1
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Cao R, Guo S, Min L, Li P. Roles of Rictor alterations in gastrointestinal tumors (Review). Oncol Rep 2024; 51:37. [PMID: 38186315 PMCID: PMC10807360 DOI: 10.3892/or.2024.8696] [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: 04/05/2023] [Accepted: 11/28/2023] [Indexed: 01/09/2024] Open
Abstract
Gastrointestinal tumors account for five of the top 10 causes of mortality from all cancers (colorectal, liver, stomach, esophageal and pancreatic cancer). Mammalian target of rapamycin (mTOR) signaling is commonly dysregulated in various human cancers. As a core component of the mTOR complex 2 (mTORC2), Rictor is a key effector molecule of the PI3K/Akt pathway. A high alteration rate of Rictor has been observed in gastrointestinal tumors, and such Rictor alterations are often associated with resistance to chemotherapy and related adverse clinical outcomes. However, the exact roles of Rictor in gastrointestinal tumors remain elusive. The aim of the present study was to critically discuss the following: i) Mutation and biological characteristics of Rictor in tumors with a detailed overview of Rictor in cell proliferation, angiogenesis, apoptosis, autophagy and drug resistance; ii) the role of Rictor in tumors of the digestive system, particularly colorectal, hepatobiliary, gastric, esophageal and pancreatic cancer and cholangiocarcinoma; and iii) the current status and prospects of targeted therapy for Rictor by inhibiting Akt activation. Despite the growing realization of the importance of Rictor/mTORC2 in cancer, the underlying mechanistic details remain poorly understood; this needs to change in order for the development of efficient targeted therapies and re‑sensitization of therapy‑resistant cancers to be made possible.
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Affiliation(s)
- Ruizhen Cao
- Department of Gastroenterology, Beijing Friendship Hospital, Capital Medical University, National Clinical Research Center for Digestive Disease, Beijing Digestive Disease Center, Beijing Key Laboratory for Precancerous Lesion of Digestive Disease, Beijing 100050, P.R. China
- Department of Gastroenterology, Ordos Central Hospital, Ordos School of Clinical Medicine, Inner Mongolia Medical University, Ordos, Inner Mongolia 017000, P.R. China
| | - Shuilong Guo
- Department of Gastroenterology, Beijing Friendship Hospital, Capital Medical University, National Clinical Research Center for Digestive Disease, Beijing Digestive Disease Center, Beijing Key Laboratory for Precancerous Lesion of Digestive Disease, Beijing 100050, P.R. China
| | - Li Min
- Department of Gastroenterology, Beijing Friendship Hospital, Capital Medical University, National Clinical Research Center for Digestive Disease, Beijing Digestive Disease Center, Beijing Key Laboratory for Precancerous Lesion of Digestive Disease, Beijing 100050, P.R. China
| | - Peng Li
- Department of Gastroenterology, Beijing Friendship Hospital, Capital Medical University, National Clinical Research Center for Digestive Disease, Beijing Digestive Disease Center, Beijing Key Laboratory for Precancerous Lesion of Digestive Disease, Beijing 100050, P.R. China
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2
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Foltman M, Sanchez-Diaz A. TOR Complex 1: Orchestrating Nutrient Signaling and Cell Cycle Progression. Int J Mol Sci 2023; 24:15745. [PMID: 37958727 PMCID: PMC10647266 DOI: 10.3390/ijms242115745] [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: 09/01/2023] [Revised: 10/26/2023] [Accepted: 10/27/2023] [Indexed: 11/15/2023] Open
Abstract
The highly conserved TOR signaling pathway is crucial for coordinating cellular growth with the cell cycle machinery in eukaryotes. One of the two TOR complexes in budding yeast, TORC1, integrates environmental cues and promotes cell growth. While cells grow, they need to copy their chromosomes, segregate them in mitosis, divide all their components during cytokinesis, and finally physically separate mother and daughter cells to start a new cell cycle apart from each other. To maintain cell size homeostasis and chromosome stability, it is crucial that mechanisms that control growth are connected and coordinated with the cell cycle. Successive periods of high and low TORC1 activity would participate in the adequate cell cycle progression. Here, we review the known molecular mechanisms through which TORC1 regulates the cell cycle in the budding yeast Saccharomyces cerevisiae that have been extensively used as a model organism to understand the role of its mammalian ortholog, mTORC1.
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Affiliation(s)
- Magdalena Foltman
- Mechanisms and Regulation of Cell Division Research Unit, Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Universidad de Cantabria-CSIC, 39011 Santander, Spain
- Departamento de Biología Molecular, Facultad de Medicina, Universidad de Cantabria, 39011 Santander, Spain
| | - Alberto Sanchez-Diaz
- Mechanisms and Regulation of Cell Division Research Unit, Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Universidad de Cantabria-CSIC, 39011 Santander, Spain
- Departamento de Biología Molecular, Facultad de Medicina, Universidad de Cantabria, 39011 Santander, Spain
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3
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Zeng Y, Xiong C, Chen Y, Yang C, Li Q. Effects and mechanism of Rictor interference in podocyte injury induced by high glucose. Exp Ther Med 2023; 26:473. [PMID: 37753299 PMCID: PMC10518650 DOI: 10.3892/etm.2023.12172] [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] [Received: 08/14/2023] [Accepted: 07/07/2023] [Indexed: 09/28/2023] Open
Abstract
Rapamycin-insensitive companion of mTOR (Rictor) is a critical effector of mTOR protein complex 2 (mTORC2). The aim of the present study was to investigate the effect of Rictor in the mTORC2 signaling pathway in high glucose (HG)-induced diabetic podocyte injury by silencing the expression of Rictor. In the present study, mouse podocytes were treated with glucose (150 mM) and mannitol (200 mM), the Rictor gene was silenced using small interfering RNA (siRNA). Apoptosis was detected by flow cytometry, whereas podocyte cytoskeletal protein expression was detected by western blotting (WB) and immunofluorescence staining. The results demonstrated that, compared with that in the control group, the podocyte apoptotic rate was significantly increased in the mannitol group (negative group) and the groups that were treated with glucose (model groups). The podocyte apoptotic rate in the model + Rictor siRNA group was significantly decreased compared with that in the negative, model and the model glucose + siRNA negative control (NC) groups. WB indicated that the protein expression levels of podocalyxin and synaptopodin were reduced in the model and model + siRNA NC groups compared with those in the normal control and negative groups. Additionally, the protein expression levels of α-smooth muscle actin (α-SMA) and P-AKT/AKT were increased in the model and model + siRNA NC groups compared with the those in control and negative groups. Compared with those the model and model + siRNA NC groups, the protein expression levels of podocalyxin and synaptopodin were increased, whilst those of the α-SMA and P-AKT/AKT proteins were decreased, in the model + Rictor siRNA group. Results from immunofluorescence analysis were basically consistent with those of WB. Therefore, results of the present study suggest that silencing of the Rictor gene may reduce the damage to podocytes induced by HG, such that the Rictor/mTORC2 signaling pathway may be involved in the remodeling of podocyte actin cytoskeletal in diabetes.
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Affiliation(s)
- Yan Zeng
- Department of Nephrology, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, P.R. China
| | - Changbin Xiong
- Department of Nephrology, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, P.R. China
| | - Yinxiang Chen
- Department of Nephrology, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, P.R. China
| | - Chunyun Yang
- Department of Nephrology, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, P.R. China
| | - Qiuyue Li
- Department of Nephrology, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, P.R. China
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4
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Zhu XM, Li L, Bao JD, Wang JY, Liang S, Zhao LL, Huang CL, Yan JY, Cai YY, Wu XY, Dong B, Liu XH, Klionsky DJ, Lin FC. MoVast2 combined with MoVast1 regulates lipid homeostasis and autophagy in Magnaporthe oryzae. Autophagy 2023; 19:2353-2371. [PMID: 36803211 PMCID: PMC10351449 DOI: 10.1080/15548627.2023.2181739] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 02/10/2023] [Accepted: 02/13/2023] [Indexed: 02/22/2023] Open
Abstract
Macroautophagy/autophagy is an evolutionarily conserved biological process among eukaryotes that degrades unwanted materials such as protein aggregates, damaged mitochondria and even viruses to maintain cell survival. Our previous studies have demonstrated that MoVast1 acts as an autophagy regulator regulating autophagy, membrane tension, and sterol homeostasis in rice blast fungus. However, the detailed regulatory relationships between autophagy and VASt domain proteins remain unsolved. Here, we identified another VASt domain-containing protein, MoVast2, and further uncovered the regulatory mechanism of MoVast2 in M. oryzae. MoVast2 interacted with MoVast1 and MoAtg8, and colocalized at the PAS and deletion of MoVAST2 results in inappropriate autophagy progress. Through TOR activity analysis, sterols and sphingolipid content detection, we found high sterol accumulation in the ΔMovast2 mutant, whereas this mutant showed low sphingolipids and low activity of both TORC1 and TORC2. In addition, MoVast2 colocalized with MoVast1. The localization of MoVast2 in the MoVAST1 deletion mutant was normal; however, deletion of MoVAST2 leads to mislocalization of MoVast1. Notably, the wide-target lipidomic analyses revealed significant changes in sterols and sphingolipids, the major PM components, in the ΔMovast2 mutant, which was involved in lipid metabolism and autophagic pathways. These findings confirmed that the functions of MoVast1 were regulated by MoVast2, revealing that MoVast2 combined with MoVast1 maintained lipid homeostasis and autophagy balance by regulating TOR activity in M. oryzae.
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Affiliation(s)
- Xue-Ming Zhu
- State Key Laboratory for Managing Biotic and Chemical Treats to the Quality and Safety of Agro-products, Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou, Zhejiang, China
| | - Lin Li
- State Key Laboratory for Managing Biotic and Chemical Treats to the Quality and Safety of Agro-products, Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou, Zhejiang, China
| | - Jian-Dong Bao
- State Key Laboratory for Managing Biotic and Chemical Treats to the Quality and Safety of Agro-products, Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou, Zhejiang, China
| | - Jiao-Yu Wang
- State Key Laboratory for Managing Biotic and Chemical Treats to the Quality and Safety of Agro-products, Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou, Zhejiang, China
| | - Shuang Liang
- State Key Laboratory for Managing Biotic and Chemical Treats to the Quality and Safety of Agro-products, Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou, Zhejiang, China
| | - Li-Li Zhao
- State Key Laboratory for Managing Biotic and Chemical Treats to the Quality and Safety of Agro-products, Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou, Zhejiang, China
| | - Chang-Li Huang
- State Key Laboratory for Managing Biotic and Chemical Treats to the Quality and Safety of Agro-products, Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou, Zhejiang, China
| | - Jiong-Yi Yan
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang, China
| | - Ying-Ying Cai
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang, China
| | - Xi-Yu Wu
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang, China
| | - Bo Dong
- Markey Cancer Center, University of Kentucky, College of Medicine, Lexington, KY, USA
| | - Xiao-Hong Liu
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang, China
| | - Daniel J. Klionsky
- Life Sciences Institute and Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - Fu-Cheng Lin
- State Key Laboratory for Managing Biotic and Chemical Treats to the Quality and Safety of Agro-products, Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou, Zhejiang, China
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang, China
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5
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Gutiérrez-Santiago F, Navarro F. Transcription by the Three RNA Polymerases under the Control of the TOR Signaling Pathway in Saccharomyces cerevisiae. Biomolecules 2023; 13:biom13040642. [PMID: 37189389 DOI: 10.3390/biom13040642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 03/30/2023] [Accepted: 04/02/2023] [Indexed: 04/05/2023] Open
Abstract
Ribosomes are the basis for protein production, whose biogenesis is essential for cells to drive growth and proliferation. Ribosome biogenesis is highly regulated in accordance with cellular energy status and stress signals. In eukaryotic cells, response to stress signals and the production of newly-synthesized ribosomes require elements to be transcribed by the three RNA polymerases (RNA pols). Thus, cells need the tight coordination of RNA pols to adjust adequate components production for ribosome biogenesis which depends on environmental cues. This complex coordination probably occurs through a signaling pathway that links nutrient availability with transcription. Several pieces of evidence strongly support that the Target of Rapamycin (TOR) pathway, conserved among eukaryotes, influences the transcription of RNA pols through different mechanisms to ensure proper ribosome components production. This review summarizes the connection between TOR and regulatory elements for the transcription of each RNA pol in the budding yeast Saccharomyces cerevisiae. It also focuses on how TOR regulates transcription depending on external cues. Finally, it discusses the simultaneous coordination of the three RNA pols through common factors regulated by TOR and summarizes the most important similarities and differences between S. cerevisiae and mammals.
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Affiliation(s)
- Francisco Gutiérrez-Santiago
- Departamento de Biología Experimental-Genética, Universidad de Jaén, Paraje de las Lagunillas, s/n, E-23071 Jaén, Spain
| | - Francisco Navarro
- Departamento de Biología Experimental-Genética, Universidad de Jaén, Paraje de las Lagunillas, s/n, E-23071 Jaén, Spain
- Centro de Estudios Avanzados en Aceite de Oliva y Olivar, Universidad de Jaén, Paraje de las Lagunillas, s/n, E-23071 Jaén, Spain
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6
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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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7
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Ren L, Ren Q, Wang J, He Y, Deng H, Wang X, Liu C. miR-199a-3p promotes gastric cancer progression by promoting its stemness potential via DDR2 mediation. Cell Signal 2023; 106:110636. [PMID: 36813149 DOI: 10.1016/j.cellsig.2023.110636] [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: 10/29/2022] [Revised: 02/04/2023] [Accepted: 02/17/2023] [Indexed: 02/22/2023]
Abstract
BACKGROUND Peritoneal metastasis (PM) is an independent prognostic factor in gastric cancer (GC), however, the underlying mechanisms of PM occurrence remain unclear. METHOD The roles of DDR2 were investigated in GC and its potential relationship to PM, and orthotopic implants into nude mice were performed to assess the biological effects of DDR2 on PM. RESULTS Herein, DDR2 level is more significantly observed to elevate in PM lesion than the primary lesion. GC with DDR2-high expression evokes a worse overall survival (OS) in TCGA, similar results of the gloomy OS with high DDR2 levels are clarified via the stratifying stage of TNM. The conspicuously increased expression of DDR2 was found in GC cell lines, luciferase reporter assays verified that miR-199a-3p directly targeted DDR2 gene, which was correlated to tumor progression. We ulteriorly observed DDR2 participated in GC stemness maintenance via mediating pluripotency factor SOX2 expression and implicated in autophagy and DNA damage of cancer stem cells (CSCs). In particular, DDR2 dominated EMT programming through recruiting NFATc1-SOX2 complex to Snai1 in governing cell progression, controlling by DDR2-mTOR-SOX2 axis in SGC-7901 CSCs. Furthermore, DDR2 promoted the tumor peritoneal dissemination in gastric xenograft mouse model. CONCLUSION Phenotype screens and disseminated verifications incriminating in GC exposit the miR-199a-3p-DDR2-mTOR-SOX2 axis as a clinically actionable target for tumor PM progression. The herein-reported DDR2-based underlying axis in GC represents novel and potent tools for studying the mechanisms of PM.
