101
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Giguère V. DNA-PK, Nuclear mTOR, and the Androgen Pathway in Prostate Cancer. Trends Cancer 2020; 6:337-347. [PMID: 32209447 DOI: 10.1016/j.trecan.2020.01.015] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 01/21/2020] [Accepted: 01/23/2020] [Indexed: 02/07/2023]
Abstract
Androgen and its receptor (AR) are major drivers of prostate cancer (PCa), a leading cause of mortality in aging men. Thus, understanding the numerous mechanisms by which AR can promote the growth and proliferation of PCa cells and enable their escape from hormone-dependent therapies, eventually leading to metastasis and death of the patient, is essential to discover alternative therapeutic approaches. Recently, two structurally related members of the phosphatidylinositol 3-kinase-like protein kinase (PIKK) family, DNA-dependent protein kinase (DNA-PK) and mammalian target of rapamycin (mTOR), were shown to have a direct role in modulating AR activity on chromatin of PCa cells. In this review, the common features of DNA-PK and mTOR and the similarities in their noncanonical roles as transcription coregulators of the AR are highlighted. An outlook on how these findings could be translated into new approaches to manage and treat PCa is provided.
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Affiliation(s)
- Vincent Giguère
- Goodman Cancer Research Centre, McGill University, Montréal, QC, H3G 1Y6, Canada.
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102
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Kim K, Choi S, Cha M, Lee BH. Effects of mTOR inhibitors on neuropathic pain revealed by optical imaging of the insular cortex in rats. Brain Res 2020; 1733:146720. [PMID: 32061737 DOI: 10.1016/j.brainres.2020.146720] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 01/22/2020] [Accepted: 02/07/2020] [Indexed: 11/24/2022]
Abstract
In the pain matrix, the insular cortex (IC) is mainly involved in discriminative sensory and motivative emotion. Abnormal signal transmission from injury site causes neuropathic pain, which generates enhanced synaptic plasticity. The mammalian target of rapamycin (mTOR) complex is the key regulator of protein synthesis; it is involved in the modulation of synaptic plasticity. To date, there has been no report on the changes in optical signals in the IC under neuropathic condition after treatment with mTOR inhibitors, such as Torin1 and XL388. Therefore, we aimed to determine the pain-relieving effect of mTOR inhibitors (Torin1 and XL388) and observe the changes in optical signals in the IC after treatment. Mechanical threshold was measured in adult male Sprague-Dawley rats after neuropathic surgery, and therapeutic effect of inhibitors was assessed on post-operative day 7 following the microinjection of Torin1 or XL388 into the IC. Optical signals were acquired to observe the neuronal activity of the IC in response to peripheral stimulation before and after treatment with mTOR inhibitors. Consequently, the inhibitors showed the most effective alleviation 4 h after microinjection into the IC. In optical imaging, peak amplitudes of optical signals and areas of activated regions were reduced after treatment with Torin1 and XL388. However, there were no significant optical signal changes in the IC before and after vehicle application. These findings suggested that Torin1 and XL388 are associated with the alleviation of neuronal activity that is excessively manifested in the IC, and is assumed to diminish synaptic plasticity.
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Affiliation(s)
- Kyeongmin Kim
- Department of Physiology, Yonsei University College of Medicine, Seoul 03722, Republic of Korea; Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul 03722, Republic of Korea
| | - Songyeon Choi
- Department of Physiology, Yonsei University College of Medicine, Seoul 03722, Republic of Korea; Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul 03722, Republic of Korea
| | - Myeounghoon Cha
- Department of Physiology, Yonsei University College of Medicine, Seoul 03722, Republic of Korea
| | - Bae Hwan Lee
- Department of Physiology, Yonsei University College of Medicine, Seoul 03722, Republic of Korea; Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul 03722, Republic of Korea.
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103
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Zhao D, Jiang M, Zhang X, Hou H. The role of RICTOR amplification in targeted therapy and drug resistance. Mol Med 2020; 26:20. [PMID: 32041519 PMCID: PMC7011243 DOI: 10.1186/s10020-020-0146-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Accepted: 01/30/2020] [Indexed: 12/11/2022] Open
Abstract
The emergence of tyrosine kinase inhibitors (TKIs) has changed the current treatment paradigm and achieved good results in recent decades. However, an increasing number of studies have indicated that the complex network of receptor tyrosine kinase (RTK) co-activation could influence the characteristic phenotypes of cancer and the tumor response to targeted treatments. One of strategies to blocking RTK co-activation is targeting the downstream factors of RTK, such as PI3K-AKT-mTOR pathway. RICTOR, a core component of mTORC2, acts as a key effector molecule of the PI3K-AKT pathway; its amplification is often associated with poor clinical outcomes and resistance to TKIs. Here, we discuss the biology of RICTOR in tumor and the prospects of targeting RICTOR as a complementary therapy to inhibit RTK co-activation.
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Affiliation(s)
- Deze Zhao
- Department of Medical Oncology, The Affiliated Hospital of Qingdao University, Qingdao University, 16 Jiangsu Road, Qingdao, 266005, China
| | - Man Jiang
- Department of Medical Oncology, The Affiliated Hospital of Qingdao University, Qingdao University, 16 Jiangsu Road, Qingdao, 266005, China
| | - Xiaochun Zhang
- Department of Medical Oncology, The Affiliated Hospital of Qingdao University, Qingdao University, 16 Jiangsu Road, Qingdao, 266005, China
| | - Helei Hou
- Department of Medical Oncology, The Affiliated Hospital of Qingdao University, Qingdao University, 16 Jiangsu Road, Qingdao, 266005, China.
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104
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Ham AS, Chojnowska K, Tintignac LA, Lin S, Schmidt A, Ham DJ, Sinnreich M, Rüegg MA. mTORC1 signalling is not essential for the maintenance of muscle mass and function in adult sedentary mice. J Cachexia Sarcopenia Muscle 2020; 11:259-273. [PMID: 31697050 PMCID: PMC7015237 DOI: 10.1002/jcsm.12505] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Accepted: 09/09/2019] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND The balance between protein synthesis and degradation (proteostasis) is a determining factor for muscle size and function. Signalling via the mammalian target of rapamycin complex 1 (mTORC1) regulates proteostasis in skeletal muscle by affecting protein synthesis and autophagosomal protein degradation. Indeed, genetic inactivation of mTORC1 in developing and growing muscle causes atrophy resulting in a lethal myopathy. However, systemic dampening of mTORC1 signalling by its allosteric inhibitor rapamycin is beneficial at the organismal level and increases lifespan. Whether the beneficial effect of rapamycin comes at the expense of muscle mass and function is yet to be established. METHODS We conditionally ablated the gene coding for the mTORC1-essential component raptor in muscle fibres of adult mice [inducible raptor muscle-specific knockout (iRAmKO)]. We performed detailed phenotypic and biochemical analyses of iRAmKO mice and compared them with muscle-specific raptor knockout (RAmKO) mice, which lack raptor in developing muscle fibres. We also used polysome profiling and proteomics to assess protein translation and associated signalling in skeletal muscle of iRAmKO mice. RESULTS Analysis at different time points reveal that, as in RAmKO mice, the proportion of oxidative fibres decreases, but slow-type fibres increase in iRAmKO mice. Nevertheless, no significant decrease in body and muscle mass or muscle fibre area was detected up to 5 months post-raptor depletion. Similarly, ex vivo muscle force was not significantly reduced in iRAmKO mice. Despite stable muscle size and function, inducible raptor depletion significantly reduced the expression of key components of the translation machinery and overall translation rates. CONCLUSIONS Raptor depletion and hence complete inhibition of mTORC1 signalling in fully grown muscle leads to metabolic and morphological changes without inducing muscle atrophy even after 5 months. Together, our data indicate that maintenance of muscle size does not require mTORC1 signalling, suggesting that rapamycin treatment is unlikely to negatively affect muscle mass and function.
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Affiliation(s)
| | | | - Lionel A Tintignac
- Department of Biomedicine, Pharmazentrum, University of Basel, Basel, Switzerland
| | - Shuo Lin
- Biozentrum, University of Basel, Basel, Switzerland
| | - Alexander Schmidt
- Proteomics Core Facility, Biozentrum, University of Basel, Basel, Switzerland
| | - Daniel J Ham
- Biozentrum, University of Basel, Basel, Switzerland
| | - Michael Sinnreich
- Department of Biomedicine, Pharmazentrum, University of Basel, Basel, Switzerland
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105
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Formisano L, Napolitano F, Rosa R, D'Amato V, Servetto A, Marciano R, De Placido P, Bianco C, Bianco R. Mechanisms of resistance to mTOR inhibitors. Crit Rev Oncol Hematol 2020; 147:102886. [PMID: 32014673 DOI: 10.1016/j.critrevonc.2020.102886] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Revised: 01/03/2020] [Accepted: 01/27/2020] [Indexed: 12/13/2022] Open
Abstract
In several tumors the PI3K/AKT/mTOR pathway is frequently disrupted, an event that results in uncontrolled cell proliferation and tumor growth. Through the years, several compounds have been developed to inhibit the pathway at different steps: the mammalian target of rapamycin (mTOR) seemed to be the most qualified target. However, this kinase has such a key role in cell survival that mechanisms of resistance are rapidly developed. Nevertheless, clinical results obtained with mTOR inhibitors in breast cancer, renal cell carcinoma, neuroendocrine tumors and mantle cell lymphoma push oncologists to actively further develop these drugs, maybe by better selecting the population to which they are offered, through the research of predictive factors of responsiveness. In this review, we aim to describe mechanisms of resistance to mTOR inhibitors, from preclinical and clinical perspectives.
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Affiliation(s)
- Luigi Formisano
- Department of Clinical Medicine and Surgery, University of Naples "Federico II", 80131, Naples, Italy
| | - Fabiana Napolitano
- Department of Clinical Medicine and Surgery, University of Naples "Federico II", 80131, Naples, Italy
| | - Roberta Rosa
- Department of Clinical Medicine and Surgery, University of Naples "Federico II", 80131, Naples, Italy
| | - Valentina D'Amato
- Department of Clinical Medicine and Surgery, University of Naples "Federico II", 80131, Naples, Italy
| | - Alberto Servetto
- Department of Clinical Medicine and Surgery, University of Naples "Federico II", 80131, Naples, Italy
| | - Roberta Marciano
- Department of Clinical Medicine and Surgery, University of Naples "Federico II", 80131, Naples, Italy
| | - Pietro De Placido
- Department of Clinical Medicine and Surgery, University of Naples "Federico II", 80131, Naples, Italy
| | - Cataldo Bianco
- Department of Experimental and Clinical Medicine, University of Catanzaro "Magna Graecia", 88100, Catanzaro, Italy.
| | - Roberto Bianco
- Department of Clinical Medicine and Surgery, University of Naples "Federico II", 80131, Naples, Italy.
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106
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Sun Y, McCorvie TJ, Yates LA, Zhang X. Structural basis of homologous recombination. Cell Mol Life Sci 2020; 77:3-18. [PMID: 31748913 PMCID: PMC6957567 DOI: 10.1007/s00018-019-03365-1] [Citation(s) in RCA: 69] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 10/10/2019] [Accepted: 10/31/2019] [Indexed: 12/12/2022]
Abstract
Homologous recombination (HR) is a pathway to faithfully repair DNA double-strand breaks (DSBs). At the core of this pathway is a DNA recombinase, which, as a nucleoprotein filament on ssDNA, pairs with homologous DNA as a template to repair the damaged site. In eukaryotes Rad51 is the recombinase capable of carrying out essential steps including strand invasion, homology search on the sister chromatid and strand exchange. Importantly, a tightly regulated process involving many protein factors has evolved to ensure proper localisation of this DNA repair machinery and its correct timing within the cell cycle. Dysregulation of any of the proteins involved can result in unchecked DNA damage, leading to uncontrolled cell division and cancer. Indeed, many are tumour suppressors and are key targets in the development of new cancer therapies. Over the past 40 years, our structural and mechanistic understanding of homologous recombination has steadily increased with notable recent advancements due to the advances in single particle cryo electron microscopy. These have resulted in higher resolution structural models of the signalling proteins ATM (ataxia telangiectasia mutated), and ATR (ataxia telangiectasia and Rad3-related protein), along with various structures of Rad51. However, structural information of the other major players involved, such as BRCA1 (breast cancer type 1 susceptibility protein) and BRCA2 (breast cancer type 2 susceptibility protein), has been limited to crystal structures of isolated domains and low-resolution electron microscopy reconstructions of the full-length proteins. Here we summarise the current structural understanding of homologous recombination, focusing on key proteins in recruitment and signalling events as well as the mediators for the Rad51 recombinase.
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Affiliation(s)
- Yueru Sun
- Section of Structural Biology, Department of Infectious Diseases, Imperial College, London, SW7 2AZ, UK
| | - Thomas J McCorvie
- Section of Structural Biology, Department of Infectious Diseases, Imperial College, London, SW7 2AZ, UK
| | - Luke A Yates
- Section of Structural Biology, Department of Infectious Diseases, Imperial College, London, SW7 2AZ, UK
| | - Xiaodong Zhang
- Section of Structural Biology, Department of Infectious Diseases, Imperial College, London, SW7 2AZ, UK.
