraveled. This review describes recent advances in the role of the lysosome as a 'signaling hub' that uses three different lysosome-derived signaling pathways to integrate metabolic inputs, organelle interactions, and the control of longevity.
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Affiliation(s)
- Marzia Savini
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Program in Developmental Biology, Baylor College of Medicine, Houston, TX 77030, USA; Huffington Center on Aging, Baylor College of Medicine, Houston, TX 77030, USA
| | - Qian Zhao
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Huffington Center on Aging, Baylor College of Medicine, Houston, TX 77030, USA
| | - Meng C Wang
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Program in Developmental Biology, Baylor College of Medicine, Houston, TX 77030, USA; Huffington Center on Aging, Baylor College of Medicine, Houston, TX 77030, USA; Howard Hughes Medical Institute, Baylor College of Medicine, Houston, TX 77030, USA.
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253
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Beaumatin F, O'Prey J, Barthet VJA, Zunino B, Parvy JP, Bachmann AM, O'Prey M, Kania E, Gonzalez PS, Macintosh R, Lao LY, Nixon C, Lopez J, Long JS, Tait SWG, Ryan KM. mTORC1 Activation Requires DRAM-1 by Facilitating Lysosomal Amino Acid Efflux. Mol Cell 2019; 76:163-176.e8. [PMID: 31492633 PMCID: PMC6892261 DOI: 10.1016/j.molcel.2019.07.021] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Revised: 05/15/2019] [Accepted: 07/15/2019] [Indexed: 02/06/2023]
Abstract
Sensing nutrient availability is essential for appropriate cellular growth, and mTORC1 is a major regulator of this process. Mechanisms causing mTORC1 activation are, however, complex and diverse. We report here an additional important step in the activation of mTORC1, which regulates the efflux of amino acids from lysosomes into the cytoplasm. This process requires DRAM-1, which binds the membrane carrier protein SCAMP3 and the amino acid transporters SLC1A5 and LAT1, directing them to lysosomes and permitting efficient mTORC1 activation. Consequently, we show that loss of DRAM-1 also impacts pathways regulated by mTORC1, including insulin signaling, glycemic balance, and adipocyte differentiation. Interestingly, although DRAM-1 can promote autophagy, this effect on mTORC1 is autophagy independent, and autophagy only becomes important for mTORC1 activation when DRAM-1 is deleted. These findings provide important insights into mTORC1 activation and highlight the importance of DRAM-1 in growth control, metabolic homeostasis, and differentiation.
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Affiliation(s)
- Florian Beaumatin
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK
| | - Jim O'Prey
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK
| | - Valentin J A Barthet
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK; Institute of Cancer Sciences, University of Glasgow, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK
| | - Barbara Zunino
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK
| | - Jean-Philippe Parvy
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK
| | | | - Margaret O'Prey
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK
| | - Elżbieta Kania
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK
| | - Pablo Sierra Gonzalez
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK; Institute of Cancer Sciences, University of Glasgow, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK
| | - Robin Macintosh
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK
| | - Laurence Y Lao
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK
| | - Colin Nixon
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK
| | - Jonathan Lopez
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK; Institute of Cancer Sciences, University of Glasgow, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK
| | - Jaclyn S Long
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK
| | - Stephen W G Tait
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK; Institute of Cancer Sciences, University of Glasgow, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK
| | - Kevin M Ryan
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK; Institute of Cancer Sciences, University of Glasgow, Garscube Estate, Switchback Road, Glasgow G61 1BD, UK.
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254
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Menchini RJ, Chaudhry FA. Multifaceted regulation of the system A transporter Slc38a2 suggests nanoscale regulation of amino acid metabolism and cellular signaling. Neuropharmacology 2019; 161:107789. [PMID: 31574264 DOI: 10.1016/j.neuropharm.2019.107789] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Revised: 09/16/2019] [Accepted: 09/20/2019] [Indexed: 02/07/2023]
Abstract
Amino acids are essential for cellular protein synthesis, growth, metabolism, signaling and in stress responses. Cell plasma membranes harbor specialized transporters accumulating amino acids to support a variety of cellular biochemical pathways. Several transporters for neutral amino acids have been characterized. However, Slc38a2 (also known as SA1, SAT2, ATA2, SNAT2) representing the classical transport system A activity stands in a unique position: Being a secondarily active transporter energized by the electrochemical gradient of Na+, it creates steep concentration gradients for amino acids such as glutamine: this may subsequently drive the accumulation of additional neutral amino acids through exchange via transport systems ASC and L. Slc38a2 is ubiquitously expressed, yet in a cell-specific manner. In this review, we show that Slc38a2 is regulated at the transcriptional and translational levels as well as by ions and proteins through direct interactions. We describe how Slc38a2 senses amino acid availability and passes this onto intracellular signaling pathways and how it regulates protein synthesis, cellular proliferation and apoptosis through the mechanistic (mammalian) target of rapamycin (mTOR) and general control nonderepressible 2 (GCN2) pathways. Furthermore, we review how this extensively regulated transporter contributes to cellular osmoadaptation and how it is regulated by endoplasmic reticulum stress and various hormonal stimuli to promote cellular metabolism, cellular signaling and cell survival. This article is part of the issue entitled 'Special Issue on Neurotransmitter Transporters'.
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Affiliation(s)
| | - Farrukh Abbas Chaudhry
- Department of Molecular Medicine, University of Oslo, Oslo, Norway; Department of Plastic and Reconstructive Surgery, Oslo University Hospital, Oslo, Norway
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255
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Garibsingh RAA, Schlessinger A. Advances and Challenges in Rational Drug Design for SLCs. Trends Pharmacol Sci 2019; 40:790-800. [PMID: 31519459 DOI: 10.1016/j.tips.2019.08.006] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 08/09/2019] [Accepted: 08/13/2019] [Indexed: 01/25/2023]
Abstract
There are over 420 human solute carrier (SLC) transporters from 65 families that are expressed ubiquitously in the body. The SLCs mediate the movement of ions, drugs, and metabolites across membranes and their dysfunction has been associated with a variety of diseases, such as diabetes, cancer, and central nervous system (CNS) disorders. Thus, SLCs are emerging as important targets for therapeutic intervention. Recent technological advances in experimental and computational biology allow better characterization of SLC pharmacology. Here we describe recent approaches to modulate SLC transporter function, with an emphasis on the use of computational approaches and computer-aided drug design (CADD) to study nutrient transporters. Finally, we discuss future perspectives in the rational design of SLC drugs.
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Affiliation(s)
- Rachel-Ann A Garibsingh
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Avner Schlessinger
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.
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256
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Anderson CM, Macleod KF. Autophagy and cancer cell metabolism. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2019; 347:145-190. [PMID: 31451213 PMCID: PMC8211395 DOI: 10.1016/bs.ircmb.2019.06.002] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Autophagy is an ancient catabolic process used by cells to clear excess or dysfunctional organelles and large subcellular structures and thus performs an important housekeeping role for the cell. Autophagy is acutely sensitive to nutrient availability and is upregulated at a transcriptional and posttranslational level in response to nutrient deprivation. This serves to promote turnover of cellular content and recycling of nutrients for continued growth and survival. While important for most normal tissues, tumor cells appear to be particularly dependent on autophagy for survival under ischemic or therapeutic stress, and in response to loss of matrix attachment; autophagy is upregulated markedly in cancers as they progress to malignancy. Ras-driven tumors appear to be particularly dependent on autophagy and thus inhibition of autophagy is being pursued as a productive clinical approach for such cancers. However, this enthusiasm needs to be offset against possible negative effects of autophagy inhibition on normal tissue function and on limiting antitumor immune responses. In addressing all of these topics, we focus in on understanding how autophagy is induced by nutrient stress, its role in recycling metabolites for growing tumors, how selective forms of autophagy, such as mitophagy and ribophagy contribute specifically to tumorigenesis, how autophagy in the tumor microenvironment and throughout the animal affects access of the tumor to nutrients, and finally how different oncogenic pathways may determine which tumors respond to autophagy inhibition and which ones will not.
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Affiliation(s)
- Cara M Anderson
- The Ben May Department for Cancer Research, The Gordon Center for Integrative Sciences, The University of Chicago, Chicago, IL, United States; The Committee on Molecular Metabolism & Nutrition, The University of Chicago, Chicago, IL, United States
| | - Kay F Macleod
- The Ben May Department for Cancer Research, The Gordon Center for Integrative Sciences, The University of Chicago, Chicago, IL, United States; The Committee on Molecular Metabolism & Nutrition, The University of Chicago, Chicago, IL, United States; The Committee on Cancer Biology, University of Chicago, Chicago, IL, United States.
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257
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Scalise M, Galluccio M, Pochini L, Cosco J, Trotta M, Rebsamen M, Superti-Furga G, Indiveri C. Insights into the transport side of the human SLC38A9 transceptor. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2019; 1861:1558-1567. [PMID: 31295473 DOI: 10.1016/j.bbamem.2019.07.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Revised: 05/17/2019] [Accepted: 07/03/2019] [Indexed: 01/06/2023]
Abstract
The lysosomal amino acid transporter SLC38A9 is referred to as transceptor, i.e. a transporter with a receptor function. The protein is responsible for coupling amino acid transport across the lysosomal membrane according to the substrate availability to mTORC1 signal transduction. This process allows cells to sense amino acid level responding to growth stimuli in physiological and pathological conditions triggering mTOR regulation. The main substrates underlying this function are glutamine and arginine. The functional and kinetic characterization of glutamine and arginine transport was performed using human SLC38A9 produced in E. coli, purified by affinity chromatography and reconstituted in liposomes. A cooperative behaviour for the wild type protein was revealed for both the substrates. A novel Na+ binding site, namely T453, was described by combined approaches of bioinformatics, site-directed mutagenesis and transport assay. Stimulation by cholesterol of glutamine and arginine transport was observed. The biological function of SLC38A9 relies on the interaction between its N-terminus and components of the mTOR complex; a deletion mutant of the N-terminus tail was produced and transport of glutamine was assayed revealing that this portion does not play any role in the intrinsic transport function of the human SLC38A9. Different features for glutamine and arginine transport were revealed: human SLC38A9 is competent for glutamine efflux, while that of arginine is negligible. In line with these results, imposed ∆pH stimulated glutamine, not arginine transport. Arginine plays, on the contrary, a modulatory function and is able to stimulate glutamine efflux. Interestingly, reciprocal inhibition experiments also supported by bioinformatics, suggested that glutamine and arginine may bind to different sites in the human SLC38A9 transporter.
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Affiliation(s)
- Mariafrancesca Scalise
- Department DiBEST (Biologia, Ecologia, Scienze della Terra) Unit of Biochemistry and Molecular Biotechnology, University of Calabria, Via P. Bucci 4C, 87036 Arcavacata di Rende, Italy
| | - Michele Galluccio
- Department DiBEST (Biologia, Ecologia, Scienze della Terra) Unit of Biochemistry and Molecular Biotechnology, University of Calabria, Via P. Bucci 4C, 87036 Arcavacata di Rende, Italy
| | - Lorena Pochini
- Department DiBEST (Biologia, Ecologia, Scienze della Terra) Unit of Biochemistry and Molecular Biotechnology, University of Calabria, Via P. Bucci 4C, 87036 Arcavacata di Rende, Italy
| | - Jessica Cosco
- Department DiBEST (Biologia, Ecologia, Scienze della Terra) Unit of Biochemistry and Molecular Biotechnology, University of Calabria, Via P. Bucci 4C, 87036 Arcavacata di Rende, Italy
| | - Miriam Trotta
- Department DiBEST (Biologia, Ecologia, Scienze della Terra) Unit of Biochemistry and Molecular Biotechnology, University of Calabria, Via P. Bucci 4C, 87036 Arcavacata di Rende, Italy
| | - Manuele Rebsamen
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, 1090 Vienna, Austria
| | - Giulio Superti-Furga
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, 1090 Vienna, Austria; Center for Physiology and Pharmacology, Medical University of Vienna, 1090 Vienna, Austria
| | - Cesare Indiveri
- Department DiBEST (Biologia, Ecologia, Scienze della Terra) Unit of Biochemistry and Molecular Biotechnology, University of Calabria, Via P. Bucci 4C, 87036 Arcavacata di Rende, Italy; CNR Institute of Biomembranes, Bioenergetics and Molecular Biotechnology, via Amendola 165/A, 70126 Bari, Italy.