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Affiliation(s)
- Lei Ren
- Department of General Surgery (Gastrointestinal Surgery), The Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan, China; Department of Surgery, Klinikum rechts der Isar, Technical University of Munich, School of Medicine, Munich, Germany
| | - Qiang Ren
- Department of Respiratory and Critical Care Medicine, The Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan, China
| | - Jianmei Wang
- Department of Pathology, The Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan, China
| | - Yonghong He
- Department of Respiratory and Critical Care Medicine, The Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan, China
| | - Hong Deng
- Department of General Surgery (Gastrointestinal Surgery), The Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan, China
| | - Xing Wang
- Inflammation and Allergic Research Unit, The Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan, China
| | - Chunfeng Liu
- Department of Respiratory and Critical Care Medicine, The Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan, China; Inflammation and Allergic Research Unit, The Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan, China; Experimental and Molecular Pathology, Institute of Pathology, Ludwig-Maximilians-University, Thalkirchner Str. 36, Munich 80336, Germany.
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8
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Jiang X, Liu K, Jiang H, Yin H, Wang ED, Cheng H, Yuan F, Xiao F, Wang F, Lu W, Peng B, Shu Y, Li X, Chen S, Guo F. SLC7A14 imports GABA to lysosomes and impairs hepatic insulin sensitivity via inhibiting mTORC2. Cell Rep 2023; 42:111984. [PMID: 36640347 DOI: 10.1016/j.celrep.2022.111984] [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: 06/07/2022] [Revised: 10/11/2022] [Accepted: 12/22/2022] [Indexed: 01/12/2023] Open
Abstract
Lysosomal amino acid accumulation is implicated in several diseases, but its role in insulin resistance, the central mechanism to type 2 diabetes and many metabolic diseases, is unclear. In this study, we show the hepatic expression of lysosomal membrane protein solute carrier family 7 member 14 (SLC7A14) is increased in insulin-resistant mice. The promoting effect of SLC7A14 on insulin resistance is demonstrated by loss- and gain-of-function experiments. SLC7A14 is further demonstrated as a transporter resulting in the accumulation of lysosomal γ-aminobutyric acid (GABA), which induces insulin resistance via inhibiting mTOR complex 2 (mTORC2)'s activity. These results establish a causal link between lysosomal amino acids and insulin resistance and suggest that SLC7A14 inhibition may provide a therapeutic strategy in treating insulin resistance-related and GABA-related diseases and may provide insights into the upstream mechanisms for mTORC2, the master regulator in many important processes.
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Affiliation(s)
- Xiaoxue Jiang
- Zhongshan Hospital, State Key Laboratory of Medical Neurobiology, Institute for Translational Brain Research, MOE Frontiers Center for Brain Science, Fudan University, 131 Dong'an Road, Shanghai 200032, China
| | - Kan Liu
- CAS Key Laboratory of Nutrition, Metabolism and Food Safety, Innovation Center for Intervention of Chronic Disease and Promotion of Health, Shanghai Institute of Nutrition and Health, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Haizhou Jiang
- CAS Key Laboratory of Nutrition, Metabolism and Food Safety, Innovation Center for Intervention of Chronic Disease and Promotion of Health, Shanghai Institute of Nutrition and Health, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Hanrui Yin
- CAS Key Laboratory of Nutrition, Metabolism and Food Safety, Innovation Center for Intervention of Chronic Disease and Promotion of Health, Shanghai Institute of Nutrition and Health, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - En-Duo Wang
- State Key Laboratory of Molecular Biology, Shanghai Key Laboratory of Molecular Andrology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai 200031, China
| | - Hong Cheng
- State Key Laboratory of Molecular Biology, Shanghai Key Laboratory of Molecular Andrology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai 200031, China
| | - Feixiang Yuan
- Zhongshan Hospital, State Key Laboratory of Medical Neurobiology, Institute for Translational Brain Research, MOE Frontiers Center for Brain Science, Fudan University, 131 Dong'an Road, Shanghai 200032, China
| | - Fei Xiao
- Zhongshan Hospital, State Key Laboratory of Medical Neurobiology, Institute for Translational Brain Research, MOE Frontiers Center for Brain Science, Fudan University, 131 Dong'an Road, Shanghai 200032, China
| | - Fenfen Wang
- CAS Key Laboratory of Nutrition, Metabolism and Food Safety, Innovation Center for Intervention of Chronic Disease and Promotion of Health, Shanghai Institute of Nutrition and Health, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Wei Lu
- Zhongshan Hospital, State Key Laboratory of Medical Neurobiology, Institute for Translational Brain Research, MOE Frontiers Center for Brain Science, Fudan University, 131 Dong'an Road, Shanghai 200032, China
| | - Bo Peng
- Zhongshan Hospital, State Key Laboratory of Medical Neurobiology, Institute for Translational Brain Research, MOE Frontiers Center for Brain Science, Fudan University, 131 Dong'an Road, Shanghai 200032, China
| | - Yousheng Shu
- Zhongshan Hospital, State Key Laboratory of Medical Neurobiology, Institute for Translational Brain Research, MOE Frontiers Center for Brain Science, Fudan University, 131 Dong'an Road, Shanghai 200032, China
| | - Xiaoying Li
- Zhongshan Hospital, State Key Laboratory of Medical Neurobiology, Institute for Translational Brain Research, MOE Frontiers Center for Brain Science, Fudan University, 131 Dong'an Road, Shanghai 200032, China
| | - Shanghai Chen
- Zhongshan Hospital, State Key Laboratory of Medical Neurobiology, Institute for Translational Brain Research, MOE Frontiers Center for Brain Science, Fudan University, 131 Dong'an Road, Shanghai 200032, China
| | - Feifan Guo
- Zhongshan Hospital, State Key Laboratory of Medical Neurobiology, Institute for Translational Brain Research, MOE Frontiers Center for Brain Science, Fudan University, 131 Dong'an Road, Shanghai 200032, China; CAS Key Laboratory of Nutrition, Metabolism and Food Safety, Innovation Center for Intervention of Chronic Disease and Promotion of Health, Shanghai Institute of Nutrition and Health, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200031, China.
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9
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Sun Y, Wang H, Qu T, Luo J, An P, Ren F, Luo Y, Li Y. mTORC2: a multifaceted regulator of autophagy. Cell Commun Signal 2023; 21:4. [PMID: 36604720 PMCID: PMC9814435 DOI: 10.1186/s12964-022-00859-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Accepted: 03/06/2022] [Indexed: 01/06/2023] Open
Abstract
Autophagy is a multi-step catabolic process that delivers cellular components to lysosomes for degradation and recycling. The dysregulation of this precisely controlled process disrupts cellular homeostasis and leads to many pathophysiological conditions. The mechanistic target of rapamycin (mTOR) is a central nutrient sensor that integrates growth signals with anabolism to fulfil biosynthetic and bioenergetic requirements. mTOR nucleates two distinct evolutionarily conserved complexes (mTORC1 and mTORC2). However, only mTORC1 is acutely inhibited by rapamycin. Consequently, mTORC1 is a well characterized regulator of autophagy. While less is known about mTORC2, the availability of acute small molecule inhibitors and multiple genetic models has led to increased understanding about the role of mTORC2 in autophagy. Emerging evidence suggests that the regulation of mTORC2 in autophagy is mainly through its downstream effector proteins, and is variable under different conditions and cellular contexts. Here, we review recent advances that describe a role for mTORC2 in this catabolic process, and propose that mTORC2 could be a potential clinical target for the treatment of autophagy-related diseases. Video abstract.
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Affiliation(s)
- Yanan Sun
- grid.22935.3f0000 0004 0530 8290Key Laboratory of Precision Nutrition and Food Quality, Department of Nutrition and Health, China Agricultural University, Beijing, 100083 China
| | - Huihui Wang
- grid.411734.40000 0004 1798 5176College of Food Science and Engineering, Gansu Agricultural University, Lanzhou, 730070 China
| | - Taiqi Qu
- grid.22935.3f0000 0004 0530 8290Key Laboratory of Precision Nutrition and Food Quality, Department of Nutrition and Health, China Agricultural University, Beijing, 100083 China
| | - Junjie Luo
- grid.22935.3f0000 0004 0530 8290Key Laboratory of Precision Nutrition and Food Quality, Department of Nutrition and Health, China Agricultural University, Beijing, 100083 China
| | - Peng An
- grid.22935.3f0000 0004 0530 8290Key Laboratory of Precision Nutrition and Food Quality, Department of Nutrition and Health, China Agricultural University, Beijing, 100083 China
| | - Fazheng Ren
- grid.22935.3f0000 0004 0530 8290Key Laboratory of Precision Nutrition and Food Quality, Department of Nutrition and Health, China Agricultural University, Beijing, 100083 China
| | - Yongting Luo
- grid.22935.3f0000 0004 0530 8290Key Laboratory of Precision Nutrition and Food Quality, Department of Nutrition and Health, China Agricultural University, Beijing, 100083 China
| | - Yixuan Li
- grid.22935.3f0000 0004 0530 8290Key Laboratory of Precision Nutrition and Food Quality, Department of Nutrition and Health, China Agricultural University, Beijing, 100083 China
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10
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TOR complex 2 is a master regulator of plasma membrane homeostasis. Biochem J 2022; 479:1917-1940. [PMID: 36149412 PMCID: PMC9555796 DOI: 10.1042/bcj20220388] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 08/30/2022] [Accepted: 09/01/2022] [Indexed: 11/17/2022]
Abstract
As first demonstrated in budding yeast (Saccharomyces cerevisiae), all eukaryotic cells contain two, distinct multi-component protein kinase complexes that each harbor the TOR (Target Of Rapamycin) polypeptide as the catalytic subunit. These ensembles, dubbed TORC1 and TORC2, function as universal, centrally important sensors, integrators, and controllers of eukaryotic cell growth and homeostasis. TORC1, activated on the cytosolic surface of the lysosome (or, in yeast, on the cytosolic surface of the vacuole), has emerged as a primary nutrient sensor that promotes cellular biosynthesis and suppresses autophagy. TORC2, located primarily at the plasma membrane, plays a major role in maintaining the proper levels and bilayer distribution of all plasma membrane components (sphingolipids, glycerophospholipids, sterols, and integral membrane proteins). This article surveys what we have learned about signaling via the TORC2 complex, largely through studies conducted in S. cerevisiae. In this yeast, conditions that challenge plasma membrane integrity can, depending on the nature of the stress, stimulate or inhibit TORC2, resulting in, respectively, up-regulation or down-regulation of the phosphorylation and thus the activity of its essential downstream effector the AGC family protein kinase Ypk1. Through the ensuing effect on the efficiency with which Ypk1 phosphorylates multiple substrates that control diverse processes, membrane homeostasis is maintained. Thus, the major focus here is on TORC2, Ypk1, and the multifarious targets of Ypk1 and how the functions of these substrates are regulated by their Ypk1-mediated phosphorylation, with emphasis on recent advances in our understanding of these processes.
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11
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Jiménez-Gutiérrez E, Fernández-Acero T, Alonso-Rodríguez E, Molina M, Martín H. Neomycin Interferes with Phosphatidylinositol-4,5-Bisphosphate at the Yeast Plasma Membrane and Activates the Cell Wall Integrity Pathway. Int J Mol Sci 2022; 23:ijms231911034. [PMID: 36232332 PMCID: PMC9569482 DOI: 10.3390/ijms231911034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Revised: 09/14/2022] [Accepted: 09/15/2022] [Indexed: 11/20/2022] Open
Abstract
The cell wall integrity pathway (CWI) is a MAPK-mediated signaling route essential for yeast cell response to cell wall damage, regulating distinct aspects of fungal physiology. We have recently proven that the incorporation of a genetic circuit that operates as a signal amplifier into this pathway allows for the identification of novel elements involved in CWI signaling. Here, we show that the strong growth inhibition triggered by pathway hyperactivation in cells carrying the “Integrity Pathway Activation Circuit” (IPAC) also allows the easy identification of new stimuli. By using the IPAC, we have found various chemical agents that activate the CWI pathway, including the aminoglycoside neomycin. Cells lacking key components of this pathway are sensitive to this antibiotic, due to the disruption of signaling upon neomycin stimulation. Neomycin reduces both phosphatidylinositol-4,5-bisphosphate (PIP2) availability at the plasma membrane and myriocin-induced TORC2-dependent Ypk1 phosphorylation, suggesting a strong interference with plasma membrane homeostasis, specifically with PIP2. The neomycin-induced transcriptional profile involves not only genes related to stress and cell wall biogenesis, but also to amino acid metabolism, reflecting the action of this antibiotic on the yeast ribosome.
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Affiliation(s)
| | | | | | - María Molina
- Correspondence: (M.M.); (H.M.); Tel.: +34-91-394-1888 (M.M. & H.M.)
| | - Humberto Martín
- Correspondence: (M.M.); (H.M.); Tel.: +34-91-394-1888 (M.M. & H.M.)
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12
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Yu Z, Chen J, Takagi E, Wang F, Saha B, Liu X, Joubert LM, Gleason CE, Jin M, Li C, Nowotny C, Agard D, Cheng Y, Pearce D. Interactions between mTORC2 core subunits Rictor and mSin1 dictate selective and context-dependent phosphorylation of substrate kinases SGK1 and Akt. J Biol Chem 2022; 298:102288. [PMID: 35926713 PMCID: PMC9440446 DOI: 10.1016/j.jbc.2022.102288] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 07/04/2022] [Accepted: 07/05/2022] [Indexed: 12/02/2022] Open
Abstract
Mechanistic target of rapamycin complex 2 (mTORC2) is a multi-subunit kinase complex, central to multiple essential signaling pathways. Two core subunits, Rictor and mSin1, distinguish it from the related mTORC1 and support context-dependent phosphorylation of its substrates. mTORC2 structures have been determined previously; however, important questions remain, particularly regarding the structural determinants mediating substrate specificity and context-dependent activity. Here, we used cryo-EM to obtain high-resolution structures of the human mTORC2 apo-complex in the presence of substrates Akt and SGK1. Using functional assays, we then tested predictions suggested by substrate-induced structural changes in mTORC2. For the first time, we visualized in the apo-state the side chain interactions between Rictor and mTOR that sterically occlude recruitment of mTORC1 substrates and confer resistance to the mTORC1 inhibitor rapamycin. Also in the apo-state, we observed that mSin1 formed extensive contacts with Rictor via a pair of short α-helices nestled between two Rictor helical repeat clusters, as well as by an extended strand that makes multiple weak contacts with Rictor helical cluster 1. In co-complex structures, we found that SGK1, but not Akt, markedly altered the conformation of the mSin1 N-terminal extended strand, disrupting multiple weak interactions while inducing a large rotation of mSin1 residue Arg-83, which then interacts with a patch of negatively charged residues within Rictor. Finally, we demonstrate mutation of Arg-83 to Ala selectively disrupts mTORC2-dependent phosphorylation of SGK1, but not of Akt, supporting context-dependent substrate selection. These findings provide new structural and functional insights into mTORC2 specificity and context-dependent activity.