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107
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Santos de Oliveira FL, Vieira Carletti J, Azevedo FFN, Freitas de Sousa FJ, Caetano EWS, Freire VN, Zanatta G. mTOR–mLST8 interaction: hot spot identification through quantum biochemistry calculations. NEW J CHEM 2020. [DOI: 10.1039/d0nj04099a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Quantum calculation of mTOR–mLST8 interaction.
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Affiliation(s)
| | | | | | | | | | | | - Geancarlo Zanatta
- Department of Physics at Federal University of Ceará
- 60455-760 Fortaleza
- Brazil
- Postgraduate Research Program in Biochemistry at Federal University of Ceará
- Fortaleza
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108
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109
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McCready K, Spencer V, Kim M. The Importance of TOR Kinase in Plant Development. FRONTIERS IN PLANT SCIENCE 2020; 11:16. [PMID: 32117365 PMCID: PMC7012898 DOI: 10.3389/fpls.2020.00016] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Accepted: 01/09/2020] [Indexed: 05/19/2023]
Abstract
TARGET OF RAPAMYCIN (TOR) kinase has been recognised as a key developmental regulator in both plants and animals. Despite their distinct developmental programmes, all eukaryotes studied possess a functional TOR kinase, which integrates environmental and nutrient signals to direct growth and development. This is particularly important in plants, as they are sessile and must sense and respond to external signals to coordinate multicellular growth appropriately. Thus, the investigation of TOR is essential for plant developmental studies in the context of the resources available for growth. Recently, links have been shown between TOR and plant development from embryogenesis through to senescence, however more investigation is crucial to fully elucidate TOR function in each developmental process.
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110
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Ormaechea MS, Hassan M, Onghanseng N, Park JH, Mahajan S, Al-Kirwi KY, Uludag G, Halim MS, Schlaen A, Sepah YJ, Do DV, Nguyen QD. Safety of systemic therapy for noninfectious uveitis. Expert Opin Drug Saf 2019; 18:1219-1235. [PMID: 31801415 DOI: 10.1080/14740338.2019.1692810] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Introduction: The treatment strategies for noninfectious uveitis (NIU) aim to achieve disease remission, prevention of recurrences, and preserving vision, while minimizing the side effects associated with the therapies used.Areas covered: The index review aims to provide a detailed overview of the adverse events and safety parameters associated with the systemic therapies for the management of the NIU.Expert opinion: Despite being the cornerstone of management of acute cases of NIU, long-term corticosteroid use is associated with multi-system side effects, requiring the use of steroid-sparing agents. Adalimumab was recently approved by the FDA for the management of NIU based on the results of VISUAL studies. Similarly, newer drugs targeting various aspects of the inflammatory cascade are being developed. However, until we completely understand the molecular pathways of the inflammatory diseases, the therapeutic profile of these newer agents needs to be broad enough to suppress inflammatory cascade and narrow enough to spare normal cellular processes. Another strategy that has shown some potential in decreasing the systemic side effects is to provide local drug delivery. Therefore, the future of management of NIU is very bright with many novel therapeutic agents and strategies of drug delivery on the horizon.
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Affiliation(s)
- Maria Soledad Ormaechea
- Department of Ophthalmology, Hospital Universitario Austral, Buenos Aires, Argentina.,Byers Eye Institute, Stanford University, Palo Alto, CA, USA
| | - Muhammad Hassan
- Byers Eye Institute, Stanford University, Palo Alto, CA, USA
| | - Neil Onghanseng
- Byers Eye Institute, Stanford University, Palo Alto, CA, USA
| | - Jung Hyun Park
- Byers Eye Institute, Stanford University, Palo Alto, CA, USA.,Department of Ophthalmology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | | | - Khalid Yusuf Al-Kirwi
- Byers Eye Institute, Stanford University, Palo Alto, CA, USA.,Department of Ophthalmology, Imamein Khadhimein Medical City University Hospital, Baghdad, Iraq
| | - Gunay Uludag
- Byers Eye Institute, Stanford University, Palo Alto, CA, USA
| | | | - Ariel Schlaen
- Department of Ophthalmology, Hospital Universitario Austral, Buenos Aires, Argentina
| | - Yasir J Sepah
- Byers Eye Institute, Stanford University, Palo Alto, CA, USA
| | - Diana V Do
- Byers Eye Institute, Stanford University, Palo Alto, CA, USA
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111
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Bhaoighill MN, Dunlop EA. Mechanistic target of rapamycin inhibitors: successes and challenges as cancer therapeutics. CANCER DRUG RESISTANCE (ALHAMBRA, CALIF.) 2019; 2:1069-1085. [PMID: 35582282 PMCID: PMC9019212 DOI: 10.20517/cdr.2019.87] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/28/2019] [Revised: 11/18/2019] [Accepted: 11/26/2019] [Indexed: 12/22/2022]
Abstract
Delineating the contributions of specific cell signalling cascades to the development and maintenance of tumours has greatly informed our understanding of tumorigenesis and has advanced the modern era of targeted cancer therapy. It has been revealed that one of the key pathways regulating cell growth, the phosphatidylinositol 3-kinase/mechanistic target of rapamycin (PI3K/mTOR) signalling axis, is commonly dysregulated in cancer. With a specific, well-tolerated inhibitor of mTOR available, the impact of inhibiting this pathway at the level of mTOR has been tested clinically. This review highlights some of the promising results seen with mTOR inhibitors in the clinic and assesses some of the challenges that remain in predicting patient outcome following mTOR-targeted therapy.
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Affiliation(s)
| | - Elaine A Dunlop
- Division of Cancer and Genetics, Cardiff University, Cardiff, CF14 4XN, UK
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112
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Lu JJ, Yang WM, Li F, Zhu W, Chen Z. Tunneling Nanotubes Mediated microRNA-155 Intercellular Transportation Promotes Bladder Cancer Cells' Invasive and Proliferative Capacity. Int J Nanomedicine 2019; 14:9731-9743. [PMID: 31849465 PMCID: PMC6911338 DOI: 10.2147/ijn.s217277] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Accepted: 11/15/2019] [Indexed: 01/07/2023] Open
Abstract
Objective To investigate differential microRNAs' expression in heterogeneous bladder cancer cells, as well as to investigate the mechanism of changes in invasive and proliferative capacity induced by tunneling nanotubes (TNTs) mediated transport of microRNA between bladder cancer cells of varying histological grade. Materials and methods Differences in microRNA expression between bladder cancer cells of different grade were identified from a literature review. The identified heterogeneous microRNAs were analyzed by qPCR in T24 (high grade) and RT4 (low grade) bladder cancer cells. Scanning electron microscopy (SEM) and laser confocal fluorescence microscopy (LCM) were used to observe tunneling nanotubes (TNTs) between RT4 and T24 cells. Differentially expressed microRNA was labeled and traced by Fluorescent In Situ Hybridization (FISH) following co-culture of T24 and RT4 cells. MicroRNA mimic and inhibition technologies were applied to investigate how TNTs-mediated intercellular transport of microRNA affects the invasive and proliferative behavior of bladder cancer cells. Results MicroRNA-155 (miR-155) levels were highly expressed in T24 cells, whereas the same was not true in RT4 cells. MiR-155 was confirmed to be a crucial factor sustaining T24 bladder cancer cell proliferation, migration and cell cycle progression by CCK8, Matrigel test and cell cycle analysis, respectively. After T24 and RT4 co-culture, TNTs were assessed by SEM and LCM between T24 and RT4 cells. In addition, we observed TNTs mediated transport of miR-155 from T24 cells to RT4 cells, which thereby acquired a higher proliferative rate, an increased frequency of cells in the S phase, and increased invasive ability in Matrigel test. At the same time, Deptor, the target protein of miR-155 in RT4 cells, was downregulated, followed by mTOR/4EBP1/p70S6K- eIF4e/S6RP signaling activation. Conclusion MiR-155 was differentially expressed between RT4 and T24 bladder cancer cells. Intercellular transport of miR-155 via TNTs can promote bladder cancer cell reprogramming by Deptor-mTOR signal pathway activation. ![]()
Point your SmartPhone at the code above. If you have a QR code reader the video abstract will appear. Or use: https://youtu.be/E2WwLr86AOg
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Affiliation(s)
- Jin Jin Lu
- Department of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, People's Republic of China.,Department of Urology, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, People's Republic of China
| | - Wei Min Yang
- Department of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, People's Republic of China
| | - Fan Li
- Department of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, People's Republic of China
| | - Wei Zhu
- Department of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, People's Republic of China
| | - Zhong Chen
- Department of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, People's Republic of China
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113
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InsP6 binding to PIKK kinases revealed by the cryo-EM structure of an SMG1–SMG8–SMG9 complex. Nat Struct Mol Biol 2019; 26:1089-1093. [DOI: 10.1038/s41594-019-0342-7] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Accepted: 10/28/2019] [Indexed: 12/30/2022]
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114
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Wang H, Bai G, Cui N, Han W, Long Y. T-cell-specific mTOR deletion in mice ameliorated CD4 + T-cell survival in lethal sepsis induced by severe invasive candidiasis. Virulence 2019; 10:892-901. [PMID: 31668132 PMCID: PMC6844314 DOI: 10.1080/21505594.2019.1685151] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 08/06/2019] [Accepted: 09/08/2019] [Indexed: 12/27/2022] Open
Abstract
The mammalian target of rapamycin (mTOR) pathway can mediate T-cell survival; however, the role of this pathway in T-cell survival during fungal sepsis is unclear. Here, we investigated the role of the mTOR pathway in CD4+ T-cell survival in a mouse model of rapidly progressive lethal sepsis induced by severe invasive candidiasis and explored the possible mechanism. The decrease in CD4+ T-cell survival following fungal sepsis was ameliorated in mice with a T-cell-specific mTOR deletion, whereas it was exacerbated in mice with a T-cell-specific tuberous sclerosis complex (TSC)1 deletion. To explore the mechanism further, we measured expression of autophagy proteins light chain 3B and p62/sequestosome 1 in CD4+ T cells. Both proteins were increased in T-cell-specific mTOR knockout mice but lower in T-cell-specific TSC1 knockout mice. Transmission electron microscopy revealed that T-cell-specific mTOR knockout mice had more autophagosomes than wild-type mice following fungal sepsis. CD4+ T-cell mTOR knockout decreased CD4+ T-cell apoptosis in fungal sepsis. Most notably, the T-cell-specific mTOR deletion mice had an increased survival rate after fungal sepsis. These results suggest that the mTOR pathway plays a vital role in CD4+ T-cell survival during fungal sepsis, partly through the autophagy-apoptosis pathway.
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Affiliation(s)
- Hao Wang
- Department of Critical Care Medicine, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Science, Beijing, China
| | - Guangxu Bai
- Department of Critical Care Medicine, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Science, Beijing, China
| | - Na Cui
- Department of Critical Care Medicine, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Science, Beijing, China
- Department of Clinical Laboratory, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Science; Beijing Key Laboratory for Mechanisms Research and Precision Diagnosis of Invasive Fungal Diseases, Beijing, China
| | - Wen Han
- Department of Critical Care Medicine, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Science, Beijing, China
| | - Yun Long
- Department of Critical Care Medicine, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Science, Beijing, China
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115
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Pereyra CM, Aznar NR, Rodriguez MS, Salerno GL, Martínez-Noël GMA. Target of rapamycin signaling is tightly and differently regulated in the plant response under distinct abiotic stresses. PLANTA 2019; 251:21. [PMID: 31781934 DOI: 10.1007/s00425-019-03305-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Accepted: 10/23/2019] [Indexed: 06/10/2023]
Abstract
TOR signaling is finely regulated under diverse abiotic stresses and may be required for the plant response with a different time-course depending on the duration and nature of the stress. Target of rapamycin (TOR) signaling is a central regulator of growth and development in eukaryotic organisms. However, its regulation under stress conditions has not yet been elucidated. In Arabidopsis, we show that TOR transcripts and activity in planta are finely regulated within hours after the onset of salt, osmotic, cold and oxidative stress. The expression of genes encoding the partner proteins of the TOR complex, RAPTOR3G and LST8-1, is also regulated. Besides, the data indicate that TOR activity increases at some time during the adverse condition. Interestingly, in oxidative stress, the major TOR activity increment occurred transiently at the early phase of treatment, while in salt, osmotic and cold stress, it was around 1 day after the unfavorable condition was applied. Those results suggest that the TOR signaling has an important role in the plant response to an exposure to stress. Moreover, basal ROS (H2O2) levels and their modification under abiotic stresses were altered in TOR complex mutants. On the other hand, the root phenotypic analysis of the effects caused by the diverse abiotic stresses on TOR complex mutants revealed that they were differently affected, being in some cases less sensitive, than wild-type plants to long-term unfavorable conditions. Therefore, in this work, we demonstrated that TOR signaling is tightly regulated under abiotic stresses, at transcript and activity level, with different and specific time-course patterns according to the type of abiotic stress in Arabidopsis. Taking our results together, we propose that TOR signaling should be necessary during the plant stress response.