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258
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Papadopoli D, Boulay K, Kazak L, Pollak M, Mallette FA, Topisirovic I, Hulea L. mTOR as a central regulator of lifespan and aging. F1000Res 2019; 8:F1000 Faculty Rev-998. [PMID: 31316753 PMCID: PMC6611156 DOI: 10.12688/f1000research.17196.1] [Citation(s) in RCA: 208] [Impact Index Per Article: 41.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 06/20/2019] [Indexed: 12/17/2022] Open
Abstract
The mammalian/mechanistic target of rapamycin (mTOR) is a key component of cellular metabolism that integrates nutrient sensing with cellular processes that fuel cell growth and proliferation. Although the involvement of the mTOR pathway in regulating life span and aging has been studied extensively in the last decade, the underpinning mechanisms remain elusive. In this review, we highlight the emerging insights that link mTOR to various processes related to aging, such as nutrient sensing, maintenance of proteostasis, autophagy, mitochondrial dysfunction, cellular senescence, and decline in stem cell function.
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Affiliation(s)
- David Papadopoli
- Gerald Bronfman Department of Oncology, McGill University, 5100 de Maisonneuve Blvd. West, Suite 720, Montréal, QC, H4A 3T2, Canada
- Lady Davis Institute, SMBD JGH, 3755 Chemin de la Côte-Sainte-Catherine, Montréal, QC, H3T 1E2, Canada
| | - Karine Boulay
- Lady Davis Institute, SMBD JGH, 3755 Chemin de la Côte-Sainte-Catherine, Montréal, QC, H3T 1E2, Canada
- Maisonneuve-Rosemont Hospital Research Centre, 5415 Assumption Blvd, Montréal, QC, H1T 2M4, Canada
- Département de Biochimie et Médecine Moléculaire, Université de Montréal, CP 6128, Succursale Centre-Ville, Montréal, QC, H3C 3J7, Canada
| | - Lawrence Kazak
- Department of Biochemistry, McGill University, 3655 Promenade Sir William Osler, Montréal, QC, H3G 1Y6, Canada
- Goodman Cancer Research Centre, 1160 Pine Avenue West, Montréal, QC, H3A 1A3, Canada
| | - Michael Pollak
- Gerald Bronfman Department of Oncology, McGill University, 5100 de Maisonneuve Blvd. West, Suite 720, Montréal, QC, H4A 3T2, Canada
- Lady Davis Institute, SMBD JGH, 3755 Chemin de la Côte-Sainte-Catherine, Montréal, QC, H3T 1E2, Canada
- Goodman Cancer Research Centre, 1160 Pine Avenue West, Montréal, QC, H3A 1A3, Canada
- Department of Experimental Medicine, McGill University, 845 Sherbrooke Street West, Montréal, QC, H3A 0G4, Canada
| | - Frédérick A. Mallette
- Maisonneuve-Rosemont Hospital Research Centre, 5415 Assumption Blvd, Montréal, QC, H1T 2M4, Canada
- Département de Biochimie et Médecine Moléculaire, Université de Montréal, CP 6128, Succursale Centre-Ville, Montréal, QC, H3C 3J7, Canada
- Département de Médecine, Université de Montréal, CP 6128, Succursale Centre-Ville, Montréal, QC, H3C 3J7, Canada
| | - Ivan Topisirovic
- Gerald Bronfman Department of Oncology, McGill University, 5100 de Maisonneuve Blvd. West, Suite 720, Montréal, QC, H4A 3T2, Canada
- Lady Davis Institute, SMBD JGH, 3755 Chemin de la Côte-Sainte-Catherine, Montréal, QC, H3T 1E2, Canada
- Department of Biochemistry, McGill University, 3655 Promenade Sir William Osler, Montréal, QC, H3G 1Y6, Canada
- Department of Experimental Medicine, McGill University, 845 Sherbrooke Street West, Montréal, QC, H3A 0G4, Canada
| | - Laura Hulea
- Maisonneuve-Rosemont Hospital Research Centre, 5415 Assumption Blvd, Montréal, QC, H1T 2M4, Canada
- Département de Biochimie et Médecine Moléculaire, Université de Montréal, CP 6128, Succursale Centre-Ville, Montréal, QC, H3C 3J7, Canada
- Département de Médecine, Université de Montréal, CP 6128, Succursale Centre-Ville, Montréal, QC, H3C 3J7, Canada
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259
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Peng W, Minakaki G, Nguyen M, Krainc D. Preserving Lysosomal Function in the Aging Brain: Insights from Neurodegeneration. Neurotherapeutics 2019; 16:611-634. [PMID: 31183763 PMCID: PMC6694346 DOI: 10.1007/s13311-019-00742-3] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Lysosomes are acidic, membrane-bound organelles that serve as the primary catabolic compartment of the cell. They are crucial to a variety of cellular processes from nutrient storage to autophagy. Given the diversity of lysosomal functions, it is unsurprising that lysosomes are also emerging as important players in aging. Lysosomal dysfunction is implicated in several aging-related neurodegenerative diseases including Alzheimer's, Parkinson's, amyotrophic lateral sclerosis/frontotemporal dementia, and Huntington's. Although the precise role of lysosomes in the aging brain is not well-elucidated, some insight into their function has been gained from our understanding of the pathophysiology of age-dependent neurodegenerative diseases. Therapeutic strategies targeting lysosomes and autophagic machinery have already been tested in several of these diseases with promising results, suggesting that improving lysosomal function could be similarly beneficial in preserving function in the aging brain.
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Affiliation(s)
- Wesley Peng
- The Ken & Ruth Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, 60611, USA
| | - Georgia Minakaki
- The Ken & Ruth Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, 60611, USA
| | - Maria Nguyen
- The Ken & Ruth Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, 60611, USA
| | - Dimitri Krainc
- The Ken & Ruth Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, 60611, USA.
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260
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Inpanathan S, Botelho RJ. The Lysosome Signaling Platform: Adapting With the Times. Front Cell Dev Biol 2019; 7:113. [PMID: 31281815 PMCID: PMC6595708 DOI: 10.3389/fcell.2019.00113] [Citation(s) in RCA: 88] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Accepted: 06/05/2019] [Indexed: 12/12/2022] Open
Abstract
Lysosomes are the terminal degradative compartment of autophagy, endocytosis and phagocytosis. What once was viewed as a simple acidic organelle in charge of macromolecular digestion has emerged as a dynamic organelle capable of integrating cellular signals and producing signal outputs. In this review, we focus on the concept that the lysosome surface serves as a platform to assemble major signaling hubs like mTORC1, AMPK, GSK3 and the inflammasome. These molecular assemblies integrate and facilitate cross-talk between signals such as amino acid and energy levels, membrane damage and infection, and ultimately enable responses such as autophagy, cell growth, membrane repair and microbe clearance. In particular, we review how molecular machinery like the vacuolar-ATPase proton pump, sestrins, the GATOR complexes, and the Ragulator, modulate mTORC1, AMPK, GSK3 and inflammation. We then elaborate how these signals control autophagy initiation and resolution, TFEB-mediated lysosome adaptation, lysosome remodeling, antigen presentation, inflammation, membrane damage repair and clearance. Overall, by being at the cross-roads for several membrane pathways, lysosomes have emerged as the ideal surveillance compartment to sense, integrate and elicit cellular behavior and adaptation in response to changing environmental and cellular conditions.
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Affiliation(s)
- Subothan Inpanathan
- Department of Chemistry and Biology, Graduate Program in Molecular Science, Ryerson University, Toronto, ON, Canada
| | - Roberto J Botelho
- Department of Chemistry and Biology, Graduate Program in Molecular Science, Ryerson University, Toronto, ON, Canada
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261
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Jung JW, Macalino SJY, Cui M, Kim JE, Kim HJ, Song DG, Nam SH, Kim S, Choi S, Lee JW. Transmembrane 4 L Six Family Member 5 Senses Arginine for mTORC1 Signaling. Cell Metab 2019; 29:1306-1319.e7. [PMID: 30956113 DOI: 10.1016/j.cmet.2019.03.005] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Revised: 01/15/2019] [Accepted: 03/06/2019] [Indexed: 12/25/2022]
Abstract
The mechanistic target of rapamycin complex (mTORC1) is a signaling hub on the lysosome surface, responding to lysosomal amino acids. Although arginine is metabolically important, the physiological arginine sensor that activates mTOR remains unclear. Here, we show that transmembrane 4 L six family member 5 (TM4SF5) translocates from plasma membrane to lysosome upon arginine sufficiency and senses arginine, culminating in mTORC1/S6K1 activation. TM4SF5 bound active mTOR upon arginine sufficiency and constitutively bound amino acid transporter SLC38A9. TM4SF5 binding to the cytosolic arginine sensor Castor1 decreased upon arginine sufficiency, thus allowing TM4SF5-mediated sensing of metabolic amino acids. TM4SF5 directly bound free L-arginine via its extracellular loop possibly for the efflux, being supported by mutant study and homology and molecular docking modeling. Therefore, we propose that lysosomal TM4SF5 senses and enables arginine efflux for mTORC1/S6K1 activation, and arginine-auxotroph in hepatocellular carcinoma may be targeted by blocking the arginine sensing using anti-TM4SF5 reagents.
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Affiliation(s)
- Jae Woo Jung
- Interdisciplinary Program in Genetic Engineering, Seoul National University, Seoul 08826, South Korea
| | - Stephani Joy Y Macalino
- National Leading Research Laboratory of Molecular Modeling & Drug Design, College of Pharmacy and Graduate School of Pharmaceutical Sciences, Ewha Womans University, Seoul 03760, South Korea
| | - Minghua Cui
- National Leading Research Laboratory of Molecular Modeling & Drug Design, College of Pharmacy and Graduate School of Pharmaceutical Sciences, Ewha Womans University, Seoul 03760, South Korea
| | - Ji Eon Kim
- Department of Pharmacy, Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 08826, South Korea
| | - Hye-Jin Kim
- Department of Pharmacy, Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 08826, South Korea
| | - Dae-Geun Song
- Department of Pharmacy, Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 08826, South Korea; Systems Biotechnology Research Center, Korea Institute of Science and Technology (KIST), Gangneung-si, Gangwon-do 25451, South Korea
| | - Seo Hee Nam
- Department of Pharmacy, Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 08826, South Korea
| | - Semi Kim
- Immunotherapy Convergence Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejon 34141, Republic of Korea
| | - Sun Choi
- National Leading Research Laboratory of Molecular Modeling & Drug Design, College of Pharmacy and Graduate School of Pharmaceutical Sciences, Ewha Womans University, Seoul 03760, South Korea.
| | - Jung Weon Lee
- Interdisciplinary Program in Genetic Engineering, Seoul National University, Seoul 08826, South Korea; Department of Pharmacy, Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 08826, South Korea.
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262
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Sullivan MR, Vander Heiden MG. Determinants of nutrient limitation in cancer. Crit Rev Biochem Mol Biol 2019; 54:193-207. [PMID: 31162937 PMCID: PMC6715536 DOI: 10.1080/10409238.2019.1611733] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2019] [Revised: 04/22/2019] [Accepted: 04/23/2019] [Indexed: 12/12/2022]
Abstract
Proliferation requires that cells accumulate sufficient biomass to grow and divide. Cancer cells within tumors must acquire a variety of nutrients, and tumor growth slows or stops if necessary metabolites are not obtained in sufficient quantities. Importantly, the metabolic demands of cancer cells can be different from those of untransformed cells, and nutrient accessibility in tumors is different than in many normal tissues. Thus, cancer cell survival and proliferation may be limited by different metabolic factors than those that are necessary to maintain noncancerous cells. Understanding the variables that dictate which nutrients are critical to sustain tumor growth may identify vulnerabilities that could be used to treat cancer. This review examines the various cell-autonomous, local, and systemic factors that determine which nutrients are limiting for tumor growth.