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Affiliation(s)
- Zanlin Yu
- Department of Biochemistry and Biophysics, University of California, San Francisco, California, USA
| | - Junliang Chen
- Department of Medicine, Division of Nephrology, and Department of Cellular and Molecular Pharmacology, UCSF, San Francisco, California, USA
| | - Enzo Takagi
- Department of Medicine, Division of Nephrology, and Department of Cellular and Molecular Pharmacology, UCSF, San Francisco, California, USA
| | - Feng Wang
- Department of Biochemistry and Biophysics, University of California, San Francisco, California, USA
| | - Bidisha Saha
- Department of Medicine, Division of Nephrology, and Department of Cellular and Molecular Pharmacology, UCSF, San Francisco, California, USA
| | - Xi Liu
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, California, USA
| | - Lydia-Marie Joubert
- Division of CryoEM and Bioimaging, SSRL, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, California, USA
| | - Catherine E Gleason
- Department of Medicine, Division of Nephrology, and Department of Cellular and Molecular Pharmacology, UCSF, San Francisco, California, USA
| | - Mingliang Jin
- Department of Biochemistry and Biophysics, University of California, San Francisco, California, USA
| | - Chengmin Li
- Department of Biochemistry and Biophysics, University of California, San Francisco, California, USA
| | - Carlos Nowotny
- Department of Biochemistry and Biophysics, University of California, San Francisco, California, USA
| | - David Agard
- Department of Biochemistry and Biophysics, University of California, San Francisco, California, USA
| | - Yifan Cheng
- Department of Biochemistry and Biophysics, University of California, San Francisco, California, USA; Howard Hughes Medical Institute, University of California San Francisco, San Francisco, California, USA
| | - David Pearce
- Department of Medicine, Division of Nephrology, and Department of Cellular and Molecular Pharmacology, UCSF, San Francisco, California, USA.
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13
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Nicastro R, Gaillard H, Zarzuela L, Péli-Gulli MP, Fernández-García E, Tomé M, García-Rodríguez N, Durán RV, De Virgilio C, Wellinger RE. Manganese is a physiologically relevant TORC1 activator in yeast and mammals. eLife 2022; 11:80497. [PMID: 35904415 PMCID: PMC9337852 DOI: 10.7554/elife.80497] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2022] [Accepted: 07/18/2022] [Indexed: 12/09/2022] Open
Abstract
The essential biometal manganese (Mn) serves as a cofactor for several enzymes that are crucial for the prevention of human diseases. Whether intracellular Mn levels may be sensed and modulate intracellular signaling events has so far remained largely unexplored. The highly conserved target of rapamycin complex 1 (TORC1, mTORC1 in mammals) protein kinase requires divalent metal cofactors such as magnesium (Mg2+) to phosphorylate effectors as part of a homeostatic process that coordinates cell growth and metabolism with nutrient and/or growth factor availability. Here, our genetic approaches reveal that TORC1 activity is stimulated in vivo by elevated cytoplasmic Mn levels, which can be induced by loss of the Golgi-resident Mn2+ transporter Pmr1 and which depend on the natural resistance-associated macrophage protein (NRAMP) metal ion transporters Smf1 and Smf2. Accordingly, genetic interventions that increase cytoplasmic Mn2+ levels antagonize the effects of rapamycin in triggering autophagy, mitophagy, and Rtg1-Rtg3-dependent mitochondrion-to-nucleus retrograde signaling. Surprisingly, our in vitro protein kinase assays uncovered that Mn2+ activates TORC1 substantially better than Mg2+, which is primarily due to its ability to lower the Km for ATP, thereby allowing more efficient ATP coordination in the catalytic cleft of TORC1. These findings, therefore, provide both a mechanism to explain our genetic observations in yeast and a rationale for how fluctuations in trace amounts of Mn can become physiologically relevant. Supporting this notion, TORC1 is also wired to feedback control mechanisms that impinge on Smf1 and Smf2. Finally, we also show that Mn2+-mediated control of TORC1 is evolutionarily conserved in mammals, which may prove relevant for our understanding of the role of Mn in human diseases.
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Affiliation(s)
- Raffaele Nicastro
- University of Fribourg, Department of Biology, Fribourg, Switzerland
| | - Hélène Gaillard
- Centro Andaluz de Biología Molecular y Medicina Regenerativa - CABIMER, Consejo Superior de Investigaciones Científicas, Universidad de Sevilla, Seville, Spain.,Departamento de Genética, Facultad de Biología, Universidad de Sevilla, Seville, Spain
| | - Laura Zarzuela
- Centro Andaluz de Biología Molecular y Medicina Regenerativa - CABIMER, Consejo Superior de Investigaciones Científicas, Universidad de Sevilla, Seville, Spain
| | | | - Elisabet Fernández-García
- Centro Andaluz de Biología Molecular y Medicina Regenerativa - CABIMER, Consejo Superior de Investigaciones Científicas, Universidad de Sevilla, Seville, Spain.,Departamento de Genética, Facultad de Biología, Universidad de Sevilla, Seville, Spain
| | - Mercedes Tomé
- Centro Andaluz de Biología Molecular y Medicina Regenerativa - CABIMER, Consejo Superior de Investigaciones Científicas, Universidad de Sevilla, Seville, Spain
| | - Néstor García-Rodríguez
- Centro Andaluz de Biología Molecular y Medicina Regenerativa - CABIMER, Consejo Superior de Investigaciones Científicas, Universidad de Sevilla, Seville, Spain.,Departamento de Genética, Facultad de Biología, Universidad de Sevilla, Seville, Spain
| | - Raúl V Durán
- Centro Andaluz de Biología Molecular y Medicina Regenerativa - CABIMER, Consejo Superior de Investigaciones Científicas, Universidad de Sevilla, Seville, Spain
| | | | - Ralf Erik Wellinger
- Centro Andaluz de Biología Molecular y Medicina Regenerativa - CABIMER, Consejo Superior de Investigaciones Científicas, Universidad de Sevilla, Seville, Spain.,Departamento de Genética, Facultad de Biología, Universidad de Sevilla, Seville, Spain
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14
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Yin X, Xue R, Wu J, Wu M, Xie B, Meng Q. PINK1 ameliorates acute-on-chronic liver failure by inhibiting apoptosis through mTORC2/AKT signaling. Cell Death Dis 2022; 8:222. [PMID: 35461334 PMCID: PMC9035184 DOI: 10.1038/s41420-022-01021-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 04/06/2022] [Accepted: 04/07/2022] [Indexed: 11/09/2022]
Abstract
Acute-on-chronic liver failure (ACLF) is a lethal syndrome with a remarkable short-term death rate. Even worse, effective internal medicine therapies are currently lacking. Increasing evidence indicates apoptosis plays a critical role in the progression of liver failure. PINK1 has an essential function in maintaining cell survival. However, the role and underlying mechanism of PINK1 in apoptosis in ACLF are incompletely understood. Herein, our team discovered that PINK1 remarkably improved ACLF, featured by a reduction in aspartate aminotransferase (AST) and alanine aminotransferase (ALT) and an amelioration in the gross and microscopy histopathology appearance of hepatic tissues. Meanwhile, PINK1 affected cleaved caspase-3 expression via mTORC2/AKT, and this effect was eliminated after further intervention with Rictor or AKT. Overall, these findings indicate that PINK1 participates in the regulation of multiple biological functions, including hepatic cell growth and apoptosis in ACLF via the mTORC2/AKT signaling pathway. The present research offers a solid theory-wise foundation for the clinic applications of PINK1 as a valid target for ACLF treatment to reverse or postpone the development of ACLF.
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Affiliation(s)
- Xuehong Yin
- Department of Critical Care Medicine of Liver Disease, Beijing You-An Hospital, Capital Medical University, Beijing, China
| | - Ran Xue
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Gastrointestinal Oncology, Peking University Cancer Hospital & Institute, Beijing, China
| | - Jing Wu
- Department of Critical Care Medicine of Liver Disease, Beijing You-An Hospital, Capital Medical University, Beijing, China
| | - Muchen Wu
- Department of Critical Care Medicine of Liver Disease, Beijing You-An Hospital, Capital Medical University, Beijing, China
| | - Bangxiang Xie
- Beijing Institute of Hepatology, Beijing You-An Hospital, Capital Medical University, Beijing, China.
| | - Qinghua Meng
- Department of Critical Care Medicine of Liver Disease, Beijing You-An Hospital, Capital Medical University, Beijing, China.
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15
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廖 晖, 王 毅, 徐 小, 周 陈, 张 健, 钟 克, 杨 定. [The dual mTORC1/2 inhibitor AZD2014 inhibits acute graft rejection in a rat liver transplantation model]. NAN FANG YI KE DA XUE XUE BAO = JOURNAL OF SOUTHERN MEDICAL UNIVERSITY 2022; 42:598-603. [PMID: 35527497 PMCID: PMC9085585 DOI: 10.12122/j.issn.1673-4254.2022.04.17] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 08/29/2021] [Indexed: 11/24/2022]
Abstract
OBJECTIVE To investigate the inhibitory effect of AZD2014, a dual mTORC1/2 inhibitor, against acute graft rejection in a rat model of allogeneic liver transplantation. METHODS Liver transplantation from Lewis rat to recipient BN rat (a donor-recipient combination that was prone to induce acute graft rejection) was performed using Kamada's two-cuff technique. The recipient BN rats were randomized into 2 groups for treatment with daily intraperitoneal injection of AZD2014 (5 mg/kg, n=4) or vehicle (2.5 mL/kg, n=4) for 14 consecutive days, starting from the first day after the transplantation. Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and total bilirubin (TBIL) levels of the rats were measured 3 days before and at 1, 3, 5, 7, 10, and 14 days after the transplantation, and the survival time of the rats within 14 days were recorded. Immunohistochemical staining was used to examine the expressions of CD3 and Foxp3 in the liver graft, and acute graft rejection was assessed using HE staining based on the Banff schema. RESULTS Three rats in the control group died within 14 days after the surgery, while no death occurred in the AZD2014 group, demonstrating a significantly longer survival time of the rats in AZD2014 group (χ2=4.213, P=0.04). Serum ALT, AST and TBIL levels in the control group increased progressively after the surgery and were all significantly higher than those in AZD2014 group at the same time point (P < 0.05). Pathological examination revealed significantly worse liver graft rejection in the control group than in AZD2014 group based on assessment of the rejection index (P < 0.01); the rats in the control group showed more serious T lymphocyte infiltration and significantly fewer Treg cells in the liver graft than those in AZD2014 group (P < 0.01). CONCLUSIONS AZD2014 can effectively inhibit acute graft rejection in rats with allogeneic liver transplantation.
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Affiliation(s)
- 晖 廖
- 南方医科大学珠江医院肝胆二科,广东 广州 510280Second Department of Hepatobiliary Surgery, Zhujiang Hospital, Southern Medical University, Guangzhou 510280, China
| | - 毅 王
- 南方医科大学珠江医院肝胆二科,广东 广州 510280Second Department of Hepatobiliary Surgery, Zhujiang Hospital, Southern Medical University, Guangzhou 510280, China
| | - 小平 徐
- 南方医科大学珠江医院肝胆二科,广东 广州 510280Second Department of Hepatobiliary Surgery, Zhujiang Hospital, Southern Medical University, Guangzhou 510280, China
| | - 陈杰 周
- 南方医科大学珠江医院肝胆二科,广东 广州 510280Second Department of Hepatobiliary Surgery, Zhujiang Hospital, Southern Medical University, Guangzhou 510280, China
| | - 健民 张
- 南方医科大学珠江医院肝胆二科,广东 广州 510280Second Department of Hepatobiliary Surgery, Zhujiang Hospital, Southern Medical University, Guangzhou 510280, China
| | - 克波 钟
- 南方医科大学珠江医院肝胆二科,广东 广州 510280Second Department of Hepatobiliary Surgery, Zhujiang Hospital, Southern Medical University, Guangzhou 510280, China
| | - 定华 杨
- 南方医科大学南方医院肝胆外科,广东 广州 510515Department of Hepatobiliary Surgery, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China
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16
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Surya A, Sarinay-Cenik E. Cell autonomous and non-autonomous consequences of deviations in translation machinery on organism growth and the connecting signalling pathways. Open Biol 2022; 12:210308. [PMID: 35472285 PMCID: PMC9042575 DOI: 10.1098/rsob.210308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Accepted: 03/31/2022] [Indexed: 01/09/2023] Open
Abstract
Translation machinery is responsible for the production of cellular proteins; thus, cells devote the majority of their resources to ribosome biogenesis and protein synthesis. Single-copy loss of function in the translation machinery components results in rare ribosomopathy disorders, such as Diamond-Blackfan anaemia in humans and similar developmental defects in various model organisms. Somatic copy number alterations of translation machinery components are also observed in specific tumours. The organism-wide response to haploinsufficient loss-of-function mutations in ribosomal proteins or translation machinery components is complex: variations in translation machinery lead to reduced ribosome biogenesis, protein translation and altered protein homeostasis and cellular signalling pathways. Cells are affected both autonomously and non-autonomously by changes in translation machinery or ribosome biogenesis through cell-cell interactions and secreted hormones. We first briefly introduce the model organisms where mutants or knockdowns of protein synthesis and ribosome biogenesis are characterized. Next, we specifically describe observations in Caenorhabditis elegans and Drosophila melanogaster, where insufficient protein synthesis in a subset of cells triggers cell non-autonomous growth or apoptosis responses that affect nearby cells and tissues. We then cover the characterized signalling pathways that interact with ribosome biogenesis/protein synthesis machinery with an emphasis on their respective functions during organism development.
