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Yu Q, Liu Y, Liu S, Li S, Zhai Y, Zhang Q, Zheng L, Zheng H, Zhai Y, Wang X. Lactobacillus melliventris promotes hive productivity and immune functionality in Bombus terrestris performance in the greenhouse. INSECT SCIENCE 2024; 31:911-926. [PMID: 37830269 DOI: 10.1111/1744-7917.13281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2023] [Revised: 08/18/2023] [Accepted: 09/15/2023] [Indexed: 10/14/2023]
Abstract
Bumblebees are important pollinators in agricultural ecosystems, but their abundance is declining globally. There is an urgent need to protect bumblebee health and their pollination services. Bumblebees possess specialized gut microbiota with potential to be used as probiotics to help defend at-risk bumblebee populations. However, evidence for probiotic benefits on bumblebees is lacking. Here, we evaluated how supplementation with Lactobacillus melliventris isolated from bumblebee gut affected the colony development of Bombus terrestris. This native strain colonized robustly and persisted long-term in bumblebees, leading to a significantly higher quality of offspring. Subsequently, the tyrosine pathway was upregulated in the brain and fat body, while the Wnt and mTOR pathways of the gut were downregulated. Notably, the field experiment in the greenhouse revealed the supplementation of L. melliventris led to a 2.5-fold increase in the bumblebee survival rate and a more than 10% increase in the number of flowers visited, indicating a better health condition and pollination ability in field conditions. Our study represents a first screening for the potential use of the native gut member, L. melliventris, as probiotic strains in hive supplement for bumblebee breeding, which may be a practical approach to improve immunity and hive health.
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Affiliation(s)
- Qianhui Yu
- Institute of Plant Protection, Shandong Academy of Agricultural Sciences, Jinan, China
- Key Laboratory of Natural Enemies Insects, Ministry of Agriculture and Rural Affairs, Jinan, China
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China
| | - Yan Liu
- Institute of Plant Protection, Shandong Academy of Agricultural Sciences, Jinan, China
- Key Laboratory of Natural Enemies Insects, Ministry of Agriculture and Rural Affairs, Jinan, China
| | - Shanshan Liu
- BGI-Qingdao, BGI-Shenzhen, Qingdao, Shandong, China
| | - Shaogang Li
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China
| | - Yifan Zhai
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China
| | - Qingchao Zhang
- Institute of Plant Protection, Shandong Academy of Agricultural Sciences, Jinan, China
- Key Laboratory of Natural Enemies Insects, Ministry of Agriculture and Rural Affairs, Jinan, China
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China
| | - Li Zheng
- Institute of Plant Protection, Shandong Academy of Agricultural Sciences, Jinan, China
- Key Laboratory of Natural Enemies Insects, Ministry of Agriculture and Rural Affairs, Jinan, China
| | - Hao Zheng
- Institute of Plant Protection, Shandong Academy of Agricultural Sciences, Jinan, China
- Key Laboratory of Natural Enemies Insects, Ministry of Agriculture and Rural Affairs, Jinan, China
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China
| | - Yifan Zhai
- Institute of Plant Protection, Shandong Academy of Agricultural Sciences, Jinan, China
- Key Laboratory of Natural Enemies Insects, Ministry of Agriculture and Rural Affairs, Jinan, China
| | - Xiaofei Wang
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China
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2
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Tran LT, Akıl C, Senju Y, Robinson RC. The eukaryotic-like characteristics of small GTPase, roadblock and TRAPPC3 proteins from Asgard archaea. Commun Biol 2024; 7:273. [PMID: 38472392 DOI: 10.1038/s42003-024-05888-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Accepted: 02/06/2024] [Indexed: 03/14/2024] Open
Abstract
Membrane-enclosed organelles are defining features of eukaryotes in distinguishing these organisms from prokaryotes. Specification of distinct membranes is critical to assemble and maintain discrete compartments. Small GTPases and their regulators are the signaling molecules that drive membrane-modifying machineries to the desired location. These signaling molecules include Rab and Rag GTPases, roadblock and longin domain proteins, and TRAPPC3-like proteins. Here, we take a structural approach to assess the relatedness of these eukaryotic-like proteins in Asgard archaea, the closest known prokaryotic relatives to eukaryotes. We find that the Asgard archaea GTPase core domains closely resemble eukaryotic Rabs and Rags. Asgard archaea roadblock, longin and TRAPPC3 domain-containing proteins form dimers similar to those found in the eukaryotic TRAPP and Ragulator complexes. We conclude that the emergence of these protein architectures predated eukaryogenesis, however further adaptations occurred in proto-eukaryotes to allow these proteins to regulate distinct internal membranes.
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Affiliation(s)
- Linh T Tran
- Research Institute for Interdisciplinary Science, Okayama University, Okayama, 700-8530, Japan
| | - Caner Akıl
- Research Institute for Interdisciplinary Science, Okayama University, Okayama, 700-8530, Japan
- Division of Structural Biology, University of Oxford, Oxford, England
| | - Yosuke Senju
- Research Institute for Interdisciplinary Science, Okayama University, Okayama, 700-8530, Japan
| | - Robert C Robinson
- Research Institute for Interdisciplinary Science, Okayama University, Okayama, 700-8530, Japan.
- School of Biomolecular Science and Engineering (BSE), Vidyasirimedhi Institute of Science and Technology (VISTEC), Rayong, 21210, Thailand.
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3
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Zhao L, Gao N, Peng X, Chen L, Meng T, Jiang C, Jin J, Zhang J, Duan Q, Tian H, Weng L, Wang X, Tan X, Li Y, Qin H, Yuan J, Ge X, Deng L, Wang P. TRAF4-Mediated LAMTOR1 Ubiquitination Promotes mTORC1 Activation and Inhibits the Inflammation-Induced Colorectal Cancer Progression. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2301164. [PMID: 38229144 DOI: 10.1002/advs.202301164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 11/28/2023] [Indexed: 01/18/2024]
Abstract
Mechanistic target of rapamycin complex 1 (mTORC1) is a conserved serine/threonine kinase that integrates various environmental signals to regulate cell growth and metabolism. mTORC1 activation requires tethering to lysosomes by the Ragulator-Rag complex. However, the dynamic regulation of the interaction between Ragulator and Rag guanosine triphosphatase (GTPase) remains unclear. In this study, that LAMTOR1, an essential component of Ragulator, is dynamically ubiquitinated depending on amino acid abundance is reported. It is found that the E3 ligase TRAF4 directly interacts with LAMTOR1 and catalyzes the K63-linked polyubiquitination of LAMTOR1 at K151. Ubiquitination of LAMTOR1 by TRAF4 promoted its binding to Rag GTPases and enhanced mTORC1 activation, K151R knock-in or TRAF4 knock-out blocks amino acid-induced mTORC1 activation and accelerates the development of inflammation-induced colon cancer. This study revealed that TRAF4-mediated LAMTOR1 ubiquitination is a regulatory mechanism for mTORC1 activation and provides a therapeutic target for diseases involving mTORC1 dysregulation.
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Affiliation(s)
- Linlin Zhao
- Tongji University Cancer Center, Shanghai Tenth People's Hospital, Shanghai Frontiers Science Center of Nanocatalytic Medicine, School of Medicine, Tongji University, Shanghai, 200092, P. R. China
| | - Ni Gao
- Tongji University Cancer Center, Shanghai Tenth People's Hospital, Shanghai Frontiers Science Center of Nanocatalytic Medicine, School of Medicine, Tongji University, Shanghai, 200092, P. R. China
| | - Xiaoping Peng
- Tongji University Cancer Center, Shanghai Tenth People's Hospital, Shanghai Frontiers Science Center of Nanocatalytic Medicine, School of Medicine, Tongji University, Shanghai, 200092, P. R. China
| | - Lei Chen
- Tongji University Cancer Center, Shanghai Tenth People's Hospital, Shanghai Frontiers Science Center of Nanocatalytic Medicine, School of Medicine, Tongji University, Shanghai, 200092, P. R. China
| | - Tong Meng
- Tongji University Cancer Center, Shanghai Tenth People's Hospital, Shanghai Frontiers Science Center of Nanocatalytic Medicine, School of Medicine, Tongji University, Shanghai, 200092, P. R. China
- Department of Orthopedics, Shanghai General Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, 200940, P. R. China
| | - Cong Jiang
- Tongji University Cancer Center, Shanghai Tenth People's Hospital, Shanghai Frontiers Science Center of Nanocatalytic Medicine, School of Medicine, Tongji University, Shanghai, 200092, P. R. China
| | - Jiali Jin
- Tongji University Cancer Center, Shanghai Tenth People's Hospital, Shanghai Frontiers Science Center of Nanocatalytic Medicine, School of Medicine, Tongji University, Shanghai, 200092, P. R. China
| | - Jiawen Zhang
- Tongji University Cancer Center, Shanghai Tenth People's Hospital, Shanghai Frontiers Science Center of Nanocatalytic Medicine, School of Medicine, Tongji University, Shanghai, 200092, P. R. China
| | - Qiuhui Duan
- Tongji University Cancer Center, Shanghai Tenth People's Hospital, Shanghai Frontiers Science Center of Nanocatalytic Medicine, School of Medicine, Tongji University, Shanghai, 200092, P. R. China
| | - Hongling Tian
- Tongji University Cancer Center, Shanghai Tenth People's Hospital, Shanghai Frontiers Science Center of Nanocatalytic Medicine, School of Medicine, Tongji University, Shanghai, 200092, P. R. China
| | - Linjun Weng
- Tongji University Cancer Center, Shanghai Tenth People's Hospital, Shanghai Frontiers Science Center of Nanocatalytic Medicine, School of Medicine, Tongji University, Shanghai, 200092, P. R. China
| | - Xinbo Wang
- Tongji University Cancer Center, Shanghai Tenth People's Hospital, Shanghai Frontiers Science Center of Nanocatalytic Medicine, School of Medicine, Tongji University, Shanghai, 200092, P. R. China
| | - Xiao Tan
- Tongji University Cancer Center, Shanghai Tenth People's Hospital, Shanghai Frontiers Science Center of Nanocatalytic Medicine, School of Medicine, Tongji University, Shanghai, 200092, P. R. China
| | - Yaxu Li
- Tongji University Cancer Center, Shanghai Tenth People's Hospital, Shanghai Frontiers Science Center of Nanocatalytic Medicine, School of Medicine, Tongji University, Shanghai, 200092, P. R. China
| | - Huanlong Qin
- Department of Gastrointestinal Surgery, Shanghai Tenth People's Hospital, Tongji University, Shanghai, 200092, P. R. China
- Research Institute of Intestinal Diseases, Tongji University School of Medicine, Shanghai, 200092, P. R. China
| | - Jian Yuan
- Department of Biochemistry and Molecular Biology, Tongji University School of Medicine, Shanghai, 200092, P. R. China
- Research Center for Translational Medicine, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, 200120, P. R. China
| | - Xin Ge
- Tongji University Cancer Center, Shanghai Tenth People's Hospital, Shanghai Frontiers Science Center of Nanocatalytic Medicine, School of Medicine, Tongji University, Shanghai, 200092, P. R. China
| | - Lu Deng
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, 712100, P. R. China
| | - Ping Wang
- Tongji University Cancer Center, Shanghai Tenth People's Hospital, Shanghai Frontiers Science Center of Nanocatalytic Medicine, School of Medicine, Tongji University, Shanghai, 200092, P. R. China
- Department of Biochemistry and Molecular Biology, Tongji University School of Medicine, Shanghai, 200092, P. R. China
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4
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Shariq M, Khan MF, Raj R, Ahsan N, Kumar P. PRKAA2, MTOR, and TFEB in the regulation of lysosomal damage response and autophagy. J Mol Med (Berl) 2024; 102:287-311. [PMID: 38183492 DOI: 10.1007/s00109-023-02411-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 12/07/2023] [Accepted: 12/18/2023] [Indexed: 01/08/2024]
Abstract
Lysosomes function as critical signaling hubs that govern essential enzyme complexes. LGALS proteins (LGALS3, LGALS8, and LGALS9) are integral to the endomembrane damage response. If ESCRT fails to rectify damage, LGALS-mediated ubiquitination occurs, recruiting autophagy receptors (CALCOCO2, TRIM16, and SQSTM1) and VCP/p97 complex containing UBXN6, PLAA, and YOD1, initiating selective autophagy. Lysosome replenishment through biogenesis is regulated by TFEB. LGALS3 interacts with TFRC and TRIM16, aiding ESCRT-mediated repair and autophagy-mediated removal of damaged lysosomes. LGALS8 inhibits MTOR and activates TFEB for ATG and lysosomal gene transcription. LGALS9 inhibits USP9X, activates PRKAA2, MAP3K7, ubiquitination, and autophagy. Conjugation of ATG8 to single membranes (CASM) initiates damage repair mediated by ATP6V1A, ATG16L1, ATG12, ATG5, ATG3, and TECPR1. ATG8ylation or CASM activates the MERIT system (ESCRT-mediated repair, autophagy-mediated clearance, MCOLN1 activation, Ca2+ release, RRAG-GTPase regulation, MTOR modulation, TFEB activation, and activation of GTPase IRGM). Annexins ANAX1 and ANAX2 aid damage repair. Stress granules stabilize damaged membranes, recruiting FLCN-FNIP1/2, G3BP1, and NUFIP1 to inhibit MTOR and activate TFEB. Lysosomes coordinate the synergistic response to endomembrane damage and are vital for innate and adaptive immunity. Future research should unveil the collaborative actions of ATG proteins, LGALSs, TRIMs, autophagy receptors, and lysosomal proteins in lysosomal damage response.