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Affiliation(s)
- Mark R Sullivan
- Koch Institute for Integrative Cancer Research and Department of Biology, Massachusetts Institute of Technology , Cambridge , MA , USA
| | - Matthew G Vander Heiden
- Koch Institute for Integrative Cancer Research and Department of Biology, Massachusetts Institute of Technology , Cambridge , MA , USA
- Dana-Farber Cancer Institute , Boston , MA , USA
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263
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Pawar H, Puri M, Fischer Weinberger R, Madhubala R, Zilberstein D. The arginine sensing and transport binding sites are distinct in the human pathogen Leishmania. PLoS Negl Trop Dis 2019; 13:e0007304. [PMID: 31017889 PMCID: PMC6502434 DOI: 10.1371/journal.pntd.0007304] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Revised: 05/06/2019] [Accepted: 03/14/2019] [Indexed: 01/08/2023] Open
Abstract
The intracellular protozoan parasite Leishmania donovani causes human visceral leishmaniasis. Intracellular L. donovani that proliferate inside macrophage phagolysosomes compete with the host for arginine, creating a situation that endangers parasite survival. Parasites have a sensor that upon arginine deficiency activates an Arginine Deprivation Response (ADR). L. donovani transport arginine via a high-affinity transporter (LdAAP3) that is rapidly up-regulated by ADR in intracellular amastigotes. To date, the sensor and its ligand have not been identified. Here, we show that the conserved amidino group at the distal cap of the arginine side chain is the ligand that activates ADR, in both promastigotes and intracellular amastigotes, and that arginine sensing and transport binding sites are distinct in L. donovani. Finally, upon addition of arginine and analogues to deprived cells, the amidino ligand activates rapid degradation of LdAAP3. This study provides the first identification of an intra-molecular ligand of a sensor that acts during infection. Leishmania donovani, the causative agent of visceral leishmaniasis, leads a digenetic life cycle as a flagellated promastigote in the vector sandfly and aflagellated amastigote within phagolysosomes of infected macrophages. Arginine is an essential amino acid for Leishmania which possesses a high specificity arginine transporter (LdAAP3), a protein that imports the amino acid into parasite cells. Arginine is primarily utilized in de novo protein synthesis and for biosynthesis of trypanothione via the polyamine pathway. It was previously reported by our group that L. donovani senses lack of arginine in the surrounding micro environment and activates a unique arginine deprivation response (ADR) pathway, thus upregulating the expression of LdAAP3 as well as other transporters. In the present study, we identified the region on the arginine molecule which is the ligand that activates ADR. We show that the conserved amidino group at the distal cap of the arginine side chain is the ligand that activates/suppresses ADR. Using arginine analogues that contain this group we observed that arginine sensing and transport are distinct in L. donovani, both in axenic promastigotes and intracellular amastigotes. Additionally, the arginine sensor responds to both arginine starvation and sufficiency.
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Affiliation(s)
- Harsh Pawar
- Faculty of Biology, Technion-Israel Institute of Technology, Haifa, Israel
| | - Madhu Puri
- School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
| | | | - Rentala Madhubala
- School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
| | - Dan Zilberstein
- Faculty of Biology, Technion-Israel Institute of Technology, Haifa, Israel
- * E-mail:
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264
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Watch What You (Self-) Eat: Autophagic Mechanisms that Modulate Metabolism. Cell Metab 2019; 29:803-826. [PMID: 30943392 PMCID: PMC6450419 DOI: 10.1016/j.cmet.2019.03.003] [Citation(s) in RCA: 188] [Impact Index Per Article: 37.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Revised: 02/07/2019] [Accepted: 03/04/2019] [Indexed: 02/07/2023]
Abstract
Autophagy is an evolutionarily conserved lysosome- or vacuole-dependent catabolic pathway in eukaryotes. Autophagy functions basally for cellular quality control and is induced to act as an alternative source of basic metabolites during nutrient deprivation. These functions of autophagy are intimately connected to the regulation of metabolism, and the metabolic status of the cell in turn controls the nature and extent of autophagic induction. Here, we highlight the co-regulation of autophagy and metabolism with a special focus on selective autophagy that, along with bulk autophagy, plays a central role in regulating and rewiring metabolic circuits. We outline the metabolic signals that activate these pathways, the mechanisms involved, and the downstream effects and implications while recognizing yet unanswered questions. We also discuss the role of autophagy in the development and maintenance of adipose tissue, an emerging player in systemic metabolic homeostasis, and describe what is currently known about the complex relationship between autophagy and cancer.
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265
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Kory N, Wyant GA, Prakash G, Uit de Bos J, Bottanelli F, Pacold ME, Chan SH, Lewis CA, Wang T, Keys HR, Guo YE, Sabatini DM. SFXN1 is a mitochondrial serine transporter required for one-carbon metabolism. Science 2019; 362:362/6416/eaat9528. [PMID: 30442778 DOI: 10.1126/science.aat9528] [Citation(s) in RCA: 139] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Accepted: 09/17/2018] [Indexed: 12/12/2022]
Abstract
One-carbon metabolism generates the one-carbon units required to synthesize many critical metabolites, including nucleotides. The pathway has cytosolic and mitochondrial branches, and a key step is the entry, through an unknown mechanism, of serine into mitochondria, where it is converted into glycine and formate. In a CRISPR-based genetic screen in human cells for genes of the mitochondrial pathway, we found sideroflexin 1 (SFXN1), a multipass inner mitochondrial membrane protein of unclear function. Like cells missing mitochondrial components of one-carbon metabolism, those null for SFXN1 are defective in glycine and purine synthesis. Cells lacking SFXN1 and one of its four homologs, SFXN3, have more severe defects, including being auxotrophic for glycine. Purified SFXN1 transports serine in vitro. Thus, SFXN1 functions as a mitochondrial serine transporter in one-carbon metabolism.
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Affiliation(s)
- Nora Kory
- Whitehead Institute for Biomedical Research, 455 Main Street, Cambridge, MA 02142, USA.,Howard Hughes Medical Institute, Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.,Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Department of Biology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA.,Broad Institute of Harvard and Massachusetts Institute of Technology, 415 Main Street, Cambridge, MA 02142, USA
| | - Gregory A Wyant
- Whitehead Institute for Biomedical Research, 455 Main Street, Cambridge, MA 02142, USA.,Howard Hughes Medical Institute, Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.,Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Department of Biology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA.,Broad Institute of Harvard and Massachusetts Institute of Technology, 415 Main Street, Cambridge, MA 02142, USA
| | - Gyan Prakash
- Whitehead Institute for Biomedical Research, 455 Main Street, Cambridge, MA 02142, USA
| | - Jelmi Uit de Bos
- Whitehead Institute for Biomedical Research, 455 Main Street, Cambridge, MA 02142, USA
| | - Francesca Bottanelli
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Michael E Pacold
- Whitehead Institute for Biomedical Research, 455 Main Street, Cambridge, MA 02142, USA.,Howard Hughes Medical Institute, Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.,Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Department of Biology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA.,Broad Institute of Harvard and Massachusetts Institute of Technology, 415 Main Street, Cambridge, MA 02142, USA.,Department of Radiation Oncology at NYU Langone Medical Center, New York, NY 10016, USA
| | - Sze Ham Chan
- Whitehead Institute for Biomedical Research, 455 Main Street, Cambridge, MA 02142, USA
| | - Caroline A Lewis
- Whitehead Institute for Biomedical Research, 455 Main Street, Cambridge, MA 02142, USA
| | - Tim Wang
- Whitehead Institute for Biomedical Research, 455 Main Street, Cambridge, MA 02142, USA.,Howard Hughes Medical Institute, Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.,Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Department of Biology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA.,Broad Institute of Harvard and Massachusetts Institute of Technology, 415 Main Street, Cambridge, MA 02142, USA
| | - Heather R Keys
- Whitehead Institute for Biomedical Research, 455 Main Street, Cambridge, MA 02142, USA
| | - Yang Eric Guo
- Whitehead Institute for Biomedical Research, 455 Main Street, Cambridge, MA 02142, USA
| | - David M Sabatini
- Whitehead Institute for Biomedical Research, 455 Main Street, Cambridge, MA 02142, USA. .,Howard Hughes Medical Institute, Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.,Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Department of Biology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA.,Broad Institute of Harvard and Massachusetts Institute of Technology, 415 Main Street, Cambridge, MA 02142, USA
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266
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Nutritional Regulation of Gene Expression: Carbohydrate-, Fat- and Amino Acid-Dependent Modulation of Transcriptional Activity. Int J Mol Sci 2019; 20:ijms20061386. [PMID: 30893897 PMCID: PMC6470599 DOI: 10.3390/ijms20061386] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 03/12/2019] [Accepted: 03/13/2019] [Indexed: 12/21/2022] Open
Abstract
The ability to detect changes in nutrient levels and generate an adequate response to these changes is essential for the proper functioning of living organisms. Adaptation to the high degree of variability in nutrient intake requires precise control of metabolic pathways. Mammals have developed different mechanisms to detect the abundance of nutrients such as sugars, lipids and amino acids and provide an integrated response. These mechanisms include the control of gene expression (from transcription to translation). This review reports the main molecular mechanisms that connect nutrients’ levels, gene expression and metabolism in health. The manuscript is focused on sugars’ signaling through the carbohydrate-responsive element binding protein (ChREBP), the role of peroxisome proliferator-activated receptors (PPARs) in the response to fat and GCN2/activating transcription factor 4 (ATF4) and mTORC1 pathways that sense amino acid concentrations. Frequently, alterations in these pathways underlie the onset of several metabolic pathologies such as obesity, insulin resistance, type 2 diabetes, cardiovascular diseases or cancer. In this context, the complete understanding of these mechanisms may improve our knowledge of metabolic diseases and may offer new therapeutic approaches based on nutritional interventions and individual genetic makeup.
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267
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Wang F, Gatica D, Ying ZX, Peterson LF, Kim P, Bernard D, Saiya-Cork K, Wang S, Kaminski MS, Chang AE, Phillips T, Klionsky DJ, Malek SN. Follicular lymphoma-associated mutations in vacuolar ATPase ATP6V1B2 activate autophagic flux and mTOR. J Clin Invest 2019; 129:1626-1640. [PMID: 30720463 PMCID: PMC6436860 DOI: 10.1172/jci98288] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Accepted: 01/29/2019] [Indexed: 12/15/2022] Open
Abstract
The discovery of recurrent mutations in subunits of the vacuolar-type H+-translocating ATPase (v-ATPase) in follicular lymphoma (FL) highlights a role for the amino acid- and energy-sensing pathway to mTOR in the pathogenesis of this disease. Here, through the use of complementary experimental approaches involving mammalian cells and Saccharomyces cerevisiae, we have demonstrated that mutations in the human v-ATPase subunit ATP6V1B2 (also known as Vma2 in yeast) activate autophagic flux and maintain mTOR/TOR in an active state. Engineered lymphoma cell lines and primary FL B cells carrying mutated ATP6V1B2 demonstrated a remarkable ability to survive low leucine concentrations. The treatment of primary FL B cells with inhibitors of autophagy uncovered an addiction for survival for FL B cells harboring ATP6V1B2 mutations. These data support the idea of mutational activation of autophagic flux by recurrent hotspot mutations in ATP6V1B2 as an adaptive mechanism in FL pathogenesis and as a possible new therapeutically targetable pathway.