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Affiliation(s)
- Cintia M Pereyra
- Instituto de Investigaciones en Biodiversidad y Biotecnología (INBIOTEC-CONICET) and Fundación para Investigaciones Biológicas Aplicadas (FIBA), Vieytes 3103, Mar Del Plata, Argentina
| | - Néstor R Aznar
- Instituto de Investigaciones en Biodiversidad y Biotecnología (INBIOTEC-CONICET) and Fundación para Investigaciones Biológicas Aplicadas (FIBA), Vieytes 3103, Mar Del Plata, Argentina
| | - Marianela S Rodriguez
- Instituto de Fisiología y Recursos Genéticos Vegetales (IFRGV), Centro de Investigaciones Agropecuarias (CIAP), Instituto Nacional de Tecnología Agropecuaria (INTA), Camino 60 cuadras km 5.5 X5020ICA, Córdoba, Argentina
- Unidad de Estudios Agropecuarios (UDEA- CONICET), Camino 60 cuadras km 5.5 X5020ICA, Córdoba, Argentina
| | - Graciela L Salerno
- Instituto de Investigaciones en Biodiversidad y Biotecnología (INBIOTEC-CONICET) and Fundación para Investigaciones Biológicas Aplicadas (FIBA), Vieytes 3103, Mar Del Plata, Argentina
| | - Giselle M A Martínez-Noël
- Instituto de Investigaciones en Biodiversidad y Biotecnología (INBIOTEC-CONICET) and Fundación para Investigaciones Biológicas Aplicadas (FIBA), Vieytes 3103, Mar Del Plata, Argentina.
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Shen K, Rogala KB, Chou HT, Huang RK, Yu Z, Sabatini DM. Cryo-EM Structure of the Human FLCN-FNIP2-Rag-Ragulator Complex. Cell 2019; 179:1319-1329.e8. [PMID: 31704029 PMCID: PMC7008705 DOI: 10.1016/j.cell.2019.10.036] [Citation(s) in RCA: 80] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2019] [Revised: 10/08/2019] [Accepted: 10/28/2019] [Indexed: 12/22/2022]
Abstract
mTORC1 controls anabolic and catabolic processes in response to nutrients through the Rag GTPase heterodimer, which is regulated by multiple upstream protein complexes. One such regulator, FLCN-FNIP2, is a GTPase activating protein (GAP) for RagC/D, but despite its important role, how it activates the Rag GTPase heterodimer remains unknown. We used cryo-EM to determine the structure of FLCN-FNIP2 in a complex with the Rag GTPases and Ragulator. FLCN-FNIP2 adopts an extended conformation with two pairs of heterodimerized domains. The Longin domains heterodimerize and contact both nucleotide binding domains of the Rag heterodimer, while the DENN domains interact at the distal end of the structure. Biochemical analyses reveal a conserved arginine on FLCN as the catalytic arginine finger and lead us to interpret our structure as an on-pathway intermediate. These data reveal features of a GAP-GTPase interaction and the structure of a critical component of the nutrient-sensing mTORC1 pathway.
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Affiliation(s)
- Kuang Shen
- Whitehead Institute for Biomedical Research and Department of Biology, Massachusetts Institute of Technology, 455 Main Street, Cambridge, MA 02142, USA; Howard Hughes Medical Institute, Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Koch Institute for Integrative Cancer Research, 77 Massachusetts Avenue, Cambridge, MA 02139, USA; Broad Institute of Harvard and Massachusetts Institute of Technology, 7 Cambridge Center, Cambridge, MA 02142, USA; Program in Molecular Medicine, University of Massachusetts Medical School, 373 Plantation Street, Worcester, 01605, USA
| | - Kacper B Rogala
- Whitehead Institute for Biomedical Research and Department of Biology, Massachusetts Institute of Technology, 455 Main Street, Cambridge, MA 02142, USA; Howard Hughes Medical Institute, Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Koch Institute for Integrative Cancer Research, 77 Massachusetts Avenue, Cambridge, MA 02139, USA; Broad Institute of Harvard and Massachusetts Institute of Technology, 7 Cambridge Center, Cambridge, MA 02142, USA
| | - Hui-Ting Chou
- Howard Hughes Medical Institute, Janelia Research Campus, 19700 Helix Drive, Ashburn, VA 20147, USA
| | - Rick K Huang
- Howard Hughes Medical Institute, Janelia Research Campus, 19700 Helix Drive, Ashburn, VA 20147, USA
| | - Zhiheng Yu
- Howard Hughes Medical Institute, Janelia Research Campus, 19700 Helix Drive, Ashburn, VA 20147, USA.
| | - David M Sabatini
- Whitehead Institute for Biomedical Research and Department of Biology, Massachusetts Institute of Technology, 455 Main Street, Cambridge, MA 02142, USA; Howard Hughes Medical Institute, Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Koch Institute for Integrative Cancer Research, 77 Massachusetts Avenue, Cambridge, MA 02139, USA; Broad Institute of Harvard and Massachusetts Institute of Technology, 7 Cambridge Center, Cambridge, MA 02142, USA.
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117
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Layoun A, Goldberg AA, Baig A, Eng M, Attias O, Nelson K, Carella A, Amberber N, Fielhaber JA, Joung KB, Schmeing TM, Han Y, Downey J, Divangahi M, Roux PP, Kristof AS. Regulation of protein kinase Cδ Nuclear Import and Apoptosis by Mechanistic Target of Rapamycin Complex-1. Sci Rep 2019; 9:17620. [PMID: 31772273 PMCID: PMC6879585 DOI: 10.1038/s41598-019-53909-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 10/24/2019] [Indexed: 11/09/2022] Open
Abstract
Inactivation of the protein complex ‘mechanistic target of rapamycin complex 1’ (mTORC1) can increase the nuclear content of transcriptional regulators of metabolism and apoptosis. Previous studies established that nuclear import of signal transducer and activator of transcription-1 (STAT1) requires the mTORC1-associated adaptor karyopherin-α1 (KPNA1) when mTORC1 activity is reduced. However, the role of other mTORC1-interacting proteins in the complex, including ‘protein kinase C delta’ (PKCδ), have not been well characterized. In this study, we demonstrate that PKCδ, a STAT1 kinase, contains a functional ‘target of rapamycin signaling’ (TOS) motif that directs its interaction with mTORC1. Depletion of KPNA1 by RNAi prevented the nuclear import of PKCδ in cells exposed to the mTORC1 inhibitor rapamycin or amino acid restriction. Mutation of the TOS motif in PKCδ led to its loss of regulation by mTORC1 or karyopherin-α1, resulting in increased constitutive nuclear content. In cells expressing wild-type PKCδ, STAT1 activity and apoptosis were increased by rapamycin or interferon-β. Those expressing the PKCδ TOS mutant exhibited increased STAT1 activity and apoptosis; further enhancement by rapamycin or interferon-β, however, was lost. Therefore, the TOS motif in PKCδ is a novel structural mechanism by which mTORC1 prevents PKCδ and STAT1 nuclear import, and apoptosis.
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Affiliation(s)
- Antonio Layoun
- Meakins-Christie Laboratories and Translational Research in Respiratory Diseases Program, Research Institute of the McGill University Health Centre, Faculty of Medicine, Departments of Medicine and Critical Care, 1001 Décarie Boulevard, EM3.2219, Montreal, Québec, H4A 3J1, Canada
| | - Alexander A Goldberg
- Meakins-Christie Laboratories and Translational Research in Respiratory Diseases Program, Research Institute of the McGill University Health Centre, Faculty of Medicine, Departments of Medicine and Critical Care, 1001 Décarie Boulevard, EM3.2219, Montreal, Québec, H4A 3J1, Canada
| | - Ayesha Baig
- Meakins-Christie Laboratories and Translational Research in Respiratory Diseases Program, Research Institute of the McGill University Health Centre, Faculty of Medicine, Departments of Medicine and Critical Care, 1001 Décarie Boulevard, EM3.2219, Montreal, Québec, H4A 3J1, Canada
| | - Mikaela Eng
- Meakins-Christie Laboratories and Translational Research in Respiratory Diseases Program, Research Institute of the McGill University Health Centre, Faculty of Medicine, Departments of Medicine and Critical Care, 1001 Décarie Boulevard, EM3.2219, Montreal, Québec, H4A 3J1, Canada
| | - Ortal Attias
- Meakins-Christie Laboratories and Translational Research in Respiratory Diseases Program, Research Institute of the McGill University Health Centre, Faculty of Medicine, Departments of Medicine and Critical Care, 1001 Décarie Boulevard, EM3.2219, Montreal, Québec, H4A 3J1, Canada
| | - Kristoff Nelson
- Meakins-Christie Laboratories and Translational Research in Respiratory Diseases Program, Research Institute of the McGill University Health Centre, Faculty of Medicine, Departments of Medicine and Critical Care, 1001 Décarie Boulevard, EM3.2219, Montreal, Québec, H4A 3J1, Canada
| | - Alexandra Carella
- Meakins-Christie Laboratories and Translational Research in Respiratory Diseases Program, Research Institute of the McGill University Health Centre, Faculty of Medicine, Departments of Medicine and Critical Care, 1001 Décarie Boulevard, EM3.2219, Montreal, Québec, H4A 3J1, Canada
| | - Nahomi Amberber
- Meakins-Christie Laboratories and Translational Research in Respiratory Diseases Program, Research Institute of the McGill University Health Centre, Faculty of Medicine, Departments of Medicine and Critical Care, 1001 Décarie Boulevard, EM3.2219, Montreal, Québec, H4A 3J1, Canada
| | - Jill A Fielhaber
- Meakins-Christie Laboratories and Translational Research in Respiratory Diseases Program, Research Institute of the McGill University Health Centre, Faculty of Medicine, Departments of Medicine and Critical Care, 1001 Décarie Boulevard, EM3.2219, Montreal, Québec, H4A 3J1, Canada
| | - Kwang-Bo Joung
- Meakins-Christie Laboratories and Translational Research in Respiratory Diseases Program, Research Institute of the McGill University Health Centre, Faculty of Medicine, Departments of Medicine and Critical Care, 1001 Décarie Boulevard, EM3.2219, Montreal, Québec, H4A 3J1, Canada
| | - T Martin Schmeing
- Department of Biochemistry, McGill University, Montréal, Québec, H3G 0B1, Canada
| | - Yingshan Han
- Meakins-Christie Laboratories and Translational Research in Respiratory Diseases Program, Research Institute of the McGill University Health Centre, Faculty of Medicine, Departments of Medicine and Critical Care, 1001 Décarie Boulevard, EM3.2219, Montreal, Québec, H4A 3J1, Canada
| | - Jeffrey Downey
- Meakins-Christie Laboratories and Translational Research in Respiratory Diseases Program, Research Institute of the McGill University Health Centre, 1001 Décarie Boulevard, EM3.2219, Montréal, Québec, H4A 3J1, Canada
| | - Maziar Divangahi
- Meakins-Christie Laboratories and Translational Research in Respiratory Diseases Program, Research Institute of the McGill University Health Centre, 1001 Décarie Boulevard, EM3.2219, Montréal, Québec, H4A 3J1, Canada
| | - Philippe P Roux
- Institute for Research in Immunology and Cancer, Faculty of Medicine, University of Montreal, P.O. Box 6128, Station Centre-Ville, Montréal, Québec, H3C 2J7, Canada
| | - Arnold S Kristof
- Meakins-Christie Laboratories and Translational Research in Respiratory Diseases Program, Research Institute of the McGill University Health Centre, Faculty of Medicine, Departments of Medicine and Critical Care, 1001 Décarie Boulevard, EM3.2219, Montreal, Québec, H4A 3J1, Canada.
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118
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Zhang Y, Thery F, Wu NC, Luhmann EK, Dussurget O, Foecke M, Bredow C, Jiménez-Fernández D, Leandro K, Beling A, Knobeloch KP, Impens F, Cossart P, Radoshevich L. The in vivo ISGylome links ISG15 to metabolic pathways and autophagy upon Listeria monocytogenes infection. Nat Commun 2019; 10:5383. [PMID: 31772204 PMCID: PMC6879477 DOI: 10.1038/s41467-019-13393-x] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Accepted: 11/07/2019] [Indexed: 12/28/2022] Open
Abstract
ISG15 is an interferon-stimulated, ubiquitin-like protein, with anti-viral and anti-bacterial activity. Here, we map the endogenous in vivo ISGylome in the liver following Listeria monocytogenes infection by combining murine models of reduced or enhanced ISGylation with quantitative proteomics. Our method identifies 930 ISG15 sites in 434 proteins and also detects changes in the host ubiquitylome. The ISGylated targets are enriched in proteins which alter cellular metabolic processes, including upstream modulators of the catabolic and antibacterial pathway of autophagy. Computational analysis of substrate structures reveals that a number of ISG15 modifications occur at catalytic sites or dimerization interfaces of enzymes. Finally, we demonstrate that animals and cells with enhanced ISGylation have increased basal and infection-induced autophagy through the modification of mTOR, WIPI2, AMBRA1, and RAB7. Taken together, these findings ascribe a role of ISGylation to temporally reprogram organismal metabolism following infection through direct modification of a subset of enzymes in the liver.
