51
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Smolen KA, Papke CM, Swingle MR, Musiyenko A, Li C, Salter EA, Camp AD, Honkanen RE, Kettenbach AN. Quantitative proteomics and phosphoproteomics of PP2A-PPP2R5D variants reveal deregulation of RPS6 phosphorylation via converging signaling cascades. J Biol Chem 2023; 299:105154. [PMID: 37572851 PMCID: PMC10485637 DOI: 10.1016/j.jbc.2023.105154] [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: 01/11/2023] [Revised: 07/28/2023] [Accepted: 07/29/2023] [Indexed: 08/14/2023] Open
Abstract
Genetic germline variants of PPP2R5D (encoding: phosphoprotein phosphatase 2 regulatory protein 5D) result in PPP2R5D-related disorder (Jordan's Syndrome), which is characterized by intellectual disability, hypotonia, seizures, macrocephaly, autism spectrum disorder, and delayed motor skill development. The disorder originates from de novo single nucleotide mutations, generating missense variants that act in a dominant manner. Pathogenic mutations altering 13 different amino acids have been identified, with the E198K variant accounting for ∼40% of reported cases. However, the generation of a heterozygous E198K variant cell line to study the molecular effects of the pathogenic mutation has been challenging. Here, we use CRISPR-PRIME genomic editing to introduce a transition (c.592G>A) in a single PPP2R5D allele in HEK293 cells, generating E198K-heterozygous lines to complement existing E420K variant lines. We generate global protein and phosphorylation profiles of WT, E198K, and E420K cell lines and find unique and shared changes between variants and WT cells in kinase- and phosphatase-controlled signaling cascades. We observed ribosomal protein S6 (RPS6) hyperphosphorylation as a shared signaling alteration, indicative of increased ribosomal protein S6-kinase activity. Treatment with rapamycin or an RPS6-kinase inhibitor (LY2584702) suppressed RPS6 phosphorylation in both, suggesting upstream activation of mTORC1/p70S6K. Intriguingly, our data suggests ERK-dependent activation of mTORC1 in both E198K and E420K variant cells, with additional AKT-mediated mTORC1 activation in the E420K variant. Thus, although upstream activation of mTORC1 differs between PPP2R5D-related disorder genotypes, inhibition of mTORC1 or RPS6 kinases warrants further investigation as potential therapeutic strategies for patients.
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Affiliation(s)
- Kali A Smolen
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - Cinta M Papke
- Department of Biochemistry and Molecular Biology, University of South Alabama, Mobile, Alabama, USA
| | - Mark R Swingle
- Department of Biochemistry and Molecular Biology, University of South Alabama, Mobile, Alabama, USA
| | - Alla Musiyenko
- Department of Biochemistry and Molecular Biology, University of South Alabama, Mobile, Alabama, USA
| | - Chenchen Li
- Department of Biochemistry and Molecular Biology, University of South Alabama, Mobile, Alabama, USA
| | - E Alan Salter
- Department of Biochemistry and Molecular Biology, University of South Alabama, Mobile, Alabama, USA
| | - Ashley D Camp
- Department of Biochemistry and Molecular Biology, University of South Alabama, Mobile, Alabama, USA
| | - Richard E Honkanen
- Department of Biochemistry and Molecular Biology, University of South Alabama, Mobile, Alabama, USA.
| | - Arminja N Kettenbach
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA; Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth, Lebanon, New Hampshire, USA.
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52
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Glaviano A, Foo ASC, Lam HY, Yap KCH, Jacot W, Jones RH, Eng H, Nair MG, Makvandi P, Geoerger B, Kulke MH, Baird RD, Prabhu JS, Carbone D, Pecoraro C, Teh DBL, Sethi G, Cavalieri V, Lin KH, Javidi-Sharifi NR, Toska E, Davids MS, Brown JR, Diana P, Stebbing J, Fruman DA, Kumar AP. PI3K/AKT/mTOR signaling transduction pathway and targeted therapies in cancer. Mol Cancer 2023; 22:138. [PMID: 37596643 PMCID: PMC10436543 DOI: 10.1186/s12943-023-01827-6] [Citation(s) in RCA: 114] [Impact Index Per Article: 114.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2023] [Accepted: 07/18/2023] [Indexed: 08/20/2023] Open
Abstract
The PI3K/AKT/mTOR (PAM) signaling pathway is a highly conserved signal transduction network in eukaryotic cells that promotes cell survival, cell growth, and cell cycle progression. Growth factor signalling to transcription factors in the PAM axis is highly regulated by multiple cross-interactions with several other signaling pathways, and dysregulation of signal transduction can predispose to cancer development. The PAM axis is the most frequently activated signaling pathway in human cancer and is often implicated in resistance to anticancer therapies. Dysfunction of components of this pathway such as hyperactivity of PI3K, loss of function of PTEN, and gain-of-function of AKT, are notorious drivers of treatment resistance and disease progression in cancer. In this review we highlight the major dysregulations in the PAM signaling pathway in cancer, and discuss the results of PI3K, AKT and mTOR inhibitors as monotherapy and in co-administation with other antineoplastic agents in clinical trials as a strategy for overcoming treatment resistance. Finally, the major mechanisms of resistance to PAM signaling targeted therapies, including PAM signaling in immunology and immunotherapies are also discussed.
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Affiliation(s)
- Antonino Glaviano
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies, University of Palermo, 90123, Palermo, Italy
| | - Aaron S C Foo
- Department of Surgery, National University Hospital Singapore, National University of Singapore, Singapore, Singapore
| | - Hiu Y Lam
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117600, Singapore
- NUS Centre for Cancer Research (N2CR), Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 119077, Singapore
| | - Kenneth C H Yap
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117600, Singapore
- NUS Centre for Cancer Research (N2CR), Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 119077, Singapore
| | - William Jacot
- Department of Medical Oncology, Institut du Cancer de Montpellier, Inserm U1194, Montpellier University, Montpellier, France
| | - Robert H Jones
- Cardiff University and Velindre Cancer Centre, Museum Avenue, Cardiff, CF10 3AX, UK
| | - Huiyan Eng
- Department of Surgery, National University Hospital Singapore, National University of Singapore, Singapore, Singapore
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117600, Singapore
| | - Madhumathy G Nair
- Division of Molecular Medicine, St. John's Research Institute, St. John's Medical College, Bangalore, 560034, India
| | - Pooyan Makvandi
- The Quzhou Affiliated Hospital of Wenzhou Medical University, Quzhou People's Hospital, Quzhou, 324000, Zhejiang, China
| | - Birgit Geoerger
- Department of Pediatric and Adolescent Oncology, Gustave Roussy Cancer Center, Inserm U1015, Université Paris-Saclay, Paris, France
| | - Matthew H Kulke
- Section of Hematology and Medical Oncology, Boston University and Boston Medical Center, Boston, MA, USA
| | - Richard D Baird
- Cancer Research UK Cambridge Centre, Hills Road, Cambridge, CB2 0QQ, UK
| | - Jyothi S Prabhu
- Division of Molecular Medicine, St. John's Research Institute, St. John's Medical College, Bangalore, 560034, India
| | - Daniela Carbone
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies, University of Palermo, 90123, Palermo, Italy
| | - Camilla Pecoraro
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies, University of Palermo, 90123, Palermo, Italy
| | - Daniel B L Teh
- Departments of Ophthalmology and Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, and Neurobiology Programme, National University of Singapore, Singapore, Singapore
| | - Gautam Sethi
- Department of Surgery, National University Hospital Singapore, National University of Singapore, Singapore, Singapore
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117600, Singapore
| | - Vincenzo Cavalieri
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies, University of Palermo, 90123, Palermo, Italy
| | - Kevin H Lin
- Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA
| | | | - Eneda Toska
- Department of Biochemistry and Molecular Biology, Johns Hopkins School of Public Health, Baltimore, MD, USA
| | - Matthew S Davids
- Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA
| | - Jennifer R Brown
- Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA
| | - Patrizia Diana
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies, University of Palermo, 90123, Palermo, Italy
| | - Justin Stebbing
- Division of Cancer, Imperial College London, Hammersmith Campus, Du Cane Road, London, W12 0NN, UK
| | - David A Fruman
- Department of Molecular Biology and Biochemistry, University of California, 216 Sprague Hall, Irvine, CA, USA
| | - Alan P Kumar
- Department of Surgery, National University Hospital Singapore, National University of Singapore, Singapore, Singapore.
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117600, Singapore.
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53
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Fallone L, Walzer T, Marçais A. Signaling Pathways Leading to mTOR Activation Downstream Cytokine Receptors in Lymphocytes in Health and Disease. Int J Mol Sci 2023; 24:12736. [PMID: 37628917 PMCID: PMC10454121 DOI: 10.3390/ijms241612736] [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: 06/12/2023] [Revised: 08/09/2023] [Accepted: 08/10/2023] [Indexed: 08/27/2023] Open
Abstract
CD8+ T cells and Natural Killer (NK) cells are cytotoxic lymphocytes important in the response to intracellular pathogens and cancer. Their activity depends on the integration of a large set of intracellular and environmental cues, including antigenic signals, cytokine stimulation and nutrient availability. This integration is achieved by signaling hubs, such as the mechanistic target of rapamycin (mTOR). mTOR is a conserved protein kinase that controls cellular growth and metabolism in eukaryotic cells and, therefore, is essential for lymphocyte development and maturation. However, our current understanding of mTOR signaling comes mostly from studies performed in transformed cell lines, which constitute a poor model for comprehending metabolic pathway regulation. Therefore, it is only quite recently that the regulation of mTOR in primary cells has been assessed. Here, we review the signaling pathways leading to mTOR activation in CD8+ T and NK cells, focusing on activation by cytokines. We also discuss how this knowledge can contribute to immunotherapy development, particularly for cancer treatment.
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Affiliation(s)
| | | | - Antoine Marçais
- CIRI—Centre International de Recherche en Infectiologie (Team Lyacts), Inserm, U1111, Université Claude Bernard Lyon 1, CNRS, UMR5308, ENS de Lyon, F-69007 Lyon, France; (L.F.); (T.W.)
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54
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Kapur P, Brugarolas J, Trpkov K. Recent Advances in Renal Tumors with TSC/mTOR Pathway Abnormalities in Patients with Tuberous Sclerosis Complex and in the Sporadic Setting. Cancers (Basel) 2023; 15:4043. [PMID: 37627070 PMCID: PMC10452688 DOI: 10.3390/cancers15164043] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Revised: 08/04/2023] [Accepted: 08/04/2023] [Indexed: 08/27/2023] Open
Abstract
A spectrum of renal tumors associated with frequent TSC/mTOR (tuberous sclerosis complex/mechanistic target of rapamycin) pathway gene alterations (in both the germline and sporadic settings) have recently been described. These include renal cell carcinoma with fibromyomatous stroma (RCC FMS), eosinophilic solid and cystic renal cell carcinoma (ESC RCC), eosinophilic vacuolated tumor (EVT), and low-grade oncocytic tumor (LOT). Most of these entities have characteristic morphologic and immunohistochemical features that enable their recognition without the need for molecular studies. In this report, we summarize recent advances and discuss their evolving complexity.
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Affiliation(s)
- Payal Kapur
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
- Department of Urology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
- Kidney Cancer Program at Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - James Brugarolas
- Kidney Cancer Program at Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
- Hematology-Oncology Division of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Kiril Trpkov
- Department of Pathology and Laboratory Medicine, Cumming School of Medicine, University of Calgary, Calgary, AB T2L 2K5, Canada
- Alberta Precision Labs, Rockyview General Hospital, 7007 14 St., Calgary, AB T2V 1P9, Canada
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55
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Wehle DT, Bass CS, Sulc J, Mirzaa G, Smith SEP. Protein interaction network analysis of mTOR signaling reveals modular organization. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.04.552011. [PMID: 37577705 PMCID: PMC10418199 DOI: 10.1101/2023.08.04.552011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/15/2023]
Abstract
The mammalian target of rapamycin (mTOR) is a serine-threonine kinase that acts as a central mediator of translation, and plays important roles in cell growth, synaptic plasticity, cancer, and a wide range of developmental disorders. The signaling cascade linking lipid kinases (PI3Ks), protein kinases (AKT) and translation initiation complexes (EIFs) to mTOR has been extensively modeled, but does not fully describe mTOR system behavior. Here, we use quantitative multiplex co-immunoprecipitation to monitor a protein interaction network (PIN) composed of 300+ binary interactions among mTOR-related proteins. Using a simple model system of serum deprived or fresh-media-fed mouse 3T3 fibroblasts, we observed extensive PIN remodeling involving 27+ individual protein interactions after one hour, despite phosphorylation changes observed after only five minutes. Using small molecule inhibitors of PI3K, AKT, mTOR, MEK and ERK, we define subsets of the PIN, termed 'modules', that respond differently to each inhibitor. Using primary fibroblasts from individuals with overgrowth disorders caused by pathogenic PIK3CA or MTOR variants, we find that hyperactivation of mTOR pathway components is reflected in a hyperactive PIN. Our data define a "modular" organization of the mTOR PIN in which coordinated groups of interactions respond to activation or inhibition of distinct nodes, and demonstrate that kinase inhibitors affect the modular network architecture in a complex manner, inconsistent with simple linear models of signal transduction.