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Affiliation(s)
- Fangyang Wang
- Department of Internal Medicine, Division of Hematology and Oncology
| | - Damián Gatica
- Life Sciences Institute, and
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Zhang Xiao Ying
- Department of Internal Medicine, Division of Hematology and Oncology
| | - Luke F. Peterson
- Department of Internal Medicine, Division of Hematology and Oncology
| | - Peter Kim
- Department of Internal Medicine, Division of Hematology and Oncology
| | | | - Kamlai Saiya-Cork
- Department of Internal Medicine, Division of Hematology and Oncology
| | - Shaomeng Wang
- Department of Internal Medicine, Division of Hematology and Oncology
| | - Mark S. Kaminski
- Department of Internal Medicine, Division of Hematology and Oncology
| | - Alfred E. Chang
- Department of Surgery, University of Michigan, Ann Arbor, Michigan, USA
| | - Tycel Phillips
- Department of Internal Medicine, Division of Hematology and Oncology
| | - Daniel J. Klionsky
- Life Sciences Institute, and
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Sami N. Malek
- Department of Internal Medicine, Division of Hematology and Oncology
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268
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Lemos H, Huang L, Prendergast GC, Mellor AL. Immune control by amino acid catabolism during tumorigenesis and therapy. Nat Rev Cancer 2019; 19:162-175. [PMID: 30696923 DOI: 10.1038/s41568-019-0106-z] [Citation(s) in RCA: 141] [Impact Index Per Article: 28.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Immune checkpoints arise from physiological changes during tumorigenesis that reprogramme inflammatory, immunological and metabolic processes in malignant lesions and local lymphoid tissues, which constitute the immunological tumour microenvironment (TME). Improving clinical responses to immune checkpoint blockade will require deeper understanding of factors that impact local immune balance in the TME. Elevated catabolism of the amino acids tryptophan (Trp) and arginine (Arg) is a common TME hallmark at clinical presentation of cancer. Cells catabolizing Trp and Arg suppress effector T cells and stabilize regulatory T cells to suppress immunity in chronic inflammatory diseases of clinical importance, including cancers. Processes that induce Trp and Arg catabolism in the TME remain incompletely defined. Indoleamine 2,3 dioxygenase (IDO) and arginase 1 (ARG1), which catabolize Trp and Arg, respectively, respond to inflammatory cues including interferons and transforming growth factor-β (TGFβ) cytokines. Dying cells generate inflammatory signals including DNA, which is sensed to stimulate the production of type I interferons via the stimulator of interferon genes (STING) adaptor. Thus, dying cells help establish local conditions that suppress antitumour immunity to promote tumorigenesis. Here, we review evidence that Trp and Arg catabolism contributes to inflammatory processes that promote tumorigenesis, impede immune responses to therapy and might promote neurological comorbidities associated with cancer.
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Affiliation(s)
- Henrique Lemos
- Institute of Cellular Medicine, Faculty of Medical Sciences, Framlington Place, Newcastle University, Newcastle-upon-Tyne, UK
| | - Lei Huang
- Institute of Cellular Medicine, Faculty of Medical Sciences, Framlington Place, Newcastle University, Newcastle-upon-Tyne, UK
| | | | - Andrew L Mellor
- Institute of Cellular Medicine, Faculty of Medical Sciences, Framlington Place, Newcastle University, Newcastle-upon-Tyne, UK.
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269
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Valvezan AJ, Manning BD. Molecular logic of mTORC1 signalling as a metabolic rheostat. Nat Metab 2019; 1:321-333. [PMID: 32694720 DOI: 10.1038/s42255-019-0038-7] [Citation(s) in RCA: 172] [Impact Index Per Article: 34.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Accepted: 01/24/2019] [Indexed: 02/05/2023]
Abstract
The protein kinase complex mechanistic target of rapamycin complex 1 (mTORC1) serves as a key conduit between growth signals and the metabolic processes underlying cell growth. The activation state of mTORC1 is controlled by intracellular nutrients and energy, as well as exogenous hormones and growth factors, thereby integrating local and systemic growth signals. Here we discuss the molecular logic of the mTORC1 signalling network and its importance in coupling growth signals to the control of cellular metabolism. After activation, mTORC1 promotes the conversion of available nutrients and energy into the major macromolecular species contributing to cellular mass, including proteins, nucleic acids and lipids, while suppressing the autophagic recycling of these macromolecules back into their nutrient constituents. Given that uncoupling of mTORC1 from its normal regulatory inputs contributes to many diseases-including cancer, genetic tumour syndromes, metabolic diseases, autoimmune diseases and neurological disorders-understanding the molecular logic of the mTORC1 network and how to modulate it may present therapeutic opportunities for treatment of a broad range of diseases and potentially even for the extension of lifespan.
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Affiliation(s)
- Alexander J Valvezan
- Department of Genetics and Complex Diseases, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Brendan D Manning
- Department of Genetics and Complex Diseases, Harvard T.H. Chan School of Public Health, Boston, MA, USA.
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270
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Abstract
In eukaryotes, TORC1/MTORC1 is a critical regulator of growth and proliferation. In response to nutrient abundance TORC1/MTORC1 favors anabolic processes and retards degradative ones. In S. cerevisiae, TORC1 is conventionally known to localize on the vacuolar membrane. In the course of their recent investigations, Hatakeyama et al. discovered a novel second site of TORC1 localization- the prevacuolar endosome. Their article, highlighted here, discusses the mechanism of TORC1 localization to the prevacuolar endosome and highlights a hitherto unappreciated mechanism by which 2 spatially separated pools of TORC1 execute the distinct functions of promoting anabolism and inhibiting degradation.
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Affiliation(s)
- Vikramjit Lahiri
- a Life Sciences Institute, and Department of Molecular, Cellular and Developmental Biology , University of Michigan , Ann Arbor , MI , USA
| | - Daniel J Klionsky
- a Life Sciences Institute, and Department of Molecular, Cellular and Developmental Biology , University of Michigan , Ann Arbor , MI , USA
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271
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Smith AG, Macleod KF. Autophagy, cancer stem cells and drug resistance. J Pathol 2019; 247:708-718. [PMID: 30570140 DOI: 10.1002/path.5222] [Citation(s) in RCA: 257] [Impact Index Per Article: 51.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 12/10/2018] [Accepted: 12/14/2018] [Indexed: 12/13/2022]
Abstract
Autophagy is a cellular survival mechanism that is induced by cancer therapy, among other stresses, and frequently contributes to cancer cell survival during long periods of dormancy and the eventual outgrowth of metastatic disease. Autophagy degrades large cellular structures that, once broken down, contribute to cellular survival through the recycling of their constituent metabolites. However, the extent to which this fuel function of autophagy is key to its role in promoting stemness, dormancy and drug resistance remains to be determined. Other roles for autophagy in determining cell fate more directly through targeted degradation of key transcription factors, such as p53 and FoxO3A, or by enforcing a reversible quiescent growth arrest, are discussed in this review. This review also highlights the need to parse out the roles of different forms of selective autophagy in stemness, CD44 expression and dormancy that, for example, are increasingly being attributed explicitly to mitophagy. The clinical relevance of this work and how an increased understanding of functions of autophagy in stemness, dormancy and drug resistance could be manipulated for increased therapeutic benefit, including eliminating minimal residual disease and preventing metastasis, are discussed. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
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Affiliation(s)
- Alexandra G Smith
- The Ben May Department for Cancer Research, The Gordon Center for Integrative Sciences, The University of Chicago, Chicago, IL, USA.,The Committee on Cancer Biology, The University of Chicago, Chicago, IL, USA.,Multi-disciplinary Training Grant in Cancer Research, University of Chicago, Chicago, IL, USA
| | - Kay F Macleod
- The Ben May Department for Cancer Research, The Gordon Center for Integrative Sciences, The University of Chicago, Chicago, IL, USA.,The Committee on Cancer Biology, The University of Chicago, Chicago, IL, USA.,Multi-disciplinary Training Grant in Cancer Research, University of Chicago, Chicago, IL, USA
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272
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Li P, Gu M, Xu H. Lysosomal Ion Channels as Decoders of Cellular Signals. Trends Biochem Sci 2019; 44:110-124. [PMID: 30424907 PMCID: PMC6340733 DOI: 10.1016/j.tibs.2018.10.006] [Citation(s) in RCA: 100] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Revised: 10/09/2018] [Accepted: 10/15/2018] [Indexed: 02/08/2023]
Abstract
Lysosomes, the degradation center of the cell, are filled with acidic hydrolases. Lysosomes generate nutrient-sensitive signals to regulate the import of H+, hydrolases, and endocytic and autophagic cargos, as well as the export of their degradation products (catabolites). In response to environmental and cellular signals, lysosomes change their positioning, number, morphology, size, composition, and activity within minutes to hours to meet the changing cellular needs. Ion channels in the lysosome are essential transducers that mediate signal-initiated Ca2+/Fe2+/Zn2+ release and H+/Na+/K+-dependent changes of membrane potential across the perimeter membrane. Dysregulation of lysosomal ion flux impairs lysosome movement, membrane trafficking, nutrient sensing, membrane repair, organelle membrane contact, and lysosome biogenesis and adaptation. Hence, activation and inhibition of lysosomal channels by synthetic modulators may tune lysosome function to maintain cellular health and promote cellular clearance in lysosome storage disorders.
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Affiliation(s)
- Ping Li
- Collaborative Innovation Center of Yangtze River Delta Region Green Pharmaceuticals, College of Pharmaceutical Sciences, Zhejiang University of Technology, Hangzhou 310014, China; Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA; These authors contributed equally to this work
| | - Mingxue Gu
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA; These authors contributed equally to this work
| | - Haoxing Xu
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA.
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273
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Boutouja F, Stiehm CM, Platta HW. mTOR: A Cellular Regulator Interface in Health and Disease. Cells 2019; 8:cells8010018. [PMID: 30609721 PMCID: PMC6356367 DOI: 10.3390/cells8010018] [Citation(s) in RCA: 94] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 12/25/2018] [Accepted: 01/01/2019] [Indexed: 12/19/2022] Open
Abstract
The mechanistic target of Rapamycin (mTOR) is a ubiquitously-conserved serine/threonine kinase, which has a central function in integrating growth signals and orchestrating their physiologic effects on cellular level. mTOR is the core component of differently composed signaling complexes that differ in protein composition and molecular targets. Newly identified classes of mTOR inhibitors are being developed to block autoimmune diseases and transplant rejections but also to treat obesity, diabetes, and different types of cancer. Therefore, the selective and context-dependent inhibition of mTOR activity itself might come into the focus as molecular target to prevent severe diseases and possibly to extend life span. This review provides a general introduction to the molecular composition and physiologic function of mTOR complexes as part of the Special Issue “2018 Select Papers by Cells’ Editorial Board Members”.
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Affiliation(s)
- Fahd Boutouja
- Biochemie Intrazellulärer Transportprozesse, Ruhr-Universität Bochum, 44801 Bochum, Germany.
| | - Christian M Stiehm
- Biochemie Intrazellulärer Transportprozesse, Ruhr-Universität Bochum, 44801 Bochum, Germany.
| | - Harald W Platta
- Biochemie Intrazellulärer Transportprozesse, Ruhr-Universität Bochum, 44801 Bochum, Germany.
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274
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Kim J, Guan KL. mTOR as a central hub of nutrient signalling and cell growth. Nat Cell Biol 2019; 21:63-71. [PMID: 30602761 DOI: 10.1038/s41556-018-0205-1] [Citation(s) in RCA: 660] [Impact Index Per Article: 132.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Accepted: 08/23/2018] [Indexed: 12/19/2022]
Abstract
The highly conserved protein kinase mechanistic target of rapamycin (mTOR; originally known as mammalian target of rapamycin) is a central cell growth regulator connecting cellular metabolism and growth with a wide range of environmental inputs as part of mTOR complex 1 (mTORC1) and mTORC2. In this Review, we introduce the landmark discoveries in the mTOR field, starting from the isolation of rapamycin to the molecular characterizations of key components of the mTORC signalling network with an emphasis on amino acid sensing, and discuss the perspectives of mTORC inhibitors in therapeutic applications.