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Affiliation(s)
- Mohd Shariq
- Quantlase Imaging Laboratory, Quantlase Lab LLC, Unit 1-8, Masdar City, Abu Dhabi, UAE.
| | - Mohammad Firoz Khan
- Quantlase Imaging Laboratory, Quantlase Lab LLC, Unit 1-8, Masdar City, Abu Dhabi, UAE.
| | - Reshmi Raj
- Quantlase Imaging Laboratory, Quantlase Lab LLC, Unit 1-8, Masdar City, Abu Dhabi, UAE
| | - Nuzhat Ahsan
- Quantlase Imaging Laboratory, Quantlase Lab LLC, Unit 1-8, Masdar City, Abu Dhabi, UAE
| | - Pramod Kumar
- Quantlase Imaging Laboratory, Quantlase Lab LLC, Unit 1-8, Masdar City, Abu Dhabi, UAE
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5
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Abudu YP, Kournoutis A, Brenne HB, Lamark T, Johansen T. MORG1 limits mTORC1 signaling by inhibiting Rag GTPases. Mol Cell 2024; 84:552-569.e11. [PMID: 38103557 DOI: 10.1016/j.molcel.2023.11.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 10/02/2023] [Accepted: 11/17/2023] [Indexed: 12/19/2023]
Abstract
Autophagy, an important quality control and recycling process vital for cellular homeostasis, is tightly regulated. The mTORC1 signaling pathway regulates autophagy under conditions of nutrient availability and scarcity. However, how mTORC1 activity is fine-tuned during nutrient availability to allow basal autophagy is unclear. Here, we report that the WD-domain repeat protein MORG1 facilitates basal constitutive autophagy by inhibiting mTORC1 signaling through Rag GTPases. Mechanistically, MORG1 interacts with active Rag GTPase complex inhibiting the Rag GTPase-mediated recruitment of mTORC1 to the lysosome. MORG1 depletion in HeLa cells increases mTORC1 activity and decreases autophagy. The autophagy receptor p62/SQSTM1 binds to MORG1, but MORG1 is not an autophagy substrate. However, p62/SQSTM1 binding to MORG1 upon re-addition of amino acids following amino acid's depletion precludes MORG1 from inhibiting the Rag GTPases, allowing mTORC1 activation. MORG1 depletion increases cell proliferation and migration. Low expression of MORG1 correlates with poor survival in several important cancers.
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Affiliation(s)
- Yakubu Princely Abudu
- Autophagy Research Group, Department of Medical Biology, University of Tromsø-The Arctic University of Norway, Tromsø, Norway; Nanoscopy Group, Department of Physics and Technology, University of Tromsø-The Arctic University of Norway, Tromsø, Norway.
| | - Athanasios Kournoutis
- Autophagy Research Group, Department of Medical Biology, University of Tromsø-The Arctic University of Norway, Tromsø, Norway
| | - Hanne Britt Brenne
- Autophagy Research Group, Department of Medical Biology, University of Tromsø-The Arctic University of Norway, Tromsø, Norway
| | - Trond Lamark
- Autophagy Research Group, Department of Medical Biology, University of Tromsø-The Arctic University of Norway, Tromsø, Norway
| | - Terje Johansen
- Autophagy Research Group, Department of Medical Biology, University of Tromsø-The Arctic University of Norway, Tromsø, Norway.
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6
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Chen J, Cui L, Lu S, Xu S. Amino acid metabolism in tumor biology and therapy. Cell Death Dis 2024; 15:42. [PMID: 38218942 PMCID: PMC10787762 DOI: 10.1038/s41419-024-06435-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 12/19/2023] [Accepted: 01/04/2024] [Indexed: 01/15/2024]
Abstract
Amino acid metabolism plays important roles in tumor biology and tumor therapy. Accumulating evidence has shown that amino acids contribute to tumorigenesis and tumor immunity by acting as nutrients, signaling molecules, and could also regulate gene transcription and epigenetic modification. Therefore, targeting amino acid metabolism will provide new ideas for tumor treatment and become an important therapeutic approach after surgery, radiotherapy, and chemotherapy. In this review, we systematically summarize the recent progress of amino acid metabolism in malignancy and their interaction with signal pathways as well as their effect on tumor microenvironment and epigenetic modification. Collectively, we also highlight the potential therapeutic application and future expectation.
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Affiliation(s)
- Jie Chen
- National Key Lab of Immunity and Inflammation and Institute of Immunology, Naval Medical University/Second Military Medical University, Shanghai, 200433, China
| | - Likun Cui
- National Key Lab of Immunity and Inflammation and Institute of Immunology, Naval Medical University/Second Military Medical University, Shanghai, 200433, China
| | - Shaoteng Lu
- National Key Lab of Immunity and Inflammation and Institute of Immunology, Naval Medical University/Second Military Medical University, Shanghai, 200433, China
| | - Sheng Xu
- National Key Lab of Immunity and Inflammation and Institute of Immunology, Naval Medical University/Second Military Medical University, Shanghai, 200433, China.
- Shanghai Institute of Stem Cell Research and Clinical Translation, Shanghai, 200120, China.
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7
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Goul C, Peruzzo R, Zoncu R. The molecular basis of nutrient sensing and signalling by mTORC1 in metabolism regulation and disease. Nat Rev Mol Cell Biol 2023; 24:857-875. [PMID: 37612414 DOI: 10.1038/s41580-023-00641-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/06/2023] [Indexed: 08/25/2023]
Abstract
The Ser/Thr kinase mechanistic target of rapamycin (mTOR) is a central regulator of cellular metabolism. As part of mTOR complex 1 (mTORC1), mTOR integrates signals such as the levels of nutrients, growth factors, energy sources and oxygen, and triggers responses that either boost anabolism or suppress catabolism. mTORC1 signalling has wide-ranging consequences for the growth and homeostasis of key tissues and organs, and its dysregulated activity promotes cancer, type 2 diabetes, neurodegeneration and other age-related disorders. How mTORC1 integrates numerous upstream cues and translates them into specific downstream responses is an outstanding question with major implications for our understanding of physiology and disease mechanisms. In this Review, we discuss recent structural and functional insights into the molecular architecture of mTORC1 and its lysosomal partners, which have greatly increased our mechanistic understanding of nutrient-dependent mTORC1 regulation. We also discuss the emerging involvement of aberrant nutrient-mTORC1 signalling in multiple diseases.
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Affiliation(s)
- Claire Goul
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA
| | - Roberta Peruzzo
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA
| | - Roberto Zoncu
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA.
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8
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Takla M, Keshri S, Rubinsztein DC. The post-translational regulation of transcription factor EB (TFEB) in health and disease. EMBO Rep 2023; 24:e57574. [PMID: 37728021 PMCID: PMC10626434 DOI: 10.15252/embr.202357574] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 08/10/2023] [Accepted: 08/25/2023] [Indexed: 09/21/2023] Open
Abstract
Transcription factor EB (TFEB) is a basic helix-loop-helix leucine zipper transcription factor that acts as a master regulator of lysosomal biogenesis, lysosomal exocytosis, and macro-autophagy. TFEB contributes to a wide range of physiological functions, including mitochondrial biogenesis and innate and adaptive immunity. As such, TFEB is an essential component of cellular adaptation to stressors, ranging from nutrient deprivation to pathogenic invasion. The activity of TFEB depends on its subcellular localisation, turnover, and DNA-binding capacity, all of which are regulated at the post-translational level. Pathological states are characterised by a specific set of stressors, which elicit post-translational modifications that promote gain or loss of TFEB function in the affected tissue. In turn, the resulting increase or decrease in survival of the tissue in which TFEB is more or less active, respectively, may either benefit or harm the organism as a whole. In this way, the post-translational modifications of TFEB account for its otherwise paradoxical protective and deleterious effects on organismal fitness in diseases ranging from neurodegeneration to cancer. In this review, we describe how the intracellular environment characteristic of different diseases alters the post-translational modification profile of TFEB, enabling cellular adaptation to a particular pathological state.
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Affiliation(s)
- Michael Takla
- Department of Medical Genetics, Cambridge Institute for Medical Research (CIMR)University of CambridgeCambridgeUK
- UK Dementia Research Institute, Cambridge Institute for Medical Research (CIMR)University of CambridgeCambridgeUK
| | - Swati Keshri
- Department of Medical Genetics, Cambridge Institute for Medical Research (CIMR)University of CambridgeCambridgeUK
- UK Dementia Research Institute, Cambridge Institute for Medical Research (CIMR)University of CambridgeCambridgeUK
| | - David C Rubinsztein
- Department of Medical Genetics, Cambridge Institute for Medical Research (CIMR)University of CambridgeCambridgeUK
- UK Dementia Research Institute, Cambridge Institute for Medical Research (CIMR)University of CambridgeCambridgeUK
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9
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Jové M, Mota-Martorell N, Fernàndez-Bernal A, Portero-Otin M, Barja G, Pamplona R. Phenotypic molecular features of long-lived animal species. Free Radic Biol Med 2023; 208:728-747. [PMID: 37748717 DOI: 10.1016/j.freeradbiomed.2023.09.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Revised: 09/12/2023] [Accepted: 09/21/2023] [Indexed: 09/27/2023]
Abstract
One of the challenges facing science/biology today is uncovering the molecular bases that support and determine animal and human longevity. Nature, in offering a diversity of animal species that differ in longevity by more than 5 orders of magnitude, is the best 'experimental laboratory' to achieve this aim. Mammals, in particular, can differ by more than 200-fold in longevity. For this reason, most of the available evidence on this topic derives from comparative physiology studies. But why can human beings, for instance, reach 120 years whereas rats only last at best 4 years? How does nature change the longevity of species? Longevity is a species-specific feature resulting from an evolutionary process. Long-lived animal species, including humans, show adaptations at all levels of biological organization, from metabolites to genome, supported by signaling and regulatory networks. The structural and functional features that define a long-lived species may suggest that longevity is a programmed biological property.
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Affiliation(s)
- Mariona Jové
- Department of Experimental Medicine, Lleida Biomedical Research Institute (IRBLleida), University of Lleida (UdL), E25198, Lleida, Spain
| | - Natàlia Mota-Martorell
- Department of Experimental Medicine, Lleida Biomedical Research Institute (IRBLleida), University of Lleida (UdL), E25198, Lleida, Spain
| | - Anna Fernàndez-Bernal
- Department of Experimental Medicine, Lleida Biomedical Research Institute (IRBLleida), University of Lleida (UdL), E25198, Lleida, Spain
| | - Manuel Portero-Otin
- Department of Experimental Medicine, Lleida Biomedical Research Institute (IRBLleida), University of Lleida (UdL), E25198, Lleida, Spain
| | - Gustavo Barja
- Department of Genetics, Physiology and Microbiology, Faculty of Biological Sciences, Complutense University of Madrid (UCM), E28040, Madrid, Spain
| | - Reinald Pamplona
- Department of Experimental Medicine, Lleida Biomedical Research Institute (IRBLleida), University of Lleida (UdL), E25198, Lleida, Spain.
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10
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Alam S, Doherty E, Ortega-Prieto P, Arizanova J, Fets L. Membrane transporters in cell physiology, cancer metabolism and drug response. Dis Model Mech 2023; 16:dmm050404. [PMID: 38037877 PMCID: PMC10695176 DOI: 10.1242/dmm.050404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2023] Open
Abstract
By controlling the passage of small molecules across lipid bilayers, membrane transporters influence not only the uptake and efflux of nutrients, but also the metabolic state of the cell. With more than 450 members, the Solute Carriers (SLCs) are the largest transporter super-family, clustering into families with different substrate specificities and regulatory properties. Cells of different types are, therefore, able to tailor their transporter expression signatures depending on their metabolic requirements, and the physiological importance of these proteins is illustrated by their mis-regulation in a number of disease states. In cancer, transporter expression is heterogeneous, and the SLC family has been shown to facilitate the accumulation of biomass, influence redox homeostasis, and also mediate metabolic crosstalk with other cell types within the tumour microenvironment. This Review explores the roles of membrane transporters in physiological and malignant settings, and how these roles can affect drug response, through either indirect modulation of sensitivity or the direct transport of small-molecule therapeutic compounds into cells.
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Affiliation(s)
- Sara Alam
- Drug Transport and Tumour Metabolism Lab, MRC Laboratory of Medical Sciences, Hammersmith Hospital Campus, Du Cane Road, London, W12 0NN, UK
| | - Emily Doherty
- Drug Transport and Tumour Metabolism Lab, MRC Laboratory of Medical Sciences, Hammersmith Hospital Campus, Du Cane Road, London, W12 0NN, UK
| | - Paula Ortega-Prieto
- Drug Transport and Tumour Metabolism Lab, MRC Laboratory of Medical Sciences, Hammersmith Hospital Campus, Du Cane Road, London, W12 0NN, UK
| | - Julia Arizanova
- Drug Transport and Tumour Metabolism Lab, MRC Laboratory of Medical Sciences, Hammersmith Hospital Campus, Du Cane Road, London, W12 0NN, UK
| | - Louise Fets
- Drug Transport and Tumour Metabolism Lab, MRC Laboratory of Medical Sciences, Hammersmith Hospital Campus, Du Cane Road, London, W12 0NN, UK
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11
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Linde-Garelli KY, Rogala KB. Structural mechanisms of the mTOR pathway. Curr Opin Struct Biol 2023; 82:102663. [PMID: 37572585 DOI: 10.1016/j.sbi.2023.102663] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 07/01/2023] [Accepted: 07/07/2023] [Indexed: 08/14/2023]
Abstract
The mTOR signaling pathway is essential for regulating cell growth and mammalian metabolism. The mTOR kinase forms two complexes, mTORC1 and mTORC2, which respond to external stimuli and regulate differential downstream targets. Cellular membrane-associated translocation mediates function and assembly of the mTOR complexes, and recent structural studies have begun uncovering the molecular basis by which the mTOR pathway (1) regulates signaling inputs, (2) recruits substrates, (3) localizes to biological membranes, and (4) becomes activated. Moreover, indications of dysregulated mTOR signaling are implicated in a wide range of diseases and an increasingly comprehensive understanding of structural mechanisms is driving novel translational development.