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Affiliation(s)
- Devin T Wehle
- Graduate Program in Neuroscience, University of Washington, Seattle, WA, USA
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA, USA
| | - Carter S Bass
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA, USA
| | - Josef Sulc
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA, USA
| | - Ghayda Mirzaa
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA, USA
- Department of Pediatrics, University of Washington School of Medicine, Seattle, WA, USA
- Brotman Baty Institute for Precision Medicine, Seattle, WA, USA
| | - Stephen E P Smith
- Graduate Program in Neuroscience, University of Washington, Seattle, WA, USA
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA, USA
- Department of Pediatrics, University of Washington School of Medicine, Seattle, WA, USA
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56
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Jeong MH, Urquhart G, Lewis C, Chi Z, Jewell JL. Inhibition of phosphodiesterase 4D suppresses mTORC1 signaling and pancreatic cancer growth. JCI Insight 2023; 8:e158098. [PMID: 37427586 PMCID: PMC10371348 DOI: 10.1172/jci.insight.158098] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Accepted: 05/23/2023] [Indexed: 07/11/2023] Open
Abstract
The mammalian target of rapamycin complex 1 (mTORC1) senses multiple upstream stimuli to orchestrate anabolic and catabolic events that regulate cell growth and metabolism. Hyperactivation of mTORC1 signaling is observed in multiple human diseases; thus, pathways that suppress mTORC1 signaling may help to identify new therapeutic targets. Here, we report that phosphodiesterase 4D (PDE4D) promotes pancreatic cancer tumor growth by increasing mTORC1 signaling. GPCRs paired to Gαs proteins activate adenylyl cyclase, which in turn elevates levels of 3',5'-cyclic adenosine monophosphate (cAMP), whereas PDEs catalyze the hydrolysis of cAMP to 5'-AMP. PDE4D forms a complex with mTORC1 and is required for mTORC1 lysosomal localization and activation. Inhibition of PDE4D and the elevation of cAMP levels block mTORC1 signaling via Raptor phosphorylation. Moreover, pancreatic cancer exhibits an upregulation of PDE4D expression, and high PDE4D levels predict the poor overall survival of patients with pancreatic cancer. Importantly, FDA-approved PDE4 inhibitors repress pancreatic cancer cell tumor growth in vivo by suppressing mTORC1 signaling. Our results identify PDE4D as an important activator of mTORC1 and suggest that targeting PDE4 with FDA-approved inhibitors may be beneficial for the treatment of human diseases with hyperactivated mTORC1 signaling.
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Affiliation(s)
- Mi-Hyeon Jeong
- Department of Molecular Biology
- Harold C. Simmons Comprehensive Cancer Center
- Hamon Center for Regenerative Science and Medicine, and
| | - Greg Urquhart
- Department of Molecular Biology
- Harold C. Simmons Comprehensive Cancer Center
- Hamon Center for Regenerative Science and Medicine, and
| | | | - Zhikai Chi
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Jenna L. Jewell
- Department of Molecular Biology
- Harold C. Simmons Comprehensive Cancer Center
- Hamon Center for Regenerative Science and Medicine, and
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57
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Lu Q, Xu S, Hao Z, Li Y, Huang Y, Ying S, Jing W, Zou S, Xu Y, Wang H. Dinotefuran exposure induces autophagy and apoptosis through oxidative stress in Bombyx mori. JOURNAL OF HAZARDOUS MATERIALS 2023; 458:131997. [PMID: 37423129 DOI: 10.1016/j.jhazmat.2023.131997] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2023] [Revised: 06/18/2023] [Accepted: 07/03/2023] [Indexed: 07/11/2023]
Abstract
As a third-generation neonicotinoid insecticide, dinotefuran is extensively used in agriculture, and its residue in the environment has potential effects on nontarget organisms. However, the toxic effects of dinotefuran exposure on nontarget organism remain largely unknown. This study explored the toxic effects of sublethal dose of dinotefuran on Bombyx mori. Dinotefuran upregulated reactive oxygen species (ROS) and malondialdehyde (MDA) levels in the midgut and fat body of B. mori. Transcriptional analysis revealed that the expression levels of many autophagy and apoptosis-associated genes were significantly altered after dinotefuran exposure, consistent with ultrastructural changes. Moreover, the expression levels of autophagy-related proteins (ATG8-PE and ATG6) and apoptosis-related proteins (BmDredd and BmICE) were increased, whereas the expression level of an autophagic key protein (sequestosome 1) was decreased in the dinotefuran-exposed group. These results indicate that dinotefuran exposure leads to oxidative stress, autophagy, and apoptosis in B. mori. In addition, its effect on the fat body was apparently greater than that on the midgut. In contrast, pretreatment with an autophagy inhibitor effectively downregulated the expression levels of ATG6 and BmDredd, but induced the expression of sequestosome 1, suggesting that dinotefuran-induced autophagy may promote apoptosis. This study reveals that ROS generation regulates the impact of dinotefuran on the crosstalk between autophagy and apoptosis, laying the foundation for studying cell death processes such as autophagy and apoptosis induced by pesticides. Furthermore, this study provides a comprehensive insight into the toxicity of dinotefuran on silkworm and contributes to the ecological risk assessment of dinotefuran in nontarget organisms.
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Affiliation(s)
- Qingyu Lu
- College of Animal Sciences, Zhejiang University, Hangzhou 310058, China
| | - Shiliang Xu
- College of Animal Sciences, Zhejiang University, Hangzhou 310058, China
| | - Zhihua Hao
- College of Animal Sciences, Zhejiang University, Hangzhou 310058, China
| | - Yinghui Li
- College of Animal Sciences, Zhejiang University, Hangzhou 310058, China
| | - Yuxin Huang
- College of Animal Sciences, Zhejiang University, Hangzhou 310058, China
| | - Shuye Ying
- College of Animal Sciences, Zhejiang University, Hangzhou 310058, China
| | - Wenhui Jing
- College of Animal Sciences, Zhejiang University, Hangzhou 310058, China
| | - Shiyu Zou
- College of Animal Sciences, Zhejiang University, Hangzhou 310058, China
| | - Yusong Xu
- College of Animal Sciences, Zhejiang University, Hangzhou 310058, China
| | - Huabing Wang
- College of Animal Sciences, Zhejiang University, Hangzhou 310058, China.
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58
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Li X, Chen K, Wang Z, Li J, Wang X, Xie C, Tong J, Shen Y. The mTOR signalling in corneal diseases: A recent update. Biochem Pharmacol 2023; 213:115620. [PMID: 37217140 DOI: 10.1016/j.bcp.2023.115620] [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: 03/23/2023] [Revised: 05/16/2023] [Accepted: 05/16/2023] [Indexed: 05/24/2023]
Abstract
Corneal diseases affect 4.2 million people worldwide and are a leading cause of vision impairment and blindness. Current treatments for corneal diseases, such as antibiotics, steroids, and surgical interventions, have numerous disadvantages and challenges. Thus, there is an urgent need for more effective therapies. Although the pathogenesis of corneal diseases is not fully understood, it is known that injury caused by various stresses and postinjury healing, such as epithelial renewal, inflammation, stromal fibrosis, and neovascularization, are highly involved. Mammalian target of rapamycin (mTOR) is a key regulator of cell growth, metabolism, and the immune response. Recent studies have revealed that activation of mTOR signalling extensively contributes to the pathogenesis of various corneal diseases, and inhibition of mTOR with rapamycin achieves promising outcomes, supporting the potential of mTOR as a therapeutic target. In this review, we detail the function of mTOR in corneal diseases and how these characteristics contribute to disease treatment using mTOR-targeted drugs.
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Affiliation(s)
- Xiang Li
- Department of Ophthalmology, the First Affiliated Hospital of Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Kuangqi Chen
- Department of Ophthalmology, the First Affiliated Hospital of Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Zixi Wang
- Bone Marrow Transplantation Center, the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Jiayuan Li
- Department of Ophthalmology, the First Affiliated Hospital of Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Xiawei Wang
- Department of Ophthalmology, the First Affiliated Hospital of Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Chen Xie
- Department of Ophthalmology, the First Affiliated Hospital of Zhejiang University, Hangzhou, Zhejiang Province, China.
| | - Jianping Tong
- Department of Ophthalmology, the First Affiliated Hospital of Zhejiang University, Hangzhou, Zhejiang Province, China.
| | - Ye Shen
- Department of Ophthalmology, the First Affiliated Hospital of Zhejiang University, Hangzhou, Zhejiang Province, China.
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59
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Doxsey DD, Tettoni SD, Egri SB, Shen K. Redundant electrostatic interactions between GATOR1 and the Rag GTPase heterodimer drive efficient amino acid sensing in human cells. J Biol Chem 2023; 299:104880. [PMID: 37269949 PMCID: PMC10316081 DOI: 10.1016/j.jbc.2023.104880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Revised: 05/23/2023] [Accepted: 05/25/2023] [Indexed: 06/05/2023] Open
Abstract
Cells need to coordinate nutrient availability with their growth and proliferation. In eukaryotic cells, this coordination is mediated by the mechanistic target of the rapamycin complex 1 (mTORC1) pathway. mTORC1 activation is regulated by two GTPase units, the Rag GTPase heterodimer and the Rheb GTPase. The RagA-RagC heterodimer controls the subcellular localization of mTORC1, and its nucleotide loading states are strictly controlled by upstream regulators including amino acid sensors. A critical negative regulator of the Rag GTPase heterodimer is GATOR1. In the absence of amino acids, GATOR1 stimulates GTP hydrolysis by the RagA subunit to turn off mTORC1 signaling. Despite the enzymatic specificity of GATOR1 to RagA, a recent cryo-EM structural model of the human GATOR1-Rag-Ragulator complex reveals an unexpected interface between Depdc5, a subunit of GATOR1, and RagC. Currently, there is no functional characterization of this interface, nor do we know its biological relevance. Here, combining structure-function analysis, enzymatic kinetic measurements, and cell-based signaling assays, we identified a critical electrostatic interaction between Depdc5 and RagC. This interaction is mediated by the positively charged Arg-1407 residue on Depdc5 and a patch of negatively charged residues on the lateral side of RagC. Abrogating this interaction impairs the GAP activity of GATOR1 and cellular response to amino acid withdrawal. Our results reveal how GATOR1 coordinates the nucleotide loading states of the Rag GTPase heterodimer, and thus precisely controls cellular behavior in the absence of amino acids.
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Affiliation(s)
- Dylan D Doxsey
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, Massachusetts, USA
| | - Steven D Tettoni
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, Massachusetts, USA
| | - Shawn B Egri
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, Massachusetts, USA
| | - Kuang Shen
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, Massachusetts, USA; Department of Biochemistry & Molecular Pharmacology, University of Massachusetts Chan Medical School, Worcester, Massachusetts, USA.
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60
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Kciuk M, Marciniak B, Celik I, Zerroug E, Dubey A, Sundaraj R, Mujwar S, Bukowski K, Mojzych M, Kontek R. Pyrazolo[4,3- e]tetrazolo[1,5- b][1,2,4]triazine Sulfonamides as an Important Scaffold for Anticancer Drug Discovery-In Vitro and In Silico Evaluation. Int J Mol Sci 2023; 24:10959. [PMID: 37446136 DOI: 10.3390/ijms241310959] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2023] [Revised: 06/26/2023] [Accepted: 06/28/2023] [Indexed: 07/15/2023] Open
Abstract
Pyrazolo[4,3-e]tetrazolo[1,5-b][1,2,4]triazine sulfonamides (MM-compounds) are a relatively new class of heterocyclic compounds that exhibit a wide variety of biological actions, including anticancer properties. Here, we used caspase enzyme activity assays, flow cytometry analysis of propidium iodide (PI)-stained cells, and a DNA laddering assay to investigate the mechanisms of cell death triggered by the MM-compounds (MM134, -6, -7, and -9). Due to inconsistent results in caspase activity assays, we have performed a bromodeoxyuridine (BrdU) incorporation assay, colony formation assay, and gene expression profiling. The compounds' cytotoxic and pro-oxidative properties were also assessed. Additionally, computational studies were performed to demonstrate the potential of the scaffold for future drug discovery endeavors. MM-compounds exhibited strong micromolar (0.06-0.35 µM) anti-proliferative and pro-oxidative activity in two cancer cell lines (BxPC-3 and PC-3). Activation of caspase 3/7 was observed following a 24-h treatment of BxPC-3 cells with IC50 concentrations of MM134, -6, and -9 compounds. However, no DNA fragmentation characteristics for apoptosis were observed in the flow cytometry and DNA laddering analysis. Gene expression data indicated up-regulation of BCL10, GADD45A, RIPK2, TNF, TNFRSF10B, and TNFRSF1A (TNF-R1) following treatment of cells with the MM134 compound. Moreover, in silico studies indicated AKT2 kinase as the primary target of compounds. MM-compounds exhibit strong cytotoxic activity with pro-oxidative, pro-apoptotic, and possibly pro-necroptotic properties that could be employed for further drug discovery approaches.