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Affiliation(s)
- Yifeng Zhang
- Department of Microbiology and Immunology, University of Iowa Carver College of Medicine, Iowa City, IA, 52242, USA
| | - Fabien Thery
- Center for Medical Biotechnology, VIB, 9000, Gent, Belgium
- Department for Biomolecular Medicine, Gent University, 9000, Gent, Belgium
| | - Nicholas C Wu
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Emma K Luhmann
- Department of Microbiology and Immunology, University of Iowa Carver College of Medicine, Iowa City, IA, 52242, USA
| | - Olivier Dussurget
- Institut Pasteur, Unité des Interactions Bactéries-Cellules, Département de Biologie Cellulaire et Infection, 75015, Paris, France
- Inserm, U604, 75015, Paris, France
- National Institute for Agronomic Research (INRA), Unité sous-contrat 2020, 75015, Paris, France
| | - Mariko Foecke
- Institut Pasteur, Unité des Interactions Bactéries-Cellules, Département de Biologie Cellulaire et Infection, 75015, Paris, France
- Inserm, U604, 75015, Paris, France
- National Institute for Agronomic Research (INRA), Unité sous-contrat 2020, 75015, Paris, France
| | - Clara Bredow
- Charité-Universitäts medizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health (BIH), Institute of Biochemistry, Berlin, Germany
| | | | - Kevin Leandro
- Center for Medical Biotechnology, VIB, 9000, Gent, Belgium
- Department for Biomolecular Medicine, Gent University, 9000, Gent, Belgium
| | - Antje Beling
- Charité-Universitäts medizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health (BIH), Institute of Biochemistry, Berlin, Germany
- Deutsches Zentrum für Herz-Kreislauf-Forschung (DZHK), Partner Site Berlin, Berlin, Germany
| | - Klaus-Peter Knobeloch
- Institute of Neuropathology, Medical Faculty, University of Freiburg, Freiburg, Germany
| | - Francis Impens
- Center for Medical Biotechnology, VIB, 9000, Gent, Belgium.
- Department for Biomolecular Medicine, Gent University, 9000, Gent, Belgium.
- VIB Proteomics Core, VIB, 9000, Gent, Belgium.
| | - Pascale Cossart
- Institut Pasteur, Unité des Interactions Bactéries-Cellules, Département de Biologie Cellulaire et Infection, 75015, Paris, France.
- Inserm, U604, 75015, Paris, France.
- National Institute for Agronomic Research (INRA), Unité sous-contrat 2020, 75015, Paris, France.
| | - Lilliana Radoshevich
- Department of Microbiology and Immunology, University of Iowa Carver College of Medicine, Iowa City, IA, 52242, USA.
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119
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Abstract
The mechanistic target of rapamycin (mTOR) signaling pathway coordinates environmental and intracellular cues to control eukaryotic cell growth. As a pivot point between anabolic and catabolic processes, mTOR complex 1 (mTORC1) signaling has established roles in regulating metabolism, translation and autophagy. Hyperactivity of the mTOR pathway is associated with numerous human diseases, including diabetes, cancer and epilepsy. Pharmacological inhibition of the mTOR pathway can extend lifespan in a variety of model organisms. Given its broad control of essential cellular processes and clear relevance to human health, there is extensive interest in elucidating how upstream inputs regulate mTORC1 activation. In this Cell Science at a Glance article and accompanying poster, we summarize our understanding of how extracellular and intracellular signals feed into the mTOR pathway, how the lysosome acts as an mTOR signaling hub, and how downstream signaling controls autophagy and lysosome biogenesis.
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Affiliation(s)
- Kendall J Condon
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA.,Department of Biology, Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.,Broad Institute, Cambridge, MA 02142, USA.,The David H. Koch Institute for Integrative Cancer Research at MIT, Cambridge, MA 02139, USA
| | - David M Sabatini
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA .,Department of Biology, Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.,Broad Institute, Cambridge, MA 02142, USA.,The David H. Koch Institute for Integrative Cancer Research at MIT, Cambridge, MA 02139, USA
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120
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Rodriguez M, Parola R, Andreola S, Pereyra C, Martínez-Noël G. TOR and SnRK1 signaling pathways in plant response to abiotic stresses: Do they always act according to the "yin-yang" model? PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2019; 288:110220. [PMID: 31521220 DOI: 10.1016/j.plantsci.2019.110220] [Citation(s) in RCA: 65] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Revised: 08/05/2019] [Accepted: 08/13/2019] [Indexed: 05/20/2023]
Abstract
Plants are sessile photo-autotrophic organisms continuously exposed to a variety of environmental stresses. Monitoring the sugar level and energy status is essential, since this knowledge allows the integration of external and internal cues required for plant physiological and developmental plasticity. Most abiotic stresses induce severe metabolic alterations and entail a great energy cost, restricting plant growth and producing important crop losses. Therefore, balancing energy requirements with supplies is a major challenge for plants under unfavorable conditions. The conserved kinases target of rapamycin (TOR) and sucrose-non-fermenting-related protein kinase-1 (SnRK1) play central roles during plant growth and development, and in response to environmental stresses; these kinases affect cellular processes and metabolic reprogramming, which has physiological and phenotypic consequences. The "yin-yang" model postulates that TOR and SnRK1 act in opposite ways in the regulation of metabolic-driven processes. In this review, we describe and discuss the current knowledge about the complex and intricate regulation of TOR and SnRK1 under abiotic stresses. We especially focus on the physiological perspective that, under certain circumstances during the plant stress response, the TOR and SnRK1 kinases could be modulated differently from what is postulated by the "yin-yang" concept.
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Affiliation(s)
- Marianela Rodriguez
- Instituto de Fisiología y Recursos Genéticos Vegetales (IFRGV), Centro de Investigaciones Agropecuarias (CIAP), Instituto Nacional de Tecnología Agropecuaria (INTA), Camino 60 Cuadras km 5.5, X5020ICA, Córdoba, Argentina; Unidad de Estudios Agropecuarios (UDEA- CONICET), Camino 60 Cuadras km 5.5 X5020ICA, Córdoba, Argentina.
| | - Rodrigo Parola
- Instituto de Fisiología y Recursos Genéticos Vegetales (IFRGV), Centro de Investigaciones Agropecuarias (CIAP), Instituto Nacional de Tecnología Agropecuaria (INTA), Camino 60 Cuadras km 5.5, X5020ICA, Córdoba, Argentina; Unidad de Estudios Agropecuarios (UDEA- CONICET), Camino 60 Cuadras km 5.5 X5020ICA, Córdoba, Argentina.
| | - Sofia Andreola
- Instituto de Fisiología y Recursos Genéticos Vegetales (IFRGV), Centro de Investigaciones Agropecuarias (CIAP), Instituto Nacional de Tecnología Agropecuaria (INTA), Camino 60 Cuadras km 5.5, X5020ICA, Córdoba, Argentina; Unidad de Estudios Agropecuarios (UDEA- CONICET), Camino 60 Cuadras km 5.5 X5020ICA, Córdoba, Argentina.
| | - Cintia Pereyra
- Instituto de Investigaciones en Biodiversidad y Biotecnología (INBIOTEC-CONICET), y Fundación para Investigaciones Biológicas Aplicadas (FIBA), Vieytes 3103, 7600, Mar del Plata, Argentina.
| | - Giselle Martínez-Noël
- Instituto de Investigaciones en Biodiversidad y Biotecnología (INBIOTEC-CONICET), y Fundación para Investigaciones Biológicas Aplicadas (FIBA), Vieytes 3103, 7600, Mar del Plata, Argentina.
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121
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Anandapadamanaban M, Masson GR, Perisic O, Berndt A, Kaufman J, Johnson CM, Santhanam B, Rogala KB, Sabatini DM, Williams RL. Architecture of human Rag GTPase heterodimers and their complex with mTORC1. Science 2019; 366:203-210. [PMID: 31601764 PMCID: PMC6795536 DOI: 10.1126/science.aax3939] [Citation(s) in RCA: 77] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Accepted: 09/03/2019] [Indexed: 12/11/2022]
Abstract
The Rag guanosine triphosphatases (GTPases) recruit the master kinase mTORC1 to lysosomes to regulate cell growth and proliferation in response to amino acid availability. The nucleotide state of Rag heterodimers is critical for their association with mTORC1. Our cryo-electron microscopy structure of RagA/RagC in complex with mTORC1 shows the details of RagA/RagC binding to the RAPTOR subunit of mTORC1 and explains why only the RagAGTP/RagCGDP nucleotide state binds mTORC1. Previous kinetic studies suggested that GTP binding to one Rag locks the heterodimer to prevent GTP binding to the other. Our crystal structures and dynamics of RagA/RagC show the mechanism for this locking and explain how oncogenic hotspot mutations disrupt this process. In contrast to allosteric activation by RHEB, Rag heterodimer binding does not change mTORC1 conformation and activates mTORC1 by targeting it to lysosomes.
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Affiliation(s)
| | - Glenn R Masson
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
| | - Olga Perisic
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
| | - Alex Berndt
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
| | | | | | | | - Kacper B Rogala
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
| | - David M Sabatini
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA
- Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Koch Institute for Integrative Cancer Research, Cambridge, MA 02139, USA
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
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122
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Antonia RJ, Castillo J, Herring LE, Serafin DS, Liu P, Graves LM, Baldwin AS, Hagan RS. TBK1 Limits mTORC1 by Promoting Phosphorylation of Raptor Ser877. Sci Rep 2019; 9:13470. [PMID: 31530866 PMCID: PMC6748941 DOI: 10.1038/s41598-019-49707-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Accepted: 08/29/2019] [Indexed: 01/02/2023] Open
Abstract
While best known for its role in the innate immune system, the TANK-binding kinase 1 (TBK1) is now known to play a role in modulating cellular growth and autophagy. One of the major ways that TBK1 accomplishes this task is by modulating the mechanistic Target of Rapamycin (mTOR), a master regulator that when activated promotes cell growth and inhibits autophagy. However, whether TBK1 promotes or inhibits mTOR activity is highly cell type and context dependent. To further understand the mechanism whereby TBK1 regulates mTOR, we tested the hypothesis that TBK1 phosphorylates a key component of the mTOR complex 1 (mTORC1), Raptor. Using kinase assays coupled with mass spectrometry, we mapped the position of the TBK1 dependent phosphorylation sites on Raptor in vitro. Among the sites identified in vitro, we found that TBK1 promotes Raptor Ser877 phosphorylation in cells both basally and in response to pathogen-associated molecules known to induce TBK1 activity. The levels of Raptor Ser877 phosphorylation were inversely correlated with the levels of mTOR activity. Expression of a mutant Raptor that could not be phosphorylated at Ser877 led to an increase in mTORC1 activity. We conclude that TBK1 limits mTORC1 activity by promoting Raptor Ser877 phosphorylation.
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Affiliation(s)
- Ricardo J Antonia
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.,The Helen Diller Family Comprehensive Cancer Center, The University of California San Francisco, San Francisco, California, USA
| | - Johnny Castillo
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Laura E Herring
- UNC Proteomics Core Facility, Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, USA
| | - D Stephen Serafin
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.,Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, USA
| | - Pengda Liu
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.,Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, USA
| | - Lee M Graves
- UNC Proteomics Core Facility, Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, USA
| | - Albert S Baldwin
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
| | - Robert S Hagan
- Division of Pulmonary Diseases and Critical Care Medicine, Department of Medicine, University of North Carolina, Chapel Hill, NC, 27599, USA. .,Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA.
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123
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Murugan AK. mTOR: Role in cancer, metastasis and drug resistance. Semin Cancer Biol 2019; 59:92-111. [PMID: 31408724 DOI: 10.1016/j.semcancer.2019.07.003] [Citation(s) in RCA: 262] [Impact Index Per Article: 52.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2019] [Revised: 06/14/2019] [Accepted: 07/03/2019] [Indexed: 02/09/2023]
Abstract
Mammalian target of rapamycin (mTOR) is a serine/threonine kinase that gets inputs from the amino acids, nutrients, growth factor, and environmental cues to regulate varieties of fundamental cellular processes which include protein synthesis, growth, metabolism, aging, regeneration, autophagy, etc. The mTOR is frequently deregulated in human cancer and activating somatic mutations of mTOR were recently identified in several types of human cancer and hence mTOR is therapeutically targeted. mTOR inhibitors were commonly used as immunosuppressors and currently, it is approved for the treatment of human malignancies. This review briefly focuses on the structure and biological functions of mTOR. It extensively discusses the genetic deregulation of mTOR including amplifications and somatic mutations, mTOR-mediated cell growth promoting signaling, therapeutic targeting of mTOR and the mechanisms of resistance, the role of mTOR in precision medicine and other recent advances in further understanding the role of mTOR in cancer.
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Affiliation(s)
- Avaniyapuram Kannan Murugan
- Department of Molecular Oncology, King Faisal Specialist Hospital & Research Centre, PO Box 3354, Research Center (MBC 03), Riyadh, 11211, Saudi Arabia.