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Affiliation(s)
- Karen Y Linde-Garelli
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA, USA; Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA, USA; Stanford Cancer Institute, Stanford University School of Medicine, Stanford, CA, USA
| | - Kacper B Rogala
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA, USA; Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA, USA; Stanford Cancer Institute, Stanford University School of Medicine, Stanford, CA, USA.
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12
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Priya A, Antoine-Bally S, Macé AS, Monteiro P, Sabatet V, Remy D, Dingli F, Loew D, Demetriades C, Gautreau AM, Chavrier P. Codependencies of mTORC1 signaling and endolysosomal actin structures. SCIENCE ADVANCES 2023; 9:eadd9084. [PMID: 37703363 PMCID: PMC10881074 DOI: 10.1126/sciadv.add9084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 08/11/2023] [Indexed: 09/15/2023]
Abstract
The mechanistic target of rapamycin complex 1 (mTORC1) is part of the amino acid sensing machinery that becomes activated on the endolysosomal surface in response to nutrient cues. Branched actin generated by WASH and Arp2/3 complexes defines endolysosomal microdomains. Here, we find mTORC1 components in close proximity to endolysosomal actin microdomains. We investigated for interactors of the mTORC1 lysosomal tether, RAGC, by proteomics and identified multiple actin filament capping proteins and their modulators. Perturbation of RAGC function affected the size of endolysosomal actin, consistent with a regulation of actin filament capping by RAGC. Reciprocally, the pharmacological inhibition of actin polymerization or alteration of endolysosomal actin obtained upon silencing of WASH or Arp2/3 complexes impaired mTORC1 activity. Mechanistically, we show that actin is required for proper association of RAGC and mTOR with endolysosomes. This study reveals an unprecedented interplay between actin and mTORC1 signaling on the endolysosomal system.
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Affiliation(s)
- Amulya Priya
- Institut Curie, CNRS UMR144, PSL Research University, Research Center, Actin and Membrane Dynamics Laboratory, 26 rue d’Ulm, Paris 75248 Cedex 05, France
| | - Sandra Antoine-Bally
- Institut Curie, CNRS UMR144, PSL Research University, Research Center, Actin and Membrane Dynamics Laboratory, 26 rue d’Ulm, Paris 75248 Cedex 05, France
| | - Anne-Sophie Macé
- Institut Curie, PSL Research University, Cell and Tissue Imaging Facility (PICT-IBiSA), 26 rue d’Ulm, Paris 75248 Cedex 05, France
| | - Pedro Monteiro
- Institut Curie, CNRS UMR144, PSL Research University, Research Center, Actin and Membrane Dynamics Laboratory, 26 rue d’Ulm, Paris 75248 Cedex 05, France
| | - Valentin Sabatet
- Institut Curie, PSL Research University, CurieCoreTech Mass Spectrometry Proteomics, 26 rue d’Ulm, Paris 75248 Cedex 05, France
| | - David Remy
- Institut Curie, CNRS UMR144, PSL Research University, Research Center, Actin and Membrane Dynamics Laboratory, 26 rue d’Ulm, Paris 75248 Cedex 05, France
| | - Florent Dingli
- Institut Curie, PSL Research University, CurieCoreTech Mass Spectrometry Proteomics, 26 rue d’Ulm, Paris 75248 Cedex 05, France
| | - Damarys Loew
- Institut Curie, PSL Research University, CurieCoreTech Mass Spectrometry Proteomics, 26 rue d’Ulm, Paris 75248 Cedex 05, France
| | - Constantinos Demetriades
- Max Planck Institute for Biology of Ageing (MPI-AGE), Cologne, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Alexis M. Gautreau
- Laboratoire de Biologie Structurale de la Cellule, CNRS, École Polytechnique, Institut Polytechnique de Paris, Palaiseau, France
| | - Philippe Chavrier
- Institut Curie, CNRS UMR144, PSL Research University, Research Center, Actin and Membrane Dynamics Laboratory, 26 rue d’Ulm, Paris 75248 Cedex 05, France
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13
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Tettoni SD, Egri SB, Doxsey DD, Veinotte K, Ouch C, Chang JY, Song K, Xu C, Shen K. Structure of the Schizosaccharomyces pombe Gtr-Lam complex reveals evolutionary divergence of mTORC1-dependent amino acid sensing. Structure 2023; 31:1065-1076.e5. [PMID: 37453417 PMCID: PMC10529327 DOI: 10.1016/j.str.2023.06.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 05/14/2023] [Accepted: 06/19/2023] [Indexed: 07/18/2023]
Abstract
mTORC1 is a protein kinase complex that controls cellular growth in response to nutrient availability. Amino acid signals are transmitted toward mTORC1 via the Rag/Gtr GTPases and their upstream regulators. An important regulator is LAMTOR, which localizes Rag/Gtr on the lysosomal/vacuole membrane. In human cells, LAMTOR consists of five subunits, but in yeast, only three or four. Currently, it is not known how variation of the subunit stoichiometry may affect its structural organization and biochemical properties. Here, we report a 3.1 Å-resolution structural model of the Gtr-Lam complex in Schizosaccharomyces pombe. We found that SpGtr shares conserved architecture as HsRag, but the intersubunit communication that coordinates nucleotide loading on the two subunits differs. In contrast, SpLam contains distinctive structural features, but its GTP-specific GEF activity toward SpGtr is evolutionarily conserved. Our results revealed unique evolutionary paths of the protein components of the mTORC1 pathway.
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Affiliation(s)
- Steven D Tettoni
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, 373 Plantation Street, Worcester, MA 01605, USA
| | - Shawn B Egri
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, 373 Plantation Street, Worcester, MA 01605, USA
| | - Dylan D Doxsey
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, 373 Plantation Street, Worcester, MA 01605, USA
| | - Kristen Veinotte
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, 373 Plantation Street, Worcester, MA 01605, USA
| | - Christna Ouch
- Department of Biochemistry & Molecular Biotechnology, University of Massachusetts Chan Medical School, 364 Plantation Street, Worcester, MA 01605, USA
| | - Jeng-Yih Chang
- Department of Biochemistry & Molecular Biotechnology, University of Massachusetts Chan Medical School, 364 Plantation Street, Worcester, MA 01605, USA
| | - Kangkang Song
- Department of Biochemistry & Molecular Biotechnology, University of Massachusetts Chan Medical School, 364 Plantation Street, Worcester, MA 01605, USA
| | - Chen Xu
- Department of Biochemistry & Molecular Biotechnology, University of Massachusetts Chan Medical School, 364 Plantation Street, Worcester, MA 01605, USA
| | - Kuang Shen
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, 373 Plantation Street, Worcester, MA 01605, USA; Department of Biochemistry & Molecular Biotechnology, University of Massachusetts Chan Medical School, 364 Plantation Street, Worcester, MA 01605, USA.
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14
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Titze S, Kümmel D. The difference is in the details: Structural and mechanistic variations in the LAMTOR-Gtr/Rag module. Structure 2023; 31:1010-1012. [PMID: 37683616 DOI: 10.1016/j.str.2023.08.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 08/04/2023] [Accepted: 08/04/2023] [Indexed: 09/10/2023]
Abstract
In this issue of Structure, Tettoni et al. present the structure and biochemical characterization of the fission yeast LAMTOR-Gtr complex, which mediates nutrient-dependent control of cell growth. The study reveals specific differences to the homologous human LAMTOR-Rag complex that might represent means of evolutionary adaptation.
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Affiliation(s)
- Sonja Titze
- Institute of Biochemistry, University of Münster, 48149 Münster, Germany
| | - Daniel Kümmel
- Institute of Biochemistry, University of Münster, 48149 Münster, Germany.
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15
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Ruocco C, Malavazos AE, Ragni M, Carruba MO, Valerio A, Iacobellis G, Nisoli E. Amino acids contribute to adaptive thermogenesis. New insights into the mechanisms of action of recent drugs for metabolic disorders are emerging. Pharmacol Res 2023; 195:106892. [PMID: 37619907 DOI: 10.1016/j.phrs.2023.106892] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 07/28/2023] [Accepted: 08/17/2023] [Indexed: 08/26/2023]
Abstract
Adaptive thermogenesis is the heat production by muscle contractions (shivering thermogenesis) or brown adipose tissue (BAT) and beige fat (non-shivering thermogenesis) in response to external stimuli, including cold exposure. BAT and beige fat communicate with peripheral organs and the brain through a variegate secretory and absorption processes - controlling adipokines, microRNAs, extracellular vesicles, and metabolites - and have received much attention as potential therapeutic targets for managing obesity-related disorders. The sympathetic nervous system and norepinephrine-releasing adipose tissue macrophages (ATM) activate uncoupling protein 1 (UCP1), expressed explicitly in brown and beige adipocytes, dissolving the electrochemical gradient and uncoupling tricarboxylic acid cycle and the electron transport chain from ATP production. Mounting evidence has attracted attention to the multiple effects of dietary and endogenously synthesised amino acids in BAT thermogenesis and metabolic phenotype in animals and humans. However, the mechanisms implicated in these processes have yet to be conclusively characterized. In the present review article, we aim to define the principal investigation areas in this context, including intestinal microbiota constitution, adipose autophagy modulation, and secretome and metabolic fluxes control, which lead to increased brown/beige thermogenesis. Finally, also based on our recent epicardial adipose tissue results, we summarise the evidence supporting the notion that the new dual and triple agonists of glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP), and glucagon (GCG) receptor - with never before seen weight loss and insulin-sensitizing efficacy - promote thermogenic-like amino acid profiles in BAT with robust heat production and likely trigger sympathetic activation and adaptive thermogenesis by controlling amino acid metabolism and ATM expansion in BAT and beige fat.
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Affiliation(s)
- Chiara Ruocco
- Center for Study and Research on Obesity, Department of Biomedical Technology and Translational Medicine, University of Milan, via Vanvitelli, 32, 20129 Milan, Italy
| | - Alexis Elias Malavazos
- Endocrinology Unit, Clinical Nutrition and Cardiovascular Prevention Service, IRCCS Policlinico San Donato, Piazza Edmondo Malan, 2, San Donato Milanese, 20097 Milan, Italy; Department of Biomedical, Surgical and Dental Sciences, University of Milan, via della Commenda, 10, 20122 Milan, Italy
| | - Maurizio Ragni
- Center for Study and Research on Obesity, Department of Biomedical Technology and Translational Medicine, University of Milan, via Vanvitelli, 32, 20129 Milan, Italy
| | - Michele O Carruba
- Center for Study and Research on Obesity, Department of Biomedical Technology and Translational Medicine, University of Milan, via Vanvitelli, 32, 20129 Milan, Italy
| | - Alessandra Valerio
- Department of Molecular and Translational Medicine, University of Brescia, viale Europa, 11, 25123 Brescia, Italy
| | - Gianluca Iacobellis
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Miami, 1400 NW 12th Ave, Miami, FL, USA
| | - Enzo Nisoli
- Center for Study and Research on Obesity, Department of Biomedical Technology and Translational Medicine, University of Milan, via Vanvitelli, 32, 20129 Milan, Italy.
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16
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Piro F, Masci S, Kannan G, Focaia R, Schultz TL, Carruthers VB, Di Cristina M. A Toxoplasma gondii putative arginine transporter localizes to the plant-like vacuolar compartment and controls parasite extracellular survival and stage differentiation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.31.555807. [PMID: 37693549 PMCID: PMC10491228 DOI: 10.1101/2023.08.31.555807] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/12/2023]
Abstract
Toxoplasma gondii is a protozoan parasite that infects a broad spectrum of hosts and can colonize many organs and cell types. The ability to reside within a wide range of different niches requires substantial adaptability to diverse microenvironments. Very little is known about how this parasite senses various milieus and adapts its metabolism to survive, replicate during the acute stage, and then differentiate to the chronic stage. Most eukaryotes, from yeast to mammals, rely on a nutrient sensing machinery involving the TORC complex as master regulator of cell growth and cell cycle progression. The lysosome functions as a signaling hub where TORC complex assembles and is activated by transceptors, which both sense and transport amino acids, including the arginine transceptor SLC38A9. While most of the TORC components are lost in T. gondii , indicating the evolution of a distinct nutrient sensing mechanism, the parasite's lysosomal plant-like vacuolar compartment (PLVAC) may still serve as a sensory platform for controlling parasite growth and differentiation. Using SLC38A9 to query the T. gondii proteome, we identified four putative amino acid transporters, termed TgAAT1-4, that structurally resemble the SLC38A9 arginine transceptor. Assessing their expression and sub-cellular localization, we found that one of them, TgAAT1, localized to the PLVAC and is necessary for normal parasite extracellular survival and bradyzoite differentiation. Moreover, we show that TgAAT1 is involved in the PLVAC efflux of arginine, an amino acid playing a key role in T. gondii differentiation, further supporting the hypothesis that TgAAT1 might play a role in nutrient sensing. IMPORTANCE T. gondii is a highly successful parasite infecting a broad range of warm-blood organisms including about one third of all humans. Although Toxoplasma infections rarely result in symptomatic disease in individuals with a healthy immune system, the incredibly high number of persons infected along with the risk of severe infection in immunocompromised patients and the potential link of chronic infection to mental disorders make this infection a significant public health concern. As a result, there is a pressing need for new treatment approaches that are both effective and well-tolerated. The limitations in understanding how Toxoplasma gondii manages its metabolism to adapt to changing environments and triggers its transformation into bradyzoites have hindered the discovery of vulnerabilities in its metabolic pathways or nutrient acquisition mechanisms to identify new therapeutic targets. In this work, we have shown that the lysosome-like organelle PLVAC, acting through the putative arginine transporter TgAAT1, plays a pivotal role in regulating the parasite's extracellular survival and differentiation into bradyzoites.