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Affiliation(s)
- Mateusz Kciuk
- Department of Molecular Biotechnology and Genetics, University of Lodz, Banacha 12/16, 90-237 Lodz, Poland
- Doctoral School of Exact and Natural Sciences, University of Lodz, Banacha Street 12/16, 90-237 Lodz, Poland
| | - Beata Marciniak
- Department of Molecular Biotechnology and Genetics, University of Lodz, Banacha 12/16, 90-237 Lodz, Poland
| | - Ismail Celik
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Erciyes University, Kayseri 38280, Turkey
| | - Enfale Zerroug
- Group of Computational and Pharmaceutical Chemistry, LMCE Laboratory, University of Biskra, BP 145, Biskra 07000, Algeria
| | - Amit Dubey
- Computational Chemistry and Drug Discovery Division, Quanta Calculus, Greater Noida 274203, Uttar Prades, India
- Department of Pharmacology, Saveetha Dental College and Hospital, Saveetha Institute of Medical and Technical Sciences, Chennai 602105, Tamil Nadu, India
| | - Rajamanikandan Sundaraj
- Centre for Drug Discovery, Department of Biochemistry, Karpagam Academy of Higher Education, Coimbatore 641021, Tamil Nadu, India
| | - Somdutt Mujwar
- Chitkara College of Pharmacy, Chitkara University, Rajpura 140401, Punjab, India
| | - Karol Bukowski
- Department of Molecular Biotechnology and Genetics, University of Lodz, Banacha 12/16, 90-237 Lodz, Poland
| | - Mariusz Mojzych
- Department of Chemistry, Siedlce University of Natural Sciences and Humanities, 3 Maja 54, 08-110 Siedlce, Poland
| | - Renata Kontek
- Department of Molecular Biotechnology and Genetics, University of Lodz, Banacha 12/16, 90-237 Lodz, Poland
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Uehara K, Santoleri D, Whitlock AEG, Titchenell PM. Insulin Regulation of Hepatic Lipid Homeostasis. Compr Physiol 2023; 13:4785-4809. [PMID: 37358513 PMCID: PMC10760932 DOI: 10.1002/cphy.c220015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/27/2023]
Abstract
The incidence of obesity, insulin resistance, and type II diabetes (T2DM) continues to rise worldwide. The liver is a central insulin-responsive metabolic organ that governs whole-body metabolic homeostasis. Therefore, defining the mechanisms underlying insulin action in the liver is essential to our understanding of the pathogenesis of insulin resistance. During periods of fasting, the liver catabolizes fatty acids and stored glycogen to meet the metabolic demands of the body. In postprandial conditions, insulin signals to the liver to store excess nutrients into triglycerides, cholesterol, and glycogen. In insulin-resistant states, such as T2DM, hepatic insulin signaling continues to promote lipid synthesis but fails to suppress glucose production, leading to hypertriglyceridemia and hyperglycemia. Insulin resistance is associated with the development of metabolic disorders such as cardiovascular and kidney disease, atherosclerosis, stroke, and cancer. Of note, nonalcoholic fatty liver disease (NAFLD), a spectrum of diseases encompassing fatty liver, inflammation, fibrosis, and cirrhosis, is linked to abnormalities in insulin-mediated lipid metabolism. Therefore, understanding the role of insulin signaling under normal and pathologic states may provide insights into preventative and therapeutic opportunities for the treatment of metabolic diseases. Here, we provide a review of the field of hepatic insulin signaling and lipid regulation, including providing historical context, detailed molecular mechanisms, and address gaps in our understanding of hepatic lipid regulation and the derangements under insulin-resistant conditions. © 2023 American Physiological Society. Compr Physiol 13:4785-4809, 2023.
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Affiliation(s)
- Kahealani Uehara
- Institute of Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Dominic Santoleri
- Institute of Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Anna E. Garcia Whitlock
- Institute of Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Department of Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Paul M. Titchenell
- Institute of Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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62
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Xie Y, Lei X, Zhao G, Guo R, Cui N. mTOR in programmed cell death and its therapeutic implications. Cytokine Growth Factor Rev 2023; 71-72:66-81. [PMID: 37380596 DOI: 10.1016/j.cytogfr.2023.06.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Revised: 06/12/2023] [Accepted: 06/19/2023] [Indexed: 06/30/2023]
Abstract
Mechanistic target of rapamycin (mTOR), a highly conserved serine/threonine kinase, is involved in cellular metabolism, protein synthesis, and cell death. Programmed cell death (PCD) assists in eliminating aging, damaged, or neoplastic cells, and is indispensable for sustaining normal growth, fighting pathogenic microorganisms, and maintaining body homeostasis. mTOR has crucial functions in the intricate signaling pathway network of multiple forms of PCD. mTOR can inhibit autophagy, which is part of PCD regulation. Cell survival is affected by mTOR through autophagy to control reactive oxygen species production and the degradation of pertinent proteins. Additionally, mTOR can regulate PCD in an autophagy-independent manner by affecting the expression levels of related genes and phosphorylating proteins. Therefore, mTOR acts through both autophagy-dependent and -independent pathways to regulate PCD. It is conceivable that mTOR exerts bidirectional regulation of PCD, such as ferroptosis, according to the complexity of signaling pathway networks, but the underlying mechanisms have not been fully explained. This review summarizes the recent advances in understanding mTOR-mediated regulatory mechanisms in PCD. Rigorous investigations into PCD-related signaling pathways have provided prospective therapeutic targets that may be clinically beneficial for treating various diseases.
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Affiliation(s)
- Yawen Xie
- Department of Critical Care Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China
| | - Xianli Lei
- Department of Critical Care Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China
| | - Guoyu Zhao
- Department of Critical Care Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China
| | - Ran Guo
- Department of Critical Care Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China
| | - Na Cui
- Department of Critical Care Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China.
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63
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Mannick JB, Lamming DW. Targeting the biology of aging with mTOR inhibitors. NATURE AGING 2023; 3:642-660. [PMID: 37142830 PMCID: PMC10330278 DOI: 10.1038/s43587-023-00416-y] [Citation(s) in RCA: 36] [Impact Index Per Article: 36.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Accepted: 04/07/2023] [Indexed: 05/06/2023]
Abstract
Inhibition of the protein kinase mechanistic target of rapamycin (mTOR) with the Food and Drug Administration (FDA)-approved therapeutic rapamycin promotes health and longevity in diverse model organisms. More recently, specific inhibition of mTORC1 to treat aging-related conditions has become the goal of basic and translational scientists, clinicians and biotechnology companies. Here, we review the effects of rapamycin on the longevity and survival of both wild-type mice and mouse models of human diseases. We discuss recent clinical trials that have explored whether existing mTOR inhibitors can safely prevent, delay or treat multiple diseases of aging. Finally, we discuss how new molecules may provide routes to the safer and more selective inhibition of mTOR complex 1 (mTORC1) in the decade ahead. We conclude by discussing what work remains to be done and the questions that will need to be addressed to make mTOR inhibitors part of the standard of care for diseases of aging.
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Affiliation(s)
| | - Dudley W Lamming
- Department of Medicine, University of Wisconsin-Madison, Madison, WI, USA.
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64
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Gong GQ, Bilanges B, Allsop B, Masson GR, Roberton V, Askwith T, Oxenford S, Madsen RR, Conduit SE, Bellini D, Fitzek M, Collier M, Najam O, He Z, Wahab B, McLaughlin SH, Chan AWE, Feierberg I, Madin A, Morelli D, Bhamra A, Vinciauskaite V, Anderson KE, Surinova S, Pinotsis N, Lopez-Guadamillas E, Wilcox M, Hooper A, Patel C, Whitehead MA, Bunney TD, Stephens LR, Hawkins PT, Katan M, Yellon DM, Davidson SM, Smith DM, Phillips JB, Angell R, Williams RL, Vanhaesebroeck B. A small-molecule PI3Kα activator for cardioprotection and neuroregeneration. Nature 2023; 618:159-168. [PMID: 37225977 PMCID: PMC7614683 DOI: 10.1038/s41586-023-05972-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Accepted: 03/17/2023] [Indexed: 05/26/2023]
Abstract
Harnessing the potential beneficial effects of kinase signalling through the generation of direct kinase activators remains an underexplored area of drug development1-5. This also applies to the PI3K signalling pathway, which has been extensively targeted by inhibitors for conditions with PI3K overactivation, such as cancer and immune dysregulation. Here we report the discovery of UCL-TRO-1938 (referred to as 1938 hereon), a small-molecule activator of the PI3Kα isoform, a crucial effector of growth factor signalling. 1938 allosterically activates PI3Kα through a distinct mechanism by enhancing multiple steps of the PI3Kα catalytic cycle and causes both local and global conformational changes in the PI3Kα structure. This compound is selective for PI3Kα over other PI3K isoforms and multiple protein and lipid kinases. It transiently activates PI3K signalling in all rodent and human cells tested, resulting in cellular responses such as proliferation and neurite outgrowth. In rodent models, acute treatment with 1938 provides cardioprotection from ischaemia-reperfusion injury and, after local administration, enhances nerve regeneration following nerve crush. This study identifies a chemical tool to directly probe the PI3Kα signalling pathway and a new approach to modulate PI3K activity, widening the therapeutic potential of targeting these enzymes through short-term activation for tissue protection and regeneration. Our findings illustrate the potential of activating kinases for therapeutic benefit, a currently largely untapped area of drug development.
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Affiliation(s)
- Grace Q Gong
- Cell Signalling, Cancer Institute, University College London, London, UK
| | - Benoit Bilanges
- Cell Signalling, Cancer Institute, University College London, London, UK
| | - Ben Allsop
- Drug Discovery Group, Translational Research Office, University College London, London, UK
| | - Glenn R Masson
- Medical Research Council Laboratory of Molecular Biology, Cambridge, UK
- Division of Cellular Medicine, School of Medicine, University of Dundee, Dundee, UK
| | - Victoria Roberton
- UCL Centre for Nerve Engineering, UCL School of Pharmacy, University College London, London, UK
| | - Trevor Askwith
- Drug Discovery Group, Translational Research Office, University College London, London, UK
| | - Sally Oxenford
- Drug Discovery Group, Translational Research Office, University College London, London, UK
| | - Ralitsa R Madsen
- Cell Signalling, Cancer Institute, University College London, London, UK
| | - Sarah E Conduit
- Cell Signalling, Cancer Institute, University College London, London, UK
| | - Dom Bellini
- Medical Research Council Laboratory of Molecular Biology, Cambridge, UK
| | - Martina Fitzek
- Hit Discovery, Discovery Sciences, R&D, AstraZeneca, Alderley Park, Macclesfield, UK
| | - Matt Collier
- Hit Discovery, Discovery Sciences, R&D, AstraZeneca, Alderley Park, Macclesfield, UK
| | - Osman Najam
- The Hatter Cardiovascular Institute, University College London, London, UK
| | - Zhenhe He
- The Hatter Cardiovascular Institute, University College London, London, UK
| | - Ben Wahab
- Medicines Discovery Institute, School of Biosciences, Cardiff University, Cardiff, UK
| | | | - A W Edith Chan
- Wolfson Institute for Biomedical Research, University College London, London, UK
| | | | - Andrew Madin
- Hit Discovery, Discovery Sciences, R&D, AstraZeneca, Cambridge, UK
| | - Daniele Morelli
- Cell Signalling, Cancer Institute, University College London, London, UK
| | - Amandeep Bhamra
- Proteomics Research Translational Technology Platform, Cancer Institute, University College London, London, UK
| | - Vanesa Vinciauskaite
- Division of Cellular Medicine, School of Medicine, University of Dundee, Dundee, UK
| | | | - Silvia Surinova
- Proteomics Research Translational Technology Platform, Cancer Institute, University College London, London, UK
| | - Nikos Pinotsis
- Institute of Structural and Molecular Biology, Birkbeck College, London, UK
| | | | - Matthew Wilcox
- UCL Centre for Nerve Engineering, UCL School of Pharmacy, University College London, London, UK
| | - Alice Hooper
- Drug Discovery Group, Translational Research Office, University College London, London, UK
| | - Chandni Patel
- Drug Discovery Group, Translational Research Office, University College London, London, UK
| | - Maria A Whitehead
- Cell Signalling, Cancer Institute, University College London, London, UK
| | - Tom D Bunney
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London, UK
| | | | | | - Matilda Katan
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London, UK
| | - Derek M Yellon
- The Hatter Cardiovascular Institute, University College London, London, UK
| | - Sean M Davidson
- The Hatter Cardiovascular Institute, University College London, London, UK
| | - David M Smith
- Emerging Innovations, Discovery Sciences, R&D, AstraZeneca, Cambridge, UK
| | - James B Phillips
- UCL Centre for Nerve Engineering, UCL School of Pharmacy, University College London, London, UK
| | - Richard Angell
- Drug Discovery Group, Translational Research Office, University College London, London, UK
- Medicines Discovery Institute, School of Biosciences, Cardiff University, Cardiff, UK
| | - Roger L Williams
- Medical Research Council Laboratory of Molecular Biology, Cambridge, UK
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65
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Wang G, Chen L, Lei X, Qin S, Geng H, Zheng Y, Xia C, Yao J, Meng T, Deng L. Role of FLCN Phosphorylation in Insulin-Mediated mTORC1 Activation and Tumorigenesis. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023:e2206826. [PMID: 37083230 DOI: 10.1002/advs.202206826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 03/18/2023] [Indexed: 05/03/2023]
Abstract
The amino acid-stimulated Rag GTPase pathway is one of the main pathways that regulate mechanistic target of rapamycin complex 1 (mTORC1) activation and function, but little is known about the effects of growth factors on Rag GTPase-mediated mTORC1 activation. Here, a highly conserved insulin-responsive phosphorylation site on folliculin (FLCN), Ser62, that is phosphorylates by AKT1 is identified and characterized. mTORC2-AKT1 is localized on lysosomes, and RagD-specific recruitment of mTORC2-AKT1 on lysosomes is identified as an essential step in insulin-AKT1-mediated FLCN phosphorylation. Additionally, FLCN phosphorylation inhibits the activity of RagC GTPase and is essential for insulin-induced mTORC1 activation. Functionally, phosphorylated FLCN promotes cell viability and induces autophagy, and also regulates in vivo tumor growth in an mTORC1-dependent manner. Its expression is also positively correlated with mTORC1 activity in colon cancer, clear cell renal cell carcinoma, and chordoma. These results indicate that FLCN is an important intermediate for cross-talk between the amino acid and growth factor pathways. Further, FLCN phosphorylation may be a promising therapeutic target for diseases characterized by mTORC1 dysregulation.