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124
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mTOR Dysregulation by Vaccinia Virus F17 Controls Multiple Processes with Varying Roles in Infection. J Virol 2019; 93:JVI.00784-19. [PMID: 31118254 DOI: 10.1128/jvi.00784-19] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Accepted: 05/14/2019] [Indexed: 12/16/2022] Open
Abstract
Despite producing enormous amounts of cytoplasmic DNA, poxviruses continue to replicate efficiently by deploying an armory of proteins that counter host antiviral responses at multiple levels. Among these, poxvirus protein F17 dysregulates the host kinase mammalian target of rapamycin (mTOR) to prevent the activation of stimulator of interferon genes (STING) expression and impair the production of interferon-stimulated genes (ISGs). However, the host DNA sensor(s) involved and their impact on infection in the absence of F17 remain unknown. Here, we show that cyclic-di-GMP-AMP (cGAMP) synthase (cGAS) is the primary sensor that mediates interferon response factor (IRF) activation and ISG responses to vaccinia virus lacking F17 in both macrophages and lung fibroblasts, although additional sensors also operate in the latter cell type. Despite this, ablation of ISG responses through cGAS or STING knockout did not rescue defects in late-viral-protein production, and the experimental data pointed to other functions of mTOR in this regard. mTOR adjusts both autophagic and protein-synthetic processes to cellular demands. No significant differences in autophagic responses to wild-type or F17 mutant viruses could be detected, with autophagic activity differing across cell types or states and exhibiting no correlations with defects in viral-protein accumulation. In contrast, results using transformed cells or altered growth conditions suggested that late-stage defects in protein accumulation reflect failure of the F17 mutant to deregulate mTOR and stimulate protein production. Finally, rescue approaches suggest that phosphorylation may partition F17's functions as a structural protein and mTOR regulator. Our findings reveal the complex multifunctionality of F17 during infection.IMPORTANCE Poxviruses are large, double-stranded DNA viruses that replicate entirely in the cytoplasm, an unusual act that activates pathogen sensors and innate antiviral responses. In order to replicate, poxviruses therefore encode a wide range of innate immune antagonists that include F17, a protein that dysregulates the kinase mammalian target of rapamycin (mTOR) to suppress interferon-stimulated gene (ISG) responses. However, the host sensor(s) that detects infection in the absence of F17 and its precise contribution to infection remains unknown. Here, we show that the cytosolic DNA sensor cGAS is primarily responsible for activating ISG responses in biologically relevant cell types infected with a poxvirus that does not express F17. However, in line with their expression of ∼100 proteins that act as immune response and ISG antagonists, while F17 helps suppress cGAS-mediated responses, we find that a critical function of its mTOR dysregulation activity is to enhance poxvirus protein production.
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125
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Hua H, Kong Q, Zhang H, Wang J, Luo T, Jiang Y. Targeting mTOR for cancer therapy. J Hematol Oncol 2019; 12:71. [PMID: 31277692 PMCID: PMC6612215 DOI: 10.1186/s13045-019-0754-1] [Citation(s) in RCA: 511] [Impact Index Per Article: 102.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Accepted: 06/14/2019] [Indexed: 02/05/2023] Open
Abstract
Mechanistic target of rapamycin (mTOR) is a protein kinase regulating cell growth, survival, metabolism, and immunity. mTOR is usually assembled into several complexes such as mTOR complex 1/2 (mTORC1/2). In cooperation with raptor, rictor, LST8, and mSin1, key components in mTORC1 or mTORC2, mTOR catalyzes the phosphorylation of multiple targets such as ribosomal protein S6 kinase β-1 (S6K1), eukaryotic translation initiation factor 4E binding protein 1 (4E-BP1), Akt, protein kinase C (PKC), and type-I insulin-like growth factor receptor (IGF-IR), thereby regulating protein synthesis, nutrients metabolism, growth factor signaling, cell growth, and migration. Activation of mTOR promotes tumor growth and metastasis. Many mTOR inhibitors have been developed to treat cancer. While some of the mTOR inhibitors have been approved to treat human cancer, more mTOR inhibitors are being evaluated in clinical trials. Here, we update recent advances in exploring mTOR signaling and the development of mTOR inhibitors for cancer therapy. In addition, we discuss the mechanisms underlying the resistance to mTOR inhibitors in cancer cells.
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Affiliation(s)
- Hui Hua
- State Key Laboratory of Biotherapy, Laboratory of Stem Cell Biology, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Qingbin Kong
- Laboratory of Oncogene, Cancer Center, West China Hospital, Sichuan University, Chengdu, China
| | - Hongying Zhang
- Laboratory of Oncogene, Cancer Center, West China Hospital, Sichuan University, Chengdu, China
| | - Jiao Wang
- School of Basic Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Ting Luo
- Cancer Center, West China Hospital, Sichuan University, Chengdu, China
| | - Yangfu Jiang
- Laboratory of Oncogene, Cancer Center, West China Hospital, Sichuan University, Chengdu, China.
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Structural and functional analysis of the role of the chaperonin CCT in mTOR complex assembly. Nat Commun 2019; 10:2865. [PMID: 31253771 PMCID: PMC6599039 DOI: 10.1038/s41467-019-10781-1] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Accepted: 06/01/2019] [Indexed: 01/01/2023] Open
Abstract
The mechanistic target of rapamycin (mTOR) kinase forms two multi-protein signaling complexes, mTORC1 and mTORC2, which are master regulators of cell growth, metabolism, survival and autophagy. Two of the subunits of these complexes are mLST8 and Raptor, β-propeller proteins that stabilize the mTOR kinase and recruit substrates, respectively. Here we report that the eukaryotic chaperonin CCT plays a key role in mTORC assembly and signaling by folding both mLST8 and Raptor. A high resolution (4.0 Å) cryo-EM structure of the human mLST8-CCT intermediate isolated directly from cells shows mLST8 in a near-native state bound to CCT deep within the folding chamber between the two CCT rings, and interacting mainly with the disordered N- and C-termini of specific CCT subunits of both rings. These findings describe a unique function of CCT in mTORC assembly and a distinct binding site in CCT for mLST8, far from those found for similar β-propeller proteins. β-propeller domains are an important class of folding substrates for the eukaryotic cytosolic chaperonin CTT. Here the authors find that CTT contributes to the folding and assembly of two β-propeller proteins from mTOR complexes, mLST8 and Raptor, and determine the 4.0 Å cryoEM structure of a human mLST8-CCT intermediate that shows mLST8 in a near-native state.
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Structural basis of allosteric regulation of Tel1/ATM kinase. Cell Res 2019; 29:655-665. [PMID: 31097817 PMCID: PMC6796912 DOI: 10.1038/s41422-019-0176-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 04/25/2019] [Indexed: 12/20/2022] Open
Abstract
ATM/Tel1 is an apical kinase that orchestrates the multifaceted DNA damage response. Mutations of ATM/Tel1 are associated with ataxia telangiectasia syndrome. Here, we report cryo-EM structures of symmetric dimer (4.1 Å) and asymmetric dimer (4.3 Å) of Saccharomyces cerevisiae Tel1. In the symmetric state, the side chains in Tel1 C-terminus (residues 1129–2787) are discernible and an atomic model is built. The substrate binding groove is completely embedded in the symmetric dimer by the intramolecular PRD and intermolecular LID domains. Point mutations in these domains sensitize the S. cerevisiae cells to DNA damage agents and hinder Tel1 activation due to reduced binding affinity for its activator Xrs2/Nbs1. In the asymmetric state, one monomer becomes more compact in two ways: the kinase N-lobe moves down and the Spiral of α-solenoid moves upwards, which resemble the conformational changes observed in active mTOR. The accessibility of the activation loop correlates with the synergistic conformational disorders in the TRD1-TRD2 linker, FATC and PRD domains, where critical post-translational modifications and activating mutations are coincidently condensed. This study reveals a tunable allosteric network in ATM/Tel1, which is important for substrate recognition, recruitment and efficient phosphorylation.
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Hwang Y, Kim LC, Song W, Edwards DN, Cook RS, Chen J. Disruption of the Scaffolding Function of mLST8 Selectively Inhibits mTORC2 Assembly and Function and Suppresses mTORC2-Dependent Tumor Growth In Vivo. Cancer Res 2019; 79:3178-3184. [PMID: 31085701 DOI: 10.1158/0008-5472.can-18-3658] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 04/05/2019] [Accepted: 05/08/2019] [Indexed: 12/24/2022]
Abstract
mTOR is a serine/threonine kinase that acts in two distinct complexes, mTORC1 and mTORC2, and is dysregulated in many diseases including cancer. mLST8 is a shared component of both mTORC1 and mTORC2, yet little is known regarding how mLST8 contributes to assembly and activity of the mTOR complexes. Here we assessed mLST8 loss in a panel of normal and cancer cells and observed little to no impact on assembly or activity of mTORC1. However, mLST8 loss blocked mTOR association with mTORC2 cofactors RICTOR and SIN1, thus abrogating mTORC2 activity. Similarly, a single pair of mutations on mLST8 with a corresponding mutation on mTOR interfered with mTORC2 assembly and activity without affecting mTORC1. We also discovered a direct interaction between mLST8 and the NH2-terminal domain of the mTORC2 cofactor SIN1. In PTEN-null prostate cancer xenografts, mLST8 mutations disrupting the mTOR interaction motif inhibited AKT S473 phosphorylation and decreased tumor cell proliferation and tumor growth in vivo. Together, these data suggest that the scaffolding function of mLST8 is critical for assembly and activity of mTORC2, but not mTORC1, an observation that could enable therapeutic mTORC2-selective inhibition as a therapeutic strategy. SIGNIFICANCE: These findings show that mLST8 functions as a scaffold to maintain mTORC2 integrity and kinase activity, unveiling a new avenue for development of mTORC2-specific inhibitors.
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Affiliation(s)
- Yoonha Hwang
- Veterans Affairs Medical Center, Tennessee Valley Healthcare System, Nashville, Tennessee
- Division of Rheumatology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Laura C Kim
- Program in Cancer Biology, Vanderbilt University, Nashville, Tennessee
| | - Wenqiang Song
- Veterans Affairs Medical Center, Tennessee Valley Healthcare System, Nashville, Tennessee
- Division of Rheumatology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Deanna N Edwards
- Veterans Affairs Medical Center, Tennessee Valley Healthcare System, Nashville, Tennessee
- Division of Rheumatology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Rebecca S Cook
- Program in Cancer Biology, Vanderbilt University, Nashville, Tennessee
- Deparment of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee
- Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, Tennessee
| | - Jin Chen
- Veterans Affairs Medical Center, Tennessee Valley Healthcare System, Nashville, Tennessee.
- Division of Rheumatology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee
- Program in Cancer Biology, Vanderbilt University, Nashville, Tennessee
- Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, Tennessee
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129
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Hua R, Wei H, Liu C, Shi Z, Xing Y. Phosphorylated mTORC1 represses autophagic-related mRNA translation in neurons exposed to ischemia-reperfusion injury. J Cell Biochem 2019; 120:15915-15923. [PMID: 31081172 DOI: 10.1002/jcb.28865] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2018] [Revised: 02/14/2019] [Accepted: 02/21/2019] [Indexed: 12/30/2022]
Abstract
OBJECTIVES The sequential reactivation of mechanistic target of rapamycin (mTOR) inhibited autophagic flux in neurons exposed to oxygen-glucose deprivation/reperfusion (OGD/R), which was characterized by reduction of autophagosome formation and restriction of autolysosome degradation. However, its detailed molecular mechanism was still unknown. In this study, we further explore the existing form of mTOR and its suppression on the transcriptional levels of related mRNA from neurons exposed to ischemia-reperfusion injury. METHODS The OGD/R or middle cerebral artery occlusion/reperfusion (MCAO/R)-treated neurons was used to simulate ischemia/reperfusion injury . Autophagy flux was monitored by means of microtubule-associated protein 1 light chain 3 (LC3) and p62. The reactivation of mTOR was determined by phosphorylation of ribosomal protein S6 kinase 1 (S6K1). Then the inhibitors of mTOR were used to confirm its existence form. Finally, the mRNA transcription levels were analyzed to observe the negative regulation of mTOR. RESULTS The sequential phosphorylation of mTOR contributed to the neuronal autophagy flux blocking. mTOR was re-phosphorylated and existed as mTOR complex 1 (mTORC1), which was supported by phosphorylation of S6K1 at Thr 389 in neurons. In addition, the phosphorylation of S6K1 was decreased roughly by applying mTORC1 inhibitors, rapamycin and torin 1. However, the administration of mTORC1/2 inhibitor PP242 could recover the phosphorylation of S6K1, which suggested that mTORC2 was involved in the regulation of mTORC1 activity. In paralleling with reactivation of mTORC1, related mRNA transcription was repressed in neurons under ischemia-reperfusion exposure in vivo and in vitro. The mRNA expression levels of LC3, Stx17, Vamp8, Snap29, Lamp2a, and Lamp2b were decreased in neurons after reperfusion, comparing with ischemia-treated neurons. CONCLUSIONS The reactivated mTORC1 could suppress the transcription levels of related mRNA, such as LC3, Stx17, Vamp8, Snap29, Lamp2a, and Lamp2b. The research will expand the horizons that mTOR would negatively regulate autophagy at transcription and post-translation levels in neurons suffering ischemia-reperfusion injury.