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Affiliation(s)
- Agustian Surya
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, USA
| | - Elif Sarinay-Cenik
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, USA
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17
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Lv N, Jin S, Liang Z, Wu X, Kang Y, Su L, Dong Y, Wang B, Ma T, Shi L. PP2Cδ Controls the Differentiation and Function of Dendritic Cells Through Regulating the NSD2/mTORC2/ACLY Pathway. Front Immunol 2022; 12:751409. [PMID: 35069527 PMCID: PMC8777276 DOI: 10.3389/fimmu.2021.751409] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2021] [Accepted: 12/16/2021] [Indexed: 12/29/2022] Open
Abstract
Dendritic cells (DCs) are recognized as a key orchestrator of immune response and homeostasis, deregulation of which may lead to autoimmunity such as experimental autoimmune encephalomyelitis (EAE). Herein we show that the phosphatase PP2Cδ played a pivotal role in regulating DC activation and function, as PP2Cδ ablation caused aberrant maturation, activation, and Th1/Th17-priming of DCs, and hence induced onset of exacerbated EAE. Mechanistically, PP2Cδ restrained the expression of the essential subunit of mTORC2, Rictor, primarily through de-phosphorylating and proteasomal degradation of the methyltransferase NSD2 via CRL4DCAF2 E3 ligase. Loss of PP2Cδ in DCs accordingly sustained activation of the Rictor/mTORC2 pathway and boosted glycolytic and mitochondrial metabolism. Consequently, ATP-citrate lyse (ACLY) was increasingly activated and catalyzed acetyl-CoA for expression of the genes compatible with hyperactivated DCs under PP2Cδ deletion. Collectively, our findings demonstrate that PP2Cδ has an essential role in controlling DCs activation and function, which is critical for prevention of autoimmunity.
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Affiliation(s)
- Nianyin Lv
- Department of Immunology, Nanjing University of Chinese Medicine, Nanjing, China
| | - Sufeng Jin
- Department of Clinical Laboratory, The Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, China.,Key Lab of Inflammation and Immunoregulation, Hangzhou Normal University School of Medicine, Hangzhou, China
| | - Zihao Liang
- Department of Immunology, Nanjing University of Chinese Medicine, Nanjing, China
| | - Xiaohui Wu
- Department of Immunology, Nanjing University of Chinese Medicine, Nanjing, China
| | - Yanhua Kang
- Department of Immunology, Nanjing University of Chinese Medicine, Nanjing, China.,Key Lab of Inflammation and Immunoregulation, Hangzhou Normal University School of Medicine, Hangzhou, China
| | - Lan Su
- Institute of Translational Medicine, Zhejiang Shuren University, Hangzhou, China
| | - Yeping Dong
- Institute of Translational Medicine, Zhejiang Shuren University, Hangzhou, China
| | - Bingwei Wang
- College of Medicine and Integrated Medicine, Nanjing University of Chinese Medicine, Nanjing, China
| | - Tonghui Ma
- College of Medicine and Integrated Medicine, Nanjing University of Chinese Medicine, Nanjing, China
| | - Liyun Shi
- Department of Immunology, Nanjing University of Chinese Medicine, Nanjing, China.,Institute of Translational Medicine, Zhejiang Shuren University, Hangzhou, China
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18
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Wang T, Woodman P, Humphrey SJ, Petersen J. Environmental control of Pub1 (NEDD4 family E3 ligase) in Schizosaccharomyces pombe is regulated by TORC2 and Gsk3. Life Sci Alliance 2022; 5:5/5/e202101082. [PMID: 35121625 PMCID: PMC8817228 DOI: 10.26508/lsa.202101082] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 01/24/2022] [Accepted: 01/25/2022] [Indexed: 11/24/2022] Open
Abstract
The NEDD4 family E3 ligase Pub1 is regulated by the nutrient environment, TORC2, and Gsk3 signalling pathway to control the level of amino acid transporters on the plasma membrane and thus nutrient uptake. Cells respond to changing nutrient environments by adjusting the abundance of surface nutrient transporters and receptors. This can be achieved by modulating ubiquitin-dependent endocytosis, which in part is regulated by the NEDD4 family of E3 ligases. Here we report novel regulation of Pub1, a fission yeast Schizosaccharomyces pombe member of the NEDD4-family of E3 ligases. We show that nitrogen stress inhibits Pub1 function, thereby increasing the abundance of the amino acid transporter Aat1 at the plasma membrane and enhancing sensitivity to the toxic arginine analogue canavanine. We show that TOR complex 2 (TORC2) signalling negatively regulates Pub1, thus TORC2 mutants under nutrient stress have decreased Aat1 at the plasma membrane and are resistant to canavanine. Inhibition of TORC2 signalling increases Pub1 phosphorylation, and this is dependent on Gsk3 activity. Addition of the Tor inhibitor Torin1 increases phosphorylation of Pub1 at serine 199 (S199) by 2.5-fold, and Pub1 protein levels in S199A phospho-ablated mutants are reduced. S199 is conserved in NEDD4 and is located immediately upstream of a WW domain required for protein interaction. Together, we describe how the major TORC2 nutrient-sensing signalling network regulates environmental control of Pub1 to modulate the abundance of nutrient transporters.
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Affiliation(s)
- Tingting Wang
- Flinders Health and Medical Research Institute, Flinders Centre for Innovation in Cancer, Flinders University, Adelaide, Australia
| | - Philip Woodman
- School of Biological Sciences, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, University of Manchester, Manchester, UK
| | - Sean J Humphrey
- Charles Perkins Centre, School of Life and Environmental Sciences, The University of Sydney, Camperdown, Australia
| | - Janni Petersen
- Flinders Health and Medical Research Institute, Flinders Centre for Innovation in Cancer, Flinders University, Adelaide, Australia
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19
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Arora M, Kutinová Canová N, Farghali H. mTOR as an eligible molecular target for possible pharmacological treatment of nonalcoholic steatohepatitis. Eur J Pharmacol 2022; 921:174857. [DOI: 10.1016/j.ejphar.2022.174857] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 02/07/2022] [Accepted: 02/22/2022] [Indexed: 12/14/2022]
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20
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EBV LMP1-activated mTORC1 and mTORC2 Coordinately Promote Nasopharyngeal Cancer Stem Cell Properties. J Virol 2022; 96:e0194121. [PMID: 35019715 DOI: 10.1128/jvi.01941-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Epstein-Barr Virus (EBV) is associated with several malignant diseases, including Burkitt's lymphoma, nasopharyngeal carcinoma (NPC), certain types of lymphomas, and a portion of gastric cancers. Virus-encoded oncoprotein LMP1 induces the epithelial-to-mesenchymal transition (EMT), leading to cancer stem cell formation. In the current study, we investigated how LMP1 contributes to cancer stem cell development in NPC. We found that LMP1 plays an essential role in acquiring CSC characteristics, including tumor initiation, metastasis, and therapeutic resistance by activating the PI3K/mTOR/Akt signaling pathway. We dissected the functions of distinct signaling (mTORC1 and mTORC2) in the acquisition of different CSC characteristics. Side population (SP) formation, which represents the chemotherapy resistance feature of CSC, requires mTORC1 signaling. Tumor initiation capability is mainly attributed to mTORC2, which confers on NPC the capabilities of proliferation and survival by activating mTORC2 downstream genes c-Myc. Both mTORC1 and mTORC2 enhance cell migration and invasion of NPC cells, suggesting that mTORC1/2 co-regulate metastasis of NPC. The revelation of the roles of the mTOR signaling pathways in distinct tumorigenic features provides a guideline for designing efficient therapies by choosing specific mTOR inhibitors targeting mTORC1, mTORC2, or both to achieve durable remission of NPC in patients. Importance LMP1 endows NPC to gain cancer stem cell characteristics through activating mTORC1 and mTORC2 pathways. The different mTOR pathways are responsible for distinct tumorigenic features. Rapamycin-insensitive mTORC1 is essential for CSC drug resistance. NPC tumor initiation capacity is mainly attributed to mTORC2 signaling. mTORC1 and mTORC2 co-regulate NPC cell migration and invasion. The revelation of the roles of mTOR signaling in NPC CSC establishment has implications for novel therapeutic strategies to treat relapsed and metastatic NPC and achieve durable remission.
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21
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Cells under pressure: how yeast cells respond to mechanical forces. Trends Microbiol 2022; 30:495-510. [PMID: 35000797 DOI: 10.1016/j.tim.2021.11.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 10/31/2021] [Accepted: 11/08/2021] [Indexed: 11/23/2022]
Abstract
In their natural habitats, unicellular fungal microbes are exposed to a myriad of mechanical cues such as shear forces from fluid flow, osmotic changes, and contact forces arising from microbial expansion in confined niches. While the rigidity of the cell wall is critical to withstand such external forces and balance high internal turgor pressure, it poses mechanical challenges during physiological processes such as cell growth, division, and mating that require cell wall remodeling. Thus, even organisms as simple as yeast have evolved complex signaling networks to sense and respond to intrinsic and extrinsic mechanical forces. In this review, we summarize the type and origin of mechanical forces experienced by unicellular yeast and discuss how these forces reorganize cell polarity and how pathogenic fungi exploit polarized assemblies to track weak spots in host tissues for successful penetration. We then describe mechanisms of force-sensing by conserved sets of mechanosensors. Finally, we elaborate downstream mechanotransduction mechanisms that orchestrate appropriate cellular responses, leading to improved mechanical fitness.
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22
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Segreto R, Bazafkan H, Millinger J, Schenk M, Atanasova L, Doppler M, Büschl C, Boeckstaens M, Soto Diaz S, Schreiner U, Sillo F, Balestrini R, Schuhmacher R, Zeilinger S. The TOR kinase pathway is relevant for nitrogen signaling and antagonism of the mycoparasite Trichoderma atroviride. PLoS One 2022; 16:e0262180. [PMID: 34972198 PMCID: PMC8719763 DOI: 10.1371/journal.pone.0262180] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Accepted: 12/18/2021] [Indexed: 01/14/2023] Open
Abstract
Trichoderma atroviride (Ascomycota, Sordariomycetes) is a well-known mycoparasite applied for protecting plants against fungal pathogens. Its mycoparasitic activity involves processes shared with plant and human pathogenic fungi such as the production of cell wall degrading enzymes and secondary metabolites and is tightly regulated by environmental cues. In eukaryotes, the conserved Target of Rapamycin (TOR) kinase serves as a central regulator of cellular growth in response to nutrient availability. Here we describe how alteration of the activity of TOR1, the single and essential TOR kinase of T. atroviride, by treatment with chemical TOR inhibitors or by genetic manipulation of selected TOR pathway components affected various cellular functions. Loss of TSC1 and TSC2, that are negative regulators of TOR complex 1 (TORC1) in mammalian cells, resulted in altered nitrogen source-dependent growth of T. atroviride, reduced mycoparasitic overgrowth and, in the case of Δtsc1, a diminished production of numerous secondary metabolites. Deletion of the gene encoding the GTPase RHE2, whose mammalian orthologue activates mTORC1, led to rapamycin hypersensitivity and altered secondary metabolism, but had an only minor effect on vegetative growth and mycoparasitic overgrowth. The latter also applied to mutants missing the npr1-1 gene that encodes a fungus-specific kinase known as TOR target in yeast. Genome-wide transcriptome analysis confirmed TOR1 as a regulatory hub that governs T. atroviride metabolism and processes associated to ribosome biogenesis, gene expression and translation. In addition, mycoparasitism-relevant genes encoding terpenoid and polyketide synthases, peptidases, glycoside hydrolases, small secreted cysteine-rich proteins, and G protein coupled receptors emerged as TOR1 targets. Our results provide the first in-depth insights into TOR signaling in a fungal mycoparasite and emphasize its importance in the regulation of processes that critically contribute to the antagonistic activity of T. atroviride.
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Affiliation(s)
- Rossana Segreto
- Department of Microbiology, University of Innsbruck, Innsbruck, Austria
| | - Hoda Bazafkan
- Department of Microbiology, University of Innsbruck, Innsbruck, Austria
| | - Julia Millinger
- Department of Microbiology, University of Innsbruck, Innsbruck, Austria
| | - Martina Schenk
- Department of Microbiology, University of Innsbruck, Innsbruck, Austria
| | - Lea Atanasova
- Institute of Food Technology, University of Natural Resources and Life Sciences (BOKU), Vienna, Austria
| | - Maria Doppler
- Department of Agrobiotechnology IFA-Tulln, Center for Analytical Chemistry, University of Natural, Resources and Life Sciences, Vienna (BOKU), Tulln, Austria
| | - Christoph Büschl
- Department of Agrobiotechnology IFA-Tulln, Center for Analytical Chemistry, University of Natural, Resources and Life Sciences, Vienna (BOKU), Tulln, Austria
| | - Mélanie Boeckstaens
- Département de Biologie Moléculaire, Laboratory of Biology of Membrane Transport, Université Libre de Bruxelles, Gosselies, Belgium
| | - Silvia Soto Diaz
- Département de Biologie Moléculaire, Laboratory of Biology of Membrane Transport, Université Libre de Bruxelles, Gosselies, Belgium
| | - Ulrike Schreiner
- Department of Microbiology, University of Innsbruck, Innsbruck, Austria
| | | | | | - Rainer Schuhmacher
- Department of Agrobiotechnology IFA-Tulln, Center for Analytical Chemistry, University of Natural, Resources and Life Sciences, Vienna (BOKU), Tulln, Austria
| | - Susanne Zeilinger
- Department of Microbiology, University of Innsbruck, Innsbruck, Austria
- * E-mail:
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23
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Ali H, Dong SXM, Gajanayaka N, Cassol E, Angel JB, Kumar A. Selective Induction of Cell Death in Human M1 Macrophages by Smac Mimetics Is Mediated by cIAP-2 and RIPK-1/3 through the Activation of mTORC. THE JOURNAL OF IMMUNOLOGY 2021; 207:2359-2373. [PMID: 34561230 DOI: 10.4049/jimmunol.2100108] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Accepted: 08/28/2021] [Indexed: 12/22/2022]
Abstract
Inflammatory macrophages have been implicated in many diseases, including rheumatoid arthritis and inflammatory bowel disease. Therefore, targeting macrophage function and activation may represent a potential strategy to treat macrophage-associated diseases. We have previously shown that IFN-γ-induced differentiation of human M0 macrophages toward proinflammatory M1 state rendered them highly susceptible to the cytocidal effects of second mitochondria-derived activator of caspases mimetics (SMs), antagonist of the inhibitors of apoptosis proteins (IAPs), whereas M0 and anti-inflammatory M2c macrophages were resistant. In this study, we investigated the mechanism governing SM-induced cell death during differentiation into M1 macrophages and in polarized M1 macrophages. IFN-γ stimulation conferred on M0 macrophages the sensitivity to SM-induced cell death through the Jak/STAT, IFN regulatory factor-1, and mammalian target of rapamycin complex-1 (mTORC-1)/ribosomal protein S6 kinase pathways. Interestingly, mTORC-1 regulated SM-induced cell death independent of M1 differentiation. In contrast, SM-induced cell death in polarized M1 macrophages is regulated by the mTORC-2 pathway. Moreover, SM-induced cell death is regulated by cellular IAP (cIAP)-2, receptor-interacting protein kinase (RIPK)-1, and RIPK-3 degradation through mTORC activation during differentiation into M1 macrophages and in polarized M1 macrophages. In contrast to cancer cell lines, SM-induced cell death in M1 macrophages is independent of endogenously produced TNF-α, as well as the NF-κB pathway. Collectively, selective induction of cell death in human M1 macrophages by SMs may be mediated by cIAP-2, RIPK-1, and RIPK-3 degradation through mTORC activation. Moreover, blocking cIAP-1/2, mTORC, or IFN regulatory factor-1 may represent a promising therapeutic strategy to control M1-associated diseases.