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Affiliation(s)
- Joungmok Kim
- Department of Oral Biochemistry and Molecular Biology, School of Dentistry, Kyung Hee University, Seoul, Korea.
| | - Kun-Liang Guan
- Department of Pharmacology and Moores Cancer Center, University of California, San Diego, La Jolla, CA, USA.
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275
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The lysosome as a cellular centre for signalling, metabolism and quality control. Nat Cell Biol 2019; 21:133-142. [DOI: 10.1038/s41556-018-0244-7] [Citation(s) in RCA: 409] [Impact Index Per Article: 81.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Accepted: 10/31/2018] [Indexed: 02/06/2023]
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276
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Wang Y, Zhang H. Regulation of Autophagy by mTOR Signaling Pathway. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1206:67-83. [PMID: 31776980 DOI: 10.1007/978-981-15-0602-4_3] [Citation(s) in RCA: 198] [Impact Index Per Article: 39.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Autophagy plays a crucial role in maintaining cellular homeostasis, and is closely related to the occurrence of variety of human diseases. It is known that autophagy occurs in response to various environmental stresses such as nutrient deficiency, growth factor deficiency, and hypoxia. Induced autophagy eliminates the damage caused by these stresses and returns to normal levels when the stresses are relieved. To comprehend the induction of autophagy under various stress conditions and the effects of autophagy on the life processes of cells, it is necessary to understand how autophagy is regulated. Many studies have shown that a number of signal transduction pathways are involved in the regulation of autophagy. Among these pathways, some pathways converge at the target of rapamycin (TOR), a highly conserved kinase important for autophagy regulation. This review will focus on the role of TOR signaling pathway in the regulation of autophagy.
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Affiliation(s)
- Ying Wang
- Department of Physiology, Chinese Academy of Medical Sciences and Peking Union Medical College, Institute of Basic Medical Sciences, Beijing, China.,Department of Molecular Orthopedics, Beijing Research Institute of Traumatology and Orthopaedics, Beijing, China
| | - Hongbing Zhang
- Department of Physiology, Chinese Academy of Medical Sciences and Peking Union Medical College, Institute of Basic Medical Sciences, Beijing, China.
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277
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Green CL, Lamming DW. Regulation of metabolic health by essential dietary amino acids. Mech Ageing Dev 2019; 177:186-200. [PMID: 30044947 PMCID: PMC6333505 DOI: 10.1016/j.mad.2018.07.004] [Citation(s) in RCA: 64] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Revised: 06/27/2018] [Accepted: 07/16/2018] [Indexed: 12/22/2022]
Abstract
Although the beneficial effects of calorie restriction (CR) on health and aging were first observed a century ago, the specific macronutrients and molecular processes that mediate the effect of CR have been heavily debated. Recently, it has become clear that dietary protein plays a key role in regulating both metabolic health and longevity, and that both the quantity and quality - the specific amino acid composition - of dietary protein mediates metabolic health. Here, we discuss recent findings in model organisms ranging from yeast to mice and humans regarding the influence of dietary protein as well as specific amino acids on metabolic health, and the physiological and molecular mechanisms which may mediate these effects. We then discuss recent findings which suggest that the restriction of specific dietary amino acids may be a potent therapy to treat or prevent metabolic syndrome. Finally, we discuss the potential for dietary restriction of specific amino acids - or pharmaceuticals which harness these same mechanisms - to promote healthy aging.
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Affiliation(s)
- Cara L Green
- Department of Medicine, University of Wisconsin-Madison, Madison, WI, USA; William S. Middleton Memorial Veterans Hospital, Madison, WI, USA
| | - Dudley W Lamming
- Department of Medicine, University of Wisconsin-Madison, Madison, WI, USA; William S. Middleton Memorial Veterans Hospital, Madison, WI, USA.
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278
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Lamming DW, Bar-Peled L. Lysosome: The metabolic signaling hub. Traffic 2019; 20:27-38. [PMID: 30306667 PMCID: PMC6294686 DOI: 10.1111/tra.12617] [Citation(s) in RCA: 94] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Revised: 09/17/2018] [Accepted: 10/07/2018] [Indexed: 12/27/2022]
Abstract
For the past five decades, the lysosome has been characterized as an unglamorous cellular recycling center. This notion has undergone a radical shift in the last 10 years, with new research revealing that this organelle serves as a major hub for metabolic signaling pathways. The discovery that master growth regulators, including the protein kinase mTOR (mechanistic target of rapamycin), make their home at the lysosomal surface has generated intense interest in the lysosome's key role in nutrient sensing and cellular homeostasis. The transcriptional networks required for lysosomal maintenance and function are just being unraveled and their connection to lysosome-based signaling pathways revealed. The catabolic and anabolic pathways that converge on the lysosome connect this organelle with multiple facets of cellular function; when these pathways are deregulated they underlie multiple human diseases, and promote cellular and organismal aging. Thus, understanding how lysosome-based signaling pathways function will not only illuminate the fascinating biology of this organelle but will also be critical in unlocking its therapeutic potentials.
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Affiliation(s)
- Dudley W. Lamming
- William S. Middleton Memorial Veterans Hospital, Madison, WI, USA
- Department of Medicine, University of Wisconsin-Madison, Madison, WI, USA
| | - Liron Bar-Peled
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, USA
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279
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MITO-Tag Mice enable rapid isolation and multimodal profiling of mitochondria from specific cell types in vivo. Proc Natl Acad Sci U S A 2018; 116:303-312. [PMID: 30541894 DOI: 10.1073/pnas.1816656115] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Mitochondria are metabolic organelles that are essential for mammalian life, but the dynamics of mitochondrial metabolism within mammalian tissues in vivo remains incompletely understood. While whole-tissue metabolite profiling has been useful for studying metabolism in vivo, such an approach lacks resolution at the cellular and subcellular level. In vivo methods for interrogating organellar metabolites in specific cell types within mammalian tissues have been limited. To address this, we built on prior work in which we exploited a mitochondrially localized 3XHA epitope tag (MITO-Tag) for the fast isolation of mitochondria from cultured cells to generate MITO-Tag Mice. Affording spatiotemporal control over MITO-Tag expression, these transgenic animals enable the rapid, cell-type-specific immunoisolation of mitochondria from tissues, which we verified using a combination of proteomic and metabolomic approaches. Using MITO-Tag Mice and targeted and untargeted metabolite profiling, we identified changes during fasted and refed conditions in a diverse array of mitochondrial metabolites in hepatocytes and found metabolites that behaved differently at the mitochondrial versus whole-tissue level. MITO-Tag Mice should have utility for studying mitochondrial physiology, and our strategy should be generally applicable for studying other mammalian organelles in specific cell types in vivo.
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280
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Abstract
Oncogenic signalling and metabolic alterations are interrelated in cancer cells. mTOR, which is frequently activated in cancer, controls cell growth and metabolism. mTOR signalling regulates amino acid, glucose, nucleotide, fatty acid and lipid metabolism. Conversely, metabolic inputs, such as amino acids, activate mTOR. In this Review, we discuss how mTOR signalling rewires cancer cell metabolism and delineate how changes in metabolism, in turn, sustain mTOR signalling and tumorigenicity. Several drugs are being developed to perturb cancer cell metabolism. However, their efficacy as stand-alone therapies, similar to mTOR inhibitors, is limited. Here, we discuss how the interdependence of mTOR signalling and metabolism can be exploited for cancer therapy.
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Affiliation(s)
| | - Sujin Park
- Biozentrum, University of Basel, Basel, Switzerland
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281
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Dikicioglu D, Dereli Eke E, Eraslan S, Oliver SG, Kirdar B. Saccharomyces cerevisiae adapted to grow in the presence of low-dose rapamycin exhibit altered amino acid metabolism. Cell Commun Signal 2018; 16:85. [PMID: 30458881 PMCID: PMC6245637 DOI: 10.1186/s12964-018-0298-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Accepted: 11/08/2018] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Rapamycin is a potent inhibitor of the highly conserved TOR kinase, the nutrient-sensitive controller of growth and aging. It has been utilised as a chemotherapeutic agent due to its anti-proliferative properties and as an immunosuppressive drug, and is also known to extend lifespan in a range of eukaryotes from yeast to mammals. However, the mechanisms through which eukaryotic cells adapt to sustained exposure to rapamycin have not yet been thoroughly investigated. METHODS Here, S. cerevisiae response to long-term rapamycin exposure was investigated by identifying the physiological, transcriptomic and metabolic differences observed for yeast populations inoculated into low-dose rapamycin-containing environment. The effect of oxygen availability and acidity of extracellular environment on this response was further deliberated by controlling or monitoring the dissolved oxygen level and pH of the culture. RESULTS Yeast populations grown in the presence of rapamycin reached higher cell densities complemented by an increase in their chronological lifespan, and these physiological adaptations were associated with a rewiring of the amino acid metabolism, particularly that of arginine. The ability to synthesise amino acids emerges as the key factor leading to the major mechanistic differences between mammalian and microbial TOR signalling pathways in relation to nutrient recognition. CONCLUSION Oxygen levels and extracellular acidity of the culture were observed to conjointly affect yeast populations, virtually acting as coupled physiological effectors; cells were best adapted when maximal oxygenation of the culture was maintained in slightly acidic pH, any deviation necessitated more extensive readjustment to additional stress factors.
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Affiliation(s)
- Duygu Dikicioglu
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, UK. .,Cambridge Systems Biology Centre, University of Cambridge, Cambridge, UK. .,Department of Chemical Engineering, Bogazici University, Istanbul, Turkey.
| | - Elif Dereli Eke
- Department of Chemical Engineering, Bogazici University, Istanbul, Turkey.,Present address: Unit of Blood Diseases and Stem Cells Transplantation, Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy
| | - Serpil Eraslan
- Department of Chemical Engineering, Bogazici University, Istanbul, Turkey.,Present address: Diagnostic Centre for Genetic Diseases, Koc University Hospital, Istanbul, Turkey
| | - Stephen G Oliver
- Cambridge Systems Biology Centre, University of Cambridge, Cambridge, UK.,Department of Biochemistry, University of Cambridge, Cambridge, UK
| | - Betul Kirdar
- Department of Chemical Engineering, Bogazici University, Istanbul, Turkey
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282
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Rudar M, Fiorotto ML, Davis TA. Regulation of Muscle Growth in Early Postnatal Life in a Swine Model. Annu Rev Anim Biosci 2018; 7:309-335. [PMID: 30388025 DOI: 10.1146/annurev-animal-020518-115130] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Skeletal muscle growth during the early postnatal period is rapid in the pig and dependent on the capacity of muscle to respond to anabolic and catabolic stimuli. Muscle mass is driven by the balance between protein synthesis and degradation. Among these processes, muscle protein synthesis in the piglet is exceptionally sensitive to the feeding-induced postprandial changes in insulin and amino acids, whereas muscle protein degradation is affected only during specific catabolic states. The developmental decline in the response of muscle to feeding is associated with changes in the signaling pathways located upstream and downstream of the mechanistic target of rapamycin protein complex. Additionally, muscle growth is supported by an accretion of nuclei derived from satellite cells. Activated satellite cells undergo proliferation, differentiation, and fusion with adjacent growing muscle fibers. Enhancing early muscle growth through modifying protein synthesis, degradation, and satellite cell activity is key to maximizing performance, productivity, and lifelong pig health.