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Affiliation(s)
- Rongrong Hua
- Department of Neurology, Aviation General Hospital, China Medical University, Beijing, People's Republic of China
| | - Haiping Wei
- Department of Neurology, Second Hospital of Lanzhou University, Lanzhou, People's Republic of China
| | - Chunyan Liu
- Department of Neurology, Aviation General Hospital, China Medical University, Beijing, People's Republic of China
| | - Zhe Shi
- Department of Neurology, Aviation General Hospital, China Medical University, Beijing, People's Republic of China
| | - Yan Xing
- Department of Neurology, Aviation General Hospital, China Medical University, Beijing, People's Republic of China
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130
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mTOR Signaling Pathway in Cancer Targets Photodynamic Therapy In Vitro. Cells 2019; 8:cells8050431. [PMID: 31075885 PMCID: PMC6563036 DOI: 10.3390/cells8050431] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2019] [Revised: 04/22/2019] [Accepted: 04/30/2019] [Indexed: 01/03/2023] Open
Abstract
The Mechanistic or Mammalian Target of Rapamycin (mTOR) is a major signaling pathway in eukaryotic cells belonging to the P13K-related kinase family of the serine/threonine protein kinase. It has been established that mTOR plays a central role in cellular processes and implicated in various cancers, diabetes, and in the aging process with very poor prognosis. Inhibition of the mTOR pathway in the cells may improve the therapeutic index in cancer treatment. Photodynamic therapy (PDT) has been established to selectively eradicate neoplasia at clearly delineated malignant lesions. This review highlights recent advances in understanding the role or regulation of mTOR in cancer therapy. It also discusses how mTOR currently contributes to cancer as well as future perspectives on targeting mTOR therapeutically in cancer in vitro.
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131
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Ryabova LA, Robaglia C, Meyer C. Target of Rapamycin kinase: central regulatory hub for plant growth and metabolism. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:2211-2216. [PMID: 30984977 PMCID: PMC6463030 DOI: 10.1093/jxb/erz108] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Affiliation(s)
- Lyubov A Ryabova
- Institut de Biologie Moléculaire des Plantes, UPR 2357 CNRS, Université de Strasbourg, Strasbourg, France
| | - Christophe Robaglia
- Laboratoire de Génétique et Biophysique des Plantes, UMR 7265, Aix Marseille Université, CEA, CNRS, BIAM, Faculté des Sciences de Luminy, Marseille, France
| | - Christian Meyer
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-Saclay, Versailles, France
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132
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Jamsheer K M, Jindal S, Laxmi A. Evolution of TOR-SnRK dynamics in green plants and its integration with phytohormone signaling networks. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:2239-2259. [PMID: 30870564 DOI: 10.1093/jxb/erz107] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Accepted: 02/26/2019] [Indexed: 05/07/2023]
Abstract
The target of rapamycin (TOR)-sucrose non-fermenting 1 (SNF1)-related protein kinase 1 (SnRK1) signaling is an ancient regulatory mechanism that originated in eukaryotes to regulate nutrient-dependent growth. Although the TOR-SnRK1 signaling cascade shows highly conserved functions among eukaryotes, studies in the past two decades have identified many important plant-specific innovations in this pathway. Plants also possess SnRK2 and SnRK3 kinases, which originated from the ancient SnRK1-related kinases and have specialized roles in controlling growth, stress responses and nutrient homeostasis in plants. Recently, an integrative picture has started to emerge in which different SnRKs and TOR kinase are highly interconnected to control nutrient and stress responses of plants. Further, these kinases are intimately involved with phytohormone signaling networks that originated at different stages of plant evolution. In this review, we highlight the evolution and divergence of TOR-SnRK signaling components in plants and their communication with each other as well as phytohormone signaling to fine-tune growth and stress responses in plants.
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Affiliation(s)
- Muhammed Jamsheer K
- Amity Food & Agriculture Foundation, Amity University Uttar Pradesh, Noida, India
| | - Sunita Jindal
- National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, India
| | - Ashverya Laxmi
- National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, India
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133
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Caldana C, Martins MCM, Mubeen U, Urrea-Castellanos R. The magic 'hammer' of TOR: the multiple faces of a single pathway in the metabolic regulation of plant growth and development. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:2217-2225. [PMID: 30722050 DOI: 10.1093/jxb/ery459] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Accepted: 12/11/2018] [Indexed: 06/09/2023]
Abstract
The target of rapamycin (TOR) pathway has emerged as a central hub synchronizing plant growth according to the nutrient/energy status and environmental inputs. Molecular mechanisms through which TOR promotes plant growth involve the positive regulation of transcription of cell proliferation-associated genes, mRNA translation initiation and ribosome biogenesis, to cite a few examples. Phytohormones, light, sugars, and sulfur have been found to broadly regulate TOR activity. TOR operates as a metabolic homeostat to fine-tune anabolic processes and efficiently enable plant growth under different circumstances. However, little is known about the multiple effectors that act up- and downstream of TOR. Here, we mainly discuss recent findings related to the TOR pathway in the context of plant metabolism and highlight areas of interest that need to be addressed to keep unravelling the intricate networks governing the regulation of TOR and its function in controlling biosynthetic growth.
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Affiliation(s)
- Camila Caldana
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg, Potsdam-Golm, Germany
| | | | - Umarah Mubeen
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg, Potsdam-Golm, Germany
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134
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Wu Y, Shi L, Li L, Fu L, Liu Y, Xiong Y, Sheen J. Integration of nutrient, energy, light, and hormone signalling via TOR in plants. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:2227-2238. [PMID: 30715492 PMCID: PMC6463029 DOI: 10.1093/jxb/erz028] [Citation(s) in RCA: 87] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Accepted: 01/08/2019] [Indexed: 05/04/2023]
Abstract
The multidomain target of rapamycin (TOR) is an atypical serine/threonine protein kinase resembling phosphatidylinositol lipid kinases, but retains high sequence identity and serves a remarkably conserved role as a master signalling integrator in yeasts, plants, and humans. TOR dynamically orchestrates cell metabolism, biogenesis, organ growth, and development transitions in response to nutrient, energy, hormone, and environmental cues. Here we review recent findings on the versatile and complex roles of TOR in transcriptome reprogramming, seedling, root, and shoot growth, and root hair production activated by sugar and energy signalling. We explore how co-ordination of TOR-mediated light and hormone signalling is involved in root and shoot apical meristem activation, proliferation of leaf primordia, cotyledon/leaf greening, and hypocotyl elongation. We also discuss the emerging TOR functions in response to sulfur assimilation and metabolism and consider potential molecular links and positive feedback loops between TOR, sugar, energy, and other essential macronutrients.
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Affiliation(s)
- Yue Wu
- Department of Molecular Biology and Centre for Computational and Integrative Biology, Massachusetts General Hospital, and Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Lin Shi
- Department of Molecular Biology and Centre for Computational and Integrative Biology, Massachusetts General Hospital, and Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Lei Li
- Department of Molecular Biology and Centre for Computational and Integrative Biology, Massachusetts General Hospital, and Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Liwen Fu
- Basic Forestry and Proteomics Research Centre, Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fujian Province, PR China
| | - Yanlin Liu
- Basic Forestry and Proteomics Research Centre, Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fujian Province, PR China
| | - Yan Xiong
- Basic Forestry and Proteomics Research Centre, Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fujian Province, PR China
| | - Jen Sheen
- Department of Molecular Biology and Centre for Computational and Integrative Biology, Massachusetts General Hospital, and Department of Genetics, Harvard Medical School, Boston, MA, USA
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135
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Moreira BP, Oliveira PF, Alves MG. Molecular Mechanisms Controlled by mTOR in Male Reproductive System. Int J Mol Sci 2019; 20:ijms20071633. [PMID: 30986927 PMCID: PMC6480367 DOI: 10.3390/ijms20071633] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 03/27/2019] [Accepted: 03/28/2019] [Indexed: 12/21/2022] Open
Abstract
In recent years, the mammalian target of rapamycin (mTOR) has emerged as a master integrator of upstream inputs, such as amino acids, growth factors and insulin availability, energy status and many others. The integration of these signals promotes a response through several downstream effectors that regulate protein synthesis, glucose metabolism and cytoskeleton organization, among others. All these biological processes are essential for male fertility, thus it is not surprising that novel molecular mechanisms controlled by mTOR in the male reproductive tract have been described. Indeed, since the first clinical evidence showed that men taking rapamycin were infertile, several studies have evidenced distinct roles for mTOR in spermatogenesis. However, there is a lack of consensus whether mTOR inhibition, which remains the experimental approach that originates the majority of available data, has a negative or positive impact on male reproductive health. Herein we discuss the latest findings concerning mTOR activity in testes, particularly its role on spermatogonial stem cell (SSC) maintenance and differentiation, as well as in the physiology of Sertoli cells (SCs), responsible for blood–testis barrier maintenance/restructuring and the nutritional support of spermatogenesis. Taken together, these recent advances highlight a crucial role for mTOR in determining the male reproductive potential.
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Affiliation(s)
- Bruno P Moreira
- Department of Microscopy, Laboratory of Cell Biology, Institute of Biomedical Sciences Abel Salazar (ICBAS) and Unit for Multidisciplinary Research in Biomedicine (UMIB), University of Porto, 4050-313 Porto, Portugal.
| | - Pedro F Oliveira
- Department of Microscopy, Laboratory of Cell Biology, Institute of Biomedical Sciences Abel Salazar (ICBAS) and Unit for Multidisciplinary Research in Biomedicine (UMIB), University of Porto, 4050-313 Porto, Portugal.
- i3S-Instituto de Investigação e Inovação em Saúde, University of Porto, 4200-135 Porto, Portugal.
- Department of Genetics, Faculty of Medicine, University of Porto, 4200-450 Porto, Portugal.
| | - Marco G Alves
- Department of Microscopy, Laboratory of Cell Biology, Institute of Biomedical Sciences Abel Salazar (ICBAS) and Unit for Multidisciplinary Research in Biomedicine (UMIB), University of Porto, 4050-313 Porto, Portugal.
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Li L, Zhu T, Song Y, Luo X, Feng L, Zhuo F, Li F, Ren M. Functional Characterization of Target of Rapamycin Signaling in Verticillium dahliae. Front Microbiol 2019; 10:501. [PMID: 30918504 PMCID: PMC6424901 DOI: 10.3389/fmicb.2019.00501] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Accepted: 02/27/2019] [Indexed: 12/11/2022] Open
Abstract
More than 200 plants have been suffering from Verticillium wilt caused by Verticillium dahliae (V. dahliae) across the world. The target of rapamycin (TOR) is a lethal gene and controls cell growth and development in various eukaryotes, but little is known about TOR signaling in V. dahliae. Here, we found that V. dahliae strain is hypersensitive to rapamycin in the presence of rapamycin binding protein VdFKBP12 while the deletion mutant aaavdfkbp12 is insensitive to rapamycin. Heterologous expressing VdFKBP12 in Arabidopsis conferred rapamycin sensitivity, indicating that VdFKBP12 can bridge the interaction between rapamycin and TOR across species. The key across species of TOR complex 1 (TORC1) and TORC2 have been identified in V. dahliae, suggesting that TOR signaling pathway is evolutionarily conserved in eukaryotic species. Furthermore, the RNA-seq analysis showed that ribosomal biogenesis, RNA polymerase II transcription factors and many metabolic processes were significantly suppressed in rapamycin treated cells of V. dahliae. Importantly, transcript levels of genes associated with cell wall degrading enzymes (CWEDs) were dramatically down-regulated in TOR-inhibited cells. Further infection assay showed that the pathogenicity of V. dahliae and occurrence of Verticillium wilt can be blocked in the presence of rapamycin. These observations suggested that VdTOR is a key target of V. dahliae for controlling and preventing Verticillium wilt in plants.
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Affiliation(s)
- Linxuan Li
- School of Life Sciences, Chongqing University, Chongqing, China
| | - Tingting Zhu
- School of Life Sciences, Chongqing University, Chongqing, China
| | - Yun Song
- Zhengzhou Research Base, State Key Laboratory of Cotton Biology, Zhengzhou University, Zhengzhou, China.,National Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, China
| | - Xiumei Luo
- School of Life Sciences, Chongqing University, Chongqing, China
| | - Li Feng
- School of Life Sciences, Chongqing University, Chongqing, China
| | - Fengping Zhuo
- School of Life Sciences, Chongqing University, Chongqing, China.,School of Chemistry and Chemical Engineering, Chongqing University of Science and Technology, Chongqing, China
| | - Fuguang Li
- Zhengzhou Research Base, State Key Laboratory of Cotton Biology, Zhengzhou University, Zhengzhou, China.,National Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, China
| | - Maozhi Ren
- School of Life Sciences, Chongqing University, Chongqing, China
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137
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Ahmed AR, Owens RJ, Stubbs CD, Parker AW, Hitchman R, Yadav RB, Dumoux M, Hawes C, Botchway SW. Direct imaging of the recruitment and phosphorylation of S6K1 in the mTORC1 pathway in living cells. Sci Rep 2019; 9:3408. [PMID: 30833605 PMCID: PMC6399282 DOI: 10.1038/s41598-019-39410-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Accepted: 01/23/2019] [Indexed: 01/11/2023] Open
Abstract
Knowledge of protein signalling pathways in the working cell is seen as a primary route to identifying and developing targeted medicines. In recent years there has been a growing awareness of the importance of the mTOR pathway, making it an attractive target for therapeutic intervention in several diseases. Within this pathway we have focused on S6 kinase 1 (S6K1), the downstream phosphorylation substrate of mTORC1, and specifically identify its juxtaposition with mTORC1. When S6K1 is co-expressed with raptor we show that S6K1 is translocated from the nucleus to the cytoplasm. By developing a novel biosensor we demonstrate in real-time, that phosphorylation and de-phosphorylation of S6K1 occurs mainly in the cytoplasm of living cells. Furthermore, we show that the scaffold protein raptor, that typically recruits mTOR substrates, is not always involved in S6K1 phosphorylation. Overall, we demonstrate how FRET-FLIM imaging technology can be used to show localisation of S6K1 phosphorylation in living cells and hence a key site of action of inhibitors targeting mTOR phosphorylation.