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17
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Jeong MH, Urquhart G, Lewis C, Chi Z, Jewell JL. Inhibition of phosphodiesterase 4D suppresses mTORC1 signaling and pancreatic cancer growth. JCI Insight 2023; 8:e158098. [PMID: 37427586 PMCID: PMC10371348 DOI: 10.1172/jci.insight.158098] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Accepted: 05/23/2023] [Indexed: 07/11/2023] Open
Abstract
The mammalian target of rapamycin complex 1 (mTORC1) senses multiple upstream stimuli to orchestrate anabolic and catabolic events that regulate cell growth and metabolism. Hyperactivation of mTORC1 signaling is observed in multiple human diseases; thus, pathways that suppress mTORC1 signaling may help to identify new therapeutic targets. Here, we report that phosphodiesterase 4D (PDE4D) promotes pancreatic cancer tumor growth by increasing mTORC1 signaling. GPCRs paired to Gαs proteins activate adenylyl cyclase, which in turn elevates levels of 3',5'-cyclic adenosine monophosphate (cAMP), whereas PDEs catalyze the hydrolysis of cAMP to 5'-AMP. PDE4D forms a complex with mTORC1 and is required for mTORC1 lysosomal localization and activation. Inhibition of PDE4D and the elevation of cAMP levels block mTORC1 signaling via Raptor phosphorylation. Moreover, pancreatic cancer exhibits an upregulation of PDE4D expression, and high PDE4D levels predict the poor overall survival of patients with pancreatic cancer. Importantly, FDA-approved PDE4 inhibitors repress pancreatic cancer cell tumor growth in vivo by suppressing mTORC1 signaling. Our results identify PDE4D as an important activator of mTORC1 and suggest that targeting PDE4 with FDA-approved inhibitors may be beneficial for the treatment of human diseases with hyperactivated mTORC1 signaling.
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Affiliation(s)
- Mi-Hyeon Jeong
- Department of Molecular Biology
- Harold C. Simmons Comprehensive Cancer Center
- Hamon Center for Regenerative Science and Medicine, and
| | - Greg Urquhart
- Department of Molecular Biology
- Harold C. Simmons Comprehensive Cancer Center
- Hamon Center for Regenerative Science and Medicine, and
| | | | - Zhikai Chi
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Jenna L Jewell
- Department of Molecular Biology
- Harold C. Simmons Comprehensive Cancer Center
- Hamon Center for Regenerative Science and Medicine, and
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18
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Doxsey DD, Tettoni SD, Egri SB, Shen K. Redundant electrostatic interactions between GATOR1 and the Rag GTPase heterodimer drive efficient amino acid sensing in human cells. J Biol Chem 2023; 299:104880. [PMID: 37269949 PMCID: PMC10316081 DOI: 10.1016/j.jbc.2023.104880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Revised: 05/23/2023] [Accepted: 05/25/2023] [Indexed: 06/05/2023] Open
Abstract
Cells need to coordinate nutrient availability with their growth and proliferation. In eukaryotic cells, this coordination is mediated by the mechanistic target of the rapamycin complex 1 (mTORC1) pathway. mTORC1 activation is regulated by two GTPase units, the Rag GTPase heterodimer and the Rheb GTPase. The RagA-RagC heterodimer controls the subcellular localization of mTORC1, and its nucleotide loading states are strictly controlled by upstream regulators including amino acid sensors. A critical negative regulator of the Rag GTPase heterodimer is GATOR1. In the absence of amino acids, GATOR1 stimulates GTP hydrolysis by the RagA subunit to turn off mTORC1 signaling. Despite the enzymatic specificity of GATOR1 to RagA, a recent cryo-EM structural model of the human GATOR1-Rag-Ragulator complex reveals an unexpected interface between Depdc5, a subunit of GATOR1, and RagC. Currently, there is no functional characterization of this interface, nor do we know its biological relevance. Here, combining structure-function analysis, enzymatic kinetic measurements, and cell-based signaling assays, we identified a critical electrostatic interaction between Depdc5 and RagC. This interaction is mediated by the positively charged Arg-1407 residue on Depdc5 and a patch of negatively charged residues on the lateral side of RagC. Abrogating this interaction impairs the GAP activity of GATOR1 and cellular response to amino acid withdrawal. Our results reveal how GATOR1 coordinates the nucleotide loading states of the Rag GTPase heterodimer, and thus precisely controls cellular behavior in the absence of amino acids.
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Affiliation(s)
- Dylan D Doxsey
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, Massachusetts, USA
| | - Steven D Tettoni
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, Massachusetts, USA
| | - Shawn B Egri
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, Massachusetts, USA
| | - Kuang Shen
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, Massachusetts, USA; Department of Biochemistry & Molecular Pharmacology, University of Massachusetts Chan Medical School, Worcester, Massachusetts, USA.
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19
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Sung Y, Yu YC, Han JM. Nutrient sensors and their crosstalk. Exp Mol Med 2023; 55:1076-1089. [PMID: 37258576 PMCID: PMC10318010 DOI: 10.1038/s12276-023-01006-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 02/22/2023] [Accepted: 03/13/2023] [Indexed: 06/02/2023] Open
Abstract
The macronutrients glucose, lipids, and amino acids are the major components that maintain life. The ability of cells to sense and respond to fluctuations in these nutrients is a crucial feature for survival. Nutrient-sensing pathways are thus developed to govern cellular energy and metabolic homeostasis and regulate diverse biological processes. Accordingly, perturbations in these sensing pathways are associated with a wide variety of pathologies, especially metabolic diseases. Molecular sensors are the core within these sensing pathways and have a certain degree of specificity and affinity to sense the intracellular fluctuation of each nutrient either by directly binding to that nutrient or indirectly binding to its surrogate molecules. Once the changes in nutrient levels are detected, sensors trigger signaling cascades to fine-tune cellular processes for energy and metabolic homeostasis, for example, by controlling uptake, de novo synthesis or catabolism of that nutrient. In this review, we summarize the major discoveries on nutrient-sensing pathways and explain how those sensors associated with each pathway respond to intracellular nutrient availability and how these mechanisms control metabolic processes. Later, we further discuss the crosstalk between these sensing pathways for each nutrient, which are intertwined to regulate overall intracellular nutrient/metabolic homeostasis.
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Affiliation(s)
- Yulseung Sung
- Yonsei Institute of Pharmaceutical Sciences, College of Pharmacy, Yonsei University, Incheon, 21983, South Korea
| | - Ya Chun Yu
- Yonsei Institute of Pharmaceutical Sciences, College of Pharmacy, Yonsei University, Incheon, 21983, South Korea
| | - Jung Min Han
- Yonsei Institute of Pharmaceutical Sciences, College of Pharmacy, Yonsei University, Incheon, 21983, South Korea.
- Department of Integrated OMICS for Biomedical Science, Yonsei University, Seoul, 03722, South Korea.
- POSTECH Biotech Center, Pohang University of Science and Technology, Pohang, 37673, South Korea.
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20
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Schaf J, Shinhmar S, Zeng Q, Pardo OE, Beesley P, Syed N, Williams RSB. Enhanced Sestrin expression through Tanshinone 2A treatment improves PI3K-dependent inhibition of glioma growth. Cell Death Discov 2023; 9:172. [PMID: 37202382 DOI: 10.1038/s41420-023-01462-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 04/28/2023] [Accepted: 05/03/2023] [Indexed: 05/20/2023] Open
Abstract
Glioblastomas are a highly aggressive cancer type which respond poorly to current pharmaceutical treatments, thus novel therapeutic approaches need to be investigated. One such approach involves the use of the bioactive natural product Tanshinone IIA (T2A) derived from the Chinese herb Danshen, where mechanistic insight for this anti-cancer agent is needed to validate its use. Here, we employ a tractable model system, Dictyostelium discoideum, to provide this insight. T2A potently inhibits cellular proliferation of Dictyostelium, suggesting molecular targets in this model. We show that T2A rapidly reduces phosphoinositide 3 kinase (PI3K) and protein kinase B (PKB) activity, but surprisingly, the downstream complex mechanistic target of rapamycin complex 1 (mTORC1) is only inhibited following chronic treatment. Investigating regulators of mTORC1, including PKB, tuberous sclerosis complex (TSC), and AMP-activated protein kinase (AMPK), suggests these enzymes were not responsible for this effect, implicating an additional molecular mechanism of T2A. We identify this mechanism as the increased expression of sestrin, a negative regulator of mTORC1. We further show that combinatory treatment using a PI3K inhibitor and T2A gives rise to a synergistic inhibition of cell proliferation. We then translate our findings to human and mouse-derived glioblastoma cell lines, where both a PI3K inhibitor (Paxalisib) and T2A reduces glioblastoma proliferation in monolayer cultures and in spheroid expansion, with combinatory treatment significantly enhancing this effect. Thus, we propose a new approach for cancer treatment, including glioblastomas, through combinatory treatment with PI3K inhibitors and T2A.
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Affiliation(s)
- Judith Schaf
- Centre for Biomedical Sciences, School of Biological Sciences, Royal Holloway University of London, Egham, TW20 0EX, UK
| | - Sonia Shinhmar
- Centre for Biomedical Sciences, School of Biological Sciences, Royal Holloway University of London, Egham, TW20 0EX, UK
| | - Qingyu Zeng
- John Fulcher Neuro-Oncology Laboratory, Imperial College London, Hammersmith Hospital, London, UK
| | - Olivier E Pardo
- Division of Cancer, Department of Surgery and Cancer, Imperial College London, London, UK
| | - Philip Beesley
- Centre for Biomedical Sciences, School of Biological Sciences, Royal Holloway University of London, Egham, TW20 0EX, UK
| | - Nelofer Syed
- John Fulcher Neuro-Oncology Laboratory, Imperial College London, Hammersmith Hospital, London, UK
| | - Robin S B Williams
- Centre for Biomedical Sciences, School of Biological Sciences, Royal Holloway University of London, Egham, TW20 0EX, UK.
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21
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Tsujimoto K, Takamatsu H, Kumanogoh A. The Ragulator complex: delving its multifunctional impact on metabolism and beyond. Inflamm Regen 2023; 43:28. [PMID: 37173755 PMCID: PMC10175929 DOI: 10.1186/s41232-023-00278-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Accepted: 05/01/2023] [Indexed: 05/15/2023] Open
Abstract
Our understanding of lysosomes has undergone a significant transformation in recent years, from the view that they are static organelles primarily responsible for the disposal and recycling of cellular waste to their recognition as highly dynamic structures. Current research posits that lysosomes function as a signaling hub that integrates both extracellular and intracellular stimuli, thereby regulating cellular homeostasis. The dysregulation of lysosomal function has been linked to a wide range of diseases. Of note, lysosomes contribute to the activation of mammalian target of rapamycin complex 1 (mTORC1), a key regulator of cellular metabolism. The Ragulator complex, a protein complex anchored on the lysosomal membrane, was initially shown to tether the mTORC1 complex to lysosomes. Recent research has substantially expanded our understanding of the roles of the Ragulator complex in lysosomes, including roles in the regulation of metabolism, inflammation, cell death, cell migration, and the maintenance of homeostasis, via interactions with various proteins. This review summarizes our current knowledge on the diverse functions of the Ragulator complex, highlighting important protein interactions.
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Affiliation(s)
- Kohei Tsujimoto
- Department of Respiratory Medicine and Clinical Immunology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
- Department of Immunopathology, Immunology Frontier Research Center (IFReC), Osaka University, Suita, Osaka, Japan
| | - Hyota Takamatsu
- Department of Respiratory Medicine and Clinical Immunology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
- Department of Immunopathology, Immunology Frontier Research Center (IFReC), Osaka University, Suita, Osaka, Japan.
| | - Atsushi Kumanogoh
- Department of Respiratory Medicine and Clinical Immunology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
- Department of Immunopathology, Immunology Frontier Research Center (IFReC), Osaka University, Suita, Osaka, Japan
- Center for Infectious Diseases Education and Research (CiDER), Osaka University, Suita, Osaka, Japan
- Integrated Frontier Research for Medical Science Division, Institute for Open and Transdisciplinary Research Initiatives (OTRI), Osaka University, Suita, Osaka, Japan
- Japan Agency for Medical Research and Development - Core Research for Evolutional Science and Technology (AMED-CREST), Osaka University, Osaka, Japan
- Center for Advanced Modalities and DDS (CAMaD), Osaka University, Osaka, Japan
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22
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Regulation of mTORC1 by the Rag GTPases. Biochem Soc Trans 2023; 51:655-664. [PMID: 36929165 DOI: 10.1042/bst20210038] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 02/21/2023] [Accepted: 02/23/2023] [Indexed: 03/18/2023]
Abstract
The Rag GTPases are an evolutionarily conserved family that play a crucial role in amino acid sensing by the mammalian target of rapamycin complex 1 (mTORC1). mTORC1 is often referred to as the master regulator of cell growth. mTORC1 hyperactivation is observed in multiple diseases such as cancer, obesity, metabolic disorders, and neurodegeneration. The Rag GTPases sense amino acid levels and form heterodimers, where RagA or RagB binds to RagC or RagD, to recruit mTORC1 to the lysosome where it becomes activated. Here, we review amino acid signaling to mTORC1 through the Rag GTPases.