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Affiliation(s)
- Guoyan Wang
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Lei Chen
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Xinjian Lei
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Senlin Qin
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Huijun Geng
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Yining Zheng
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Chao Xia
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Junhu Yao
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Tong Meng
- Department of Orthopedics, Shanghai General Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, 200240, China
| | - Lu Deng
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, 712100, China
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66
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Cui Z, Joiner AMN, Jansen RM, Hurley JH. Amino acid sensing and lysosomal signaling complexes. Curr Opin Struct Biol 2023; 79:102544. [PMID: 36804703 DOI: 10.1016/j.sbi.2023.102544] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 01/05/2023] [Accepted: 01/11/2023] [Indexed: 02/18/2023]
Abstract
Amino acid pools in the cell are monitored by dedicated sensors, whose structures are now coming into view. The lysosomal Rag GTPases are central to this pathway, and the regulation of their GAP complexes, FLCN-FNIP and GATOR1, have been worked out in detail. For FLCN-FNIP, the entire chain of events from the arginine transporter SLC38A9 to substrate-specific mTORC1 activation has been visualized. The structure GATOR2 has been determined, hinting at an ordering of amino acid signaling across a larger size scale than anticipated. The centerpiece of lysosomal signaling, mTORC1, has been revealed to recognize its substrates by more nuanced and substrate-specific mechanisms than previous appreciated. Beyond the well-studied Rag GTPase and mTORC1 machinery, another lysosomal amino acid sensor/effector system, that of PQLC2 and the C9orf72-containing CSW complex, is coming into structural view. These developments hold promise for further insights into lysosomal physiology and lysosome-centric therapeutics.
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Affiliation(s)
- Zhicheng Cui
- Department of Molecular and Cell Biology, University of California Berkeley, Berkeley CA 94720, USA; California Institute for Quantitative Biosciences, University of California, Berkeley, CA, 94720, USA
| | - Aaron M N Joiner
- Department of Molecular and Cell Biology, University of California Berkeley, Berkeley CA 94720, USA; California Institute for Quantitative Biosciences, University of California, Berkeley, CA, 94720, USA
| | - Rachel M Jansen
- Department of Molecular and Cell Biology, University of California Berkeley, Berkeley CA 94720, USA; California Institute for Quantitative Biosciences, University of California, Berkeley, CA, 94720, USA
| | - James H Hurley
- Department of Molecular and Cell Biology, University of California Berkeley, Berkeley CA 94720, USA; California Institute for Quantitative Biosciences, University of California, Berkeley, CA, 94720, USA; Helen Wills Neuroscience Institute, University of California, Berkeley, CA 94720, USA.
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67
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Makhoul C, Houghton FJ, Hinde E, Gleeson PA. Arf5-mediated regulation of mTORC1 at the plasma membrane. Mol Biol Cell 2023; 34:ar23. [PMID: 36735494 PMCID: PMC10092653 DOI: 10.1091/mbc.e22-07-0302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The mechanistic target of rapamycin (mTOR) kinase regulates a major signaling pathway in eukaryotic cells. In addition to regulation of mTORC1 at lysosomes, mTORC1 is also localized at other locations. However, little is known about the recruitment and activation of mTORC1 at nonlysosomal sites. To identify regulators of mTORC1 recruitment to nonlysosomal compartments, novel interacting partners with the mTORC1 subunit, Raptor, were identified using immunoprecipitation and mass spectrometry. We show that one of the interacting partners, Arf5, is a novel regulator of mTORC1 signaling at plasma membrane ruffles. Arf5-GFP localizes with endogenous mTOR at PI3,4P2-enriched membrane ruffles together with the GTPase required for mTORC1 activation, Rheb. Knockdown of Arf5 reduced the recruitment of mTOR to membrane ruffles. The activation of mTORC1 at membrane ruffles was directly demonstrated using a plasma membrane-targeted mTORC1 biosensor, and Arf5 was shown to enhance the phosphorylation of the mTORC1 biosensor substrate. In addition, endogenous Arf5 was shown to be required for rapid activation of mTORC1-mediated S6 phosphorylation following nutrient starvation and refeeding. Our findings reveal a novel Arf5-dependent pathway for recruitment and activation of mTORC1 at plasma membrane ruffles, a process relevant for spatial and temporal regulation of mTORC1 by receptor and nutrient stimuli.
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Affiliation(s)
- Christian Makhoul
- Department of Biochemistry and Pharmacology and Bio21 Molecular Science and Biotechnology Institute and
| | - Fiona J Houghton
- Department of Biochemistry and Pharmacology and Bio21 Molecular Science and Biotechnology Institute and
| | - Elizabeth Hinde
- Department of Biochemistry and Pharmacology and Bio21 Molecular Science and Biotechnology Institute and.,School of Physics, The University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Paul A Gleeson
- Department of Biochemistry and Pharmacology and Bio21 Molecular Science and Biotechnology Institute and
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68
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KA S, CM P, Swingle MR, A M, C L, AD C, RE H, AN K. Quantitative proteomics and phosphoproteomics of PPP2R5D variants reveal deregulation of RPS6 phosphorylation through converging signaling cascades. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.27.534397. [PMID: 37034727 PMCID: PMC10081281 DOI: 10.1101/2023.03.27.534397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Variants in the phosphoprotein phosphatase-2 regulatory protein-5D gene ( PPP2R5D ) cause the clinical phenotype of Jordan's Syndrome (PPP2R5D-related disorder), which includes intellectual disability, hypotonia, seizures, macrocephaly, autism spectrum disorder and delayed motor skill development. The disorder originates from de novo single nucleotide mutations, generating missense variants that act in a dominant manner. Pathogenic mutations altering 13 different amino acids have been identified, with the E198K variant accounting for ∼40% of reported cases. Here, we use CRISPR-PRIME genomic editing to introduce a transition (c.592G>A) in the PPP2R5D allele in a heterozygous manner in HEK293 cells, generating E198K-heterozygous lines to complement existing E420K variant lines. We generate global protein and phosphorylation profiles of wild-type, E198K, and E420K cell lines and find unique and shared changes between variants and wild-type cells in kinase- and phosphatase-controlled signaling cascades. As shared signaling alterations, we observed ribosomal protein S6 (RPS6) hyperphosphorylation, indicative of increased ribosomal protein S6-kinase activity. Rapamycin treatment suppressed RPS6 phosphorylation in both, suggesting activation of mTORC1. Intriguingly, our data suggest AKT-dependent (E420K) and -independent (E198K) activation of mTORC1. Thus, although upstream activation of mTORC1 differs between PPP2R5D-related disorder genotypes, treatment with rapamycin or a p70S6K inhibitor warrants further investigation as potential therapeutic strategies for patients.
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Affiliation(s)
- Smolen KA
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755, USA
| | - Papke CM
- Department of Biochemistry and Molecular Biology, University of South Alabama, Mobile, AL 36688, USA
| | - MR Swingle
- Department of Biochemistry and Molecular Biology, University of South Alabama, Mobile, AL 36688, USA
| | - Musiyenko A
- Department of Biochemistry and Molecular Biology, University of South Alabama, Mobile, AL 36688, USA
| | - Li C
- Department of Biochemistry and Molecular Biology, University of South Alabama, Mobile, AL 36688, USA
| | - Camp AD
- Department of Biochemistry and Molecular Biology, University of South Alabama, Mobile, AL 36688, USA
| | - Honkanen RE
- Department of Biochemistry and Molecular Biology, University of South Alabama, Mobile, AL 36688, USA
| | - Kettenbach AN
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755, USA
- Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth, Lebanon, NH 03756, USA
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69
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Ibrahim YH, Pantelios S, Mutvei AP. An affinity tool for the isolation of endogenous active mTORC1 from various cellular sources. J Biol Chem 2023; 299:104644. [PMID: 36965617 PMCID: PMC10164890 DOI: 10.1016/j.jbc.2023.104644] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 03/02/2023] [Accepted: 03/13/2023] [Indexed: 03/27/2023] Open
Abstract
The mechanistic target of rapamycin complex 1 (mTORC1) is a central regulator of mammalian cell growth that is dysregulated in a number of human diseases, including metabolic syndromes, aging and cancer. Structural, biochemical and pharmacological studies that have increased our understanding of how mTORC1 executes growth control often relied upon purified mTORC1 protein. However, current immunoaffinity-based purification methods are expensive, inefficient, and do not necessarily isolate endogenous mTORC1, hampering their overall utility in research. Here we present a simple tool to isolate endogenous mTORC1 from various cellular sources. By recombinantly expressing and isolating mTORC1-binding Rag GTPases from E. Coli and using them as affinity probes, we demonstrate that mTORC1 can be isolated from mouse, bovine and human sources. Our results indicate that mTORC1 isolated by this relatively inexpensive method is catalytically active and amenable to scaling. Collectively, this tool may be utilized to isolate mTORC1 from various cellular sources, organs, and disease contexts, aiding mTORC1-related research.
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Affiliation(s)
| | - Spyridon Pantelios
- Department of Immunology, Pathology and Genetics, Uppsala University, Uppsala, Sweden
| | - Anders P Mutvei
- Department of Immunology, Pathology and Genetics, Uppsala University, Uppsala, Sweden.
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70
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Lee WS, Macdonald-Laurs E, Stephenson SEM, D'Arcy C, MacGregor D, Leventer RJ, Maixner W, Harvey AS, Lockhart PJ. Basal ganglia dysplasia and mTORopathy: A potential cause of postoperative seizures in focal cortical dysplasia. Epilepsia Open 2023; 8:205-210. [PMID: 36461712 PMCID: PMC9977751 DOI: 10.1002/epi4.12678] [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: 08/25/2022] [Accepted: 12/01/2022] [Indexed: 12/05/2022] Open
Abstract
Pathogenic somatic MTOR variants in the cerebral cortex are a frequent cause of focal cortical dysplasia (FCD). We describe a child with drug and surgery-resistant focal epilepsy due to FCD type II who developed progressive enlargement and T2 signal hyperintensity in the ipsilateral caudate and lentiform nuclei. Histopathology of caudate nucleus biopsies showed dysmorphic neurons, similar to those in resected cortex. Genetic analysis of frontal and temporal cortex and caudate nucleus identified a pathogenic somatic MTOR variant [NM_004958.4:c.4375G > C (p.Ala1459Pro)] that was not present in blood-derived gDNA. The mean variant allele frequency ranged from 0.4% to 3.2% in cerebral cortex and up to 5.4% in the caudate nucleus. The basal ganglia abnormalities suggest more widespread, potentially hemispheric dysplasia in this patient, consistent with the pathogenic variant occurring in early cerebral development. This finding provides a potential explanation for persistent seizures in some patients with seemingly complete resection of FCD or disconnection of a dysplastic hemisphere.
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Affiliation(s)
- Wei Shern Lee
- Murdoch Children's Research Institute, Parkville, Victoria, Australia.,Department of Paediatrics, The University of Melbourne, Parkville, Victoria, Australia
| | - Emma Macdonald-Laurs
- Department of Paediatrics, The University of Melbourne, Parkville, Victoria, Australia.,Department of Neurology, The Royal Children's Hospital, Parkville, Victoria, Australia
| | - Sarah E M Stephenson
- Murdoch Children's Research Institute, Parkville, Victoria, Australia.,Department of Paediatrics, The University of Melbourne, Parkville, Victoria, Australia
| | - Colleen D'Arcy
- Department of Anatomical Pathology, The Royal Children's Hospital, Parkville, Victoria, Australia
| | - Duncan MacGregor
- Department of Anatomical Pathology, The Royal Children's Hospital, Parkville, Victoria, Australia
| | - Richard J Leventer
- Murdoch Children's Research Institute, Parkville, Victoria, Australia.,Department of Paediatrics, The University of Melbourne, Parkville, Victoria, Australia.,Department of Neurology, The Royal Children's Hospital, Parkville, Victoria, Australia
| | - Wirginia Maixner
- Murdoch Children's Research Institute, Parkville, Victoria, Australia.,Department of Paediatrics, The University of Melbourne, Parkville, Victoria, Australia.,Department of Neurosurgery, The Royal Children's Hospital, Parkville, Victoria, Australia
| | - A Simon Harvey
- Murdoch Children's Research Institute, Parkville, Victoria, Australia.,Department of Paediatrics, The University of Melbourne, Parkville, Victoria, Australia.,Department of Neurology, The Royal Children's Hospital, Parkville, Victoria, Australia
| | - Paul J Lockhart
- Murdoch Children's Research Institute, Parkville, Victoria, Australia.,Department of Paediatrics, The University of Melbourne, Parkville, Victoria, Australia
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71
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Yang Z, Yu Z, Xiao B. Coordinated Regulation of Myelination by Growth Factor and Amino-acid Signaling Pathways. Neurosci Bull 2023; 39:453-465. [PMID: 36352321 PMCID: PMC10043148 DOI: 10.1007/s12264-022-00967-x] [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: 03/11/2022] [Accepted: 06/27/2022] [Indexed: 11/11/2022] Open
Abstract
Myelin-forming oligodendrocytes in the central nervous system (CNS) and Schwann cells in the peripheral nervous system (PNS) are essential for structural and functional homeostasis of nervous tissue. Albeit with certain similarities, the regulation of CNS and PNS myelination is executed differently. Recent advances highlight the coordinated regulation of oligodendrocyte myelination by amino-acid sensing and growth factor signaling pathways. In this review, we discuss novel insights into the understanding of differential regulation of oligodendrocyte and Schwann cell biology in CNS and PNS myelination, with particular focus on the roles of growth factor-stimulated RHEB-mTORC1 and GATOR2-mediated amino-acid sensing/signaling pathways. We also discuss recent progress on the metabolic regulation of oligodendrocytes and Schwann cells and the impact of their dysfunction on neuronal function and disease.
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Affiliation(s)
- Zhiwen Yang
- Shenzhen Key Laboratory of Gene Regulation and Systems Biology, Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518000, China
| | - Zongyan Yu
- Shenzhen Key Laboratory of Gene Regulation and Systems Biology, Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518000, China.
| | - Bo Xiao
- Shenzhen Key Laboratory of Gene Regulation and Systems Biology, Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518000, China.
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72
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Frias MA, Hatipoglu A, Foster DA. Regulation of mTOR by phosphatidic acid. Trends Endocrinol Metab 2023; 34:170-180. [PMID: 36732094 PMCID: PMC9957947 DOI: 10.1016/j.tem.2023.01.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2022] [Accepted: 01/03/2023] [Indexed: 02/03/2023]
Abstract
mTORC1, the mammalian target of rapamycin complex 1, is a key regulator of cellular physiology. The lipid metabolite phosphatidic acid (PA) binds to and activates mTORC1 in response to nutrients and growth factors. We review structural findings and propose a model for PA activation of mTORC1. PA binds to a highly conserved sequence in the α4 helix of the FK506 binding protein 12 (FKBP12)/rapamycin-binding (FRB) domain of mTOR. It is proposed that PA binding to two adjacent positively charged amino acids breaks and shortens the C-terminal region of helix α4. This has profound consequences for both substrate binding and the catalytic activity of mTORC1.