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Affiliation(s)
- Hamza Ali
- Department of Biochemistry, Microbiology, and Immunology, University of Ottawa, Ontario, Canada; .,Apoptosis Research Centre, Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, Ontario, Canada.,Faculty of Applied Medical Sciences, Taibah University, Medina, Kingdom of Saudi Arabia
| | - Simon Xin Min Dong
- Apoptosis Research Centre, Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, Ontario, Canada
| | - Niranjala Gajanayaka
- Apoptosis Research Centre, Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, Ontario, Canada
| | - Edana Cassol
- Department of Health Sciences, Carleton University, Ottawa, Ontario, Canada
| | - Jonathan B Angel
- Department of Biochemistry, Microbiology, and Immunology, University of Ottawa, Ontario, Canada.,Chronic Disease Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada.,Department of Medicine, Faculty of Medicine, University of Ottawa, Ontario, Canada; and
| | - Ashok Kumar
- Department of Biochemistry, Microbiology, and Immunology, University of Ottawa, Ontario, Canada; .,Apoptosis Research Centre, Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, Ontario, Canada.,Department of Pathology and Laboratory Medicine, University of Ottawa, Ontario, Canada
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24
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Li L, Zhu T, Song Y, Luo X, Datla R, Ren M. Target of rapamycin controls hyphal growth and pathogenicity through FoTIP4 in Fusarium oxysporum. MOLECULAR PLANT PATHOLOGY 2021; 22:1239-1255. [PMID: 34288333 PMCID: PMC8435236 DOI: 10.1111/mpp.13108] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 06/21/2021] [Accepted: 06/22/2021] [Indexed: 05/07/2023]
Abstract
Fusarium oxysporum is the causal agent of the devastating Fusarium wilt by invading and colonizing the vascular system in various plants, resulting in substantial economic losses worldwide. Target of rapamycin (TOR) is a central regulator that controls intracellular metabolism, cell growth, and stress responses in eukaryotes, but little is known about TOR signalling in F. oxysporum. In this study, we identified conserved FoTOR signalling pathway components including FoTORC1 and FoTORC2. Pharmacological assays showed that F. oxysporum is hypersensitive to rapamycin in the presence of FoFKBP12 while the deletion mutant strain ΔFofkbp12 is insensitive to rapamycin. Transcriptomic data indicated that FoTOR signalling controls multiple metabolic processes including ribosome biogenesis and cell wall-degrading enzymes (CWDEs). Genetic analysis revealed that FoTOR1 interacting protein 4 (FoTIP4) acts as a new component of FoTOR signalling to regulate hyphal growth and pathogenicity of F. oxysporum. Importantly, transcript levels of genes associated with ribosome biogenesis and CWDEs were dramatically downregulated in the ΔFotip4 mutant strain. Electrophoretic mobility shift assays showed that FoTIP4 can bind to the promoters of ribosome biogenesis- and CWDE-related genes to positively regulate the expression of these genes. These results suggest that FoTOR signalling plays central roles in regulating hyphal growth and pathogenicity of F. oxysporum and provide new insights into FoTOR1 as a target for controlling and preventing Fusarium wilt in plants.
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Affiliation(s)
- Linxuan Li
- Institute of Urban AgricultureChinese Academy of Agricultural SciencesChengdu National Agricultural Science and Technology CenterChengduChina
| | - Tingting Zhu
- Institute of Urban AgricultureChinese Academy of Agricultural SciencesChengdu National Agricultural Science and Technology CenterChengduChina
| | - Yun Song
- Zhengzhou Research BaseState Key Laboratory of Cotton BiologyZhengzhou UniversityZhengzhouChina
- School of Life SciencesLiaocheng UniversityLiaochengChina
| | - Xiumei Luo
- Institute of Urban AgricultureChinese Academy of Agricultural SciencesChengdu National Agricultural Science and Technology CenterChengduChina
| | - Raju Datla
- Global Institute for Food Security in SaskatoonUniversity of SaskatchewanSaskatoonCanada
| | - Maozhi Ren
- Institute of Urban AgricultureChinese Academy of Agricultural SciencesChengdu National Agricultural Science and Technology CenterChengduChina
- Zhengzhou Research BaseState Key Laboratory of Cotton BiologyZhengzhou UniversityZhengzhouChina
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25
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Navratilova A, Kovar M, Trakovicka A, Pozgajova M. Nickel induced cell impairments are negatively regulated by the Tor1 kinase in Schizosaccharomyces pombe. World J Microbiol Biotechnol 2021; 37:165. [PMID: 34458935 DOI: 10.1007/s11274-021-03130-2] [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: 02/08/2021] [Accepted: 08/17/2021] [Indexed: 11/26/2022]
Abstract
In our study we investigated the effect of different nickel (NiSO4·6H2O) (Ni) concentrations on cell division, cellular morphology and ionome homeostasis of the eukaryotic model organism Schizosaccharomyces pombe. Target of rapamycin (TOR) protein kinase is one of the key regulators of cell growth under different environmental stresses. We analyzed the effect of Ni on cell strains lacking the Tor1 signaling pathway utilizing light-absorbance spectroscopy, visualization, microscopy and inductively coupled plasma optical emission spectroscopy. Interestingly, our findings revealed that Ni mediated cell growth alterations are noticeably lower in Tor1 deficient cells. Greater size of Tor1 depleted cells reached similar quantitative parameters to wild type cells upon incubation with 400 μM Ni. Differences of ion levels among the two tested yeast strains were detected even before Ni addition. Addition of high concentration (1 mM) of the heavy metal, representing acute contamination, caused considerable changes in the ionome of both strains. Strikingly, Tor1 deficient cells displayed largely reduced Ni content after treatment compared to wild type controls (644.1 ± 49 vs. 2096.8 ± 75 μg/g), suggesting its significant role in Ni trafficking. Together our results predict yet undefined role for the Tor1 signaling in metal uptake and/or metabolism.
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Affiliation(s)
- Alica Navratilova
- Department of Genetics and Breeding Biology, Faculty of Agrobiology and Food Resources, Slovak University of Agriculture in Nitra, Tr. A. Hlinku 2, 94976, Nitra, Slovakia
| | - Marek Kovar
- Department of Plant Physiology, Faculty of Agrobiology and Food Resources, Slovak University of Agriculture in Nitra, Tr. A. Hlinku 2, 94976, Nitra, Slovakia
| | - Anna Trakovicka
- Department of Genetics and Breeding Biology, Faculty of Agrobiology and Food Resources, Slovak University of Agriculture in Nitra, Tr. A. Hlinku 2, 94976, Nitra, Slovakia
| | - Miroslava Pozgajova
- AgroBioTech Research Centre, Slovak University of Agriculture in Nitra, Tr. A. Hlinku 2, 94976, Nitra, Slovakia.
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26
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Castel P, Dharmaiah S, Sale MJ, Messing S, Rizzuto G, Cuevas-Navarro A, Cheng A, Trnka MJ, Urisman A, Esposito D, Simanshu DK, McCormick F. RAS interaction with Sin1 is dispensable for mTORC2 assembly and activity. Proc Natl Acad Sci U S A 2021; 118:e2103261118. [PMID: 34380736 PMCID: PMC8379911 DOI: 10.1073/pnas.2103261118] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
RAS proteins are molecular switches that interact with effector proteins when bound to guanosine triphosphate, stimulating downstream signaling in response to multiple stimuli. Although several canonical downstream effectors have been extensively studied and tested as potential targets for RAS-driven cancers, many of these remain poorly characterized. In this study, we undertook a biochemical and structural approach to further study the role of Sin1 as a RAS effector. Sin1 interacted predominantly with KRAS isoform 4A in cells through an atypical RAS-binding domain that we have characterized by X-ray crystallography. Despite the essential role of Sin1 in the assembly and activity of mTORC2, we find that the interaction with RAS is not required for these functions. Cells and mice expressing a mutant of Sin1 that is unable to bind RAS are proficient for activation and assembly of mTORC2. Our results suggest that Sin1 is a bona fide RAS effector that regulates downstream signaling in an mTORC2-independent manner.
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Affiliation(s)
- Pau Castel
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, CA 94158
| | - Srisathiyanarayanan Dharmaiah
- National Cancer Institute (NCI) RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc., Frederick, MD 21702
| | - Matthew J Sale
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, CA 94158
| | - Simon Messing
- National Cancer Institute (NCI) RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc., Frederick, MD 21702
| | - Gabrielle Rizzuto
- Department of Anatomic Pathology, University of California, San Francisco, CA 94158
| | - Antonio Cuevas-Navarro
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, CA 94158
| | - Alice Cheng
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, CA 94158
| | - Michael J Trnka
- Department of Pharmaceutical Chemistry, University of California, San Francisco, CA 94158
| | - Anatoly Urisman
- Department of Anatomic Pathology, University of California, San Francisco, CA 94158
| | - Dominic Esposito
- National Cancer Institute (NCI) RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc., Frederick, MD 21702
| | - Dhirendra K Simanshu
- National Cancer Institute (NCI) RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc., Frederick, MD 21702;
| | - Frank McCormick
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, CA 94158;
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27
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Branco JR, Esteves AM, Leandro JGB, Demaria TM, Godoi V, Marette A, Valença HDM, Lanzetti M, Peyot ML, Farfari S, Prentki M, Zancan P, Sola-Penna M. Dietary citrate acutely induces insulin resistance and markers of liver inflammation in mice. J Nutr Biochem 2021; 98:108834. [PMID: 34371126 DOI: 10.1016/j.jnutbio.2021.108834] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Revised: 07/13/2021] [Accepted: 07/14/2021] [Indexed: 10/20/2022]
Abstract
Citrate is widely used as a food additive being part of virtually all processed foods. Although considered inert by most of the regulatory agencies in the world, plasma citrate has been proposed to play immunometabolic functions in multiple tissues through altering a plethora of cellular pathways. Here, we used a short-term alimentary intervention (24 hours) with standard chow supplemented with citrate in amount corresponding to that found in processed foods to evaluate its effects on glucose homeostasis and liver physiology in C57BL/6J mice. Animals supplemented with dietary citrate showed glucose intolerance and insulin resistance as revealed by glucose and insulin tolerance tests. Moreover, animals supplemented with citrate in their food displayed fed and fasted hyperinsulinemia and enhanced insulin secretion during an oral glucose tolerance test. Citrate treatment also amplified glucose-induced insulin secretion in vitro in INS1-E cells. Citrate supplemented animals had increased liver PKCα activity and altered phosphorylation at serine or threonine residues of components of insulin signaling including IRS-1, Akt, GSK-3 and FoxO1. Furthermore, citrate supplementation enhanced the hepatic expression of lipogenic genes suggesting increased de novo lipogenesis, a finding that was reproduced after citrate treatment of hepatic FAO cells. Finally, liver inflammation markers were higher in citrate supplemented animals. Overall, the results demonstrate that dietary citrate supplementation in mice causes hyperinsulinemia and insulin resistance both in vivo and in vitro, and therefore call for a note of caution on the use of citrate as a food additive given its potential role in metabolic dysregulation.
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Affiliation(s)
- Jessica Ristow Branco
- Laboratório de Oncobiologia Molecular (LabOMol), Departamento de Biotecnologia Farmacêutica, Faculdade de Farmácia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Amanda Moreira Esteves
- Laboratório de Oncobiologia Molecular (LabOMol), Departamento de Biotecnologia Farmacêutica, Faculdade de Farmácia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - João Gabriel Bernardo Leandro
- Laboratório de Enzimologia e Controle do Metabolismo (LabECoM) Departamento de Biotecnologia Farmacêutica, Faculdade de Farmácia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Thainá M Demaria
- Laboratório de Enzimologia e Controle do Metabolismo (LabECoM) Departamento de Biotecnologia Farmacêutica, Faculdade de Farmácia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Vilma Godoi
- Laboratório de Oncobiologia Molecular (LabOMol), Departamento de Biotecnologia Farmacêutica, Faculdade de Farmácia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil; Laboratório de Enzimologia e Controle do Metabolismo (LabECoM) Departamento de Biotecnologia Farmacêutica, Faculdade de Farmácia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil; Departamento de Ciências Morfológicas, Universidade Estadual de Maringá, Maringá, PR, Brazil
| | - André Marette
- Department of Medicine, Quebec Heart and Lung Institute, Hôpital Laval, Pavillon Marguerite d'Youville, Québec, Canada
| | - Helber da Maia Valença
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Manuella Lanzetti
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Marie-Line Peyot
- Molecular Nutrition Unit, Montreal Diabetes Research Center at the Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), department of Nutrition, Université de Montréal, Montréal, Canada
| | - Salah Farfari
- Molecular Nutrition Unit, Montreal Diabetes Research Center at the Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), department of Nutrition, Université de Montréal, Montréal, Canada
| | - Marc Prentki
- Molecular Nutrition Unit, Montreal Diabetes Research Center at the Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), department of Nutrition, Université de Montréal, Montréal, Canada
| | - Patricia Zancan
- Laboratório de Oncobiologia Molecular (LabOMol), Departamento de Biotecnologia Farmacêutica, Faculdade de Farmácia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Mauro Sola-Penna
- Laboratório de Enzimologia e Controle do Metabolismo (LabECoM) Departamento de Biotecnologia Farmacêutica, Faculdade de Farmácia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
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28
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Ballesteros‐Álvarez J, Andersen JK. mTORC2: The other mTOR in autophagy regulation. Aging Cell 2021; 20:e13431. [PMID: 34250734 PMCID: PMC8373318 DOI: 10.1111/acel.13431] [Citation(s) in RCA: 76] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 06/15/2021] [Accepted: 06/24/2021] [Indexed: 12/13/2022] Open
Abstract
The mechanistic target of rapamycin (mTOR) has gathered significant attention as a ubiquitously expressed multimeric kinase with key implications for cell growth, proliferation, and survival. This kinase forms the central core of two distinct complexes, mTORC1 and mTORC2, which share the ability of integrating environmental, nutritional, and hormonal cues but which regulate separate molecular pathways that result in different cellular responses. Particularly, mTORC1 has been described as a major negative regulator of endosomal biogenesis and autophagy, a catabolic process that degrades intracellular components and organelles within the lysosomes and is thought to play a key role in human health and disease. In contrast, the role of mTORC2 in the regulation of autophagy has been considerably less studied despite mounting evidence this complex may regulate autophagy in a different and perhaps complementary manner to that of mTORC1. Genetic ablation of unique subunits is currently being utilized to study the differential effects of the two mTOR complexes. RICTOR is the best‐described subunit specific to mTORC2 and as such has become a useful tool for investigating the specific actions of this complex. The development of complex‐specific inhibitors for mTORC2 is also an area of intense interest. Studies to date have demonstrated that mTORC1/2 complexes each signal to a variety of exclusive downstream molecules with distinct biological roles. Pinpointing the particular effects of these downstream effectors is crucial toward the development of novel therapies aimed at accurately modulating autophagy in the context of human aging and disease.