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Affiliation(s)
- Marko Rudar
- USDA/ARS Children's Nutrition Research Center, Baylor College of Medicine, Houston, Texas 77030, USA; , ,
| | - Marta L Fiorotto
- USDA/ARS Children's Nutrition Research Center, Baylor College of Medicine, Houston, Texas 77030, USA; , ,
| | - Teresa A Davis
- USDA/ARS Children's Nutrition Research Center, Baylor College of Medicine, Houston, Texas 77030, USA; , ,
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283
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Qi H, Meng C, Jin X, Li X, Li P, Gao X. Methionine Promotes Milk Protein and Fat Synthesis and Cell Proliferation via the SNAT2-PI3K Signaling Pathway in Bovine Mammary Epithelial Cells. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2018; 66:11027-11033. [PMID: 30274521 DOI: 10.1021/acs.jafc.8b04241] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Methionine (Met) plays a critical regulatory role in milk production, however, the molecular mechanism of action of Met is largely unknown. This study therefore aimed to investigate the influence of Met on milk synthesis in and proliferation of bovine mammary epithelial cells (BMECs) and explore the underlying mechanism. BMECs cultured in fetal bovine serum (FBS) free Dulbecco's modified eagle's medium (DMEM)/F-12 medium were treated with Met (0, 0.3, 0.6, 0.9, and 1.2 mM). Results showed that Met (0.6 mM) significantly increased milk protein and fat synthesis and cell proliferation. Met stimulation also increased mTOR phosphorylation and protein expression of SREBP-1c and Cyclin D1. Gene function study approaches further revealed that SNAT2 is a key regulator of these signaling pathways. PI3K inhibition experiments demonstrated that SNAT2 stimulates these pathways through regulating PI3K activity, and SNAT2 inhibition experiments further revealed that SNAT2 is required for Met to activate PI3K. Furthermore, immunofluorescence observation detected that Met stimulates SNAT2 cytoplasmic expression. Collectively, these findings demonstrate that Met positively regulates milk protein and fat synthesis and cell proliferation via the SNAT2-PI3K signaling pathway in BMECs.
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Affiliation(s)
- Hao Qi
- The Key Laboratory of Dairy Science of Education Ministry , Northeast Agricultural University , Harbin 150030 , China
| | - Chunyu Meng
- The Key Laboratory of Dairy Science of Education Ministry , Northeast Agricultural University , Harbin 150030 , China
| | - Xin Jin
- The Key Laboratory of Dairy Science of Education Ministry , Northeast Agricultural University , Harbin 150030 , China
| | - Xueying Li
- The Key Laboratory of Dairy Science of Education Ministry , Northeast Agricultural University , Harbin 150030 , China
| | - Ping Li
- The Key Laboratory of Dairy Science of Education Ministry , Northeast Agricultural University , Harbin 150030 , China
| | - Xuejun Gao
- The Key Laboratory of Dairy Science of Education Ministry , Northeast Agricultural University , Harbin 150030 , China
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284
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Velentzas PD, Zhang L, Das G, Chang TK, Nelson C, Kobertz WR, Baehrecke EH. The Proton-Coupled Monocarboxylate Transporter Hermes Is Necessary for Autophagy during Cell Death. Dev Cell 2018; 47:281-293.e4. [PMID: 30318245 DOI: 10.1016/j.devcel.2018.09.015] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 07/25/2018] [Accepted: 09/14/2018] [Indexed: 02/06/2023]
Abstract
Nutrient availability influences the production and degradation of materials that are required for cell growth and survival. Autophagy is a nutrient-regulated process that is used to degrade cytoplasmic materials and has been associated with human diseases. Solute transporters influence nutrient availability and sensing, yet we know little about how transporters influence autophagy. Here, we screen for solute transporters that are required for autophagy-dependent cell death and identify CG11665/hermes. We show that hermes is required for both autophagy during steroid-triggered salivary gland cell death and TNF-induced non-apoptotic eye cell death. hermes encodes a proton-coupled monocarboxylate transporter that preferentially transports pyruvate over lactate. mTOR signaling is elevated in hermes mutant cells, and decreased mTOR function suppresses the hermes salivary gland cell death phenotype. Hermes is most similar to human SLC16A11, a protein that was recently implicated in type 2 diabetes, thus providing a link between pyruvate, mTOR, autophagy, and possibly metabolic disorders.
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Affiliation(s)
- Panagiotis D Velentzas
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Lejie Zhang
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Gautam Das
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Tsun-Kai Chang
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA 01605, USA; Cancer Immunology, Genentech Inc, South San Francisco, CA 94080, USA
| | - Charles Nelson
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA 01605, USA; Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - William R Kobertz
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Eric H Baehrecke
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA 01605, USA.
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285
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Abstract
Cancer cells reprogramme metabolism to maximize the use of nitrogen and carbon for the anabolic synthesis of macromolecules that are required during tumour proliferation and growth. To achieve this aim, one strategy is to reduce catabolism and nitrogen disposal. The urea cycle (UC) in the liver is the main metabolic pathway to convert excess nitrogen into disposable urea. Outside the liver, UC enzymes are differentially expressed, enabling the use of nitrogen for the synthesis of UC intermediates that are required to accommodate cellular needs. Interestingly, the expression of UC enzymes is altered in cancer, revealing a revolutionary mechanism to maximize nitrogen incorporation into biomass. In this Review, we discuss the metabolic benefits underlying UC deregulation in cancer and the relevance of these alterations for cancer diagnosis and therapy.
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Affiliation(s)
- Rom Keshet
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel
| | - Peter Szlosarek
- Centre for Molecular Oncology, Barts Cancer Institute, Queen Mary University of London, John Vane Science Centre, London, UK
- Barts Health NHS Trust, St Bartholomew's Hospital, London, UK
| | - Arkaitz Carracedo
- CIC bioGUNE, Bizkaia, Spain
- CIBERONC, Instituto de Salud Carlos III, Madrid, Spain
- Ikerbasque, Basque Foundation for Science, Bilbao, Spain
- Biochemistry and Molecular Biology Department, University of the Basque Country, Bilbao, Spain
| | - Ayelet Erez
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel.
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286
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Freeman SA, Grinstein S. Resolution of macropinosomes, phagosomes and autolysosomes: Osmotically driven shrinkage enables tubulation and vesiculation. Traffic 2018; 19:965-974. [DOI: 10.1111/tra.12614] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2018] [Revised: 08/15/2018] [Accepted: 08/16/2018] [Indexed: 12/14/2022]
Affiliation(s)
- Spencer A. Freeman
- Program in Cell Biology; Peter Gilgan Centre for Research and Learning, Hospital for Sick Children; Toronto Ontario Canada
| | - Sergio Grinstein
- Program in Cell Biology; Peter Gilgan Centre for Research and Learning, Hospital for Sick Children; Toronto Ontario Canada
- Keenan Research Centre of the Li Ka Shing Knowledge Institute, St. Michael's Hospital; Toronto Ontario Canada
- Department of Biochemistry; University of Toronto; Toronto Ontario Canada
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287
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Ragulator and SLC38A9 activate the Rag GTPases through noncanonical GEF mechanisms. Proc Natl Acad Sci U S A 2018; 115:9545-9550. [PMID: 30181260 DOI: 10.1073/pnas.1811727115] [Citation(s) in RCA: 100] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The mechanistic target of rapamycin complex 1 (mTORC1) growth pathway detects nutrients through a variety of sensors and regulators that converge on the Rag GTPases, which form heterodimers consisting of RagA or RagB tightly bound to RagC or RagD and control the subcellular localization of mTORC1. The Rag heterodimer uses a unique "locking" mechanism to stabilize its active (GTPRagA-RagCGDP) or inactive (GDPRagA-RagCGTP) nucleotide states. The Ragulator complex tethers the Rag heterodimer to the lysosomal surface, and the SLC38A9 transmembrane protein is a lysosomal arginine sensor that upon activation stimulates mTORC1 activity through the Rag GTPases. How Ragulator and SLC38A9 control the nucleotide loading state of the Rag GTPases remains incompletely understood. Here we find that Ragulator and SLC38A9 are each unique guanine exchange factors (GEFs) that collectively push the Rag GTPases toward the active state. Ragulator triggers GTP release from RagC, thus resolving the locked inactivated state of the Rag GTPases. Upon arginine binding, SLC38A9 converts RagA from the GDP- to the GTP-loaded state, and therefore activates the Rag GTPase heterodimer. Altogether, Ragulator and SLC38A9 act on the Rag GTPases to activate the mTORC1 pathway in response to nutrient sufficiency.
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288
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Kandasamy P, Gyimesi G, Kanai Y, Hediger MA. Amino acid transporters revisited: New views in health and disease. Trends Biochem Sci 2018; 43:752-789. [PMID: 30177408 DOI: 10.1016/j.tibs.2018.05.003] [Citation(s) in RCA: 263] [Impact Index Per Article: 43.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2018] [Revised: 05/23/2018] [Accepted: 05/25/2018] [Indexed: 02/09/2023]
Abstract
Amino acid transporters (AATs) are membrane-bound transport proteins that mediate transfer of amino acids into and out of cells or cellular organelles. AATs have diverse functional roles ranging from neurotransmission to acid-base balance, intracellular energy metabolism, and anabolic and catabolic reactions. In cancer cells and diabetes, dysregulation of AATs leads to metabolic reprogramming, which changes intracellular amino acid levels, contributing to the pathogenesis of cancer, obesity and diabetes. Indeed, the neutral amino acid transporters (NATs) SLC7A5/LAT1 and SLC1A5/ASCT2 are likely involved in several human malignancies. However, a clinical therapy that directly targets AATs has not yet been developed. The purpose of this review is to highlight the structural and functional diversity of AATs, their diverse physiological roles in different tissues and organs, their wide-ranging implications in human diseases and the emerging strategies and tools that will be necessary to target AATs therapeutically.
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Affiliation(s)
- Palanivel Kandasamy
- Institute of Biochemistry and Molecular Medicine, University of Bern, Bühlstrasse 28, CH-3012 Bern, Switzerland
| | - Gergely Gyimesi
- Institute of Biochemistry and Molecular Medicine, University of Bern, Bühlstrasse 28, CH-3012 Bern, Switzerland
| | - Yoshikatsu Kanai
- Division of Bio-system Pharmacology, Graduate School of Medicine, Osaka University, Osaka, Japan.
| | - Matthias A Hediger
- Institute of Biochemistry and Molecular Medicine, University of Bern, Bühlstrasse 28, CH-3012 Bern, Switzerland.
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289
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Ma Y, Vassetzky Y, Dokudovskaya S. mTORC1 pathway in DNA damage response. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2018; 1865:1293-1311. [PMID: 29936127 DOI: 10.1016/j.bbamcr.2018.06.011] [Citation(s) in RCA: 89] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Revised: 06/18/2018] [Accepted: 06/19/2018] [Indexed: 12/27/2022]
Abstract
Living organisms have evolved various mechanisms to control their metabolism and response to various stresses, allowing them to survive and grow in different environments. In eukaryotes, the highly conserved mechanistic target of rapamycin (mTOR) signaling pathway integrates both intracellular and extracellular signals and serves as a central regulator of cellular metabolism, proliferation and survival. A growing body of evidence indicates that mTOR signaling is closely related to another cellular protection mechanism, the DNA damage response (DDR). Many factors important for the DDR are also involved in the mTOR pathway. In this review, we discuss how these two pathways communicate to ensure an efficient protection of the cell against metabolic and genotoxic stresses. We also describe how anticancer therapies benefit from simultaneous targeting of the DDR and mTOR pathways.
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Affiliation(s)
- Yinxing Ma
- CNRS UMR 8126, Université Paris-Sud 11, Institut Gustave Roussy, 114, rue Edouard Vaillant, 94805 Villejuif, France
| | - Yegor Vassetzky
- CNRS UMR 8126, Université Paris-Sud 11, Institut Gustave Roussy, 114, rue Edouard Vaillant, 94805 Villejuif, France
| | - Svetlana Dokudovskaya
- CNRS UMR 8126, Université Paris-Sud 11, Institut Gustave Roussy, 114, rue Edouard Vaillant, 94805 Villejuif, France.