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Affiliation(s)
- Maria A Frias
- Department of Biology and Health Promotion, St. Francis College, Brooklyn, NY 11201, USA; Department of Biological Sciences, Hunter College of the City University of New York, New York, NY 10065, USA.
| | - Ahmet Hatipoglu
- Department of Biological Sciences, Hunter College of the City University of New York, New York, NY 10065, USA; Biochemistry Program, Graduate Center of the City University of New York, New York, NY 10016, USA
| | - David A Foster
- Department of Biological Sciences, Hunter College of the City University of New York, New York, NY 10065, USA; Biochemistry Program, Graduate Center of the City University of New York, New York, NY 10016, USA; Biology Program, Graduate Center of the City University of New York, New York, NY 10016, USA; Department of Pharmacology, Weill Cornell Medicine, New York, NY 10021, USA.
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73
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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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74
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Cui Z, Napolitano G, de Araujo MEG, Esposito A, Monfregola J, Huber LA, Ballabio A, Hurley JH. Structure of the lysosomal mTORC1-TFEB-Rag-Ragulator megacomplex. Nature 2023; 614:572-579. [PMID: 36697823 PMCID: PMC9931586 DOI: 10.1038/s41586-022-05652-7] [Citation(s) in RCA: 45] [Impact Index Per Article: 45.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Accepted: 12/13/2022] [Indexed: 01/26/2023]
Abstract
The transcription factor TFEB is a master regulator of lysosomal biogenesis and autophagy1. The phosphorylation of TFEB by the mechanistic target of rapamycin complex 1 (mTORC1)2-5 is unique in its mTORC1 substrate recruitment mechanism, which is strictly dependent on the amino acid-mediated activation of the RagC GTPase activating protein FLCN6,7. TFEB lacks the TOR signalling motif responsible for the recruitment of other mTORC1 substrates. We used cryogenic-electron microscopy to determine the structure of TFEB as presented to mTORC1 for phosphorylation, which we refer to as the 'megacomplex'. Two full Rag-Ragulator complexes present each molecule of TFEB to the mTOR active site. One Rag-Ragulator complex is bound to Raptor in the canonical mode seen previously in the absence of TFEB. A second Rag-Ragulator complex (non-canonical) docks onto the first through a RagC GDP-dependent contact with the second Ragulator complex. The non-canonical Rag dimer binds the first helix of TFEB with a RagCGDP-dependent aspartate clamp in the cleft between the Rag G domains. In cellulo mutation of the clamp drives TFEB constitutively into the nucleus while having no effect on mTORC1 localization. The remainder of the 108-amino acid TFEB docking domain winds around Raptor and then back to RagA. The double use of RagC GDP contacts in both Rag dimers explains the strong dependence of TFEB phosphorylation on FLCN and the RagC GDP state.
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Affiliation(s)
- Zhicheng Cui
- Department of Molecular and Cell Biology, University of California Berkeley, Berkeley, CA, USA
- California Institute for Quantitative Biosciences, University of California, Berkeley, CA, USA
| | - Gennaro Napolitano
- Telethon Institute of Genetics and Medicine (TIGEM), Naples, Italy
- Medical Genetics Unit, Department of Medical and Translational Science, Federico II University, Naples, Italy
| | - Mariana E G de Araujo
- Institute of Cell Biology, Biocenter, Medical University of Innsbruck, Innsbruck, Austria
| | - Alessandra Esposito
- Telethon Institute of Genetics and Medicine (TIGEM), Naples, Italy
- Medical Genetics Unit, Department of Medical and Translational Science, Federico II University, Naples, Italy
| | - Jlenia Monfregola
- Telethon Institute of Genetics and Medicine (TIGEM), Naples, Italy
- Medical Genetics Unit, Department of Medical and Translational Science, Federico II University, Naples, Italy
| | - Lukas A Huber
- Institute of Cell Biology, Biocenter, Medical University of Innsbruck, Innsbruck, Austria
| | - Andrea Ballabio
- Telethon Institute of Genetics and Medicine (TIGEM), Naples, Italy.
- Medical Genetics Unit, Department of Medical and Translational Science, Federico II University, Naples, Italy.
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA.
- SSM School for Advanced Studies, Federico II University, Naples, Italy.
| | - James H Hurley
- Department of Molecular and Cell Biology, University of California Berkeley, Berkeley, CA, USA.
- California Institute for Quantitative Biosciences, University of California, Berkeley, CA, USA.
- Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA, USA.
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A transient protein megacomplex that controls degradation of cell components. Nature 2023:10.1038/d41586-022-04538-y. [PMID: 36697728 DOI: 10.1038/d41586-022-04538-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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76
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Wu Q, Lv Q, Liu X, Ye X, Cao L, Wang M, Li J, Yang Y, Li L, Wang S. Natural compounds from botanical drugs targeting mTOR signaling pathway as promising therapeutics for atherosclerosis: A review. Front Pharmacol 2023; 14:1083875. [PMID: 36744254 PMCID: PMC9894899 DOI: 10.3389/fphar.2023.1083875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2022] [Accepted: 01/05/2023] [Indexed: 01/22/2023] Open
Abstract
Atherosclerosis (AS) is a chronic inflammatory disease that is a major cause of cardiovascular diseases (CVDs), including coronary artery disease, hypertension, myocardial infarction, and heart failure. Hence, the mechanisms of AS are still being explored. A growing compendium of evidence supports that the activity of the mechanistic/mammalian target of rapamycin (mTOR) is highly correlated with the risk of AS. The mTOR signaling pathway contributes to AS progression by regulating autophagy, cell senescence, immune response, and lipid metabolism. Various botanical drugs and their functional compounds have been found to exert anti- AS effects by modulating the activity of the mTOR signaling pathway. In this review, we summarize the pathogenesis of AS based on the mTOR signaling pathway from the aspects of immune response, autophagy, cell senescence, and lipid metabolism, and comb the recent advances in natural compounds from botanical drugs to inhibit the mTOR signaling pathway and delay AS development. This review will provide a new perspective on the mechanisms and precision treatments of AS.
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Affiliation(s)
- Qian Wu
- Guang’anmen Hospital, Chinese Academy of Chinese Medical Sciences, Beijing, China
| | - Qianyu Lv
- Guang’anmen Hospital, Chinese Academy of Chinese Medical Sciences, Beijing, China
| | - Xiao’an Liu
- Capital University of Medical, Beijing, China
| | - Xuejiao Ye
- Guang’anmen Hospital, Chinese Academy of Chinese Medical Sciences, Beijing, China
| | - Linlin Cao
- Guang’anmen Hospital, Chinese Academy of Chinese Medical Sciences, Beijing, China
| | - Manshi Wang
- Beijing Xicheng District Guangwai Hospital, Beijing, China
| | - Junjia Li
- Guang’anmen Hospital, Chinese Academy of Chinese Medical Sciences, Beijing, China
| | - Yingtian Yang
- Guang’anmen Hospital, Chinese Academy of Chinese Medical Sciences, Beijing, China
| | - Lanlan Li
- Guang’anmen Hospital, Chinese Academy of Chinese Medical Sciences, Beijing, China
| | - Shihan Wang
- Guang’anmen Hospital, Chinese Academy of Chinese Medical Sciences, Beijing, China,*Correspondence: Shihan Wang,
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77
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Liu Q, Deng C, Xing X, Hu Y, Wang Z, Liang Y. Silencing RIPK1/mTORC1 signalling attenuated the inflammation and oxidative stress in diabetic cardiomyopathy. Exp Cell Res 2023; 422:113417. [PMID: 36379276 DOI: 10.1016/j.yexcr.2022.113417] [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: 07/31/2022] [Revised: 10/20/2022] [Accepted: 11/09/2022] [Indexed: 11/13/2022]
Abstract
BACKGROUND Diabetes cardiomyopathy (DCM) is one of the major risk factors for the heart failure of the diabetic patients. RIPK1 maybe participate in the regulation of the oxidative stress and inflammation during DCM. METHODS H&E and Masson staining were utilized to assess the inflammation and fibrosis in myocardial tissues. CCK-8 and TUNEL staining were utilized to analyze cell viability and apoptosis, respectively. SOD activity and MDA content were detected utilizing the kits. The formation of autophagosomes was measured by immunofluorescence assay. RESULTS RIPK1 and RPTOR (a component of mTORC1) expression and oxidative stress level were upregulated, but autophagy was decreased in the myocardial tissues of DCM rat characterized by the high body weight and blood glucose, abnormal cardiac function, myocardial inflammation and fibrosis. High glucose (HG) treatment resulted in cell viability and autophagy level decreasing, inflammatory cytokines expression increasing and oxidative stress increasing in cardiac fibroblasts (CFs). Meanwhile, RIPK1 and RPTOR expression also was increased in HG-treated cells. HG-induced CFs apoptosis, inflammation, oxidative stress and the inhibition of HG to cell viability and autophagy was partly reversed by the inhibitor of RIPK1 and mTORC1. CONCLUSION Overall, RIPK1/mTORC1 signalling suppression improved HG-induced apoptosis, inflammation and oxidative stress through activation autophagy. These data provided a reliable evidence that RIPK1 may be a potential target for DCM therapeutic.
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Affiliation(s)
- Qin Liu
- Department of Anesthesiology, The Second Affiliated Hospital of Nanchang University, Nanchang, 330006, Jiangxi Province, PR China
| | - Changqing Deng
- Department of Gastroenterology, The Affiliated Hospital of Jiangxi University of Traditional Chinese Medicine, Nanchang, 330006, Jiangxi Province, PR China
| | - Xianliang Xing
- Department of Anesthesiology, The Second Affiliated Hospital of Nanchang University, Nanchang, 330006, Jiangxi Province, PR China
| | - Yanhui Hu
- Department of Anesthesiology, The Second Affiliated Hospital of Nanchang University, Nanchang, 330006, Jiangxi Province, PR China
| | - Zhong Wang
- Department of Anesthesiology, The Second Affiliated Hospital of Nanchang University, Nanchang, 330006, Jiangxi Province, PR China.
| | - Yingping Liang
- Department of Anesthesiology, The Second Affiliated Hospital of Nanchang University, Nanchang, 330006, Jiangxi Province, PR China.
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Caligaris M, Nicastro R, Hu Z, Tripodi F, Hummel JE, Pillet B, Deprez MA, Winderickx J, Rospert S, Coccetti P, Dengjel J, De Virgilio C. Snf1/AMPK fine-tunes TORC1 signaling in response to glucose starvation. eLife 2023; 12:84319. [PMID: 36749016 PMCID: PMC9937656 DOI: 10.7554/elife.84319] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Accepted: 02/06/2023] [Indexed: 02/08/2023] Open
Abstract
The AMP-activated protein kinase (AMPK) and the target of rapamycin complex 1 (TORC1) are central kinase modules of two opposing signaling pathways that control eukaryotic cell growth and metabolism in response to the availability of energy and nutrients. Accordingly, energy depletion activates AMPK to inhibit growth, while nutrients and high energy levels activate TORC1 to promote growth. Both in mammals and lower eukaryotes such as yeast, the AMPK and TORC1 pathways are wired to each other at different levels, which ensures homeostatic control of growth and metabolism. In this context, a previous study (Hughes Hallett et al., 2015) reported that AMPK in yeast, that is Snf1, prevents the transient TORC1 reactivation during the early phase following acute glucose starvation, but the underlying mechanism has remained elusive. Using a combination of unbiased mass spectrometry (MS)-based phosphoproteomics, genetic, biochemical, and physiological experiments, we show here that Snf1 temporally maintains TORC1 inactive in glucose-starved cells primarily through the TORC1-regulatory protein Pib2. Our data, therefore, extend the function of Pib2 to a hub that integrates both glucose and, as reported earlier, glutamine signals to control TORC1. We further demonstrate that Snf1 phosphorylates the TORC1 effector kinase Sch9 within its N-terminal region and thereby antagonizes the phosphorylation of a C-terminal TORC1-target residue within Sch9 itself that is critical for its activity. The consequences of Snf1-mediated phosphorylation of Pib2 and Sch9 are physiologically additive and sufficient to explain the role of Snf1 in short-term inhibition of TORC1 in acutely glucose-starved cells.
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Affiliation(s)
- Marco Caligaris
- Department of Biology, University of FribourgFribourgSwitzerland
| | | | - Zehan Hu
- Department of Biology, University of FribourgFribourgSwitzerland
| | - Farida Tripodi
- Department of Biotechnology and Biosciences, University of Milano-BicoccaMilanoItaly
| | - Johannes Erwin Hummel
- Institute of Biochemistry and Molecular Biology, Faculty of Medicine, University of FreiburgFreiburgGermany
| | - Benjamin Pillet
- Department of Biology, University of FribourgFribourgSwitzerland
| | | | | | - Sabine Rospert
- Institute of Biochemistry and Molecular Biology, Faculty of Medicine, University of FreiburgFreiburgGermany,Signalling Research Centres BIOSS and CIBSS, University of FreiburgFreiburgGermany
| | - Paola Coccetti
- Department of Biotechnology and Biosciences, University of Milano-BicoccaMilanoItaly
| | - Jörn Dengjel
- Department of Biology, University of FribourgFribourgSwitzerland
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79
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Scalia P, Williams SJ, Fujita-Yamaguchi Y, Giordano A. Cell cycle control by the insulin-like growth factor signal: at the crossroad between cell growth and mitotic regulation. Cell Cycle 2023; 22:1-37. [PMID: 36005738 PMCID: PMC9769454 DOI: 10.1080/15384101.2022.2108117] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
In proliferating cells and tissues a number of checkpoints (G1/S and G2/M) preceding cell division (M-phase) require the signal provided by growth factors present in serum. IGFs (I and II) have been demonstrated to constitute key intrinsic components of the peptidic active fraction of mammalian serum. In vivo genetic ablation studies have shown that the cellular signal triggered by the IGFs through their cellular receptors represents a non-replaceable requirement for cell growth and cell cycle progression. Retroactive and current evaluation of published literature sheds light on the intracellular circuitry activated by these factors providing us with a better picture of the pleiotropic mechanistic actions by which IGFs regulate both cell size and mitogenesis under developmental growth as well as in malignant proliferation. The present work aims to summarize the cumulative knowledge learned from the IGF ligands/receptors and their intracellular signaling transducers towards control of cell size and cell-cycle with particular focus to their actionable circuits in human cancer. Furthermore, we bring novel perspectives on key functional discriminants of the IGF growth-mitogenic pathway allowing re-evaluation on some of its signal components based upon established evidences.