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29
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An P, Xu W, Luo J, Luo Y. Expanding TOR Complex 2 Signaling: Emerging Regulators and New Connections. Front Cell Dev Biol 2021; 9:713806. [PMID: 34395443 PMCID: PMC8363310 DOI: 10.3389/fcell.2021.713806] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Accepted: 07/15/2021] [Indexed: 12/16/2022] Open
Abstract
Almost three decades after its seminal discovery, our understanding of the remarkable TOR pathway continues to expand. As a TOR complex, TORC2 lies at the nexus of many signaling pathways and directs a diverse array of fundamental processes such as cell survival, proliferation, and metabolism by integrating environmental and intracellular cues. The dysregulation of TORC2 activity disrupts cellular homeostasis and leads to many pathophysiological conditions. With continued efforts at mapping the signaling landscape, the pace of discovery in TORC2 regulation has been accelerated in recent years. Consequently, emerging evidence has expanded the repertoire of upstream regulators and has revealed unexpected diversity in the modes of TORC2 regulation. Multiple environmental cues and plasma membrane proteins that fine-tune TORC2 activity are unfolding. Furthermore, TORC2 signaling is intricately intertwined with other major signaling pathways. Therefore, feedback and crosstalk regulation also extensively modulate TORC2. In this context, we provide a comprehensive overview of revolutionary concepts regarding emerging regulators of TORC2 and discuss evidence of feedback and crosstalk regulation that shed new light on TORC2 biology.
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Affiliation(s)
- Peng An
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, Key Laboratory of Precision Nutrition and Food Quality, Department of Nutrition and Health, China Agricultural University, Beijing, China
| | - Wenyi Xu
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, Key Laboratory of Precision Nutrition and Food Quality, Department of Nutrition and Health, China Agricultural University, Beijing, China
| | - Junjie Luo
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, Key Laboratory of Precision Nutrition and Food Quality, Department of Nutrition and Health, China Agricultural University, Beijing, China
| | - Yongting Luo
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, Key Laboratory of Precision Nutrition and Food Quality, Department of Nutrition and Health, China Agricultural University, Beijing, China
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30
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Antiproliferative effect of bacterial cyclodipeptides in the HeLa line of human cervical cancer reveals multiple protein kinase targeting, including mTORC1/C2 complex inhibition in a TSC1/2-dependent manner. Apoptosis 2021; 25:632-647. [PMID: 32617785 DOI: 10.1007/s10495-020-01619-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Cervix adenocarcinoma rendered by human papillomavirus (HPV) integration is an aggressive cancer that occurs by dysregulation of multiple pathways, including oncogenes, proto-oncogenes, and tumor suppressors. The PI3K/Akt/mTOR pathway, which cross-talks with the Ras-ERK pathway, has been associated with cervical cancers (CC), which includes signaling pathways related to carcinoma aggressiveness, metastasis, recurrence, and drug resistance. Since bacterial cyclodipeptides (CDPs) possess cytotoxic properties in HeLa cells with inhibiting Akt/S6k phosphorylation, the mechanism of CDPs cytotoxicity involved was deepened. Results showed that the antiproliferative effect of CDPs occurred by blocking the PI3K/Akt/mTOR pathway, inhibiting the mTORC1/mTORC2 complexes in a TSC1/TSC2-dependent manner. In addition, the CDPs blocked protein kinases from multiple signaling pathways involved in survival, proliferation, invasiveness, apoptosis, autophagy, and energy metabolism, such as PI3K/Akt/mTOR, Ras/Raf/MEK/ERK1/2, PI3K/JNK/PKA, p27Kip1/CDK1/survivin, MAPK, HIF-1, Wnt/β-catenin, HSP27, EMT, CSCs, and receptors, such as EGF/ErbB2/HGF/Met. Thus, the antiproliferative effect of the CDPs made it possible to identify the crosstalk of the signaling pathways involved in HeLa cell malignancy and to suggest that bacterial CDPs may be considered as a potential anti-neoplastic drug in human cervical adenocarcinoma therapy.
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31
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Querfurth H, Lee HK. Mammalian/mechanistic target of rapamycin (mTOR) complexes in neurodegeneration. Mol Neurodegener 2021; 16:44. [PMID: 34215308 PMCID: PMC8252260 DOI: 10.1186/s13024-021-00428-5] [Citation(s) in RCA: 106] [Impact Index Per Article: 35.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 02/01/2021] [Indexed: 12/12/2022] Open
Abstract
Novel targets to arrest neurodegeneration in several dementing conditions involving misfolded protein accumulations may be found in the diverse signaling pathways of the Mammalian/mechanistic target of rapamycin (mTOR). As a nutrient sensor, mTOR has important homeostatic functions to regulate energy metabolism and support neuronal growth and plasticity. However, in Alzheimer's disease (AD), mTOR alternately plays important pathogenic roles by inhibiting both insulin signaling and autophagic removal of β-amyloid (Aβ) and phospho-tau (ptau) aggregates. It also plays a role in the cerebrovascular dysfunction of AD. mTOR is a serine/threonine kinase residing at the core in either of two multiprotein complexes termed mTORC1 and mTORC2. Recent data suggest that their balanced actions also have implications for Parkinson's disease (PD) and Huntington's disease (HD), Frontotemporal dementia (FTD) and Amyotrophic Lateral Sclerosis (ALS). Beyond rapamycin; an mTOR inhibitor, there are rapalogs having greater tolerability and micro delivery modes, that hold promise in arresting these age dependent conditions.
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Affiliation(s)
- Henry Querfurth
- Department of Neurology, Tufts Medical Center, Boston, Massachusetts, USA.
| | - Han-Kyu Lee
- Department of Neurology, Tufts Medical Center, Boston, Massachusetts, USA
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Fabian DK, Fuentealba M, Dönertaş HM, Partridge L, Thornton JM. Functional conservation in genes and pathways linking ageing and immunity. IMMUNITY & AGEING 2021; 18:23. [PMID: 33990202 PMCID: PMC8120713 DOI: 10.1186/s12979-021-00232-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 04/06/2021] [Indexed: 12/31/2022]
Abstract
At first glance, longevity and immunity appear to be different traits that have not much in common except the fact that the immune system promotes survival upon pathogenic infection. Substantial evidence however points to a molecularly intertwined relationship between the immune system and ageing. Although this link is well-known throughout the animal kingdom, its genetic basis is complex and still poorly understood. To address this question, we here provide a compilation of all genes concomitantly known to be involved in immunity and ageing in humans and three well-studied model organisms, the nematode worm Caenorhabditis elegans, the fruit fly Drosophila melanogaster, and the house mouse Mus musculus. By analysing human orthologs among these species, we identified 7 evolutionarily conserved signalling cascades, the insulin/TOR network, three MAPK (ERK, p38, JNK), JAK/STAT, TGF-β, and Nf-κB pathways that act pleiotropically on ageing and immunity. We review current evidence for these pathways linking immunity and lifespan, and their role in the detrimental dysregulation of the immune system with age, known as immunosenescence. We argue that the phenotypic effects of these pathways are often context-dependent and vary, for example, between tissues, sexes, and types of pathogenic infection. Future research therefore needs to explore a higher temporal, spatial and environmental resolution to fully comprehend the connection between ageing and immunity.
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Affiliation(s)
- Daniel K Fabian
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Genome Campus, Hinxton, UK. .,Institute of Healthy Ageing, Department of Genetics, Evolution and Environment, University College London, London, UK.
| | - Matías Fuentealba
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Genome Campus, Hinxton, UK.,Institute of Healthy Ageing, Department of Genetics, Evolution and Environment, University College London, London, UK
| | - Handan Melike Dönertaş
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Genome Campus, Hinxton, UK
| | - Linda Partridge
- Institute of Healthy Ageing, Department of Genetics, Evolution and Environment, University College London, London, UK.,Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - Janet M Thornton
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Genome Campus, Hinxton, UK
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Halova L, Cobley D, Franz-Wachtel M, Wang T, Morrison KR, Krug K, Nalpas N, Maček B, Hagan IM, Humphrey SJ, Petersen J. A TOR (target of rapamycin) and nutritional phosphoproteome of fission yeast reveals novel targets in networks conserved in humans. Open Biol 2021; 11:200405. [PMID: 33823663 PMCID: PMC8025308 DOI: 10.1098/rsob.200405] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 03/05/2021] [Indexed: 12/21/2022] Open
Abstract
Fluctuations in TOR, AMPK and MAP-kinase signalling maintain cellular homeostasis and coordinate growth and division with environmental context. We have applied quantitative, SILAC mass spectrometry to map TOR and nutrient-controlled signalling in the fission yeast Schizosaccharomyces pombe. Phosphorylation levels at more than 1000 sites were altered following nitrogen stress or Torin1 inhibition of the TORC1 and TORC2 networks that comprise TOR signalling. One hundred and thirty of these sites were regulated by both perturbations, and the majority of these (119) new targets have not previously been linked to either nutritional or TOR control in either yeasts or humans. Elimination of AMPK inhibition of TORC1, by removal of AMPKα (ssp2::ura4+), identified phosphosites where nitrogen stress-induced changes were independent of TOR control. Using a yeast strain with an ATP analogue-sensitized Cdc2 kinase, we excluded sites that were changed as an indirect consequence of mitotic control modulation by nitrogen stress or TOR signalling. Nutritional control of gene expression was reflected in multiple targets in RNA metabolism, while significant modulation of actin cytoskeletal components points to adaptations in morphogenesis and cell integrity networks. Reduced phosphorylation of the MAPKK Byr1, at a site whose human equivalent controls docking between MEK and ERK, prevented sexual differentiation when resources were sparse but not eliminated.
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Affiliation(s)
- Lenka Halova
- Faculty of Life Sciences, University of Manchester, Oxford Road, Manchester M13 9PT, UK
- Cancer Research UK Manchester Institute, Alderley Park, Macclesfield SK10 4TG, UK
| | - David Cobley
- Faculty of Life Sciences, University of Manchester, Oxford Road, Manchester M13 9PT, UK
| | - Mirita Franz-Wachtel
- Proteome Center Tuebingen, University of Tuebingen, Auf der Morgenstelle 15, 72076 Tuebingen, Germany
| | - Tingting Wang
- Flinders Health and Medical Research Institute, Flinders Centre for Innovation in Cancer, Flinders University, Adelaide, South Australia 5042, Australia
| | - Kaitlin R. Morrison
- Flinders Health and Medical Research Institute, Flinders Centre for Innovation in Cancer, Flinders University, Adelaide, South Australia 5042, Australia
| | - Karsten Krug
- Proteome Center Tuebingen, University of Tuebingen, Auf der Morgenstelle 15, 72076 Tuebingen, Germany
| | - Nicolas Nalpas
- Proteome Center Tuebingen, University of Tuebingen, Auf der Morgenstelle 15, 72076 Tuebingen, Germany
| | - Boris Maček
- Proteome Center Tuebingen, University of Tuebingen, Auf der Morgenstelle 15, 72076 Tuebingen, Germany
| | - Iain M. Hagan
- Cancer Research UK Manchester Institute, Alderley Park, Macclesfield SK10 4TG, UK
| | - Sean J. Humphrey
- Charles Perkins Centre, School of Life and Environmental Sciences, The University of Sydney, Camperdown, New South Wales, Australia
| | - Janni Petersen
- Faculty of Life Sciences, University of Manchester, Oxford Road, Manchester M13 9PT, UK
- Flinders Health and Medical Research Institute, Flinders Centre for Innovation in Cancer, Flinders University, Adelaide, South Australia 5042, Australia
- Nutrition and Metabolism, South Australia Health and Medical Research Institute, North Terrace, Adelaide, South Australia 5000, Australia
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Hepowit NL, Macedo JKA, Young LEA, Liu K, Sun RC, MacGurn JA, Dickson RC. Enhancing lifespan of budding yeast by pharmacological lowering of amino acid pools. Aging (Albany NY) 2021; 13:7846-7871. [PMID: 33744865 PMCID: PMC8034917 DOI: 10.18632/aging.202849] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Accepted: 01/21/2021] [Indexed: 04/20/2023]
Abstract
The increasing prevalence of age-related diseases and resulting healthcare insecurity and emotional burden require novel treatment approaches. Several promising strategies seek to limit nutrients and promote healthy aging. Unfortunately, the human desire to consume food means this strategy is not practical for most people but pharmacological approaches might be a viable alternative. We previously showed that myriocin, which impairs sphingolipid synthesis, increases lifespan in Saccharomyces cerevisiae by modulating signaling pathways including the target of rapamycin complex 1 (TORC1). Since TORC1 senses cellular amino acids, we analyzed amino acid pools and identified 17 that are lowered by myriocin treatment. Studying the methionine transporter, Mup1, we found that newly synthesized Mup1 traffics to the plasma membrane and is stable for several hours but is inactive in drug-treated cells. Activity can be restored by adding phytosphingosine to culture medium thereby bypassing drug inhibition, thus confirming a sphingolipid requirement for Mup1 activity. Importantly, genetic analysis of myriocin-induced longevity revealed a requirement for the Gtr1/2 (mammalian Rags) and Vps34-Pib2 amino acid sensing pathways upstream of TORC1, consistent with a mechanism of action involving decreased amino acid availability. These studies demonstrate the feasibility of pharmacologically inducing a state resembling amino acid restriction to promote healthy aging.