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290
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Fan SJ, Goberdhan DCI. PATs and SNATs: Amino Acid Sensors in Disguise. Front Pharmacol 2018; 9:640. [PMID: 29971004 PMCID: PMC6018406 DOI: 10.3389/fphar.2018.00640] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Accepted: 05/29/2018] [Indexed: 11/30/2022] Open
Abstract
Solute Carriers (SLCs) are involved in the transport of substances across lipid bilayers, including nutrients like amino acids. Amino acids increase the activity of the microenvironmental sensor mechanistic Target of Rapamycin Complex 1 (mTORC1) to promote cellular growth and anabolic processes. They can be brought in to cells by a wide range of SLCs including the closely related Proton-assisted Amino acid Transporter (PAT or SLC36) and Sodium-coupled Neutral Amino acid Transporter (SNAT or SLC38) families. More than a decade ago, the first evidence emerged that members of the PAT family can act as amino acid-stimulated receptors, or so-called "transceptors," connecting amino acids to mTORC1 activation. Since then, further studies in human cell models have suggested that other PAT and SNAT family members, which share significant homology within their transmembrane domains, can act as transceptors. A paradigm shift has also led to the PATs and SNATs at the surface of multiple intracellular compartments being linked to the recruitment and activation of different pools of mTORC1. Much focus has been on late endosomes and lysosomes as mTORC1 regulatory hubs, but more recently a Golgi-localized PAT was shown to be required for mTORC1 activation. PATs and SNATs can also traffic between the cell surface and intracellular compartments, with regulation of this movement providing a means of controlling their mTORC1 regulatory activity. These emerging features of PAT and SNAT amino acid sensors, including the transceptor mechanism, have implications for the pharmacological inhibition of mTORC1 and new therapeutic interventions.
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Affiliation(s)
| | - Deborah C. I. Goberdhan
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
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291
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Crystal structure of arginine-bound lysosomal transporter SLC38A9 in the cytosol-open state. Nat Struct Mol Biol 2018; 25:522-527. [PMID: 29872228 PMCID: PMC7346717 DOI: 10.1038/s41594-018-0072-2] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 05/02/2018] [Indexed: 12/18/2022]
Abstract
Recent advances in understanding intracellular amino acid transport and mechanistic target of rapamycin complex 1 (mTORC1) signaling shed light on solute carrier 38, family A member 9 (SLC38A9), a lysosomal transporter responsible for the binding and translocation of several essential amino acids. Here we present the first crystal structure of SLC38A9 from Danio rerio in complex with arginine. As captured in the cytosol-open state, the bound arginine was locked in a transitional state stabilized by transmembrane helix 1 (TM1) of drSLC38A9, which was anchored at the groove between TM5 and TM7. These anchoring interactions were mediated by the highly conserved WNTMM motif in TM1, and mutations in this motif abolished arginine transport by drSLC38A9. The underlying mechanism of substrate binding is critical for sensitizing the mTORC1 signaling pathway to amino acids and for maintenance of lysosomal amino acid homeostasis. This study offers a first glimpse into a prototypical model for SLC38 transporters.
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292
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Brügger B. Inconspicuous Little Allies: How Membrane Lipids Help Modulate Protein Function. ACS CENTRAL SCIENCE 2018; 4:530-531. [PMID: 29805997 PMCID: PMC5968507 DOI: 10.1021/acscentsci.8b00283] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
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293
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294
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Yu Z, Surface LE, Park CY, Horlbeck MA, Wyant GA, Abu-Remaileh M, Peterson TR, Sabatini DM, Weissman JS, O'Shea EK. Identification of a transporter complex responsible for the cytosolic entry of nitrogen-containing bisphosphonates. eLife 2018; 7:36620. [PMID: 29745899 PMCID: PMC6021172 DOI: 10.7554/elife.36620] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 05/09/2018] [Indexed: 11/13/2022] Open
Abstract
Nitrogen-containing-bisphosphonates (N-BPs) are a class of drugs widely prescribed to treat osteoporosis and other bone-related diseases. Although previous studies have established that N-BPs function by inhibiting the mevalonate pathway in osteoclasts, the mechanism by which N-BPs enter the cytosol from the extracellular space to reach their molecular target is not understood. Here, we implemented a CRISPRi-mediated genome-wide screen and identified SLC37A3 (solute carrier family 37 member A3) as a gene required for the action of N-BPs in mammalian cells. We observed that SLC37A3 forms a complex with ATRAID (all-trans retinoic acid-induced differentiation factor), a previously identified genetic target of N-BPs. SLC37A3 and ATRAID localize to lysosomes and are required for releasing N-BP molecules that have trafficked to lysosomes through fluid-phase endocytosis into the cytosol. Our results elucidate the route by which N-BPs are delivered to their molecular target, addressing a key aspect of the mechanism of action of N-BPs that may have significant clinical relevance. As some people age, their bones may become weak, brittle, and break easily. This condition is called osteoporosis. To treat osteoporosis, doctors often prescribe drugs called nitrogen-containing bisphosphonates (NBPs). These drugs destroy cells called osteoclasts, which break down bone. This helps restore bone mass. To kill osteoclasts, the drugs must enter these cells. First, they must pass through an oily protective layer called a membrane. It is not completely clear how NBPs, which prefer to stay in water-like environments, can cross this oily membrane and enter osteoclasts. Understanding how NBPs cross the membrane is important to ensure the drugs work effectively. If NBPs do not efficiently cross the membrane, they will not work properly and may cause harmful side effects. Many patients who take NBPs suffer from side effects such as abnormal fractures. Now, Yu et al. show that two proteins help NBPs cross the membrane. In the experiments, proteins were removed from human cancer cells one at a time using a technique called CRISPRi. CRISPRi enabled the researchers to systematically turn off the genes for each protein and track what affect this had on the NBPs’ ability to cross the membrane. When one of the two genes called SLC37A3 and ATRAID was turned off, NBPs could not get into cells. The protein produced by the SLC37A3 gene opens a gate in the cell membrane allowing NBPs to enter osteoclasts. The protein made by the ATRAID gene helps this gate protein, and without it, the SLC37A3 proteins are unstable and NBPs cannot enter. Some people have variations of the SLC37A3 and ATRAID genes. Testing whether these genetic variations may alter NBPs’ ability to cross the membrane of osteoclasts in mice, might one day help physicians predict which patients with have side effects.
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Affiliation(s)
- Zhou Yu
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, United States.,Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Lauren E Surface
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, United States.,Faculty of Arts and Sciences Center for Systems Biology, Harvard University, Cambridge, United States.,Department of Chemistry and Chemical Biology, Harvard University, Cambridge, United States.,Howard Hughes Medical Institute, Bethesda, United States
| | - Chong Yon Park
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, United States
| | - Max A Horlbeck
- Howard Hughes Medical Institute, Bethesda, United States.,Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, United States.,Center for RNA Systems Biology, University of California, San Francisco, San Francisco, United States
| | - Gregory A Wyant
- Howard Hughes Medical Institute, Bethesda, United States.,Whitehead Institute for Biomedical Research, Cambridge, United States.,Department of Biology, Massachusetts Institute of Technology, Cambridge, United States.,Koch Institute for Integrative Cancer Research, Cambridge, United States.,Broad Institute of MIT and Harvard, Cambridge, United States
| | - Monther Abu-Remaileh
- Howard Hughes Medical Institute, Bethesda, United States.,Whitehead Institute for Biomedical Research, Cambridge, United States.,Department of Biology, Massachusetts Institute of Technology, Cambridge, United States.,Koch Institute for Integrative Cancer Research, Cambridge, United States.,Broad Institute of MIT and Harvard, Cambridge, United States
| | - Timothy R Peterson
- Division of Bone & Mineral Diseases, Department of Genetics, Institute for Public Health, Washington University School of Medicine, St. Louis, United States
| | - David M Sabatini
- Howard Hughes Medical Institute, Bethesda, United States.,Whitehead Institute for Biomedical Research, Cambridge, United States.,Department of Biology, Massachusetts Institute of Technology, Cambridge, United States.,Koch Institute for Integrative Cancer Research, Cambridge, United States.,Broad Institute of MIT and Harvard, Cambridge, United States
| | - Jonathan S Weissman
- Howard Hughes Medical Institute, Bethesda, United States.,Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, United States.,Center for RNA Systems Biology, University of California, San Francisco, San Francisco, United States
| | - Erin K O'Shea
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, United States.,Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States.,Faculty of Arts and Sciences Center for Systems Biology, Harvard University, Cambridge, United States.,Department of Chemistry and Chemical Biology, Harvard University, Cambridge, United States.,Howard Hughes Medical Institute, Bethesda, United States
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295
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Matsumoto N, Kaneko M, Watanabe N, Itaoka M, Seki Y, Morimoto T, Torii T, Miyamoto Y, Keiichi Homma, Yamauchi J. Treacher Collins syndrome 3 (TCS3)-associated POLR1C mutants are localized in the lysosome and inhibits chondrogenic differentiation. Biochem Biophys Res Commun 2018; 499:78-85. [PMID: 29567474 DOI: 10.1016/j.bbrc.2018.03.136] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Accepted: 03/18/2018] [Indexed: 11/30/2022]
Abstract
Treacher Collins syndrome (TCS) is a craniofacial developmental disorder whose key feature is a combination of symptoms. For example, a patient could have bilateral downward slanting of the palpebral fissures, colobomas of the lower eyelids, hypoplasia of the facial bones, cleft palate, malformation of the external ears, and atresia of the external auditory canals. TCS3 is caused by mutations of the polr1c gene, which encodes RNA polymerase I and III subunit C (POLR1C). There have been two known missense mutations (Arg279-to-Gln [R279Q] and Arg279-to-Trp [R279W]) at the Arg-279 position. However, it remains to be clarified whether or how both or each individual mutation affects the cellular properties of POLR1C. Here we show that TCS3-associated missense mutations cause aberrant intracellular localization of POLR1C, inhibiting chondrogenic differentiation. The wild type POLR1C is normally localized in the nuclei. The R279Q or R279W mutant is primarily found to be localized in the lysosome. Expression of the R279Q or R279W mutant in mouse chondrogenic ATDC5 cells decreases phosphorylation of 4E-BP1 and ribosomal S6 proteins, which belong to the mammalian target of rapamycin (mTOR) signaling involved in critical roles in the lysosome. Furthermore, expression of the R279Q or R279W mutant inhibits chondrogenic differentiation in ATDC5 cells. Taken together, TCS3-associated mutation leads to the localization of POLR1C into the lysosome and inhibits chondrogenic differentiation, possibly explaining a portion of the pathological molecular basis underlying Treacher Collins syndrome.
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Affiliation(s)
- Naoto Matsumoto
- Laboratory of Molecular Neuroscience and Neurology, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0392, Japan
| | - Minami Kaneko
- Laboratory of Molecular Neuroscience and Neurology, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0392, Japan
| | - Natsumi Watanabe
- Laboratory of Molecular Neuroscience and Neurology, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0392, Japan
| | - Misa Itaoka
- Laboratory of Molecular Neuroscience and Neurology, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0392, Japan
| | - Yoich Seki
- Laboratory of Molecular Neuroscience and Neurology, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0392, Japan
| | - Takako Morimoto
- Laboratory of Molecular Neuroscience and Neurology, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0392, Japan
| | - Tomohiro Torii
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
| | - Yuki Miyamoto
- Laboratory of Molecular Neuroscience and Neurology, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0392, Japan; Department of Pharmacology, National Research Institute for Child Health and Development, Setagaya, Tokyo 157-8535, Japan
| | - Keiichi Homma
- Department of Life Science and Informatics, Maebashi Institute of Technology, Maebashi, Gunma 371-0816, Japan
| | - Junji Yamauchi
- Laboratory of Molecular Neuroscience and Neurology, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0392, Japan; Department of Pharmacology, National Research Institute for Child Health and Development, Setagaya, Tokyo 157-8535, Japan.