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Affiliation(s)
- Pierluigi Scalia
- ISOPROG-Somatolink EPFP Research Network, Philadelphia, PA, USA, Caltanissetta, Italy,CST, Biology, Sbarro Institute for Cancer Research and Molecular Medicine, Temple University, Philadelphia, PA, United states,CONTACT Pierluigi Scalia ISOPROG-Somatolink EPFP Research Network, Philadelphia, PA9102, USA
| | - Stephen J Williams
- ISOPROG-Somatolink EPFP Research Network, Philadelphia, PA, USA, Caltanissetta, Italy,CST, Biology, Sbarro Institute for Cancer Research and Molecular Medicine, Temple University, Philadelphia, PA, United states
| | - Yoko Fujita-Yamaguchi
- Arthur Riggs Diabetes & Metabolism Research Institute, Beckman Research Institute of City of Hope, Duarte, CA, USA
| | - Antonio Giordano
- ISOPROG-Somatolink EPFP Research Network, Philadelphia, PA, USA, Caltanissetta, Italy,School of Medical Biotechnology, University of Siena, Italy
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80
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Ni R, Li Z, Li L, Peng D, Ming Y, Li L, Liu Y. Rethinking glutamine metabolism and the regulation of glutamine addiction by oncogenes in cancer. Front Oncol 2023; 13:1143798. [PMID: 36959802 PMCID: PMC10029103 DOI: 10.3389/fonc.2023.1143798] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Accepted: 02/24/2023] [Indexed: 03/09/2023] Open
Abstract
Glutamine, the most abundant non-essential amino acid in human blood, is crucial for cancer cell growth and cancer progression. Glutamine mainly functions as a carbon and nitrogen source for biosynthesis, energy metabolism, and redox homeostasis maintenance in cancer cells. Dysregulated glutamine metabolism is a notable metabolic characteristic of cancer cells. Some carcinogen-driven cancers exhibit a marked dependence on glutamine, also known as glutamine addiction, which has rendered the glutamine metabolic pathway a breakpoint in cancer therapeutics. However, some cancer cells can adapt to the glutamine unavailability by reprogramming metabolism, thus limiting the success of this therapeutic approach. Given the complexity of metabolic networks and the limited impact of inhibiting glutamine metabolism alone, the combination of glutamine metabolism inhibition and other therapeutic methods may outperform corresponding monotherapies in the treatment of cancers. This review summarizes the uptake, transport, and metabolic characteristics of glutamine, as well as the regulation of glutamine dependence by some important oncogenes in various cancers to emphasize the therapeutic potential of targeting glutamine metabolism. Furthermore, we discuss a glutamine metabolic pathway, the glutaminase II pathway, that has been substantially overlooked. Finally, we discuss the applicability of polytherapeutic strategies targeting glutamine metabolism to provide a new perspective on cancer therapeutics.
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Affiliation(s)
- Rui Ni
- Department of pharmacy, Daping Hospital, Army Medical University, Chongqing, China
| | - Ziwei Li
- Department of pharmacy, Daping Hospital, Army Medical University, Chongqing, China
| | - Li Li
- Department of pharmacy, Daping Hospital, Army Medical University, Chongqing, China
| | - Dan Peng
- Department of pharmacy, Daping Hospital, Army Medical University, Chongqing, China
| | - Yue Ming
- Department of pharmacy, Daping Hospital, Army Medical University, Chongqing, China
| | - Lin Li
- Department of pharmacy, Women and Children’s Hospital of Chongqing Medical University, Chongqing Health Center for Women and Children, Chongqing, China
- *Correspondence: Lin Li, ; Yao Liu,
| | - Yao Liu
- Department of pharmacy, Daping Hospital, Army Medical University, Chongqing, China
- *Correspondence: Lin Li, ; Yao Liu,
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81
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Al-Huseini I, Sirasanagandla SR, Babu KS, Sofin RGS, Das S. Kinase Inhibitors Involved in the Regulation of Autophagy: Molecular Concepts and Clinical Implications. Curr Med Chem 2023; 30:1502-1528. [PMID: 35078392 DOI: 10.2174/0929867329666220117114306] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 11/08/2021] [Accepted: 11/22/2021] [Indexed: 11/22/2022]
Abstract
All cells and intracellular components are remodeled and recycled in order to replace the old and damaged cells. Autophagy is a process by which damaged, and unwanted cells are degraded in the lysosomes. There are three different types of autophagy: macroautophagy, microautophagy, and chaperone-mediated autophagy. Autophagy has an effect on adaptive and innate immunity, suppression of any tumour, and the elimination of various microbial pathogens. The process of autophagy has both positive and negative effects, and this pertains to any specific disease or its stage of progression. Autophagy involves various processes which are controlled by various signaling pathways, such as Jun N-terminal kinase, GSK3, ERK1, Leucine-rich repeat kinase 2, and PTEN-induced putative kinase 1 and parkin RBR E3. Protein kinases are also important for the regulation of autophagy as they regulate the process of autophagy either by activation or inhibition. The present review discusses the kinase catalyzed phosphorylated reactions, the kinase inhibitors, types of protein kinase inhibitors and their binding properties to protein kinase domains, the structures of active and inactive kinases, and the hydrophobic spine structures in active and inactive protein kinase domains. The intervention of autophagy by targeting specific kinases may form the mainstay of treatment of many diseases and lead the road to future drug discovery.
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Affiliation(s)
- Isehaq Al-Huseini
- Department of Physiology, College of Medicine and Health Sciences, Sultan Qaboos University, Muscat, Al-Khodh 123, Oman
| | - Srinivasa Rao Sirasanagandla
- Department of Human and Clinical Anatomy, College of Medicine and Health Sciences, Sultan Qaboos University, Muscat, Al-Khodh 123, Oman
| | - Kondaveeti Suresh Babu
- Department of Biochemistry, Symbiosis Medical College for Women, Symbiosis International (Deemed) University, Pune, Maharashtra, India
| | | | - Srijit Das
- Department of Human and Clinical Anatomy, College of Medicine and Health Sciences, Sultan Qaboos University, Muscat, Al-Khodh 123, Oman
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82
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Stary D, Nepovimova E, Kuca K, Bajda M. Searching for new mTOR kinase inhibitors: Analysis of binding sites and validation of docking protocols. Chem Biol Drug Des 2023; 101:103-119. [PMID: 35945665 DOI: 10.1111/cbdd.14126] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 07/18/2022] [Accepted: 07/30/2022] [Indexed: 12/15/2022]
Abstract
The mammalian target of rapamycin (mTOR) is an important biological target for development of novel anticancer drugs and potential antiageing agents. Therefore, many scientific groups search for mTOR kinase inhibitors. Herein, we present structure-based approach which could be helpful in the studies on new bioactive compounds. Method validation was preceded by structural analysis of ATP catalytic cleft and FRB domain. In silico studies allowed us to point crucial amino acid residues for ligand binding and develop optimal docking protocols. The presented methodology could be applied for design and development of potential mTOR kinase inhibitors.
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Affiliation(s)
- Dorota Stary
- Department of Physicochemical Drug Analysis, Faculty of Pharmacy, Jagiellonian University Medical College, Cracow, Poland.,Department of Chemistry, Faculty of Science, University of Hradec Kralove, Hradec Kralove, Czech Republic.,Doctoral School of Medical and Health Sciences, Jagiellonian University Medical College, Cracow, Poland
| | - Eugenie Nepovimova
- Department of Chemistry, Faculty of Science, University of Hradec Kralove, Hradec Kralove, Czech Republic
| | - Kamil Kuca
- Department of Chemistry, Faculty of Science, University of Hradec Kralove, Hradec Kralove, Czech Republic
| | - Marek Bajda
- Department of Physicochemical Drug Analysis, Faculty of Pharmacy, Jagiellonian University Medical College, Cracow, Poland.,Department of Chemistry, Faculty of Science, University of Hradec Kralove, Hradec Kralove, Czech Republic
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Burnett GL, Yang YC, Aggen JB, Pitzen J, Gliedt MK, Semko CM, Marquez A, Evans JW, Wang G, Won WS, Tomlinson ACA, Kiss G, Tzitzilonis C, Thottumkara AP, Cregg J, Mellem KT, Choi JS, Lee JC, Zhao Y, Lee BJ, Meyerowitz JG, Knox JE, Jiang J, Wang Z, Wildes D, Wang Z, Singh M, Smith JA, Gill AL. Discovery of RMC-5552, a Selective Bi-Steric Inhibitor of mTORC1, for the Treatment of mTORC1-Activated Tumors. J Med Chem 2022; 66:149-169. [PMID: 36533617 PMCID: PMC9841523 DOI: 10.1021/acs.jmedchem.2c01658] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Hyperactivation of mTOR kinase by mutations in the PI3K/mTOR pathway or by crosstalk with other mutant cancer drivers, such as RAS, is a feature of many tumors. Multiple allosteric inhibitors of mTORC1 and orthosteric dual inhibitors of mTORC1 and mTORC2 have been developed as anticancer drugs, but their clinical utility has been limited. To address these limitations, we have developed a novel class of "bi-steric inhibitors" that interact with both the orthosteric and the allosteric binding sites in order to deepen the inhibition of mTORC1 while also preserving selectivity for mTORC1 over mTORC2. In this report, we describe the discovery and preclinical profile of the development candidate RMC-5552 and the in vivo preclinical tool compound RMC-6272. We also present evidence that selective inhibition of mTORC1 in combination with covalent inhibition of KRASG12C shows increased antitumor activity in a preclinical model of KRASG12C mutant NSCLC that exhibits resistance to KRASG12C inhibitor monotherapy.
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84
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Tinline-Goodfellow CT, Lees MJ, Hodson N. The skeletal muscle fiber periphery: A nexus of mTOR-related anabolism. SPORTS MEDICINE AND HEALTH SCIENCE 2022; 5:10-19. [PMID: 36994172 PMCID: PMC10040390 DOI: 10.1016/j.smhs.2022.11.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 11/16/2022] [Accepted: 11/23/2022] [Indexed: 12/02/2022] Open
Abstract
Skeletal muscle anabolism is driven by numerous stimuli such as growth factors, nutrients (i.e., amino acids, glucose), and mechanical stress. These stimuli are integrated by the mechanistic target of rapamycin (mTOR) complex 1 (mTORC1) signal transduction cascade. In recent years, work from our laboratory and elsewhere has sought to unravel the molecular mechanisms underpinning the mTOR-related activation of muscle protein synthesis (MPS), as well as the spatial regulation of these mechanisms within the skeletal muscle cell. These studies have suggested that the skeletal muscle fiber periphery is a region of central importance in anabolism (i.e., growth/MPS). Indeed, the fiber periphery is replete with the substrates, molecular machinery, and translational apparatus necessary to facilitate MPS. This review provides a summary of the mechanisms underpinning the mTOR-associated activation of MPS from cell, rodent, and human studies. It also presents an overview of the spatial regulation of mTORC1 in response to anabolic stimuli and outlines the factors that distinguish the periphery of the cell as a highly notable region of skeletal muscle for the induction of MPS. Future research should seek to further explore the nutrient-induced activation of mTORC1 at the periphery of skeletal muscle fibers.
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Affiliation(s)
| | - Matthew J. Lees
- Faculty of Kinesiology and Physical Education, University of Toronto, Canada
| | - Nathan Hodson
- Faculty of Kinesiology and Physical Education, University of Toronto, Canada
- Institute of Sport, Manchester Metropolitan University, Manchester, United Kingdom
- Department of Sport and Exercise Sciences, Manchester Metropolitan University, Manchester, United Kingdom
- Corresponding author. Faculty of Kinesiology and Physical Education, University of Toronto, Canada.
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85
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Nikolic M, Novakovic J, Ramenskaya G, Kokorekin V, Jeremic N, Jakovljevic V. Cooling down with Entresto. Can sacubitril/valsartan combination enhance browning more than coldness? Diabetol Metab Syndr 2022; 14:175. [PMID: 36419097 PMCID: PMC9686067 DOI: 10.1186/s13098-022-00944-4] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Accepted: 11/04/2022] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND It is a growing importance to induce a new treatment approach to encourage weight loss but also to improve maintenance of lost weight. It has been shown that promotion of brown adipose tissue (BAT) function or acquisition of BAT characteristics in white adipose tissue (terms referred as "browning") can be protective against obesity. MAIN TEXT Amongst numerous established environmental influences on BAT activity, cold exposure is the best interested technique due to its not only effects on of BAT depots in proliferation process but also de novo differentiation of precursor cells via β-adrenergic receptor activation. A novel combination drug, sacubitril/valsartan, has been shown to be more efficient in reducing cardiovascular events and heart failure readmission compared to conventional therapy. Also, this combination of drugs increases the postprandial lipid oxidation contributing to energy expenditure, promotes lipolysis in adipocytes and reduces body weight. To date, there is no research examining potential of combined sacubitril/valsartan use to promote browning or mechanisms in the basis of this thermogenic process. CONCLUSION Due to the pronounced effects of cold and sacubitril/valsartan treatment on function and metabolism of BAT, the primary goal of further research should focused on investigation of the synergistic effects of the sacubitril/valsartan treatment at low temperature environmental conditions.