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Affiliation(s)
- Nathaniel L. Hepowit
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37240, USA
| | - Jessica K. A. Macedo
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY 40536, USA
- Markey Cancer Center, University of Kentucky, Lexington, KY 40536, USA
| | - Lyndsay E. A. Young
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY 40536, USA
| | - Ke Liu
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, Sichuan University, Chengdu 610000, Sichuan, P. R. China
| | - Ramon C. Sun
- Markey Cancer Center, University of Kentucky, Lexington, KY 40536, USA
- Department of Neuroscience, University of Kentucky, Lexington, KY 40536, USA
| | - Jason A. MacGurn
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37240, USA
| | - Robert C. Dickson
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY 40536, USA
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Alao JP, Legon L, Rallis C. Crosstalk between the mTOR and DNA Damage Response Pathways in Fission Yeast. Cells 2021; 10:cells10020305. [PMID: 33540829 PMCID: PMC7913062 DOI: 10.3390/cells10020305] [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: 01/09/2021] [Revised: 01/27/2021] [Accepted: 01/28/2021] [Indexed: 12/14/2022] Open
Abstract
Cells have developed response systems to constantly monitor environmental changes and accordingly adjust growth, differentiation, and cellular stress programs. The evolutionarily conserved, nutrient-responsive, mechanistic target of rapamycin signaling (mTOR) pathway coordinates basic anabolic and catabolic cellular processes such as gene transcription, protein translation, autophagy, and metabolism, and is directly implicated in cellular and organismal aging as well as age-related diseases. mTOR mediates these processes in response to a broad range of inputs such as oxygen, amino acids, hormones, and energy levels, as well as stresses, including DNA damage. Here, we briefly summarize data relating to the interplays of the mTOR pathway with DNA damage response pathways in fission yeast, a favorite model in cell biology, and how these interactions shape cell decisions, growth, and cell-cycle progression. We, especially, comment on the roles of caffeine-mediated DNA-damage override. Understanding the biology of nutrient response, DNA damage and related pharmacological treatments can lead to the design of interventions towards improved cellular and organismal fitness, health, and survival.
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Affiliation(s)
- John-Patrick Alao
- ZEAB Therapeutic, University of East London, Stratford Campus, Water Lane, Stratford, London E15 4LZ, UK;
| | - Luc Legon
- School of Health, Sport and Bioscience, University of East London, Stratford Campus, Water Lane, Stratford, London E15 4LZ, UK;
| | - Charalampos Rallis
- School of Life Sciences, University of Essex, Wivenhoe Park, Colchester CO4 3SQ, UK
- Correspondence:
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A Tour of TOR Complex Signaling in Plants. Trends Biochem Sci 2020; 46:417-428. [PMID: 33309324 DOI: 10.1016/j.tibs.2020.11.004] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 10/26/2020] [Accepted: 11/09/2020] [Indexed: 01/07/2023]
Abstract
To identify the appropriate times for growth and development, organisms must sense and process information about the availability of nutrients, energy status, and environmental cues. For sessile eukaryotes such as plants, integrating such information can be critical in life or death decisions. For nearly 30 years, the conserved phosphatidylinositol 3-kinase-related protein kinases (PIKKs) target of rapamycin (TOR) has been established as a central hub for integrating external and internal metabolic cues. Despite the functional conservation across eukaryotes, the TOR complex has evolved specific functional and mechanistic features in plants. Here, we present recent findings on the plant TOR complex that highlight the conserved and unique nature of this critical growth regulator and its role in multiple aspects of plant life.
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Senoo H, Wai M, Matsubayashi HT, Sesaki H, Iijima M. Hetero-oligomerization of Rho and Ras GTPases Connects GPCR Activation to mTORC2-AKT Signaling. Cell Rep 2020; 33:108427. [PMID: 33238110 DOI: 10.1016/j.celrep.2020.108427] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 09/14/2020] [Accepted: 11/02/2020] [Indexed: 12/19/2022] Open
Abstract
The activation of G-protein-coupled receptors (GPCRs) leads to the activation of mTORC2 in cell migration and metabolism. However, the mechanism that links GPCRs to mTORC2 remains unknown. Here, using Dictyostelium cells, we show that GPCR-mediated chemotactic stimulation induces hetero-oligomerization of phosphorylated GDP-bound Rho GTPase and GTP-bound Ras GTPase in directed cell migration. The Rho-Ras hetero-oligomers directly and specifically stimulate mTORC2 activity toward AKT in cells and after biochemical reconstitution using purified proteins in vitro. The Rho-Ras hetero-oligomers do not activate ERK/MAPK, another kinase that functions downstream of GPCRs and Ras. Human KRas4B functionally replace Dictyostelium Ras in mTORC2 activation. In contrast to GDP-Rho, GTP-Rho antagonizes mTORC2-AKT signaling by inhibiting the oligomerization of GDP-Rho with GTP-Ras. These data reveal that GPCR-stimulated hetero-oligomerization of Rho and Ras provides a critical regulatory step that controls mTORC2-AKT signaling.
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Affiliation(s)
- Hiroshi Senoo
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - May Wai
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Hideaki T Matsubayashi
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Hiromi Sesaki
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
| | - Miho Iijima
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
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Translational control in the naked mole-rat as a model highly resistant to cancer. Biochim Biophys Acta Rev Cancer 2020; 1875:188455. [PMID: 33148499 DOI: 10.1016/j.bbcan.2020.188455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 09/23/2020] [Accepted: 10/15/2020] [Indexed: 12/24/2022]
Abstract
Dysregulation of mRNA translation is involved in the onset and progression of different types of cancer. To gain insight into novel genetic strategies to avoid this malady, we reviewed the available genomic, transcriptomic, and proteomic data about the translational machinery from the naked-mole rat (NMR) Heterocephalus glaber, a new model of study that exhibits high resistance to cancer. The principal features that might confer cancer resistance are 28S rRNA fragmentation, RPL26 and eIF4G overexpression, global downregulation of mTOR pathway, specific amino acid residues in RAPTOR (P908) and RICTOR (V1695), and the absence of 4E-BP3. These features are not only associated with cancer but also might couple longevity and adaptation to hypoxia. We propose that the regulation of translation is among the strategies endowing NMR cancer resistance.
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Høgh RI, Møller SH, Jepsen SD, Mellergaard M, Lund A, Pejtersen M, Fitzner E, Andresen L, Skov S. Metabolism of short-chain fatty acid propionate induces surface expression of NKG2D ligands on cancer cells. FASEB J 2020; 34:15531-15546. [PMID: 32996653 DOI: 10.1096/fj.202000162r] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Revised: 08/30/2020] [Accepted: 09/15/2020] [Indexed: 12/13/2022]
Abstract
SCFAs are primarily produced in the colon by bacterial fermentation of nondigestible carbohydrates. Besides providing energy, SCFAs can suppress development of colon cancer. The mechanism, however, remains elusive. Here, we demonstrate that the SCFA propionate upregulates surface expression of the immune stimulatory NKG2D ligands, MICA/B by imposing metabolic changes in dividing cells. Propionate-mediated MICA/B expression did not rely on GPR41/GPR43 receptors but depended on functional mitochondria. By siRNA-directed knockdown, we could further link phosphoenolpyruvate carboxykinase (PEPCK), the rate-limiting enzyme in gluconeogenesis to propionate regulation of MICA/B expression. Moreover, knockdown of Rictor and specific mTOR inhibitors implicated mTORC2 activity with metabolic changes that control MICA/B expression. SCFAs are precursors to short-chain acyl-CoAs that are used for histone acylation thereby linking the metabolic state to chromatin structure and gene expression. Propionate increased the overall acetylation and propionylation and inhibition of lysine acetyltransferases (KATs) that are responsible for adding acyl-CoAs to histones reduced propionate-mediated MICA/B expression, suggesting that propionate-induced acylation increases MICA/B expression. Notably, propionate upregulated MICA/B surface expression on colon cancer cells in an acylation-dependent manner; however, the impact of mitochondrial metabolism on MICA/B expression was different in colon cancer cells compared with Jurkat cells, suggesting that continuous exposure to propionate in the colon may provide an enhanced capacity to metabolize propionate. Together, our findings support that propionate causes metabolic changes resulting in NKG2D ligand surface expression, which holds potential as an immune activating anticancer therapy.
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Affiliation(s)
- Rikke Illum Høgh
- Laboratory of Immunology, Section for Experimental Animal Models, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Sofie Hedlund Møller
- Laboratory of Immunology, Section for Experimental Animal Models, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Stine Dam Jepsen
- Laboratory of Immunology, Section for Experimental Animal Models, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Maiken Mellergaard
- Laboratory of Immunology, Section for Experimental Animal Models, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Astrid Lund
- Laboratory of Immunology, Section for Experimental Animal Models, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Mikala Pejtersen
- Laboratory of Immunology, Section for Experimental Animal Models, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Emil Fitzner
- Laboratory of Immunology, Section for Experimental Animal Models, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Lars Andresen
- Laboratory of Immunology, Section for Experimental Animal Models, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Søren Skov
- Laboratory of Immunology, Section for Experimental Animal Models, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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Xu W, Hua H, Chiu YH, Li G, Zhi H, Yu Z, Ren F, Luo Y, Cui W. CD146 Regulates Growth Factor-Induced mTORC2 Activity Independent of the PI3K and mTORC1 Pathways. Cell Rep 2020; 29:1311-1322.e5. [PMID: 31665642 DOI: 10.1016/j.celrep.2019.09.047] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Revised: 08/09/2019] [Accepted: 09/17/2019] [Indexed: 12/21/2022] Open
Abstract
The mechanistic target of rapamycin complex 2 (mTORC2) coordinates cell proliferation, survival, and metabolism with environmental inputs, yet how extracellular stimuli such as growth factors (GFs) activate mTORC2 remains enigmatic. Here we demonstrate that in human endothelial cells, activation of mTORC2 signaling by GFs is mediated by transmembrane cell adhesion protein CD146. Upon GF stimulation, the cytoplasmic tail of CD146 is phosphorylated, which permits its positively charged, juxtamembrane KKGK motif to interact with Rictor, the defining subunit of mTORC2. The formation of the CD146-Rictor/mTORC2 complex protects Rictor from ubiquitin-proteasome-mediated degradation, thereby specifically upregulating mTORC2 activity with no intervention of the PI3K and mTORC1 pathways. This CD146-mediated mTORC2 activation in response to GF stimulation promotes cell proliferation and survival. Therefore, our findings identify a molecular mechanism by which extracellular stimuli regulate mTORC2 activity, linking environmental cues with mTORC2 regulation.
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Affiliation(s)
- Wenyi Xu
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, China Agricultural University, Beijing 100193, China; College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China
| | - Huijuan Hua
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, China Agricultural University, Beijing 100193, China; College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Yueh-Ho Chiu
- Institute of Reproductive and Developmental Biology, Faculty of Medicine, Imperial College London, Du Cane Road, London W12 0NN, UK
| | - Guannan Li
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, China Agricultural University, Beijing 100193, China; College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China
| | - Huihan Zhi
- Institute of Reproductive and Developmental Biology, Faculty of Medicine, Imperial College London, Du Cane Road, London W12 0NN, UK
| | - Zhengquan Yu
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, China Agricultural University, Beijing 100193, China; College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Fazheng Ren
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, China Agricultural University, Beijing 100193, China; College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China
| | - Yongting Luo
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, China Agricultural University, Beijing 100193, China.
| | - Wei Cui
- Institute of Reproductive and Developmental Biology, Faculty of Medicine, Imperial College London, Du Cane Road, London W12 0NN, UK.
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Feng G, Cai J, Huang Y, Zhu X, Gong B, Yang Z, Yan C, Hu Z, Yang L, Wang Z. G-Protein-Coupled Estrogen Receptor 1 Promotes Gender Disparities in Hepatocellular Carcinoma via Modulation of SIN1 and mTOR Complex 2 Activity. Mol Cancer Res 2020; 18:1863-1875. [PMID: 32873626 DOI: 10.1158/1541-7786.mcr-20-0173] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2020] [Revised: 06/30/2020] [Accepted: 08/25/2020] [Indexed: 11/16/2022]
Abstract
Due to its intricate heterogeneity and limited treatment, hepatocellular carcinoma (HCC) has been considered a major cause of cancer-related mortality worldwide. Increasing evidence indicates that G-protein-coupled estrogen receptor 1 (GPER1) can promote estrogen-dependent hepatocellular proliferation by activating AKT signaling. The mTOR complex 2 (mTORC2), whose integrity and activity are modulated by its subunit Sin1, controls the activation of AKT by phosphorylation at position S473. In this study, we investigate the modulation of Sin1 and how estrogen signaling may influence the mTORC2-AKT cascade in HCC cells and a DEN-induced mouse model. We have found that estradiol-dependent Sin1 expression is transcriptionally modulated by GPER1 as well as ERα. GPER1 is able to regulate Sin1 stability via nuclear translocation, therefore increasing Sin1-mTORC2-AKT activation. Moreover, Sin1 interacts with ERα and further enhances its transcriptional activity. Sin1 is highly expressed in acute liver injury and in cases of HCC harboring high expression of GPER1 and constitutive activation of mTORC2-AKT signaling. GPER1 inhibition using the antagonist G-15 reverses DEN-induced acute liver injury by suppressing Sin1 expression and mTORC2-AKT activation. Notably, SIN1 expression varies between male and female mice in the context of both liver injury and liver cancer. In addition, high SIN1 expression is predictive of good prognosis in both male and female patients with HCC who are free from hepatitis virus infection and who report low alcohol consumption. Hence, here we demonstrate that Sin1 can be regulated by GPER1 both through nongenomic and indirect genomic signaling. IMPLICATIONS: This study suggests that Sin1 may be a novel HCC biomarker which is gender-dependent and sensitive to particular risk factor.
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Affiliation(s)
- Guanying Feng
- School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
| | - Jingshu Cai
- School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
| | - Yunchuanxiang Huang
- School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
| | - Xianjun Zhu
- Key Laboratory for Human Disease Gene Study, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
| | - Bo Gong
- Key Laboratory for Human Disease Gene Study, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
| | - Zhenglin Yang
- Key Laboratory for Human Disease Gene Study, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
| | - Chunhong Yan
- Georgia Cancer Center, Augusta University, Augusta, Georgia
- Department of Biochemistry and Molecular Biology, Medical College of Georgia, Augusta University, Augusta, Georgia
| | - Zhuowei Hu
- State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Lu Yang
- School of Medicine, University of Electronic Science and Technology of China, Chengdu, China.
| | - Ziyan Wang
- School of Medicine, University of Electronic Science and Technology of China, Chengdu, China.