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Affiliation(s)
- Abdullah R Ahmed
- Central Laser Facility, Research Complex at Harwell, STFC Rutherford Appleton Laboratory, Harwell Campus, Didcot, OX11 0FA, UK
| | - Raymond J Owens
- Protein Production UK, Research Complex at Harwell, Rutherford Appleton Laboratory, Harwell Campus, Didcot, OX11 0FA, UK.,The Wellcome Centre for Human Genetics, Roosevelt Drive, Oxford, OX3 7BN, UK
| | - Christopher D Stubbs
- Central Laser Facility, Research Complex at Harwell, STFC Rutherford Appleton Laboratory, Harwell Campus, Didcot, OX11 0FA, UK
| | - Anthony W Parker
- Central Laser Facility, Research Complex at Harwell, STFC Rutherford Appleton Laboratory, Harwell Campus, Didcot, OX11 0FA, UK
| | - Richard Hitchman
- Evotec (UK) Ltd, 114 Innovation Drive, Milton Park, Abingdon, Oxfordshire, OX14 4RZ, UK
| | - Rahul B Yadav
- Evotec (UK) Ltd, 114 Innovation Drive, Milton Park, Abingdon, Oxfordshire, OX14 4RZ, UK
| | - Maud Dumoux
- Protein Production UK, Research Complex at Harwell, Rutherford Appleton Laboratory, Harwell Campus, Didcot, OX11 0FA, UK.,Diamond Light Source, Harwell Campus, Didcot, OX11 0DE, UK
| | - Chris Hawes
- Oxford Brookes University, Headington Campus, Oxford, OX3 0BP, UK
| | - Stanley W Botchway
- Central Laser Facility, Research Complex at Harwell, STFC Rutherford Appleton Laboratory, Harwell Campus, Didcot, OX11 0FA, UK.
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138
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Sullivan A, Wallace RL, Wellington R, Luo X, Capaldi AP. Multilayered regulation of TORC1-body formation in budding yeast. Mol Biol Cell 2019; 30:400-410. [PMID: 30485160 PMCID: PMC6589571 DOI: 10.1091/mbc.e18-05-0297] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Revised: 11/08/2018] [Accepted: 11/20/2018] [Indexed: 02/05/2023] Open
Abstract
The target of rapamycin kinase complex 1 (TORC1) regulates cell growth and metabolism in eukaryotes. In Saccharomyces cerevisiae, TORC1 activity is known to be controlled by the conserved GTPases, Gtr1/2, and movement into and out of an inactive agglomerate/body. However, it is unclear whether/how these regulatory steps are coupled. Here we show that active Gtr1/2 is a potent inhibitor of TORC1-body formation, but cells missing Gtr1/2 still form TORC1-bodies in a glucose/nitrogen starvation-dependent manner. We also identify 13 new activators of TORC1-body formation and show that seven of these proteins regulate the Gtr1/2-dependent repression of TORC1-body formation, while the remaining proteins drive the subsequent steps in TORC1 agglomeration. Finally, we show that the conserved phosphatidylinositol-3-phosphate (PI(3)P) binding protein, Pib2, forms a complex with TORC1 and overrides the Gtr1/2-dependent repression of TORC1-body formation during starvation. These data provide a unified, systems-level model of TORC1 regulation in yeast.
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Affiliation(s)
- Arron Sullivan
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, AZ 85721-0206
| | - Ryan L. Wallace
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, AZ 85721-0206
| | - Rachel Wellington
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, AZ 85721-0206
| | - Xiangxia Luo
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, AZ 85721-0206
| | - Andrew P. Capaldi
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, AZ 85721-0206
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139
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Chao LH, Avruch J. Cryo-EM insight into the structure of MTOR complex 1 and its interactions with Rheb and substrates. F1000Res 2019; 8. [PMID: 30647914 PMCID: PMC6325617 DOI: 10.12688/f1000research.16109.1] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/18/2018] [Indexed: 12/31/2022] Open
Abstract
The mechanistic target of rapamycin (MTOR) is a giant protein kinase that, together with the accessory proteins Raptor and mLst8, forms a complex of over 1 MDa known as MTOR complex 1 (MTORC1). MTORC1, through its protein kinase activity, controls the accretion of cell mass through the regulation of gene transcription, mRNA translation, and protein turnover. MTORC1 is activated in an interdependent manner by insulin/growth factors and nutrients, especially amino acids, and is inhibited by stressors such as hypoxia and by the drug rapamycin. The action of insulin/growth factors converges on the small GTPase Rheb, which binds directly to the MTOR polypeptide in MTORC1 and, in its GTP-bound state, initiates kinase activation. Biochemical studies established that MTORC1 exists as a dimer of the MTOR/Raptor/mLst8 trimer, and progressive refinements in cryo-electron microscopy (cryo-EM) have enabled an increasingly clear picture of the architecture of MTORC1, culminating in a deep understanding of how MTORC1 interacts with and phosphorylates its best-known substrates-the eIF-4E binding protein/4E-BP, the p70 S6 kinase/S6K1B, and PRAS40/AKT1S1-and how this is inhibited by rapamycin. Most recently, Rheb-GTP has been shown to bind to MTORC1 in a cooperative manner at an allosteric site remote from the kinase domain that twists the latter into a catalytically competent configuration. Herein, we review the recent cryo-EM and associated biochemical studies of MTORC1 and seek to integrate these new results with the known physiology of MTORC1 regulation and signaling.
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Affiliation(s)
- Luke H Chao
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA, USA.,Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Joseph Avruch
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA, USA.,Department of Medicine, Harvard Medical School, Boston, MA, USA
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140
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Boutouja F, Stiehm CM, Platta HW. mTOR: A Cellular Regulator Interface in Health and Disease. Cells 2019; 8:cells8010018. [PMID: 30609721 PMCID: PMC6356367 DOI: 10.3390/cells8010018] [Citation(s) in RCA: 93] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 12/25/2018] [Accepted: 01/01/2019] [Indexed: 12/19/2022] Open
Abstract
The mechanistic target of Rapamycin (mTOR) is a ubiquitously-conserved serine/threonine kinase, which has a central function in integrating growth signals and orchestrating their physiologic effects on cellular level. mTOR is the core component of differently composed signaling complexes that differ in protein composition and molecular targets. Newly identified classes of mTOR inhibitors are being developed to block autoimmune diseases and transplant rejections but also to treat obesity, diabetes, and different types of cancer. Therefore, the selective and context-dependent inhibition of mTOR activity itself might come into the focus as molecular target to prevent severe diseases and possibly to extend life span. This review provides a general introduction to the molecular composition and physiologic function of mTOR complexes as part of the Special Issue “2018 Select Papers by Cells’ Editorial Board Members”.
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Affiliation(s)
- Fahd Boutouja
- Biochemie Intrazellulärer Transportprozesse, Ruhr-Universität Bochum, 44801 Bochum, Germany.
| | - Christian M Stiehm
- Biochemie Intrazellulärer Transportprozesse, Ruhr-Universität Bochum, 44801 Bochum, Germany.
| | - Harald W Platta
- Biochemie Intrazellulärer Transportprozesse, Ruhr-Universität Bochum, 44801 Bochum, Germany.
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141
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Kim J, Guan KL. mTOR as a central hub of nutrient signalling and cell growth. Nat Cell Biol 2019; 21:63-71. [PMID: 30602761 DOI: 10.1038/s41556-018-0205-1] [Citation(s) in RCA: 626] [Impact Index Per Article: 125.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Accepted: 08/23/2018] [Indexed: 12/19/2022]
Abstract
The highly conserved protein kinase mechanistic target of rapamycin (mTOR; originally known as mammalian target of rapamycin) is a central cell growth regulator connecting cellular metabolism and growth with a wide range of environmental inputs as part of mTOR complex 1 (mTORC1) and mTORC2. In this Review, we introduce the landmark discoveries in the mTOR field, starting from the isolation of rapamycin to the molecular characterizations of key components of the mTORC signalling network with an emphasis on amino acid sensing, and discuss the perspectives of mTORC inhibitors in therapeutic applications.
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Affiliation(s)
- Joungmok Kim
- Department of Oral Biochemistry and Molecular Biology, School of Dentistry, Kyung Hee University, Seoul, Korea.
| | - Kun-Liang Guan
- Department of Pharmacology and Moores Cancer Center, University of California, San Diego, La Jolla, CA, USA.
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142
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Takeuchi T, Benning C. Nitrogen-dependent coordination of cell cycle, quiescence and TAG accumulation in Chlamydomonas. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:292. [PMID: 31890020 PMCID: PMC6927116 DOI: 10.1186/s13068-019-1635-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Accepted: 12/12/2019] [Indexed: 05/07/2023]
Abstract
Microalgae hold great promises as sustainable cellular factories for the production of alternative fuels, feeds, and biopharmaceuticals for human health. While the biorefinery approach for fuels along with the coproduction of high-value compounds with industrial, therapeutic, or nutraceutical applications have the potential to make algal biofuels more economically viable, a number of challenges continue to hamper algal production systems at all levels. One such hurdle includes the metabolic trade-off often observed between the increased yields of desired products, such as triacylglycerols (TAG), and the growth of an organism. Initial genetic engineering strategies to improve lipid productivity in microalgae, which focused on overproducing the enzymes involved in fatty acid and TAG biosynthesis or inactivating competing carbon (C) metabolism, have seen some successes albeit at the cost of often greatly reduced biomass. Emergent approaches that aim at modifying the dynamics of entire metabolic pathways by engineering of pertinent transcription factors or signaling networks appear to have successfully achieved a balance between growth and neutral lipid accumulation. However, the biological knowledge of key signaling networks and molecular components linking these two processes is still incomplete in photosynthetic eukaryotes, making it difficult to optimize metabolic engineering strategies for microalgae. Here, we focus on nitrogen (N) starvation of the model green microalga, Chlamydomonas reinhardtii, to present the current understanding of the nutrient-dependent switch between proliferation and quiescence, and the drastic reprogramming of metabolism that results in the storage of C compounds following N starvation. We discuss the potential components mediating the transcriptional repression of cell cycle genes and the establishment of quiescence in Chlamydomonas, and highlight the importance of signaling pathways such as those governed by the target of rapamycin (TOR) and sucrose nonfermenting-related (SnRK) kinases in the coordination of metabolic status with cellular growth. A better understanding of how the cell division cycle is regulated in response to nutrient scarcity and of the signaling pathways linking cellular growth to energy and lipid homeostasis, is essential to improve the prospects of biofuels and biomass production in microalgae.
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Affiliation(s)
- Tomomi Takeuchi
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824 USA
- Department of Energy-Plant Research Laboratory, Michigan State University, East Lansing, MI 48824 USA
| | - Christoph Benning
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824 USA
- Department of Energy-Plant Research Laboratory, Michigan State University, East Lansing, MI 48824 USA
- Department of Plant Biology, Michigan State University, East Lansing, MI 48824 USA
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143
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Prouteau M, Loewith R. Regulation of Cellular Metabolism through Phase Separation of Enzymes. Biomolecules 2018; 8:biom8040160. [PMID: 30513998 PMCID: PMC6316564 DOI: 10.3390/biom8040160] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Revised: 11/22/2018] [Accepted: 11/22/2018] [Indexed: 01/21/2023] Open
Abstract
Metabolism is the sum of the life-giving chemical processes that occur within a cell. Proper regulation of these processes is essential for all organisms to thrive and prosper. When external factors are too extreme, or if internal regulation is corrupted through genetic or epigenetic changes, metabolic homeostasis is no longer achievable and diseases such as metabolic syndrome or cancer, aging, and, ultimately, death ensue. Metabolic reactions are catalyzed by proteins, and the in vitro kinetic properties of these enzymes have been studied by biochemists for many decades. These efforts led to the appreciation that enzyme activities can be acutely regulated and that this regulation is critical to metabolic homeostasis. Regulation can be mediated through allosteric interactions with metabolites themselves or via post-translational modifications triggered by intracellular signal transduction pathways. More recently, enzyme regulation has attracted the attention of cell biologists who noticed that change in growth conditions often triggers the condensation of diffusely localized enzymes into one or more discrete foci, easily visible by light microscopy. This reorganization from a soluble to a condensed state is best described as a phase separation. As summarized in this review, stimulus-induced phase separation has now been observed for dozens of enzymes suggesting that this could represent a widespread mode of activity regulation, rather than, or in addition to, a storage form of temporarily superfluous enzymes. Building on our recent structure determination of TOROIDs (TORc1 Organized in Inhibited Domain), the condensate formed by the protein kinase Target Of Rapamycin Complex 1 (TORC1), we will highlight that the molecular organization of enzyme condensates can vary dramatically and that future work aimed at the structural characterization of enzyme condensates will be critical to understand how phase separation regulates enzyme activity and consequently metabolic homeostasis. This information may ultimately facilitate the design of strategies to target the assembly or disassembly of specific enzymes condensates as a therapeutic approach to restore metabolic homeostasis in certain diseases.