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296
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Wyant GA, Abu-Remaileh M, Frenkel EM, Laqtom NN, Dharamdasani V, Lewis CA, Chan SH, Heinze I, Ori A, Sabatini DM. NUFIP1 is a ribosome receptor for starvation-induced ribophagy. Science 2018; 360:751-758. [PMID: 29700228 DOI: 10.1126/science.aar2663] [Citation(s) in RCA: 242] [Impact Index Per Article: 40.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Accepted: 03/19/2018] [Indexed: 12/11/2022]
Abstract
The lysosome degrades and recycles macromolecules, signals to the master growth regulator mTORC1 [mechanistic target of rapamycin (mTOR) complex 1], and is associated with human disease. We performed quantitative proteomic analyses of rapidly isolated lysosomes and found that nutrient levels and mTOR dynamically modulate the lysosomal proteome. Upon mTORC1 inhibition, NUFIP1 (nuclear fragile X mental retardation-interacting protein 1) redistributes from the nucleus to autophagosomes and lysosomes. Upon these conditions, NUFIP1 interacts with ribosomes and delivers them to autophagosomes by directly binding to microtubule-associated proteins 1A/1B light chain 3B (LC3B). The starvation-induced degradation of ribosomes via autophagy (ribophagy) depends on the capacity of NUFIP1 to bind LC3B and promotes cell survival. We propose that NUFIP1 is a receptor for the selective autophagy of ribosomes.
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Affiliation(s)
- Gregory A Wyant
- Whitehead Institute for Biomedical Research and Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA.,Howard Hughes Medical Institute, Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.,Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02142, USA.,Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA
| | - Monther Abu-Remaileh
- Whitehead Institute for Biomedical Research and Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA.,Howard Hughes Medical Institute, Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.,Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02142, USA.,Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA
| | - Evgeni M Frenkel
- Whitehead Institute for Biomedical Research and Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA.,Howard Hughes Medical Institute, Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.,Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02142, USA.,Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA
| | - Nouf N Laqtom
- Whitehead Institute for Biomedical Research and Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA.,Howard Hughes Medical Institute, Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.,Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02142, USA.,Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA
| | - Vimisha Dharamdasani
- Whitehead Institute for Biomedical Research and Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA.,Howard Hughes Medical Institute, Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.,Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02142, USA.,Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA
| | - Caroline A Lewis
- Whitehead Institute for Biomedical Research and Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA
| | - Sze Ham Chan
- Whitehead Institute for Biomedical Research and Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA
| | - Ivonne Heinze
- Leibniz Institute on Aging-Fritz Lipmann Institute, 07745 Jena, Germany
| | - Alessandro Ori
- Leibniz Institute on Aging-Fritz Lipmann Institute, 07745 Jena, Germany.
| | - David M Sabatini
- Whitehead Institute for Biomedical Research and Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA. .,Howard Hughes Medical Institute, Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.,Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02142, USA.,Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA
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297
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González-Ballester D, Sanz-Luque E, Galván A, Fernández E, de Montaigu A. Arginine is a component of the ammonium-CYG56 signalling cascade that represses genes of the nitrogen assimilation pathway in Chlamydomonas reinhardtii. PLoS One 2018; 13:e0196167. [PMID: 29684072 PMCID: PMC5912763 DOI: 10.1371/journal.pone.0196167] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Accepted: 04/06/2018] [Indexed: 01/23/2023] Open
Abstract
Nitrogen assimilation and metabolism are essential processes for all living organisms, yet there is still much to be learnt on how they are regulated. The use of Chlamydomonas reinhardtii as a model system has been instrumental not only in identifying conserved regulation mechanisms that control the nitrogen assimilation pathway, but also in understanding how the intracellular nitrogen status regulates metabolic processes of industrial interest such as the synthesis of biolipids. While the genetic regulators that control the nitrogen pathway are successfully being unravelled, other layers of regulation have received less attention. Amino acids, for example, regulate nitrogen assimilation in certain organisms, but their role in Chlamydomonas has not thoroughly been explored. Previous results had suggested that arginine might repress key genes of the nitrogen assimilation pathway by acting within the ammonium negative signalling cascade, upstream of the nitric oxide (NO) inducible guanylate cyclase CYG56. We tested this hypothesis with a combination of genetic and chemical approaches. Antagonising the effects of arginine with an arginine biosynthesis mutant or with two chemical analogues released gene expression from ammonium mediated repression. The cyg56 and related non1 mutants, which are partially insensitive to ammonium repression, were also partially insensitive to repression by arginine. Finally, we show that the addition of arginine to the medium leads to an increase in intracellular NO. Our data reveal that arginine acts as a negative signal for the assimilation of nitrogen within the ammonium-CYG56 negative signalling cascade, and provide a connection between amino acid metabolism and nitrogen assimilation in microalgae.
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Affiliation(s)
- David González-Ballester
- Departamento de Bioquímica y Biología Molecular, Campus de Rabanales, Universidad de Córdoba, Córdoba, Spain
| | - Emanuel Sanz-Luque
- Departamento de Bioquímica y Biología Molecular, Campus de Rabanales, Universidad de Córdoba, Córdoba, Spain
| | - Aurora Galván
- Departamento de Bioquímica y Biología Molecular, Campus de Rabanales, Universidad de Córdoba, Córdoba, Spain
| | - Emilio Fernández
- Departamento de Bioquímica y Biología Molecular, Campus de Rabanales, Universidad de Córdoba, Córdoba, Spain
| | - Amaury de Montaigu
- Departamento de Bioquímica y Biología Molecular, Campus de Rabanales, Universidad de Córdoba, Córdoba, Spain
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298
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Yoshida S, Pacitto R, Inoki K, Swanson J. Macropinocytosis, mTORC1 and cellular growth control. Cell Mol Life Sci 2018; 75:1227-1239. [PMID: 29119228 PMCID: PMC5843684 DOI: 10.1007/s00018-017-2710-y] [Citation(s) in RCA: 75] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Revised: 10/31/2017] [Accepted: 11/03/2017] [Indexed: 12/15/2022]
Abstract
The growth and proliferation of metazoan cells are driven by cellular nutrient status and by extracellular growth factors. Growth factor receptors on cell surfaces initiate biochemical signals that increase anabolic metabolism and macropinocytosis, an actin-dependent endocytic process in which relatively large volumes of extracellular solutes and nutrients are internalized and delivered efficiently into lysosomes. Macropinocytosis is prominent in many kinds of cancer cells, and supports the growth of cells transformed by oncogenic K-Ras. Growth factor receptor signaling and the overall metabolic status of the cell are coordinated in the cytoplasm by the mechanistic target-of-rapamycin complex-1 (mTORC1), which positively regulates protein synthesis and negatively regulates molecular salvage pathways such as autophagy. mTORC1 is activated by two distinct Ras-related small GTPases, Rag and Rheb, which associate with lysosomal membranes inside the cell. Rag recruits mTORC1 to the lysosomal surface where Rheb directly binds to and activates mTORC1. Rag is activated by both lysosomal luminal and cytosolic amino acids; Rheb activation requires phosphoinositide 3-kinase, Akt, and the tuberous sclerosis complex-1/2. Signals for activation of Rag and Rheb converge at the lysosomal membrane, and several lines of evidence support the idea that growth factor-dependent endocytosis facilitates amino acid transfer into the lysosome leading to the activation of Rag. This review summarizes evidence that growth factor-stimulated macropinocytosis is essential for amino acid-dependent activation of mTORC1, and that increased solute accumulation by macropinocytosis in transformed cells supports unchecked cell growth.
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Affiliation(s)
- Sei Yoshida
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI, 48109-5620, USA
| | - Regina Pacitto
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI, 48109-5620, USA
| | - Ken Inoki
- Department of Integrative and Molecular Physiology and Internal Medicine, Life Sciences Institute, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Joel Swanson
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI, 48109-5620, USA.
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299
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Nie C, He T, Zhang W, Zhang G, Ma X. Branched Chain Amino Acids: Beyond Nutrition Metabolism. Int J Mol Sci 2018; 19:E954. [PMID: 29570613 PMCID: PMC5979320 DOI: 10.3390/ijms19040954] [Citation(s) in RCA: 383] [Impact Index Per Article: 63.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Revised: 03/01/2018] [Accepted: 03/14/2018] [Indexed: 12/14/2022] Open
Abstract
Branched chain amino acids (BCAAs), including leucine (Leu), isoleucine (Ile), and valine (Val), play critical roles in the regulation of energy homeostasis, nutrition metabolism, gut health, immunity and disease in humans and animals. As the most abundant of essential amino acids (EAAs), BCAAs are not only the substrates for synthesis of nitrogenous compounds, they also serve as signaling molecules regulating metabolism of glucose, lipid, and protein synthesis, intestinal health, and immunity via special signaling network, especially phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/AKT/mTOR) signal pathway. Current evidence supports BCAAs and their derivatives as the potential biomarkers of diseases such as insulin resistance (IR), type 2 diabetes mellitus (T2DM), cancer, and cardiovascular diseases (CVDs). These diseases are closely associated with catabolism and balance of BCAAs. Hence, optimizing dietary BCAA levels should have a positive effect on the parameters associated with health and diseases. This review focuses on recent findings of BCAAs in metabolic pathways and regulation, and underlying the relationship of BCAAs to related disease processes.
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Affiliation(s)
- Cunxi Nie
- State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, No. 2. Yuanmingyuan West Road, Beijing 100193, China.
- College of Animal Science and Technology, Shihezi University, No. 221. Beisi Road, Shihezi, Xinjiang 832003, China.
| | - Ting He
- State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, No. 2. Yuanmingyuan West Road, Beijing 100193, China.
| | - Wenju Zhang
- College of Animal Science and Technology, Shihezi University, No. 221. Beisi Road, Shihezi, Xinjiang 832003, China.
| | - Guolong Zhang
- Department of Animal Science, Oklahoma State University, Stillwater, OK 74078, USA.
| | - Xi Ma
- State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, No. 2. Yuanmingyuan West Road, Beijing 100193, China.
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
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300
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Bhinderwala F, Lonergan S, Woods J, Zhou C, Fey PD, Powers R. Expanding the Coverage of the Metabolome with Nitrogen-Based NMR. Anal Chem 2018; 90:4521-4528. [PMID: 29505241 DOI: 10.1021/acs.analchem.7b04922] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Isotopically labeling a metabolite and tracing its metabolic fate has provided invaluable insights about the role of metabolism in human diseases in addition to a variety of other issues. 13C-labeled metabolite tracers or unlabeled 1H-based NMR experiments are currently the most common application of NMR to metabolomics studies. Unfortunately, the coverage of the metabolome has been consequently limited to the most abundant carbon-containing metabolites. To expand the coverage of the metabolome and enhance the impact of metabolomics studies, we present a protocol for 15N-labeled metabolite tracer experiments that may also be combined with routine 13C tracer experiments to simultaneously detect both 15N- and 13C-labeled metabolites in metabolic samples. A database consisting of 2D 1H-15N HSQC natural-abundance spectra of 50 nitrogen-containing metabolites are also presented to facilitate the assignment of 15N-labeled metabolites. The methodology is demonstrated by labeling Escherichia coli and Staphylococcus aureus metabolomes with 15N1-ammonium chloride, 15N4-arginine, and 13C2-acetate. Efficient 15N and 13C metabolite labeling and identification were achieved utilizing standard cell culture and sample preparation protocols.
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Affiliation(s)
| | | | | | - Chunyi Zhou
- Center for Staphylococcal Research, Department of Pathology and Microbiology , University of Nebraska Medical Center , Omaha , Nebraska 68198-5900 , United States
| | - Paul D Fey
- Center for Staphylococcal Research, Department of Pathology and Microbiology , University of Nebraska Medical Center , Omaha , Nebraska 68198-5900 , United States
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