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Affiliation(s)
- Marina Nikolic
- Department of Physiology, Faculty of Medical Sciences, University of Kragujevac, Kragujevac, Serbia
| | - Jovana Novakovic
- Department of Pharmacy, Faculty of Medical Sciences, University of Kragujevac, Kragujevac, Serbia
| | | | | | - Nevena Jeremic
- Department of Pharmacy, Faculty of Medical Sciences, University of Kragujevac, Kragujevac, Serbia.
- First Moscow State Medical University IM Sechenov, Moscow, Russia.
| | - Vladimir Jakovljevic
- Department of Physiology, Faculty of Medical Sciences, University of Kragujevac, Kragujevac, Serbia
- Department of Human Pathology, First Moscow State Medical University IM Sechenov, Moscow, Russia
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86
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Yang M, Hu M, Zhang Y, Jia S, Sun X, Zhao W, Ge M, Dong B. Sarcopenic obesity is associated with frailty among community-dwelling older adults: findings from the WCHAT study. BMC Geriatr 2022; 22:863. [PMCID: PMC9667677 DOI: 10.1186/s12877-022-03617-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 11/14/2022] [Indexed: 11/18/2022] Open
Abstract
Objective Uncertainties remain regarding the relationship between sarcopenic obesity and frailty. This study aimed to explore the association of these two common geriatric syndromes among community-dwelling older adults. Methods Baseline data from the West China Health and Aging Trend (WCHAT) study was used. Sarcopenia was assessed based on the criteria established by the Asian working group for sarcopenia. Body fat percentages above the 60th percentile specified by sex were classified as obesity. Sarcopenic obesity was defined as the concurrence of obesity and sarcopenia. Frailty was assessed by Fried criteria. Multinomial logistic regression was adopted to explore associations of sarcopenic obesity with frailty. Results Overall, 2372 older adults (mean age 67.6 ± 5.9) were involved in this study. The prevalence of frailty and sarcopenic obesity was 6.2 and 6.28%, respectively. After adjusting for covariates, sarcopenic obesity was significantly associated with prefrailty (OR = 1.74, 95% CI = 1.15–2.64, P = 0.009) and frailty (OR = 4.42, 95% CI = 2.19–8.93, P < 0.001) compared to nonsarcopenia and nonobesity. Conclusions Sarcopenic obesity was significantly correlated with prefrailty and frailty among older adults. Intervention for sarcopenic obesity may contribute to the prevention of incident frailty.
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Affiliation(s)
- Mei Yang
- grid.13291.380000 0001 0807 1581National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, GuoXueXiang 37, Chengdu, 610041 China
| | - Meng Hu
- grid.13291.380000 0001 0807 1581National Clinical Research Center for Geriatrics and Department of General Practice, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, and Collaborative Innovation Center of Biotherapy, Chengdu, China
| | - Yan Zhang
- grid.13291.380000 0001 0807 1581National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, GuoXueXiang 37, Chengdu, 610041 China
| | - Shuli Jia
- grid.13291.380000 0001 0807 1581National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, GuoXueXiang 37, Chengdu, 610041 China
| | - Xuelian Sun
- grid.13291.380000 0001 0807 1581National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, GuoXueXiang 37, Chengdu, 610041 China
| | - Wanyu Zhao
- grid.13291.380000 0001 0807 1581National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, GuoXueXiang 37, Chengdu, 610041 China ,grid.13291.380000 0001 0807 1581Center of Gerontology and Geriatrics, West China Hospital, Sichuan University, GuoXueXiang 37, Chengdu, 610041 China
| | - Meiling Ge
- grid.13291.380000 0001 0807 1581National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, GuoXueXiang 37, Chengdu, 610041 China ,grid.13291.380000 0001 0807 1581Center of Gerontology and Geriatrics, West China Hospital, Sichuan University, GuoXueXiang 37, Chengdu, 610041 China
| | - Birong Dong
- grid.13291.380000 0001 0807 1581National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, GuoXueXiang 37, Chengdu, 610041 China ,grid.13291.380000 0001 0807 1581Center of Gerontology and Geriatrics, West China Hospital, Sichuan University, GuoXueXiang 37, Chengdu, 610041 China
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Jamsheer K M, Awasthi P, Laxmi A. The social network of target of rapamycin complex 1 in plants. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:7026-7040. [PMID: 35781571 DOI: 10.1093/jxb/erac278] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 06/20/2022] [Indexed: 06/15/2023]
Abstract
Target of rapamycin complex 1 (TORC1) is a highly conserved serine-threonine protein kinase crucial for coordinating growth according to nutrient availability in eukaryotes. It works as a central integrator of multiple nutrient inputs such as sugar, nitrogen, and phosphate and promotes growth and biomass accumulation in response to nutrient sufficiency. Studies, especially in the past decade, have identified the central role of TORC1 in regulating growth through interaction with hormones, photoreceptors, and stress signaling machinery in plants. In this review, we comprehensively analyse the interactome and phosphoproteome of the Arabidopsis TORC1 signaling network. Our analysis highlights the role of TORC1 as a central hub kinase communicating with the transcriptional and translational apparatus, ribosomes, chaperones, protein kinases, metabolic enzymes, and autophagy and stress response machinery to orchestrate growth in response to nutrient signals. This analysis also suggests that along with the conserved downstream components shared with other eukaryotic lineages, plant TORC1 signaling underwent several evolutionary innovations and co-opted many lineage-specific components during. Based on the protein-protein interaction and phosphoproteome data, we also discuss several uncharacterized and unexplored components of the TORC1 signaling network, highlighting potential links for future studies.
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Affiliation(s)
- Muhammed Jamsheer K
- Amity Institute of Genome Engineering, Amity University Uttar Pradesh, Noida 201313, India
| | - Prakhar Awasthi
- National Institute of Plant Genome Research, New Delhi 110067, India
| | - Ashverya Laxmi
- National Institute of Plant Genome Research, New Delhi 110067, India
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88
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Mallén-Ponce MJ, Pérez-Pérez ME, Crespo JL. Deciphering the function and evolution of the target of rapamycin signaling pathway in microalgae. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:6993-7005. [PMID: 35710309 PMCID: PMC9664231 DOI: 10.1093/jxb/erac264] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Accepted: 06/16/2022] [Indexed: 06/15/2023]
Abstract
Microalgae constitute a highly diverse group of photosynthetic microorganisms that are widely distributed on Earth. The rich diversity of microalgae arose from endosymbiotic events that took place early in the evolution of eukaryotes and gave rise to multiple lineages including green algae, the ancestors of land plants. In addition to their fundamental role as the primary source of marine and freshwater food chains, microalgae are essential producers of oxygen on the planet and a major biotechnological target for sustainable biofuel production and CO2 mitigation. Microalgae integrate light and nutrient signals to regulate cell growth. Recent studies identified the target of rapamycin (TOR) kinase as a central regulator of cell growth and a nutrient sensor in microalgae. TOR promotes protein synthesis and regulates processes that are induced under nutrient stress such as autophagy and the accumulation of triacylglycerol and starch. A detailed analysis of representative genomes from the entire microalgal lineage revealed that the highly conserved central components of the TOR pathway are likely to have been present in the last eukaryotic common ancestor, and the loss of specific TOR signaling elements at an early stage in the evolution of microalgae. Here we examine the evolutionary conservation of TOR signaling components in diverse microalgae and discuss recent progress of this signaling pathway in these organisms.
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Affiliation(s)
- Manuel J Mallén-Ponce
- Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas-Universidad de Sevilla, Sevilla, Spain
| | - María Esther Pérez-Pérez
- Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas-Universidad de Sevilla, Sevilla, Spain
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Napolitano G, Di Malta C, Ballabio A. Non-canonical mTORC1 signaling at the lysosome. Trends Cell Biol 2022; 32:920-931. [PMID: 35654731 DOI: 10.1016/j.tcb.2022.04.012] [Citation(s) in RCA: 44] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 04/28/2022] [Accepted: 04/29/2022] [Indexed: 01/21/2023]
Abstract
The mechanistic target of rapamycin complex 1 (mTORC1) signaling hub integrates multiple environmental cues to modulate cell growth and metabolism. Over the past decade considerable knowledge has been gained on the mechanisms modulating mTORC1 lysosomal recruitment and activation. However, whether and how mTORC1 is able to elicit selective responses to diverse signals has remained elusive until recently. We discuss emerging evidence for a 'non-canonical' mTORC1 signaling pathway that controls the function of microphthalmia/transcription factor E (MiT-TFE) transcription factors, key regulators of cell metabolism. This signaling pathway is mediated by a specific mechanism of substrate recruitment, and responds to stimuli that appear to converge on the lysosomal surface. We discuss the relevance of this pathway in physiological and disease conditions.
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Affiliation(s)
- Gennaro Napolitano
- Telethon Institute of Genetics and Medicine (TIGEM), Via Campi Flegrei 34, 80078 Pozzuoli, Naples, Italy; Medical Genetics Unit, Department of Medical and Translational Science, Federico II University, Via Pansini 5, 80131 Naples, Italy.
| | - Chiara Di Malta
- Telethon Institute of Genetics and Medicine (TIGEM), Via Campi Flegrei 34, 80078 Pozzuoli, Naples, Italy; Medical Genetics Unit, Department of Medical and Translational Science, Federico II University, Via Pansini 5, 80131 Naples, Italy.
| | - Andrea Ballabio
- Telethon Institute of Genetics and Medicine (TIGEM), Via Campi Flegrei 34, 80078 Pozzuoli, Naples, Italy; Medical Genetics Unit, Department of Medical and Translational Science, Federico II University, Via Pansini 5, 80131 Naples, Italy; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA.
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90
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Hypomethylation of RPTOR in peripheral blood is associated with very early-stage lung cancer. Clin Chim Acta 2022; 537:173-180. [DOI: 10.1016/j.cca.2022.10.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 10/07/2022] [Accepted: 10/17/2022] [Indexed: 11/05/2022]
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91
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Abou Daher A, Alkhansa S, Azar WS, Rafeh R, Ghadieh HE, Eid AA. Translational Aspects of the Mammalian Target of Rapamycin Complexes in Diabetic Nephropathy. Antioxid Redox Signal 2022; 37:802-819. [PMID: 34544257 DOI: 10.1089/ars.2021.0217] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Significance: Despite the many efforts put into understanding diabetic nephropathy (DN), direct treatments for DN have yet to be discovered. Understanding the mechanisms behind DN is an essential step in the development of novel therapeutic regimens. The mammalian target of rapamycin (mTOR) pathway has emerged as an important candidate in the quest for drug discovery because of its role in regulating growth, proliferation, as well as protein and lipid metabolism. Recent Advances: Kidney cells have been found to rely on basal autophagy for survival and for conserving kidney integrity. Recent studies have shown that diabetes induces renal autophagy deregulation, leading to kidney injury. Hyper-activation of the mTOR pathway and oxidative stress have been suggested to play a role in diabetes-induced autophagy imbalance. Critical Issues: A detailed understanding of the role of mTOR signaling in diabetes-associated complications is of major importance in the search for a cure. In this review, we provide evidence that mTOR is heavily implicated in diabetes-induced kidney injury. We suggest possible mechanisms through which mTOR exerts its negative effects by increasing insulin resistance, upregulating oxidative stress, and inhibiting autophagy. Future Directions: Both increased oxidative stress and autophagy deregulation are deeply embedded in DN. However, the mechanisms controlling oxidative stress and autophagy are not well understood. Although Akt/mTOR signaling seems to play an important role in oxidative stress and autophagy, further investigation is required to uncover the details of this signaling pathway. Antioxid. Redox Signal. 37, 802-819.