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23
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Influence of mTOR-regulated anabolic pathways on equine skeletal muscle health. J Equine Vet Sci 2023; 124:104281. [PMID: 36905972 DOI: 10.1016/j.jevs.2023.104281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 03/04/2023] [Accepted: 03/06/2023] [Indexed: 03/11/2023]
Abstract
Skeletal muscle is a highly dynamic organ that is essential for locomotion as well as endocrine regulation in all populations of horses. However, despite the importance of adequate muscle development and maintenance, the mechanisms underlying protein anabolism in horses on different diets, exercise programs, and at different life stages remain obscure. Mechanistic target of rapamycin (mTOR) is a key component of the protein synthesis pathway and is regulated by biological factors such as insulin and amino acid availability. Providing a diet ample in vital amino acids, such as leucine and glutamine, is essential in activating sensory pathways that recruit mTOR to the lysosome and assist in the translation of important downstream targets. When the diet is well balanced, mitochondrial biogenesis and protein synthesis are activated in response to increased exercise bouts in the performing athlete. It is important to note that the mTOR kinase pathways are multi-faceted and very complex, with several binding partners and targets that lead to specific functions in protein turnover of the cell, and ultimately, the capacity to maintain or grow muscle mass. Further, these pathways are likely altered across the lifespan, with an emphasis of growth in young horses while decreases in musculature with aged horses appears to be attributable to degradation or other regulators of protein synthesis rather than alterations in the mTOR pathway. Previous work has begun to pinpoint ways in which the mTOR pathway is influenced by diet, exercise, and age; however, future research is warranted to quantify the functional outcomes related to changes in mTOR. Promisingly, this could provide direction on appropriate management techniques to support skeletal muscle growth and maximize athletic potential in differing equine populations.
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Prouteau M, Bourgoint C, Felix J, Bonadei L, Sadian Y, Gabus C, Savvides SN, Gutsche I, Desfosses A, Loewith R. EGOC inhibits TOROID polymerization by structurally activating TORC1. Nat Struct Mol Biol 2023; 30:273-285. [PMID: 36702972 PMCID: PMC10023571 DOI: 10.1038/s41594-022-00912-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Accepted: 11/21/2022] [Indexed: 01/27/2023]
Abstract
Target of rapamycin complex 1 (TORC1) is a protein kinase controlling cell homeostasis and growth in response to nutrients and stresses. In Saccharomyces cerevisiae, glucose depletion triggers a redistribution of TORC1 from a dispersed localization over the vacuole surface into a large, inactive condensate called TOROID (TORC1 organized in inhibited domains). However, the mechanisms governing this transition have been unclear. Here, we show that acute depletion and repletion of EGO complex (EGOC) activity is sufficient to control TOROID distribution, independently of other nutrient-signaling pathways. The 3.9-Å-resolution structure of TORC1 from TOROID cryo-EM data together with interrogation of key interactions in vivo provide structural insights into TORC1-TORC1' and TORC1-EGOC interaction interfaces. These data support a model in which glucose-dependent activation of EGOC triggers binding to TORC1 at an interface required for TOROID assembly, preventing TORC1 polymerization and promoting release of active TORC1.
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Affiliation(s)
- Manoël Prouteau
- Department of Molecular and Cellular Biology, University of Geneva, Geneva, Switzerland.
| | - Clélia Bourgoint
- Department of Molecular and Cellular Biology, University of Geneva, Geneva, Switzerland
| | - Jan Felix
- Unit for Structural Biology, Department of Biochemistry and Microbiology, Ghent University, Ghent, Belgium.
- Unit for Structural Biology, VIB-UGent Center for Inflammation Research, Ghent, Belgium.
| | - Lenny Bonadei
- Department of Molecular and Cellular Biology, University of Geneva, Geneva, Switzerland
| | - Yashar Sadian
- CryoGEnic facility (DCI Geneva), University of Geneva, Geneva, Switzerland
| | - Caroline Gabus
- Department of Molecular and Cellular Biology, University of Geneva, Geneva, Switzerland
| | - Savvas N Savvides
- Unit for Structural Biology, Department of Biochemistry and Microbiology, Ghent University, Ghent, Belgium
- Unit for Structural Biology, VIB-UGent Center for Inflammation Research, Ghent, Belgium
| | - Irina Gutsche
- Institut de Biologie Structurale, Université Grenoble Alpes, CEA, CNRS, IBS, Grenoble, France
| | - Ambroise Desfosses
- Institut de Biologie Structurale, Université Grenoble Alpes, CEA, CNRS, IBS, Grenoble, France
| | - Robbie Loewith
- Department of Molecular and Cellular Biology, University of Geneva, Geneva, Switzerland.
- Swiss National Centre for Competence in Research Chemical Biology, Geneva, Switzerland.
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25
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New Insights into the Regulation of mTOR Signaling via Ca 2+-Binding Proteins. Int J Mol Sci 2023; 24:ijms24043923. [PMID: 36835331 PMCID: PMC9959742 DOI: 10.3390/ijms24043923] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 02/09/2023] [Accepted: 02/13/2023] [Indexed: 02/17/2023] Open
Abstract
Environmental factors are important regulators of cell growth and proliferation. Mechanistic target of rapamycin (mTOR) is a central kinase that maintains cellular homeostasis in response to a variety of extracellular and intracellular inputs. Dysregulation of mTOR signaling is associated with many diseases, including diabetes and cancer. Calcium ion (Ca2+) is important as a second messenger in various biological processes, and its intracellular concentration is tightly regulated. Although the involvement of Ca2+ mobilization in mTOR signaling has been reported, the detailed molecular mechanisms by which mTOR signaling is regulated are not fully understood. The link between Ca2+ homeostasis and mTOR activation in pathological hypertrophy has heightened the importance in understanding Ca2+-regulated mTOR signaling as a key mechanism of mTOR regulation. In this review, we introduce recent findings on the molecular mechanisms of regulation of mTOR signaling by Ca2+-binding proteins, particularly calmodulin (CaM).
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26
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Huynh C, Ryu J, Lee J, Inoki A, Inoki K. Nutrient-sensing mTORC1 and AMPK pathways in chronic kidney diseases. Nat Rev Nephrol 2023; 19:102-122. [PMID: 36434160 DOI: 10.1038/s41581-022-00648-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/20/2022] [Indexed: 11/27/2022]
Abstract
Nutrients such as glucose, amino acids and lipids are fundamental sources for the maintenance of essential cellular processes and homeostasis in all organisms. The nutrient-sensing kinases mechanistic target of rapamycin (mTOR) and AMP-activated protein kinase (AMPK) are expressed in many cell types and have key roles in the control of cell growth, proliferation, differentiation, metabolism and survival, ultimately contributing to the physiological development and functions of various organs, including the kidney. Dysregulation of these kinases leads to many human health problems, including cancer, neurodegenerative diseases, metabolic disorders and kidney diseases. In the kidney, physiological levels of mTOR and AMPK activity are required to support kidney cell growth and differentiation and to maintain kidney cell integrity and normal nephron function, including transport of electrolytes, water and glucose. mTOR forms two functional multi-protein kinase complexes, mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2). Hyperactivation of mTORC1 leads to podocyte and tubular cell dysfunction and vulnerability to injury, thereby contributing to the development of chronic kidney diseases, including diabetic kidney disease, obesity-related kidney disease and polycystic kidney disease. Emerging evidence suggests that targeting mTOR and/or AMPK could be an effective therapeutic approach to controlling or preventing these diseases.
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Affiliation(s)
- Christopher Huynh
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA.,Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Jaewhee Ryu
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
| | - Jooho Lee
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
| | - Ayaka Inoki
- Department of Biology, Johns Hopkins University, Baltimore, MD, USA.,Department of Internal Medicine, Division of Nephrology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Ken Inoki
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA. .,Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, USA. .,Department of Internal Medicine, Division of Nephrology, University of Michigan Medical School, Ann Arbor, MI, USA.
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27
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Hirose S, Waku T, Tani M, Masuda H, Endo K, Ashitani S, Aketa I, Kitano H, Nakada S, Wada A, Hatanaka A, Osawa T, Soga T, Kobayashi A. NRF3 activates mTORC1 arginine-dependently for cancer cell viability. iScience 2023; 26:106045. [PMID: 36818298 PMCID: PMC9932127 DOI: 10.1016/j.isci.2023.106045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 12/18/2022] [Accepted: 01/20/2023] [Indexed: 01/26/2023] Open
Abstract
Cancer cells coordinate the mTORC1 signals and the related metabolic pathways to robustly and rapidly grow in response to nutrient conditions. Although a CNC-family transcription factor NRF3 promotes cancer development, the biological relevance between NRF3 function and mTORC1 signals in cancer cells remains unknown. Hence, we showed that NRF3 contributes to cancer cell viability through mTORC1 activation in response to amino acids, particularly arginine. NRF3 induced SLC38A9 and RagC expression for the arginine-dependent mTORC1 recruitment onto lysosomes, and it also enhanced RAB5-mediated bulk macropinocytosis and SLC7A1-mediated selective transport for arginine loading into lysosomes. Besides, the inhibition of the NRF3-mTORC1 axis impaired mitochondrial function, leading to cancer cell apoptosis. Consistently, the aberrant upregulation of the axis caused tumor growth and poor prognosis. In conclusion, this study sheds light on the unique function of NRF3 in arginine-dependent mTORC1 activation and the pathophysiological aspects of the NRF3-mTORC1 axis in cancer development.
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Affiliation(s)
- Shuuhei Hirose
- Laboratory for Genetic Code, Graduate School of Life and Medical Sciences, Doshisha University, 1–3 Miyakodani, Tatara, Kyotanabe, Kyoto 610–0394, Japan,Research Fellow of Japan Society for the Promotion of Science
| | - Tsuyoshi Waku
- Laboratory for Genetic Code, Department of Medical Life Systems, Faculty of Life and Medical Sciences, Doshisha University, Kyotanabe, Kyoto 610–0394, Japan,Corresponding author
| | - Misato Tani
- Laboratory for Genetic Code, Graduate School of Life and Medical Sciences, Doshisha University, 1–3 Miyakodani, Tatara, Kyotanabe, Kyoto 610–0394, Japan
| | - Haruka Masuda
- Laboratory for Genetic Code, Graduate School of Life and Medical Sciences, Doshisha University, 1–3 Miyakodani, Tatara, Kyotanabe, Kyoto 610–0394, Japan
| | - Keiko Endo
- Institute for Advanced Biosciences, Keio University, Kakuganji, Tsuruoka 997-0052, Japan
| | - Sanae Ashitani
- Institute for Advanced Biosciences, Keio University, Kakuganji, Tsuruoka 997-0052, Japan
| | - Iori Aketa
- Laboratory for Genetic Code, Graduate School of Life and Medical Sciences, Doshisha University, 1–3 Miyakodani, Tatara, Kyotanabe, Kyoto 610–0394, Japan
| | - Hina Kitano
- Laboratory for Genetic Code, Department of Medical Life Systems, Faculty of Life and Medical Sciences, Doshisha University, Kyotanabe, Kyoto 610–0394, Japan
| | - Sota Nakada
- Laboratory for Genetic Code, Department of Medical Life Systems, Faculty of Life and Medical Sciences, Doshisha University, Kyotanabe, Kyoto 610–0394, Japan
| | - Ayaka Wada
- Laboratory for Genetic Code, Graduate School of Life and Medical Sciences, Doshisha University, 1–3 Miyakodani, Tatara, Kyotanabe, Kyoto 610–0394, Japan
| | - Atsushi Hatanaka
- Laboratory for Genetic Code, Graduate School of Life and Medical Sciences, Doshisha University, 1–3 Miyakodani, Tatara, Kyotanabe, Kyoto 610–0394, Japan
| | - Tsuyoshi Osawa
- Division of Integrative Nutriomics and Oncology, RCAST, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan
| | - Tomoyoshi Soga
- Institute for Advanced Biosciences, Keio University, Kakuganji, Tsuruoka 997-0052, Japan
| | - Akira Kobayashi
- Laboratory for Genetic Code, Graduate School of Life and Medical Sciences, Doshisha University, 1–3 Miyakodani, Tatara, Kyotanabe, Kyoto 610–0394, Japan,Laboratory for Genetic Code, Department of Medical Life Systems, Faculty of Life and Medical Sciences, Doshisha University, Kyotanabe, Kyoto 610–0394, Japan,Corresponding author
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Jiang C, Dai X, He S, Zhou H, Fang L, Guo J, Liu S, Zhang T, Pan W, Yu H, Fu T, Li D, Inuzuka H, Wang P, Xiao J, Wei W. Ring domains are essential for GATOR2-dependent mTORC1 activation. Mol Cell 2023; 83:74-89.e9. [PMID: 36528027 PMCID: PMC11027793 DOI: 10.1016/j.molcel.2022.11.021] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 09/14/2022] [Accepted: 11/22/2022] [Indexed: 12/23/2022]
Abstract
The GATOR2-GATOR1 signaling axis is essential for amino-acid-dependent mTORC1 activation. However, the molecular function of the GATOR2 complex remains unknown. Here, we report that disruption of the Ring domains of Mios, WDR24, or WDR59 completely impedes amino-acid-mediated mTORC1 activation. Mechanistically, via interacting with Ring domains of WDR59 and WDR24, the Ring domain of Mios acts as a hub to maintain GATOR2 integrity, disruption of which leads to self-ubiquitination of WDR24. Physiologically, leucine stimulation dissociates Sestrin2 from the Ring domain of WDR24 and confers its availability to UBE2D3 and subsequent ubiquitination of NPRL2, contributing to GATOR2-mediated GATOR1 inactivation. As such, WDR24 ablation or Ring deletion prevents mTORC1 activation, leading to severe growth defects and embryonic lethality at E10.5 in mice. Hence, our findings demonstrate that Ring domains are essential for GATOR2 to transmit amino acid availability to mTORC1 and further reveal the essentiality of nutrient sensing during embryonic development.