- Key Laboratory for Human Disease Gene Study, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
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SGK1 is a signalling hub that controls protein synthesis and proliferation in endothelial cells. FEBS Lett 2020; 594:3200-3215. [DOI: 10.1002/1873-3468.13901] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Revised: 07/22/2020] [Accepted: 07/30/2020] [Indexed: 11/07/2022]
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43
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Pathological Consequences of Hepatic mTORC1 Dysregulation. Genes (Basel) 2020; 11:genes11080896. [PMID: 32764389 PMCID: PMC7465966 DOI: 10.3390/genes11080896] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 07/30/2020] [Accepted: 08/02/2020] [Indexed: 12/28/2022] Open
Abstract
The mammalian target of rapamycin complex 1 (mTORC1) is a central regulator of metabolism that integrates environmental inputs, including nutrients, growth factors, and stress signals. mTORC1 activation upregulates anabolism of diverse macromolecules, such as proteins, lipids, and nucleic acids, while downregulating autolysosomal catabolism. mTORC1 dysregulation is often found in various diseases, including cancer, cardiovascular and neurodegenerative diseases, as well as metabolic syndromes involving obesity and type II diabetes. As an essential metabolic organ, the liver requires proper regulation of mTORC1 for maintaining homeostasis and preventing pathologies. For instance, aberrant hyper- or hypoactivation of mTORC1 disrupts hepatocellular homeostasis and damages the structural and functional integrity of the tissue, leading to prominent liver injury and the development of hepatocellular carcinogenesis. Proper regulation of mTORC1 during liver diseases may be beneficial for restoring liver function and ameliorating the detrimental consequences of liver failure.
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Athanasopoulos A, André B, Sophianopoulou V, Gournas C. Fungal plasma membrane domains. FEMS Microbiol Rev 2020; 43:642-673. [PMID: 31504467 DOI: 10.1093/femsre/fuz022] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Accepted: 08/25/2019] [Indexed: 12/11/2022] Open
Abstract
The plasma membrane (PM) performs a plethora of physiological processes, the coordination of which requires spatial and temporal organization into specialized domains of different sizes, stability, protein/lipid composition and overall architecture. Compartmentalization of the PM has been particularly well studied in the yeast Saccharomyces cerevisiae, where five non-overlapping domains have been described: The Membrane Compartments containing the arginine permease Can1 (MCC), the H+-ATPase Pma1 (MCP), the TORC2 kinase (MCT), the sterol transporters Ltc3/4 (MCL), and the cell wall stress mechanosensor Wsc1 (MCW). Additional cortical foci at the fungal PM are the sites where clathrin-dependent endocytosis occurs, the sites where the external pH sensing complex PAL/Rim localizes, and sterol-rich domains found in apically grown regions of fungal membranes. In this review, we summarize knowledge from several fungal species regarding the organization of the lateral PM segregation. We discuss the mechanisms of formation of these domains, and the mechanisms of partitioning of proteins there. Finally, we discuss the physiological roles of the best-known membrane compartments, including the regulation of membrane and cell wall homeostasis, apical growth of fungal cells and the newly emerging role of MCCs as starvation-protective membrane domains.
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Affiliation(s)
- Alexandros Athanasopoulos
- Microbial Molecular Genetics Laboratory, Institute of Biosciences and Applications, National Centre for Scientific Research 'Demokritos,' Patr. Grigoriou E & 27 Neapoleos St. 15341, Agia Paraskevi, Greece
| | - Bruno André
- Molecular Physiology of the Cell laboratory, Université Libre de Bruxelles (ULB), Institut de Biologie et de Médecine Moléculaires, rue des Pr Jeener et Brachet 12, 6041, Gosselies, Belgium
| | - Vicky Sophianopoulou
- Microbial Molecular Genetics Laboratory, Institute of Biosciences and Applications, National Centre for Scientific Research 'Demokritos,' Patr. Grigoriou E & 27 Neapoleos St. 15341, Agia Paraskevi, Greece
| | - Christos Gournas
- Microbial Molecular Genetics Laboratory, Institute of Biosciences and Applications, National Centre for Scientific Research 'Demokritos,' Patr. Grigoriou E & 27 Neapoleos St. 15341, Agia Paraskevi, Greece
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Bouquier N, Moutin E, Tintignac LA, Reverbel A, Jublanc E, Sinnreich M, Chastagnier Y, Averous J, Fafournoux P, Verpelli C, Boeckers T, Carnac G, Perroy J, Ollendorff V. AIMTOR, a BRET biosensor for live imaging, reveals subcellular mTOR signaling and dysfunctions. BMC Biol 2020; 18:81. [PMID: 32620110 PMCID: PMC7334845 DOI: 10.1186/s12915-020-00790-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Accepted: 05/06/2020] [Indexed: 11/24/2022] Open
Abstract
Background mTOR signaling is an essential nutrient and energetic sensing pathway. Here we describe AIMTOR, a sensitive genetically encoded BRET (Bioluminescent Resonance Energy Transfer) biosensor to study mTOR activity in living cells. Results As a proof of principle, we show in both cell lines and primary cell cultures that AIMTOR BRET intensities are modified by mTOR activity changes induced by specific inhibitors and activators of mTORC1 including amino acids and insulin. We further engineered several versions of AIMTOR enabling subcellular-specific assessment of mTOR activities. We then used AIMTOR to decipher mTOR signaling in physio-pathological conditions. First, we show that mTORC1 activity increases during muscle cell differentiation and in response to leucine stimulation in different subcellular compartments such as the cytosol and at the surface of the lysosome, the nucleus, and near the mitochondria. Second, in hippocampal neurons, we found that the enhancement of neuronal activity increases mTOR signaling. AIMTOR further reveals mTOR-signaling dysfunctions in neurons from mouse models of autism spectrum disorder. Conclusions Altogether, our results demonstrate that AIMTOR is a sensitive and specific tool to investigate mTOR-signaling dynamics in living cells and phenotype mTORopathies.
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Affiliation(s)
| | - Enora Moutin
- IGF, University of Montpellier, CNRS, INSERM, Montpellier, France
| | - Lionel A Tintignac
- University Hospital Basel, Department of Biomedecine, Basel, Switzerland
| | | | - Elodie Jublanc
- DMEM, University of Montpellier, INRAE, Montpellier, France
| | - Michael Sinnreich
- University Hospital Basel, Department of Biomedecine, Basel, Switzerland
| | - Yan Chastagnier
- IGF, University of Montpellier, CNRS, INSERM, Montpellier, France
| | - Julien Averous
- Université Clermont Auvergne, INRAE, Unité de Nutrition Humaine, UMR1019, Clermont-Ferrand, France
| | - Pierre Fafournoux
- Université Clermont Auvergne, INRAE, Unité de Nutrition Humaine, UMR1019, Clermont-Ferrand, France
| | - Chiara Verpelli
- Cnr Institute of Neuroscience, Via Vanvitelli, 3220129, Milan, Italy
| | - Tobias Boeckers
- Anatomie und Zellbiologie Universität Ulm, Albert-Einstein Allee 11, Raumnummer 4105, M24, 89081, Ulm, Germany
| | - Gilles Carnac
- Phymedexp, University of Montpellier, CNRS, INSERM, Montpellier, France
| | - Julie Perroy
- IGF, University of Montpellier, CNRS, INSERM, Montpellier, France.
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Laribee RN, Weisman R. Nuclear Functions of TOR: Impact on Transcription and the Epigenome. Genes (Basel) 2020; 11:E641. [PMID: 32532005 PMCID: PMC7349558 DOI: 10.3390/genes11060641] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 06/04/2020] [Accepted: 06/09/2020] [Indexed: 12/15/2022] Open
Abstract
The target of rapamycin (TOR) protein kinase is at the core of growth factor- and nutrient-dependent signaling pathways that are well-known for their regulation of metabolism, growth, and proliferation. However, TOR is also involved in the regulation of gene expression, genomic and epigenomic stability. TOR affects nuclear functions indirectly through its activity in the cytoplasm, but also directly through active nuclear TOR pools. The mechanisms by which TOR regulates its nuclear functions are less well-understood compared with its cytoplasmic activities. TOR is an important pharmacological target for several diseases, including cancer, metabolic and neurological disorders. Thus, studies of the nuclear functions of TOR are important for our understanding of basic biological processes, as well as for clinical implications.
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Affiliation(s)
- R. Nicholas Laribee
- Department of Pathology and Laboratory Medicine, College of Medicine and Center for Cancer Research, University of Tennessee Health Science Center, 19 South Manassas, Cancer Research Building Rm 318, Memphis, TN 38163, USA
| | - Ronit Weisman
- Department of Natural and Life Sciences, The Open University of Israel, University Road 1, Ra’anana 4353701, Israel
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Pancha I, Chokshi K, Tanaka K, Imamura S. Microalgal Target of Rapamycin (TOR): A Central Regulatory Hub for Growth, Stress Response and Biomass Production. PLANT & CELL PHYSIOLOGY 2020; 61:675-684. [PMID: 32105317 DOI: 10.1093/pcp/pcaa023] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Accepted: 02/17/2020] [Indexed: 06/10/2023]
Abstract
Target of rapamycin (TOR) is an evolutionarily conserved protein kinase that plays an important role in the regulation of cell growth and the sensing of nutrient and energy status in eukaryotes. In yeasts and mammals, the roles of TOR have been very well described and various functions of TOR signaling in plant lineages have also been revealed over the past 20 years. In the case of microalgae, the functions of TOR have been primarily studied in the model green alga Chlamydomonas reinhardtii and were summarized in an earlier single review article. However, the recent development of tools for the functional analysis of TOR has helped to reveal the involvement of TOR in various functions, including autophagy, transcription, translation, accumulation of energy storage molecules, etc., in microalgae. In the present review, we discuss recent novel findings relating to TOR signaling and its roles in microalgae along with relevant information on land plants and also provide details of topics that must be addressed in future studies to reveal how TOR regulates various physiological functions in microalgae.
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Affiliation(s)
- Imran Pancha
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, 4259-R1 Nagatsuta, Midori-ku, Yokohama, 226-8503 Japan
- Department of Biology, SRM University-AP, Amaravati, Andhra Pradesh 522502, India
| | - Kaumeel Chokshi
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, 4259-R1 Nagatsuta, Midori-ku, Yokohama, 226-8503 Japan
| | - Kan Tanaka
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, 4259-R1 Nagatsuta, Midori-ku, Yokohama, 226-8503 Japan
| | - Sousuke Imamura
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, 4259-R1 Nagatsuta, Midori-ku, Yokohama, 226-8503 Japan
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Babst M. Regulation of nutrient transporters by metabolic and environmental stresses. Curr Opin Cell Biol 2020; 65:35-41. [PMID: 32200208 DOI: 10.1016/j.ceb.2020.02.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Accepted: 02/15/2020] [Indexed: 12/17/2022]
Abstract
The yeast plasma membrane is a selective barrier between an erratic environment and the cell's metabolism. Nutrient transporters are the gatekeepers that control the import of molecules feeding into the metabolic pathways. Nutrient import adjusts rapidly to changes in metabolism and the environment, which is accomplished by regulating the surface expression of transporters. Recent studies indicate that the lipid environment in which transporters function regulates ubiquitination efficiency and endocytosis of these proteins. Changes in the lipid environment are caused by lateral movements of the transporters between different membrane domains and by the influence of the extracellular environment on the fluidity of the plasma membrane.
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Affiliation(s)
- Markus Babst
- Henry Eyring Center for Cell and Genome Science, University of Utah, Salt Lake City, UT 84112, USA.
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Acevo-Rodríguez PS, Maldonado G, Castro-Obregón S, Hernández G. Autophagy Regulation by the Translation Machinery and Its Implications in Cancer. Front Oncol 2020; 10:322. [PMID: 32232004 PMCID: PMC7082396 DOI: 10.3389/fonc.2020.00322] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2019] [Accepted: 02/24/2020] [Indexed: 12/14/2022] Open
Abstract
Various metabolic pathways and molecular processes in the cell act intertwined, and dysregulating the interplay between some of them may lead to cancer. It is only recently that defects in the translation process, i.e., the synthesis of proteins by the ribosome using a messenger (m)RNA as a template and translation factors, have begun to gain strong attention as a cause of autophagy dysregulation with effects in different maladies, including cancer. Autophagy is an evolutionarily conserved catabolic process that degrades cytoplasmic elements in lysosomes. It maintains cellular homeostasis and preserves cell viability under various stress conditions, which is crucial for all eukaryotic cells. In this review, we discuss recent advances shedding light on the crosstalk between the translation and the autophagy machineries and its impact on tumorigenesis. We also summarize how this interaction is being the target for novel therapies to treat cancer.
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Affiliation(s)
- Pilar Sarah Acevo-Rodríguez
- PSA-R and SC-O, División de Neurociencias, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México (UNAM), Mexico City, Mexico
| | - Giovanna Maldonado
- Translation and Cancer Laboratory, Unit of Biomedical Research on Cancer, National Institute of Cancer (Instituto Nacional de Cancerología, INCan), Mexico City, Mexico
| | - Susana Castro-Obregón
- PSA-R and SC-O, División de Neurociencias, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México (UNAM), Mexico City, Mexico
| | - Greco Hernández
- Translation and Cancer Laboratory, Unit of Biomedical Research on Cancer, National Institute of Cancer (Instituto Nacional de Cancerología, INCan), Mexico City, Mexico
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Carroll B. Spatial regulation of mTORC1 signalling: Beyond the Rag GTPases. Semin Cell Dev Biol 2020; 107:103-111. [PMID: 32122730 DOI: 10.1016/j.semcdb.2020.02.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 02/17/2020] [Accepted: 02/20/2020] [Indexed: 12/15/2022]
Abstract
The mechanistic (or mammalian) Target of Rapamycin Complex 1 (mTORC1) is a central regulator of cell growth and metabolism. By integrating mitogenic signals, mTORC1-dependent phosphorylation of substrates dictates the balance between anabolic, pro-growth and catabolic, recycling processes in the cell. The discovery that amino acids activate mTORC1 by promoting its translocation to the lysosome was a fundamental advance in the understanding of mTORC1 signalling. It has since become clear that the lysosome-cytoplasm shuttling of mTORC1 represents just one layer of spatial control of this signalling pathway. This review will focus on exploring the subcellular localisation of mTORC1 and its regulators to multiple sites within the cell. We will discuss how these spatially distinct regions such as endoplasmic reticulum, plasma membrane and the endosomal pathway co-operate to transduce nutrient availability to mTORC1, allowing for tight control of cell growth.
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Affiliation(s)
- Bernadette Carroll
- School of Biochemistry, Biomedical Sciences Building, University Walk, Bristol, BS8, United Kingdom.
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