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Affiliation(s)
- Manoël Prouteau
- Department of Molecular Biology, University of Geneva, 30 Quai Ernest-Ansermet, CH1211 Geneva, Switzerland.
- Institute of Genetics and Genomics of Geneva (iGE3), University of Geneva, 30 Quai Ernest-Ansermet, CH1211 Geneva, Switzerland.
| | - Robbie Loewith
- Department of Molecular Biology, University of Geneva, 30 Quai Ernest-Ansermet, CH1211 Geneva, Switzerland.
- Institute of Genetics and Genomics of Geneva (iGE3), University of Geneva, 30 Quai Ernest-Ansermet, CH1211 Geneva, Switzerland.
- Swiss National Centre for Competence in Research (NCCR) in Chemical Biology, University of Geneva, Sciences II, Room 3-308, 30 Quai Ernest-Ansermet, CH1211 Geneva, Switzerland.
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144
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Weighing In on mTOR Complex 2 Signaling: The Expanding Role in Cell Metabolism. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2018; 2018:7838647. [PMID: 30510625 PMCID: PMC6232796 DOI: 10.1155/2018/7838647] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/17/2018] [Revised: 08/29/2018] [Accepted: 09/18/2018] [Indexed: 12/21/2022]
Abstract
In all eukaryotes, the mechanistic target of rapamycin (mTOR) signaling emerges as a master regulator of homeostasis, which integrates environmental inputs, including nutrients, energy, and growth factors, to regulate many fundamental cellular processes such as cell growth and metabolism. mTOR signaling functions through two structurally and functionally distinct complexes, mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2), which correspond to two major branches of signal output. While mTORC1 is well characterized for its structure, regulation, and function in the last decade, information of mTORC2 signaling is only rapidly expanding in recent years, from structural biology, signaling network, to functional impact. Here we review the recent advances in many aspects of the mTORC2 signaling, with particular focus on its involvement in the control of cell metabolism and its physiological implications in metabolic diseases and aging.
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145
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da Silva RB, Machado CR, Rodrigues ARA, Pedrosa AL. Selective human inhibitors of ATR and ATM render Leishmania major promastigotes sensitive to oxidative damage. PLoS One 2018; 13:e0205033. [PMID: 30265735 PMCID: PMC6161909 DOI: 10.1371/journal.pone.0205033] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2018] [Accepted: 09/18/2018] [Indexed: 12/13/2022] Open
Abstract
All cellular processes, including those involved in normal cell metabolism to those responsible for cell proliferation or death, are finely controlled by cell signaling pathways, whose core proteins constitute the family of phosphatidylinositol 3-kinase-related kinases (PIKKs). Ataxia Telangiectasia Mutated (ATM) and Ataxia Telangiectasia and Rad3 related (ATR) are two important PIKK proteins that act in response to DNA damage, phosphorylating a large number of proteins to exert control over genomic integrity. The genus Leishmania belongs to a group of early divergent eukaryotes in evolution and has a highly plastic genome, probably owing to the existence of signaling pathways designed to maintain genomic integrity. The objective of this study was to evaluate the use of specific human inhibitors of ATR and ATM in Leishmania major. Bioinformatic analyses revealed the existence of the putative PIKK genes ATR and ATM, in addition to mTOR and DNA-PKcs in Leishmania spp. Moreover, it was possible to suggest that the inhibitors VE-821 and KU-55933 have binding affinity for the catalytic sites of putative L. major ATR and ATM, respectively. Promastigotes of L. major exposed to these inhibitors show slight growth impairment and minor changes in cell cycle and morphology. It is noteworthy that treatment of promastigotes with inhibitors VE-821 and KU-55933 enhanced the oxidative damage caused by hydrogen peroxide. These inhibitors could significantly reduce the number of surviving L. major cells following H2O2 exposure whilst also decreasing their evaluated IC50 to H2O2 to less than half of that observed for non-treated cells. These results suggest that the use of specific inhibitors of ATR and ATM in Leishmania interferes in the signaling pathways of this parasite, which can impair its tolerance to DNA damage and affect its genome integrity. ATR and ATM could constitute novel targets for drug development and/or repositioning for treatment of leishmaniases.
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Affiliation(s)
- Raíssa Bernardes da Silva
- Departamento de Bioquímica, Farmacologia e Fisiologia, Instituto de Ciências Biológicas e Naturais, Universidade Federal do Triângulo Mineiro, Uberaba, Minas Gerais, Brazil
| | - Carlos Renato Machado
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Aldo Rogelis Aquiles Rodrigues
- Departamento de Bioquímica, Farmacologia e Fisiologia, Instituto de Ciências Biológicas e Naturais, Universidade Federal do Triângulo Mineiro, Uberaba, Minas Gerais, Brazil
| | - André Luiz Pedrosa
- Departamento de Bioquímica, Farmacologia e Fisiologia, Instituto de Ciências Biológicas e Naturais, Universidade Federal do Triângulo Mineiro, Uberaba, Minas Gerais, Brazil
- * E-mail:
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146
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Harwood FC, Klein Geltink RI, O’Hara BP, Cardone M, Janke L, Finkelstein D, Entin I, Paul L, Houghton PJ, Grosveld GC. ETV7 is an essential component of a rapamycin-insensitive mTOR complex in cancer. SCIENCE ADVANCES 2018; 4:eaar3938. [PMID: 30258985 PMCID: PMC6156121 DOI: 10.1126/sciadv.aar3938] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Accepted: 08/03/2018] [Indexed: 05/14/2023]
Abstract
The mechanistic target of rapamycin (mTOR) serine/threonine kinase, a critical regulator of cell proliferation, is frequently deregulated in human cancer. Although rapamycin inhibits the two canonical mTOR complexes, mTORC1 and mTORC2, it often shows minimal benefit as an anticancer drug. This is caused by rapamycin resistance of many different tumors, and we show that a third mTOR complex, mTORC3, contributes to this resistance. The ETS (E26 transformation-specific) transcription factor ETV7 interacts with mTOR in the cytoplasm and assembles mTORC3, which is independent of ETV7's transcriptional activity. This complex exhibits bimodal mTORC1/2 activity but is devoid of crucial mTORC1/2 components. Many human cancers activate mTORC3 at considerable frequency, and tumor cell lines that lose mTORC3 expression become rapamycin-sensitive. We show mTORC3's tumorigenicity in a rhabdomyosarcoma mouse model in which transgenic ETV7 expression accelerates tumor onset and promotes tumor penetrance. Discovery of mTORC3 represents an mTOR paradigm shift and identifies a novel target for anticancer drug development.
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Affiliation(s)
- Franklin C. Harwood
- Department of Genetics, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | | | - Brendan P. O’Hara
- Department of Genetics, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - Monica Cardone
- Department of Genetics, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - Laura Janke
- Department of Veterinary Pathology, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - David Finkelstein
- Department of Computational Biology, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - Igor Entin
- Department of Genetics, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - Leena Paul
- Department of Genetics, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - Peter J. Houghton
- Greehey Children’s Cancer Research Institute, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - Gerard C. Grosveld
- Department of Genetics, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
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147
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Varlakhanova NV, Tornabene BA, Ford MGJ. Feedback regulation of TORC1 by its downstream effectors Npr1 and Par32. Mol Biol Cell 2018; 29:2751-2765. [PMID: 30156471 PMCID: PMC6249832 DOI: 10.1091/mbc.e18-03-0158] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
TORC1 (target of rapamycin complex) integrates complex nutrient signals to generate and fine-tune a growth and metabolic response. Npr1 (nitrogen permease reactivator) is a downstream effector kinase of TORC1 that regulates the stability, activity, and trafficking of various nutrient permeases including the ammonium permeases Mep1, Mep2, and Mep3 and the general amino acid permease Gap1. Npr1 exerts its regulatory effects on Mep1 and Mep3 via Par32 (phosphorylated after rapamycin). Activation of Npr1 leads to phosphorylation of Par32, resulting in changes in its subcellular localization and function. Here we demonstrate that Par32 is a positive regulator of TORC1 activity. Loss of Par32 renders cells unable to recover from exposure to rapamycin and reverses the resistance to rapamycin of Δ npr1 cells. The sensitivity to rapamycin of cells lacking Par32 is dependent on Mep1 and Mep3 and the presence of ammonium, linking ammonium metabolism to TORC1 activity. Par32 function requires its conserved repeated glycine-rich motifs to be intact but, surprisingly, does not require its localization to the plasma membrane. In all, this work elucidates a novel mechanism by which Npr1 and Par32 exert regulatory feedback on TORC1.
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Affiliation(s)
- Natalia V Varlakhanova
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261
| | - Bryan A Tornabene
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261
| | - Marijn G J Ford
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261
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148
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Emerging Role of mTOR Signaling-Related miRNAs in Cardiovascular Diseases. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2018; 2018:6141902. [PMID: 30305865 PMCID: PMC6165581 DOI: 10.1155/2018/6141902] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/05/2018] [Accepted: 07/04/2018] [Indexed: 12/21/2022]
Abstract
Mechanistic/mammalian target of rapamycin (mTOR), an atypical serine/threonine kinase of the phosphoinositide 3-kinase- (PI3K-) related kinase family, elicits a vital role in diverse cellular processes, including cellular growth, proliferation, survival, protein synthesis, autophagy, and metabolism. In the cardiovascular system, the mTOR signaling pathway integrates both intracellular and extracellular signals and serves as a central regulator of both physiological and pathological processes. MicroRNAs (miRs), a class of short noncoding RNA, are an emerging intricate posttranscriptional modulator of critical gene expression for the development and maintenance of homeostasis across a wide array of tissues, including the cardiovascular system. Over the last decade, numerous studies have revealed an interplay between miRNAs and the mTOR signaling circuit in the different cardiovascular pathophysiology, like myocardial infarction, hypertrophy, fibrosis, heart failure, arrhythmia, inflammation, and atherosclerosis. In this review, we provide a comprehensive state of the current knowledge regarding the mechanisms of interactions between the mTOR signaling pathway and miRs. We have also highlighted the latest advances on mTOR-targeted therapy in clinical trials and the new perspective therapeutic strategies with mTOR-targeting miRs in cardiovascular diseases.
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149
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Cross Talk Networks of Mammalian Target of Rapamycin Signaling With the Ubiquitin Proteasome System and Their Clinical Implications in Multiple Myeloma. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2018; 343:219-297. [PMID: 30712673 DOI: 10.1016/bs.ircmb.2018.06.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Multiple myeloma (MM) is the second most common hematological malignancy and results from the clonal amplification of plasma cells. Despite recent advances in treatment, MM remains incurable with a median survival time of only 5-6years, thus necessitating further insights into MM biology and exploitation of novel therapeutic approaches. Both the ubiquitin proteasome system (UPS) and the PI3K/Akt/mTOR signaling pathways have been implicated in the pathogenesis, and treatment of MM and different lines of evidence suggest a close cross talk between these central cell-regulatory signaling networks. In this review, we outline the interplay between the UPS and mTOR pathways and discuss their implications for the pathophysiology and therapy of MM.
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150
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Meade N, Furey C, Li H, Verma R, Chai Q, Rollins MG, DiGiuseppe S, Naghavi MH, Walsh D. Poxviruses Evade Cytosolic Sensing through Disruption of an mTORC1-mTORC2 Regulatory Circuit. Cell 2018; 174:1143-1157.e17. [PMID: 30078703 DOI: 10.1016/j.cell.2018.06.053] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Revised: 04/19/2018] [Accepted: 06/27/2018] [Indexed: 01/12/2023]
Abstract
Viruses employ elaborate strategies to coopt the cellular processes they require to replicate while simultaneously thwarting host antiviral responses. In many instances, how this is accomplished remains poorly understood. Here, we identify a protein, F17 encoded by cytoplasmically replicating poxviruses, that binds and sequesters Raptor and Rictor, regulators of mammalian target of rapamycin complexes mTORC1 and mTORC2, respectively. This disrupts mTORC1-mTORC2 crosstalk that coordinates host responses to poxvirus infection. During infection with poxvirus lacking F17, cGAS accumulates together with endoplasmic reticulum vesicles around the Golgi, where activated STING puncta form, leading to interferon-stimulated gene expression. By contrast, poxvirus expressing F17 dysregulates mTOR, which localizes to the Golgi and blocks these antiviral responses in part through mTOR-dependent cGAS degradation. Ancestral conservation of Raptor/Rictor across eukaryotes, along with expression of F17 across poxviruses, suggests that mTOR dysregulation forms a conserved poxvirus strategy to counter cytosolic sensing while maintaining the metabolic benefits of mTOR activity.
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Affiliation(s)
- Nathan Meade
- Department of Microbiology-Immunology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Colleen Furey
- Department of Microbiology-Immunology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Hua Li
- Department of Microbiology-Immunology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Rita Verma
- Department of Microbiology-Immunology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Qingqing Chai
- Department of Microbiology-Immunology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Madeline G Rollins
- Department of Microbiology-Immunology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Stephen DiGiuseppe
- Department of Microbiology-Immunology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Mojgan H Naghavi
- Department of Microbiology-Immunology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Derek Walsh
- Department of Microbiology-Immunology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA.
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