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Affiliation(s)
- Cong Jiang
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA
| | - Xiaoming Dai
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA
| | - Shaohui He
- Joint Research Center for Musculoskeletal Tumor of Shanghai Changzheng Hospital and University of Shanghai for Science and Technology, Spinal Tumor Center, Department of Orthopedic Oncology, Shanghai Changzheng Hospital, Shanghai 200003, China
| | - Hongfei Zhou
- Joint Research Center for Musculoskeletal Tumor of Shanghai Changzheng Hospital and University of Shanghai for Science and Technology, Spinal Tumor Center, Department of Orthopedic Oncology, Shanghai Changzheng Hospital, Shanghai 200003, China
| | - Lan Fang
- Tongji University Cancer Center, Shanghai Tenth People's Hospital, School of Medicine, Tongji University, Shanghai 200092, China
| | - Jianping Guo
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA
| | - Songlei Liu
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Tao Zhang
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA
| | - Weijuan Pan
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai 200241, China
| | - Haihong Yu
- Tongji University Cancer Center, Shanghai Tenth People's Hospital, School of Medicine, Tongji University, Shanghai 200092, China
| | - Tianmin Fu
- Department of Biological Chemistry and Pharmacology, The Ohio State University, Columbus, OH 43210, USA
| | - Dali Li
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai 200241, China
| | - Hiroyuki Inuzuka
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA
| | - Ping Wang
- Tongji University Cancer Center, Shanghai Tenth People's Hospital, School of Medicine, Tongji University, Shanghai 200092, China
| | - Jianru Xiao
- Joint Research Center for Musculoskeletal Tumor of Shanghai Changzheng Hospital and University of Shanghai for Science and Technology, Spinal Tumor Center, Department of Orthopedic Oncology, Shanghai Changzheng Hospital, Shanghai 200003, China.
| | - Wenyi Wei
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA.
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Intracellular galectin-3 is a lipopolysaccharide sensor that promotes glycolysis through mTORC1 activation. Nat Commun 2022; 13:7578. [PMID: 36481721 PMCID: PMC9732310 DOI: 10.1038/s41467-022-35334-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 11/29/2022] [Indexed: 12/13/2022] Open
Abstract
How the carbohydrate binding protein galectin-3 might act as a diabetogenic and tumorogenic factor remains to be investigated. Here we report that intracellular galectin-3 interacts with Rag GTPases and Ragulator on lysosomes. We show that galectin-3 senses lipopolysaccharide (LPS) to facilitate the interaction of Rag GTPases and Ragulator, leading to the activation of mTORC1. We find that the lipopolysaccharide/galectin-3-Rag GTPases/Ragulator-mTORC1 axis regulates a cohort of genes including GLUT1, and HK2, and PKM2 that are critically involved in glucose uptake and glycolysis. Indeed, galectin-3 deficiency severely compromises LPS-promoted glycolysis. Importantly, the expression of HK2 is significantly reduced in diabetes patients. In multiple types of cancer including hepatocellular carcinoma (HCC), galectin-3 is highly expressed, and its level of expression is positively correlated with that of HK2 and PKM2 and negatively correlated with the prognosis of HCC patients. Our study unravels that galectin-3 is a sensor of LPS, an important modulator of the mTORC1 signaling, and a critical regulator of glucose metabolism.
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Wang G, Chen L, Qin S, Zheng Y, Xia C, Yao J, Wang P, Deng L. Cystine Induced-mTORC2 Activation through Promoting Sin1 Phosphorylation to Suppress Cancer Cell Ferroptosis. Mol Nutr Food Res 2022; 66:e2200186. [PMID: 36189894 DOI: 10.1002/mnfr.202200186] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 09/19/2022] [Indexed: 01/18/2023]
Abstract
SCOPE Mechanistic target of rapamycin (mTOR) serves as a central signaling node in the coordination of cell growth and metabolism, and it functions via two distinct complexes, namely, mTOR complex 1 (mTORC1) and mTORC2. mTORC1 plays a crucial role in sensing amino acids, whereas mTORC2 involves in sensing growth factors. However, it remains largely unclear whether mTORC2 can sense amino acids and the mechanism by which amino acids regulate mTORC2 has not been studied. METHODS AND RESULTS After treating cells with indicated concentration of amino acids for different time, it is found that the mTORC2 activation is significantly increased in response to amino acids stimulation, especially cystine. Particularly, knockdown solute carrier family 7 member 11 (SLC7A11) by siRNA shows that SLC7A11-mediated cystine uptake is responsible for activating mTORC2. Mechanistically, the study finds that p38 is activated in response to cystine stimulation, and co-immunoprecipitation (Co-IP) experiments suggest that p38 regulates the assembly of components within mTORC2 by mediating the phosphorylation of the mTORC2 subunit mitogen-activated protein kinase-interacting protein 1 (Sin1) in a cystine-dependent manner. Finally, combined with inducers and inhibitors of ferroptosis and cell viability assay, the study observes that cystine-mediated regulation of the p38-Sin1-mTOR-AKT pathway induces resistance to ferroptosis. CONCLUSION These results indicate that cystine-induced activation of the p38-Sin1-mTORC2-AKT pathway suppresses ferroptosis.
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Affiliation(s)
- GuoYan Wang
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Lei Chen
- Division of Laboratory Safety and Services, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - SenLin Qin
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - YiNing Zheng
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Chao Xia
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - JunHu Yao
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Ping Wang
- Tongji University Cancer Center, Shanghai Tenth People's Hospital of Tongji University, School of Medicine, Tongji University, Shanghai, 200092, China
| | - Lu Deng
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, 712100, China
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31
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Tinline-Goodfellow CT, Lees MJ, Hodson N. The skeletal muscle fiber periphery: A nexus of mTOR-related anabolism. SPORTS MEDICINE AND HEALTH SCIENCE 2022; 5:10-19. [PMID: 36994172 PMCID: PMC10040390 DOI: 10.1016/j.smhs.2022.11.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 11/16/2022] [Accepted: 11/23/2022] [Indexed: 12/02/2022] Open
Abstract
Skeletal muscle anabolism is driven by numerous stimuli such as growth factors, nutrients (i.e., amino acids, glucose), and mechanical stress. These stimuli are integrated by the mechanistic target of rapamycin (mTOR) complex 1 (mTORC1) signal transduction cascade. In recent years, work from our laboratory and elsewhere has sought to unravel the molecular mechanisms underpinning the mTOR-related activation of muscle protein synthesis (MPS), as well as the spatial regulation of these mechanisms within the skeletal muscle cell. These studies have suggested that the skeletal muscle fiber periphery is a region of central importance in anabolism (i.e., growth/MPS). Indeed, the fiber periphery is replete with the substrates, molecular machinery, and translational apparatus necessary to facilitate MPS. This review provides a summary of the mechanisms underpinning the mTOR-associated activation of MPS from cell, rodent, and human studies. It also presents an overview of the spatial regulation of mTORC1 in response to anabolic stimuli and outlines the factors that distinguish the periphery of the cell as a highly notable region of skeletal muscle for the induction of MPS. Future research should seek to further explore the nutrient-induced activation of mTORC1 at the periphery of skeletal muscle fibers.
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Affiliation(s)
| | - Matthew J. Lees
- Faculty of Kinesiology and Physical Education, University of Toronto, Canada
| | - Nathan Hodson
- Faculty of Kinesiology and Physical Education, University of Toronto, Canada
- Institute of Sport, Manchester Metropolitan University, Manchester, United Kingdom
- Department of Sport and Exercise Sciences, Manchester Metropolitan University, Manchester, United Kingdom
- Corresponding author. Faculty of Kinesiology and Physical Education, University of Toronto, Canada.
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Abstract
The mechanistic target of rapamycin complex 1 (mTORC1) senses nutrient levels in the cell and based on the availability, regulates cellular growth and proliferation. Its activity is tightly modulated by two GTPase units, the Rag GTPases and the Rheb GTPase. The Rag GTPases are the central hub of amino acid sensing as they summarize the amino acid signals from upstream regulators and control the subcellular localization of mTORC1. Unique from canonical signaling GTPases, the Rag GTPases are obligatory heterodimers, and the two subunits coordinate their nucleotide loading states to regulate their functional states. Robust biochemical analysis is indispensable to understanding the molecular mechanism governing the GTPase cycle. This chapter discusses protocols for purifying and biochemically characterizing the Rag GTPase heterodimer. We described two purification protocols to recombinantly produce the Rag GTPase heterodimer in large quantities. We then described assays to quantitatively measure the nucleotide binding and hydrolysis by the Rag GTPases. These assays allow for a thorough investigation of this unique heterodimeric GTPase, and they could be applicable to investigations of other noncanonical GTPases.
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Affiliation(s)
- Dylan D Doxsey
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, MA, United States
| | - Kuang Shen
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, MA, United States.
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Yue S, Li G, He S, Li T. The central role of mTORC1 in amino acid sensing. Cancer Res 2022; 82:2964-2974. [PMID: 35749594 DOI: 10.1158/0008-5472.can-21-4403] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 04/28/2022] [Accepted: 06/17/2022] [Indexed: 11/16/2022]
Abstract
The mechanistic target of rapamycin (mTOR) is a master regulator of cell growth that controls cell homeostasis in response to nutrients, growth factors, and other environmental cues. Recent studies have emphasized the importance of lysosomes as a hub for nutrient sensing, especially amino acid sensing by mTORC1. This review highlights recent advances in understanding the amino acid-mTORC1 signaling axis and the role of mTORC1 in cancer.
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34
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Egri SB, Ouch C, Chou HT, Yu Z, Song K, Xu C, Shen K. Cryo-EM structures of the human GATOR1-Rag-Ragulator complex reveal a spatial-constraint regulated GAP mechanism. Mol Cell 2022; 82:1836-1849.e5. [PMID: 35338845 PMCID: PMC9133170 DOI: 10.1016/j.molcel.2022.03.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Revised: 12/09/2021] [Accepted: 02/28/2022] [Indexed: 12/20/2022]
Abstract
mTORC1 controls cellular metabolic processes in response to nutrient availability. Amino acid signals are transmitted to mTORC1 through the Rag GTPases, which are localized on the lysosomal surface by the Ragulator complex. The Rag GTPases receive amino acid signals from multiple upstream regulators. One negative regulator, GATOR1, is a GTPase activating protein (GAP) for RagA. GATOR1 binds to the Rag GTPases via two modes: an inhibitory mode and a GAP mode. How these two binding interactions coordinate to process amino acid signals is unknown. Here, we resolved three cryo-EM structural models of the GATOR1-Rag-Ragulator complex, with the Rag-Ragulator subcomplex occupying the inhibitory site, the GAP site, and both binding sites simultaneously. When the Rag GTPases bind to GATOR1 at the GAP site, both Rag subunits contact GATOR1 to coordinate their nucleotide loading states. These results reveal a potential GAP mechanism of GATOR1 during the mTORC1 inactivation process.
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Affiliation(s)
- Shawn B Egri
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, 373 Plantation St, Worcester, MA 01605, USA
| | - Christna Ouch
- Department of Biochemistry & Molecular Pharmacology, University of Massachusetts Chan Medical School, 364 Plantation St, Worcester, MA 01605, USA
| | - Hui-Ting Chou
- Howard Hughes Medical Institute, Janelia Research Campus, 19700 Helix Drive, Ashburn, VA 20147, USA
| | - Zhiheng Yu
- Howard Hughes Medical Institute, Janelia Research Campus, 19700 Helix Drive, Ashburn, VA 20147, USA
| | - Kangkang Song
- Department of Biochemistry & Molecular Pharmacology, University of Massachusetts Chan Medical School, 364 Plantation St, Worcester, MA 01605, USA
| | - Chen Xu
- Department of Biochemistry & Molecular Pharmacology, University of Massachusetts Chan Medical School, 364 Plantation St, Worcester, MA 01605, USA
| | - Kuang Shen
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, 373 Plantation St, Worcester, MA 01605, USA.
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35
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Wang G, Chen L, Qin S, Zhang T, Yao J, Yi Y, Deng L. Mechanistic Target of Rapamycin Complex 1: From a Nutrient Sensor to a Key Regulator of Metabolism and Health. Adv Nutr 2022; 13:1882-1900. [PMID: 35561748 PMCID: PMC9526850 DOI: 10.1093/advances/nmac055] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 04/26/2022] [Accepted: 05/09/2022] [Indexed: 01/28/2023] Open
Abstract
Mechanistic target of rapamycin complex 1 (mTORC1) is a multi-protein complex widely found in eukaryotes. It serves as a central signaling node to coordinate cell growth and metabolism by sensing diverse extracellular and intracellular inputs, including amino acid-, growth factor-, glucose-, and nucleotide-related signals. It is well documented that mTORC1 is recruited to the lysosomal surface, where it is activated and, accordingly, modulates downstream effectors involved in regulating protein, lipid, and glucose metabolism. mTORC1 is thus the central node for coordinating the storage and mobilization of nutrients and energy across various tissues. However, emerging evidence indicated that the overactivation of mTORC1 induced by nutritional disorders leads to the occurrence of a variety of metabolic diseases, including obesity and type 2 diabetes, as well as cancer, neurodegenerative disorders, and aging. That the mTORC1 pathway plays a crucial role in regulating the occurrence of metabolic diseases renders it a prime target for the development of effective therapeutic strategies. Here, we focus on recent advances in our understanding of the regulatory mechanisms underlying how mTORC1 integrates metabolic inputs as well as the role of mTORC1 in the regulation of nutritional and metabolic diseases.