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Affiliation(s)
- Alaa Abou Daher
- Department of Anatomy, Cell Biology and Physiological Sciences, Faculty of Medicine and Medical Center, American University of Beirut, Beirut, Lebanon
| | - Sahar Alkhansa
- Department of Anatomy, Cell Biology and Physiological Sciences, Faculty of Medicine and Medical Center, American University of Beirut, Beirut, Lebanon.,AUB Diabetes, Faculty of Medicine and Medical Center, American University of Beirut, Beirut, Lebanon
| | - William S Azar
- Department of Anatomy, Cell Biology and Physiological Sciences, Faculty of Medicine and Medical Center, American University of Beirut, Beirut, Lebanon.,AUB Diabetes, Faculty of Medicine and Medical Center, American University of Beirut, Beirut, Lebanon.,Department of Physiology and Biophysics, Georgetown University Medical School, Washington, District of Columbia, USA
| | - Rim Rafeh
- Department of Anatomy, Cell Biology and Physiological Sciences, Faculty of Medicine and Medical Center, American University of Beirut, Beirut, Lebanon.,AUB Diabetes, Faculty of Medicine and Medical Center, American University of Beirut, Beirut, Lebanon
| | - Hilda E Ghadieh
- Department of Anatomy, Cell Biology and Physiological Sciences, Faculty of Medicine and Medical Center, American University of Beirut, Beirut, Lebanon.,AUB Diabetes, Faculty of Medicine and Medical Center, American University of Beirut, Beirut, Lebanon
| | - Assaad A Eid
- Department of Anatomy, Cell Biology and Physiological Sciences, Faculty of Medicine and Medical Center, American University of Beirut, Beirut, Lebanon.,AUB Diabetes, Faculty of Medicine and Medical Center, American University of Beirut, Beirut, Lebanon
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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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93
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Petsri K, Thongsom S, Racha S, Chamni S, Jindapol S, Kaekratoke N, Zou H, Chanvorachote P. Novel mechanism of napabucasin, a naturally derived furanonaphthoquinone: apoptosis and autophagy induction in lung cancer cells through direct targeting on Akt/mTOR proteins. BMC Complement Med Ther 2022; 22:250. [PMID: 36180880 PMCID: PMC9524025 DOI: 10.1186/s12906-022-03727-6] [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: 06/09/2022] [Accepted: 09/15/2022] [Indexed: 11/22/2022] Open
Abstract
Background Akt and mTOR are aberrantly activated in cancers and targeting these proteins are interesting for cancer drug discovery. Napabucasin (NB), a phytochemical compound, has been reported as potential anti-cancer agent, however, Akt and mTOR targeting mechanisms remain unclear. Method Apoptosis induction was investigated by Hoechst 33342/PI double staining and annexin V/PI staining with flowcytometry. Autophagy was evaluated by monodansylcadaverine staining and Western blot analysis. Binding affinity of NB and essential signaling proteins (PI3K, Akt, and mTOR) was investigated using molecular docking and confirmed by Western blot analysis. Result A structure modification from changing methyl moiety of acetyl group of NB to hydroxyl moiety of carboxyl group of NB derivative (napabucasin-acid or NB-acid) greatly affected the compound activities. NB showed more potent anti-cancer activity. NB reduced cell viability with an approximately 20 times lower IC50 and inhibited the colony formation capacity much more than NB-acid treated cells. NB induced cell apoptosis, which was accompanied by decrease Bcl‑2 and Mcl-1 and clevage of PARP, while NB-acid show lesser effect on Mcl-1. NB was found to strongly induce autophagy indicated by acidic vesicle staining and the LC3B conversion. Interestingly, computational molecular docking analysis further demonstrated that NB directly bound to Akt and mTOR (complex 1 and 2) proteins at their critical sites indicating that NB targets the upstream regulators of apoptosis and autophagy. The docking results were confirmed by decrease of p-Akt/Akt, p-mTOR/mTOR, and c-Myc a downstream target of Akt protein levels. Conclusion Results show for the first time that NB exerts an anti-cancer activity through the direct interaction to Akt and mTOR proteins. The methyl moiety of acetyl group of NB is required for its potent anti-cancer activities. These data encourage further development of NB compounds for Akt and mTOR driven cancers. Supplementary Information The online version contains supplementary material available at 10.1186/s12906-022-03727-6.
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94
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Structures of Mec1/ATR kinase endogenously stimulated by different genotoxins. Cell Discov 2022; 8:98. [PMID: 36175395 PMCID: PMC9523049 DOI: 10.1038/s41421-022-00461-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 08/20/2022] [Indexed: 11/16/2022] Open
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Roberson PA, Jefferson LS, Kimball SR. Convergence of signaling pathways in mediating actions of leucine and IGF-1 on mTORC1 in L6 myoblasts. Am J Physiol Cell Physiol 2022; 323:C804-C812. [PMID: 35912992 PMCID: PMC9448342 DOI: 10.1152/ajpcell.00183.2022] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Revised: 07/27/2022] [Accepted: 07/28/2022] [Indexed: 11/22/2022]
Abstract
Leucine and insulin-like growth factor-1 (IGF-1) are important regulators of protein synthesis in skeletal muscle. The mechanistic target of rapamycin complex 1 (mTORC1) is of particular importance in their mechanism of action. In the present study, pathways through which leucine and IGF-1 converge to mediate activation of mTORC1 were examined in L6 myoblasts that were deprived of leucine and serum followed by readdition of either leucine or IGF-1. Compared with leucine- and serum-deprived myoblasts, IGF-1, but not leucine, promoted phosphorylation of protein kinase B (AKT), tuberous sclerosis complex 2 (TSC2), and the autophosphorylation site on mTOR (S2481) and also stimulated mTOR kinase activity in mTOR immunoprecipitated samples. Both leucine and IGF-1 promoted phosphorylation of mTOR on S2448. The association of mTOR with the regulatory-associated protein of mTOR (Raptor) was altered by IGF-1 treatment and trended (P = 0.065) to be altered by leucine treatment. Alterations in the association of mTOR with Raptor were proportional to changes in phosphorylation of the mTOR substrates, eIF4E-binding protein 1 (4E-BP1), and ribosomal protein S6 Kinase-β1 (p70S6K1). Surprisingly, leucine, but not IGF-1, stimulated protein synthesis suggesting a unique role for nutrients in regulating protein synthesis. Overall, the results are consistent with a model whereby IGF-1 stimulates phosphorylation of 4E-BP1 and p70S6K1 in L6 myoblasts through an AKT-TSC2-mTORC1 signaling pathway that also involves changes in the interaction between mTOR and Raptor. In contrast, leucine signaling to mTOR results in alterations in certain mTOR phosphorylation sites and the interaction between mTOR and Raptor and stimulates protein synthesis.
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Affiliation(s)
- Paul A Roberson
- Department of Cellular and Molecular Physiology, Penn State College of Medicine, Hershey, Pennsylvania
| | - Leonard S Jefferson
- Department of Cellular and Molecular Physiology, Penn State College of Medicine, Hershey, Pennsylvania
| | - Scot R Kimball
- Department of Cellular and Molecular Physiology, Penn State College of Medicine, Hershey, Pennsylvania
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Wallace RL, Lu E, Luo X, Capaldi AP. Ait1 regulates TORC1 signaling and localization in budding yeast. eLife 2022; 11:68773. [PMID: 36047762 PMCID: PMC9499541 DOI: 10.7554/elife.68773] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 08/31/2022] [Indexed: 11/23/2022] Open
Abstract
The target of rapamycin complex I (TORC1) regulates cell growth and metabolism in eukaryotes. Previous studies have shown that nitrogen and amino acid signals activate TORC1 via the highly conserved small GTPases, Gtr1/2 (RagA/C in humans), and the GTPase activating complex SEAC/GATOR. However, it remains unclear if, and how, other proteins/pathways regulate TORC1 in simple eukaryotes like yeast. Here, we report that the previously unstudied GPCR-like protein, Ait1, binds to TORC1-Gtr1/2 in Saccharomyces cerevisiae and holds TORC1 around the vacuole during log-phase growth. Then, during amino acid starvation, Ait1 inhibits TORC1 via Gtr1/2 using a loop that resembles the RagA/C-binding domain in the human protein SLC38A9. Importantly, Ait1 is only found in the Saccharomycetaceae/codaceae, two closely related families of yeast that have lost the ancient TORC1 regulators Rheb and TSC1/2. Thus, the TORC1 circuit found in the Saccharomycetaceae/codaceae, and likely other simple eukaryotes, has undergone significant rewiring during evolution.
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Affiliation(s)
- Ryan L Wallace
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, United States
| | - Eric Lu
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, United States
| | - Xiangxia Luo
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, United States
| | - Andrew P Capaldi
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, United States
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97
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tRNA-Derived Fragment tRF-5009A Regulates Autophagy and Degeneration of Cartilage in Osteoarthritis via Targeting mTOR. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2022; 2022:5781660. [PMID: 36035226 PMCID: PMC9410839 DOI: 10.1155/2022/5781660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 07/22/2022] [Indexed: 11/18/2022]
Abstract
tRNA-derived fragments (tRFs) have been reported to have critical regulatory roles in osteoarthritis (OA). Recent studies have suggested that autophagy promotes the homeostasis of the extracellular matrix of chondrocytes in OA. However, the role of tRFs in posttranscriptional gene regulation during autophagy in OA is unknown. Therefore, we explored the role of tRF-5009A in the posttranscriptional gene regulation of autophagy and cartilage degeneration in OA. Using RNA sequencing, we identified tRF-5009A, the tRNAValCAC-derived fragment, in OA tissues and explored its expression by quantitative reverse transcription PCR and fluorescence in situ hybridization. We further investigated the relationship between the expression of tRF-5009A and clinical factors in OA. Chondrocytes were transfected with a tRF-5009A inhibitor or mimic to determine their functions, including in relation to autophagy and the cartilage phenotype. A rescue experiment and dual-luciferase reporter assay were conducted to determine whether the 3′-untranslated region (UTR) of mTOR contains a tRF-5009A-binding site. tRF-5009A was downregulated in the cartilage of OA knees, especially in damaged areas. mTOR was highly expressed in damaged cartilage and negatively correlated with the expression of tRF-5009A; transfection with a tRF-5009A inhibitor promoted the expression of mTOR and suppressed autophagy, whereas transfection with a tRF-5009A mimic had the opposite effect. A dual-luciferase reporter assay showed that tRF-5009A silenced the expression of mTOR by binding to its 3′-UTR. Thus, tRF-5009A regulates autophagy and cartilage degeneration in OA by targeting mTOR. In summary, these findings provide an additional tool for the clinical diagnosis and novel targeted therapy of OA.
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98
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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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99
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Yang AJT, Mohammad A, Tsiani E, Necakov A, MacPherson REK. Chronic AMPK Activation Reduces the Expression and Alters Distribution of Synaptic Proteins in Neuronal SH-SY5Y Cells. Cells 2022; 11:cells11152354. [PMID: 35954198 PMCID: PMC9367429 DOI: 10.3390/cells11152354] [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: 06/19/2022] [Revised: 07/22/2022] [Accepted: 07/25/2022] [Indexed: 11/16/2022] Open
Abstract
Neuronal growth and synaptic function are dependent on precise protein production and turnover at the synapse. AMPK-activated protein kinase (AMPK) represents a metabolic node involved in energy sensing and in regulating synaptic protein homeostasis. However, there is ambiguity surrounding the role of AMPK in regulating neuronal growth and health. This study examined the effect of chronic AMPK activation on markers of synaptic function and growth. Retinoic-acid-differentiated SH-SY5Y human neuroblastoma cells were treated with A-769662 (100 nM) or Compound C (30 nM) for 1, 3, or 5 days before AMPK, mTORC1, and markers for synapse function were examined. Cell morphology, neuronal marker content, and location were quantified after 5 days of treatment. AMPK phosphorylation was maintained throughout all 5 days of treatment with A-769662 and resulted in chronic mTORC1 inhibition. Lower total, soma, and neuritic neuronal marker contents were observed following 5 d of AMPK activation. Neurite protein abundance and distribution was lower following 5 days of A-769662 treatment. Our data suggest that chronic AMPK activation impacts synaptic protein content and reduces neurite protein abundance and distribution. These results highlight a distinct role that metabolism plays on markers of synapse health and function.
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Affiliation(s)
- Alex J. T. Yang
- Department of Health Sciences, Brock University, St. Catharines, ON L2S 3A1, Canada; (A.J.T.Y.); (A.M.); (E.T.)
| | - Ahmad Mohammad
- Department of Health Sciences, Brock University, St. Catharines, ON L2S 3A1, Canada; (A.J.T.Y.); (A.M.); (E.T.)
| | - Evangelia Tsiani
- Department of Health Sciences, Brock University, St. Catharines, ON L2S 3A1, Canada; (A.J.T.Y.); (A.M.); (E.T.)
| | - Aleksandar Necakov
- Department of Biological Sciences, Brock University, St. Catharines, ON L2S 3A1, Canada;
- Centre for Neuroscience, Brock University, St. Catharines, ON L2S 3A1, Canada
| | - Rebecca E. K. MacPherson
- Department of Health Sciences, Brock University, St. Catharines, ON L2S 3A1, Canada; (A.J.T.Y.); (A.M.); (E.T.)
- Centre for Neuroscience, Brock University, St. Catharines, ON L2S 3A1, Canada
- Correspondence:
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100
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Shams R, Ito Y, Miyatake H. Development of an RHEB-Targeting Peptide To Inhibit mTORC1 Kinase Activity. ACS OMEGA 2022; 7:23479-23486. [PMID: 35847293 PMCID: PMC9280966 DOI: 10.1021/acsomega.2c01865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
In cancer, the mechanistic/mammalian target of rapamycin complex-1 (mTORC1) is hyperactivated to promote survival under adverse conditions. The kinase activity of mTORC1 is activated by small-GTPase RHEB-GTP. Therefore, a new modality to inhibit mTORC1 activity has emerged, through intercepting RHEB. However, due to the relatively large contact area involved in the interaction between RHEB and mTORC1, facilitating this inhibition through small molecules has been challenging. Here, we report the development of a peptide that can inhibit the RHEB-mTORC1 interaction. The peptide, P1_WT, was designed based on the α-helix (aa 101-115) of the N-heat domain of mTOR to interact with switch II of RHEB. P1_WT bound to RHEB (K D = 0.14 μM) and inhibited RHEB-mTORN-heat interaction (IC50 = 0.33 μM) in vitro. Consequently, P1_WT inhibited mTORC1 activity at a sub-micromolar level (IC50 ∼ 0.3 μM). P1_WT was predicted to be cell-permeable due to the rich content of arginine (23%), enhancing the intracellular translocation. These results show that P1_WT is a potential compound to further develop inhibitors for mTORC1 by intercepting RHEB from mTORC1.
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Affiliation(s)
- Raef Shams
- Emergent
Bioengineering Materials Research Team, RIKEN Center for Emergent Matter Science, Wako, Saitama 351-0198, Japan
- Department
of Life Science, Graduate School of Science and Engineering, Saitama University, Saitama City, Saitama 338-8570, Japan
| | - Yoshihiro Ito
- Emergent
Bioengineering Materials Research Team, RIKEN Center for Emergent Matter Science, Wako, Saitama 351-0198, Japan
- Nano
Medical Engineering Laboratory, RIKEN Cluster
for Pioneering Research, Wako, Saitama 351-0198, Japan
| | - Hideyuki Miyatake
- Department
of Life Science, Graduate School of Science and Engineering, Saitama University, Saitama City, Saitama 338-8570, Japan
- Nano
Medical Engineering Laboratory, RIKEN Cluster
for Pioneering Research, Wako, Saitama 351-0198, Japan
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