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Affiliation(s)
- Guoyan Wang
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, China
| | - Lei Chen
- Division of Laboratory Safety and Services, Northwest A&F University, Yangling Shaanxi, China
| | - Senlin Qin
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, China
| | - Tingting Zhang
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi, China
| | - Junhu Yao
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, China
| | - Yanglei Yi
- Address correspondence to YLY (e-mail: )
| | - Lu Deng
- Address correspondence to LD (e-mail: )
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Oleksak P, Nepovimova E, Chrienova Z, Musilek K, Patocka J, Kuca K. Contemporary mTOR inhibitor scaffolds to diseases breakdown: A patent review (2015–2021). Eur J Med Chem 2022; 238:114498. [DOI: 10.1016/j.ejmech.2022.114498] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2022] [Revised: 05/16/2022] [Accepted: 05/26/2022] [Indexed: 02/06/2023]
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Wu X, Chen J, Liu C, Wang X, Zhou H, Mai K, He G. Slc38a9 Deficiency Induces Apoptosis and Metabolic Dysregulation and Leads to Premature Death in Zebrafish. Int J Mol Sci 2022; 23:ijms23084200. [PMID: 35457018 PMCID: PMC9025135 DOI: 10.3390/ijms23084200] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 04/04/2022] [Accepted: 04/05/2022] [Indexed: 02/05/2023] Open
Abstract
Eukaryotic cells control nutritional homeostasis and determine cell metabolic fate through a series of nutrient transporters and metabolic regulation pathways. Lysosomal localized amino acid transporter member 9 of the solute carrier family 38 (SLC38A9) regulates essential amino acids’ efflux from lysosomes in an arginine-regulated fashion. To better understand the physiological role of SLC38A9, we first described the spatiotemporal expression pattern of the slc38a9 gene in zebrafish. A quarter of slc38a9−/− mutant embryos developed pericardial edema and died prematurely, while the remaining mutants were viable and grew normally. By profiling the transcriptome of the abnormally developed embryos using RNA-seq, we identified increased apoptosis, dysregulated amino acid metabolism, and glycolysis/gluconeogenesis disorders that occurred in slc38a9−/− mutant fish. slc38a9 deficiency increased whole-body free amino acid and lactate levels but reduced glucose and pyruvate levels. The change of glycolysis-related metabolites in viable slc38a9−/− mutant fish was ameliorated. Moreover, loss of slc38a9 resulted in a significant reduction in hypoxia-inducible gene expression and hypoxia-inducible factor 1-alpha (Hif1α) protein levels. These results improved our understanding of the physiological functions of SLC38A9 and revealed its indispensable role in embryonic development, metabolic regulation, and stress adaption.
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Affiliation(s)
- Xiya Wu
- Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao 266003, China; (X.W.); (J.C.); (X.W.); (H.Z.); (K.M.); (G.H.)
- Key Laboratory of Aquaculture Nutrition and Feeds, Ministry of Agriculture, Ocean University of China, Qingdao 266003, China
| | - Jianyang Chen
- Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao 266003, China; (X.W.); (J.C.); (X.W.); (H.Z.); (K.M.); (G.H.)
- Key Laboratory of Aquaculture Nutrition and Feeds, Ministry of Agriculture, Ocean University of China, Qingdao 266003, China
| | - Chengdong Liu
- Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao 266003, China; (X.W.); (J.C.); (X.W.); (H.Z.); (K.M.); (G.H.)
- Key Laboratory of Aquaculture Nutrition and Feeds, Ministry of Agriculture, Ocean University of China, Qingdao 266003, China
- Correspondence:
| | - Xuan Wang
- Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao 266003, China; (X.W.); (J.C.); (X.W.); (H.Z.); (K.M.); (G.H.)
- Key Laboratory of Aquaculture Nutrition and Feeds, Ministry of Agriculture, Ocean University of China, Qingdao 266003, China
| | - Huihui Zhou
- Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao 266003, China; (X.W.); (J.C.); (X.W.); (H.Z.); (K.M.); (G.H.)
- Key Laboratory of Aquaculture Nutrition and Feeds, Ministry of Agriculture, Ocean University of China, Qingdao 266003, China
| | - Kangsen Mai
- Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao 266003, China; (X.W.); (J.C.); (X.W.); (H.Z.); (K.M.); (G.H.)
- Key Laboratory of Aquaculture Nutrition and Feeds, Ministry of Agriculture, Ocean University of China, Qingdao 266003, China
| | - Gen He
- Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao 266003, China; (X.W.); (J.C.); (X.W.); (H.Z.); (K.M.); (G.H.)
- Key Laboratory of Aquaculture Nutrition and Feeds, Ministry of Agriculture, Ocean University of China, Qingdao 266003, China
- Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266003, China
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Simcox J, Lamming DW. The central moTOR of metabolism. Dev Cell 2022; 57:691-706. [PMID: 35316619 PMCID: PMC9004513 DOI: 10.1016/j.devcel.2022.02.024] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 02/20/2022] [Accepted: 02/24/2022] [Indexed: 12/21/2022]
Abstract
The protein kinase mechanistic target of rapamycin (mTOR) functions as a central regulator of metabolism, integrating diverse nutritional and hormonal cues to control anabolic processes, organismal physiology, and even aging. This review discusses the current state of knowledge regarding the regulation of mTOR signaling and the metabolic regulation of the four macromolecular building blocks of the cell: carbohydrate, nucleic acid, lipid, and protein by mTOR. We review the role of mTOR in the control of organismal physiology and aging through its action in key tissues and discuss the potential for clinical translation of mTOR inhibition for the treatment and prevention of diseases of aging.
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Affiliation(s)
- Judith Simcox
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, USA.
| | - Dudley W Lamming
- William S. Middleton Memorial Veterans Hospital, Madison, WI, USA; Department of Medicine, University of Wisconsin-Madison, Madison, WI, USA.
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Nowosad A, Besson A. Lysosomes at the Crossroads of Cell Metabolism, Cell Cycle, and Stemness. Int J Mol Sci 2022; 23:ijms23042290. [PMID: 35216401 PMCID: PMC8879101 DOI: 10.3390/ijms23042290] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Revised: 02/11/2022] [Accepted: 02/16/2022] [Indexed: 02/07/2023] Open
Abstract
Initially described as lytic bodies due to their degradative and recycling functions, lysosomes play a critical role in metabolic adaptation to nutrient availability. More recently, the contribution of lysosomal proteins to cell signaling has been established, and lysosomes have emerged as signaling hubs that regulate diverse cellular processes, including cell proliferation and cell fate. Deciphering these signaling pathways has revealed an extensive crosstalk between the lysosomal and cell cycle machineries that is only beginning to be understood. Recent studies also indicate that a number of lysosomal proteins are involved in the regulation of embryonic and adult stem cell fate and identity. In this review, we will focus on the role of the lysosome as a signaling platform with an emphasis on its function in integrating nutrient sensing with proliferation and cell cycle progression, as well as in stemness-related features, such as self-renewal and quiescence.
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Affiliation(s)
- Ada Nowosad
- Molecular, Cellular and Developmental Biology Department (MCD), Centre de Biologie Intégrative (CBI), University of Toulouse, CNRS, UPS, 31062 Toulouse, France;
- Department of Oncology, KULeuven, Laboratory for Molecular Cancer Biology, Center for Cancer Biology, VIB, 3000 Leuven, Belgium
| | - Arnaud Besson
- Molecular, Cellular and Developmental Biology Department (MCD), Centre de Biologie Intégrative (CBI), University of Toulouse, CNRS, UPS, 31062 Toulouse, France;
- Correspondence: ; Tel.: +33-561558486
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40
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Doxsey DD, Veinotte K, Shen K. A New Crosslinking Assay to Study Guanine Nucleotide Binding in the Gtr Heterodimer of S. cerevisiae. Small GTPases 2022; 13:327-334. [PMID: 36328771 PMCID: PMC9639563 DOI: 10.1080/21541248.2022.2141019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The mechanistic target of rapamycin (mTOR) complex is responsible for coordinating nutrient availability with eukaryotic cell growth. Amino acid signals are transmitted towards mTOR via the Rag/Gtr heterodimers. Due to the obligatory heterodimeric architecture of the Rag/Gtr GTPases, investigating their biochemical properties has been challenging. Here, we describe an updated assay that allows us to probe the guanine nucleotide-binding affinity and kinetics to the Gtr heterodimers in Saccharomyces cerevisiae. We first identified the structural element that Gtr2p lacks to enable crosslinking. By using a sequence conservation-based mutation, we restored the crosslinking between Gtr2p and the bound nucleotides. Using this construct, we determined the nucleotide-binding affinities of the Gtr heterodimer, and found that it operates under a different form of intersubunit communication than human Rag GTPases. Our study defines the evolutionary divergence of the Gtr/Rag-mTOR axis of nutrient sensing.
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Affiliation(s)
- Dylan D. Doxsey
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, 373 Plantation St, Worcester, MA, 01605, USA
| | - Kristen Veinotte
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, 373 Plantation St, Worcester, MA, 01605, USA
| | - Kuang Shen
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, 373 Plantation St, Worcester, MA, 01605, USA,Department of Biochemistry & Molecular Biotechnology, University of Massachusetts Chan Medical School, 364 Plantation St, Worcester, MA, 01605, USA,CONTACT Kuang Shen Program in Molecular Medicine, University of Massachusetts Chan Medical School, 373 Plantation St, Worcester, MA, 01605, USA
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Artzi L, Alon A, Brock KP, Green AG, Tam A, Ramírez-Guadiana FH, Marks D, Kruse A, Rudner DZ. Dormant spores sense amino acids through the B subunits of their germination receptors. Nat Commun 2021; 12:6842. [PMID: 34824238 PMCID: PMC8617281 DOI: 10.1038/s41467-021-27235-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 11/01/2021] [Indexed: 01/19/2023] Open
Abstract
Bacteria from the orders Bacillales and Clostridiales differentiate into stress-resistant spores that can remain dormant for years, yet rapidly germinate upon nutrient sensing. How spores monitor nutrients is poorly understood but in most cases requires putative membrane receptors. The prototypical receptor from Bacillus subtilis consists of three proteins (GerAA, GerAB, GerAC) required for germination in response to L-alanine. GerAB belongs to the Amino Acid-Polyamine-Organocation superfamily of transporters. Using evolutionary co-variation analysis, we provide evidence that GerAB adopts a structure similar to an L-alanine transporter from this superfamily. We show that mutations in gerAB predicted to disrupt the ligand-binding pocket impair germination, while mutations predicted to function in L-alanine recognition enable spores to respond to L-leucine or L-serine. Finally, substitutions of bulkier residues at these positions cause constitutive germination. These data suggest that GerAB is the L-alanine sensor and that B subunits in this broadly conserved family function in nutrient detection.
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Affiliation(s)
- Lior Artzi
- Department of Microbiology, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, MA, 02115, USA
| | - Assaf Alon
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, 250 Longwood Avenue, Boston, MA, 02115, USA
| | - Kelly P Brock
- Department of Systems Biology, Harvard Medical School, 200 Longwood Avenue, Boston, MA, 02115, USA
| | - Anna G Green
- Department of Systems Biology, Harvard Medical School, 200 Longwood Avenue, Boston, MA, 02115, USA
| | - Amy Tam
- Department of Systems Biology, Harvard Medical School, 200 Longwood Avenue, Boston, MA, 02115, USA
| | | | - Debora Marks
- Department of Systems Biology, Harvard Medical School, 200 Longwood Avenue, Boston, MA, 02115, USA
| | - Andrew Kruse
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, 250 Longwood Avenue, Boston, MA, 02115, USA
| | - David Z Rudner
- Department of Microbiology, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, MA, 02115, USA.
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Zhang S, Lin X, Hou Q, Hu Z, Wang Y, Wang Z. Regulation of mTORC1 by amino acids in mammalian cells: A general picture of recent advances. ACTA ACUST UNITED AC 2021; 7:1009-1023. [PMID: 34738031 PMCID: PMC8536509 DOI: 10.1016/j.aninu.2021.05.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 05/13/2021] [Accepted: 05/18/2021] [Indexed: 12/11/2022]
Abstract
The mechanistic target of rapamycin complex 1 (mTORC1) integrates various types of signal inputs, such as energy, growth factors, and amino acids to regulate cell growth and proliferation mainly through the 2 direct downstream targets, eukaryotic translation initiation factor 4E-binding protein 1 (4EBP1) and ribosomal protein S6 kinase 1 (S6K1). Most of the signal arms upstream of mTORC1 including energy status, stress signals, and growth factors converge on the tuberous sclerosis complex (TSC) - Ras homologue enriched in brain (Rheb) axis. Amino acids, however, are distinct from other signals and modulate mTORC1 using a unique pathway. In recent years, the transmission mechanism of amino acid signals upstream of mTORC1 has been gradually elucidated, and some sensors or signal transmission pathways for individual amino acids have also been discovered. With the help of these findings, we propose a general picture of recent advances, which demonstrates that various amino acids from lysosomes, cytoplasm, and Golgi are sensed by their respective sensors. These signals converge on mTORC1 and form a huge and complicated signal network with multiple synergies, antagonisms, and feedback mechanisms.
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Affiliation(s)
- Shizhe Zhang
- Key Laboratory of Ruminant Nutrition and Physiology, College of Animal Science and Technology, Shandong Agricultural University, No. 61, Daizong Street, Tai'an, Shandong, China
| | - Xueyan Lin
- Key Laboratory of Ruminant Nutrition and Physiology, College of Animal Science and Technology, Shandong Agricultural University, No. 61, Daizong Street, Tai'an, Shandong, China
| | - Qiuling Hou
- Key Laboratory of Ruminant Nutrition and Physiology, College of Animal Science and Technology, Shandong Agricultural University, No. 61, Daizong Street, Tai'an, Shandong, China
| | - Zhiyong Hu
- Key Laboratory of Ruminant Nutrition and Physiology, College of Animal Science and Technology, Shandong Agricultural University, No. 61, Daizong Street, Tai'an, Shandong, China
| | - Yun Wang
- Key Laboratory of Ruminant Nutrition and Physiology, College of Animal Science and Technology, Shandong Agricultural University, No. 61, Daizong Street, Tai'an, Shandong, China
| | - Zhonghua Wang
- Key Laboratory of Ruminant Nutrition and Physiology, College of Animal Science and Technology, Shandong Agricultural University, No. 61, Daizong Street, Tai'an, Shandong, China
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Loissell-Baltazar YA, Dokudovskaya S. SEA and GATOR 10 Years Later. Cells 2021; 10:cells10102689. [PMID: 34685669 PMCID: PMC8534245 DOI: 10.3390/cells10102689] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 09/30/2021] [Accepted: 10/03/2021] [Indexed: 12/17/2022] Open
Abstract
The SEA complex was described for the first time in yeast Saccharomyces cerevisiae ten years ago, and its human homologue GATOR complex two years later. During the past decade, many advances on the SEA/GATOR biology in different organisms have been made that allowed its role as an essential upstream regulator of the mTORC1 pathway to be defined. In this review, we describe these advances in relation to the identification of multiple functions of the SEA/GATOR complex in nutrient response and beyond and highlight the consequence of GATOR mutations in cancer and neurodegenerative diseases.
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Insights into the Interaction of Lysosomal Amino Acid Transporters SLC38A9 and SLC36A1 Involved in mTORC1 Signaling in C2C12 Cells. Biomolecules 2021; 11:biom11091314. [PMID: 34572527 PMCID: PMC8467208 DOI: 10.3390/biom11091314] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2021] [Revised: 08/28/2021] [Accepted: 08/31/2021] [Indexed: 11/16/2022] Open
Abstract
Amino acids are critical for mammalian target of rapamycin complex 1 (mTORC1) activation on the lysosomal surface. Amino acid transporters SLC38A9 and SLC36A1 are the members of the lysosomal amino acid sensing machinery that activates mTORC1. The current study aims to clarify the interaction of SLC38A9 and SLC36A1. Here, we discovered that leucine increased expressions of SLC38A9 and SLC36A1, leading to mTORC1 activation. SLC38A9 interacted with SLC36A1 and they enhanced each other's expression levels and locations on the lysosomal surface. Additionally, the interacting proteins of SLC38A9 in C2C12 cells were identified to participate in amino acid sensing mechanism, mTORC1 signaling pathway, and protein synthesis, which provided a resource for future investigations of skeletal muscle mass.
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Fernandes SA, Demetriades C. The Multifaceted Role of Nutrient Sensing and mTORC1 Signaling in Physiology and Aging. FRONTIERS IN AGING 2021; 2:707372. [PMID: 35822019 PMCID: PMC9261424 DOI: 10.3389/fragi.2021.707372] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/09/2021] [Accepted: 08/12/2021] [Indexed: 01/10/2023]
Abstract
The mechanistic Target of Rapamycin (mTOR) is a growth-related kinase that, in the context of the mTOR complex 1 (mTORC1), touches upon most fundamental cellular processes. Consequently, its activity is a critical determinant for cellular and organismal physiology, while its dysregulation is commonly linked to human aging and age-related disease. Presumably the most important stimulus that regulates mTORC1 activity is nutrient sufficiency, whereby amino acids play a predominant role. In fact, mTORC1 functions as a molecular sensor for amino acids, linking the cellular demand to the nutritional supply. Notably, dietary restriction (DR), a nutritional regimen that has been shown to extend lifespan and improve healthspan in a broad spectrum of organisms, works via limiting nutrient uptake and changes in mTORC1 activity. Furthermore, pharmacological inhibition of mTORC1, using rapamycin or its analogs (rapalogs), can mimic the pro-longevity effects of DR. Conversely, nutritional amino acid overload has been tightly linked to aging and diseases, such as cancer, type 2 diabetes and obesity. Similar effects can also be recapitulated by mutations in upstream mTORC1 regulators, thus establishing a tight connection between mTORC1 signaling and aging. Although the role of growth factor signaling upstream of mTORC1 in aging has been investigated extensively, the involvement of signaling components participating in the nutrient sensing branch is less well understood. In this review, we provide a comprehensive overview of the molecular and cellular mechanisms that signal nutrient availability to mTORC1, and summarize the role that nutrients, nutrient sensors, and other components of the nutrient sensing machinery play in cellular and organismal aging.
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Affiliation(s)
- Stephanie A. Fernandes
- Max Planck Institute for Biology of Ageing (MPI-AGE), Cologne, Germany
- Cologne Graduate School for Ageing Research (CGA), Cologne, Germany
| | - Constantinos Demetriades
- Max Planck Institute for Biology of Ageing (MPI-AGE), Cologne, Germany
- Cologne Graduate School for Ageing Research (CGA), Cologne, Germany
- University of Cologne, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Cologne, Germany
- *Correspondence: Constantinos Demetriades,
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Shams R, Ito Y, Miyatake H. Evaluation of the Binding Kinetics of RHEB with mTORC1 by In-Cell and In Vitro Assays. Int J Mol Sci 2021; 22:ijms22168766. [PMID: 34445471 PMCID: PMC8395731 DOI: 10.3390/ijms22168766] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Revised: 08/04/2021] [Accepted: 08/13/2021] [Indexed: 11/16/2022] Open
Abstract
The mammalian/mechanistic target of rapamycin complex 1 (mTORC1) is activated by the small G-protein, Ras homolog enriched in brain (RHEB–GTPase). On lysosome, RHEB activates mTORC1 by binding the domains of N-heat, M-heat, and the focal adhesion targeting (FAT) domain, which allosterically regulates ATP binding in the active site for further phosphorylation. The crucial role of RHEB in regulating growth and survival through mTORC1 makes it a targetable site for anti-cancer therapeutics. However, the binding kinetics of RHEB to mTORC1 is still unknown at the molecular level. Therefore, we studied the kinetics by in vitro and in-cell protein–protein interaction (PPI) assays. To this end, we used the split-luciferase system (NanoBiT®) for in-cell studies and prepared proteins for the in vitro measurements. Consequently, we demonstrated that RHEB binds to the whole mTOR both in the presence or absence of GTPγS, with five-fold weaker affinity in the presence of GTPγS. In addition, RHEB bound to the truncated mTOR fragments of N-heat domain (∆N, aa 60–167) or M-heat domain (∆M, aa 967–1023) with the same affinity in the absence of GTP. The reconstructed binding site of RHEB, ∆N-FAT-M, however, bound to RHEB with the same affinity as ∆N-M, indicating that the FAT domain (∆FAT, aa 1240–1360) is dispensable for RHEB binding. Furthermore, RHEB bound to the truncated kinase domain (∆ATP, aa 2148–2300) with higher affinity than to ∆N-FAT-M. In conclusion, RHEB engages two different binding sites of mTOR, ∆N-FAT-M and ∆ATP, with higher affinity for ∆ATP, which likely regulates the kinase activity of mTOR through multiple different biding modes.
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Affiliation(s)
- Raef Shams
- Emergent Bioengineering Materials Research Team, RIKEN Center for Emergent Matter Science, RIKEN, Wako 351-0198, Saitama, Japan; (R.S.); (Y.I.)
- Department of Life Science, Graduate School of Science and Engineering, Saitama University, Saitama City 338-8570, Saitama, Japan
| | - Yoshihiro Ito
- Emergent Bioengineering Materials Research Team, RIKEN Center for Emergent Matter Science, RIKEN, Wako 351-0198, Saitama, Japan; (R.S.); (Y.I.)
- Nano Medical Engineering Laboratory, RIKEN Cluster for Pioneering Research, RIKEN, Wako 351-0198, Saitama, Japan
| | - Hideyuki Miyatake
- Department of Life Science, Graduate School of Science and Engineering, Saitama University, Saitama City 338-8570, Saitama, Japan
- Nano Medical Engineering Laboratory, RIKEN Cluster for Pioneering Research, RIKEN, Wako 351-0198, Saitama, Japan
- Correspondence: ; Tel.: +81-48-467-4979
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Chu A, Zirngibl RA, Manolson MF. The V-ATPase a3 Subunit: Structure, Function and Therapeutic Potential of an Essential Biomolecule in Osteoclastic Bone Resorption. Int J Mol Sci 2021; 22:ijms22136934. [PMID: 34203247 PMCID: PMC8269383 DOI: 10.3390/ijms22136934] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 06/18/2021] [Accepted: 06/21/2021] [Indexed: 12/29/2022] Open
Abstract
This review focuses on one of the 16 proteins composing the V-ATPase complex responsible for resorbing bone: the a3 subunit. The rationale for focusing on this biomolecule is that mutations in this one protein account for over 50% of osteopetrosis cases, highlighting its critical role in bone physiology. Despite its essential role in bone remodeling and its involvement in bone diseases, little is known about the way in which this subunit is targeted and regulated within osteoclasts. To this end, this review is broadened to include the three other mammalian paralogues (a1, a2 and a4) and the two yeast orthologs (Vph1p and Stv1p). By examining the literature on all of the paralogues/orthologs of the V-ATPase a subunit, we hope to provide insight into the molecular mechanisms and future research directions specific to a3. This review starts with an overview on bone, highlighting the role of V-ATPases in osteoclastic bone resorption. We then cover V-ATPases in other location/functions, highlighting the roles which the four mammalian a subunit paralogues might play in differential targeting and/or regulation. We review the ways in which the energy of ATP hydrolysis is converted into proton translocation, and go in depth into the diverse role of the a subunit, not only in proton translocation but also in lipid binding, cell signaling and human diseases. Finally, the therapeutic implication of targeting a3 specifically for bone diseases and cancer is discussed, with concluding remarks on future directions.
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Seibert M, Kurrle N, Schnütgen F, Serve H. Amino acid sensory complex proteins in mTORC1 and macroautophagy regulation. Matrix Biol 2021; 100-101:65-83. [DOI: 10.1016/j.matbio.2021.01.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 01/02/2021] [Accepted: 01/02/2021] [Indexed: 12/15/2022]
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Alboushi L, Hackett AP, Naeli P, Bakhti M, Jafarnejad SM. Multifaceted control of mRNA translation machinery in cancer. Cell Signal 2021; 84:110037. [PMID: 33975011 DOI: 10.1016/j.cellsig.2021.110037] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Accepted: 05/06/2021] [Indexed: 12/15/2022]
Abstract
The mRNA translation machinery is tightly regulated through several, at times overlapping, mechanisms that modulate its efficiency and accuracy. Due to their fast rate of growth and metabolism, cancer cells require an excessive amount of mRNA translation and protein synthesis. However, unfavorable conditions, such as hypoxia, amino acid starvation, and oxidative stress, which are abundant in cancer, as well as many anti-cancer treatments inhibit mRNA translation. Cancer cells adapt to the various internal and environmental stresses by employing specialised transcript-specific translation to survive and gain a proliferative advantage. We will highlight the major signaling pathways and mechanisms of translation that regulate the global or mRNA-specific translation in response to the intra- or extra-cellular signals and stresses that are key components in the process of tumourigenesis.
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Affiliation(s)
- Lilas Alboushi
- Patrick G. Johnston Centre for Cancer Research, Queen's University Belfast, Belfast, UK
| | - Angela P Hackett
- Patrick G. Johnston Centre for Cancer Research, Queen's University Belfast, Belfast, UK
| | - Parisa Naeli
- Patrick G. Johnston Centre for Cancer Research, Queen's University Belfast, Belfast, UK
| | - Mostafa Bakhti
- Institute of Diabetes and Regeneration Research, Helmholtz Zentrum München, 85764 Neuherberg, Germany
| | - Seyed Mehdi Jafarnejad
- Patrick G. Johnston Centre for Cancer Research, Queen's University Belfast, Belfast, UK.
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Abstract
mTORC1 is a central player in cell growth, a process that is tightly regulated by the availability of nutrients and that controls various aspects of metabolism in the normal cell and in severe diseases such as cancers. mTORC1 is a large multiprotein complex, composed of the kinase subunit mTOR, of Ragulator, which attaches mTOR to the lysosome membrane, of the atypical Rag GTPases and the small GTPase RheB, whose nucleotide states directly dictate its localization to the lysosome and its kinase activity, and of RAPTOR, an adaptor that assembles the complex. The activity of the Rag GTPases is further controlled by the GATOR1 and folliculin complexes, which regulate their GTP/GDP conversion. Here, we review recent structures of important components of the mTORC1 machinery, determined by cryo-electron microscopy for the most part, which allow to reconstitute the architecture of active mTORC1 at near atomic resolution. Notably, we discuss how these structures shed new light on the roles of Rag GTPases and their regulators in mTORC1 regulation, and the perspectives that they open towards understanding the inner workings of mTORC1 on the lysosomal membrane.
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Affiliation(s)
- Agata Nawrotek
- CNRS, LBPA, UMR 8113,École normale supérieure Paris-Saclay, Université Paris-Saclay, 4 avenue des Sciences, 91190 Gif-sur-Yvette, France
| | - Jacqueline Cherfils
- CNRS, LBPA, UMR 8113,École normale supérieure Paris-Saclay, Université Paris-Saclay, 4 avenue des Sciences, 91190 Gif-sur-Yvette, France
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