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Trivellin C, Torello Pianale L, Olsson L. Robustness quantification of a mutant library screen revealed key genetic markers in yeast. Microb Cell Fact 2024; 23:218. [PMID: 39098937 PMCID: PMC11298085 DOI: 10.1186/s12934-024-02490-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Accepted: 07/24/2024] [Indexed: 08/06/2024] Open
Abstract
BACKGROUND Microbial robustness is crucial for developing cell factories that maintain consistent performance in a challenging environment such as large-scale bioreactors. Although tools exist to assess and understand robustness at a phenotypic level, the underlying metabolic and genetic mechanisms are not well defined, which limits our ability to engineer more strains with robust functions. RESULTS This study encompassed four steps. (I) Fitness and robustness were analyzed from a published dataset of yeast mutants grown in multiple environments. (II) Genes and metabolic processes affecting robustness or fitness were identified, and 14 of these genes were deleted in Saccharomyces cerevisiae CEN.PK113-7D. (III) The mutants bearing gene deletions were cultivated in three perturbation spaces mimicking typical industrial processes. (IV) Fitness and robustness were determined for each mutant in each perturbation space. We report that robustness varied according to the perturbation space. We identified genes associated with increased robustness such as MET28, linked to sulfur metabolism; as well as genes associated with decreased robustness, including TIR3 and WWM1, both involved in stress response and apoptosis. CONCLUSION The present study demonstrates how phenomics datasets can be analyzed to reveal the relationship between phenotypic response and associated genes. Specifically, robustness analysis makes it possible to study the influence of single genes and metabolic processes on stable microbial performance in different perturbation spaces. Ultimately, this information can be used to enhance robustness in targeted strains.
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Affiliation(s)
- Cecilia Trivellin
- Department of Life Sciences, Division of Industrial Biotechnology, Chalmers University of Technology, 412 96, Gothenburg, Sweden
| | - Luca Torello Pianale
- Department of Life Sciences, Division of Industrial Biotechnology, Chalmers University of Technology, 412 96, Gothenburg, Sweden
| | - Lisbeth Olsson
- Department of Life Sciences, Division of Industrial Biotechnology, Chalmers University of Technology, 412 96, Gothenburg, Sweden.
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Over Fifty Years of Life, Death, and Cannibalism: A Historical Recollection of Apoptosis and Autophagy. Int J Mol Sci 2021; 22:ijms222212466. [PMID: 34830349 PMCID: PMC8618802 DOI: 10.3390/ijms222212466] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 11/02/2021] [Accepted: 11/03/2021] [Indexed: 01/18/2023] Open
Abstract
Research in biomedical sciences has changed dramatically over the past fifty years. There is no doubt that the discovery of apoptosis and autophagy as two highly synchronized and regulated mechanisms in cellular homeostasis are among the most important discoveries in these decades. Along with the advancement in molecular biology, identifying the genetic players in apoptosis and autophagy has shed light on our understanding of their function in physiological and pathological conditions. In this review, we first describe the history of key discoveries in apoptosis with a molecular insight and continue with apoptosis pathways and their regulation. We touch upon the role of apoptosis in human health and its malfunction in several diseases. We discuss the path to the morphological and molecular discovery of autophagy. Moreover, we dive deep into the precise regulation of autophagy and recent findings from basic research to clinical applications of autophagy modulation in human health and illnesses and the available therapies for many diseases caused by impaired autophagy. We conclude with the exciting crosstalk between apoptosis and autophagy, from the early discoveries to recent findings.
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Karalis V, Bateup HS. Current Approaches and Future Directions for the Treatment of mTORopathies. Dev Neurosci 2021; 43:143-158. [PMID: 33910214 PMCID: PMC8440338 DOI: 10.1159/000515672] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 02/13/2021] [Indexed: 11/19/2022] Open
Abstract
The mechanistic target of rapamycin (mTOR) is a kinase at the center of an evolutionarily conserved signaling pathway that orchestrates cell growth and metabolism. mTOR responds to an array of intra- and extracellular stimuli and in turn controls multiple cellular anabolic and catabolic processes. Aberrant mTOR activity is associated with numerous diseases, with particularly profound impact on the nervous system. mTOR is found in two protein complexes, mTOR complex 1 (mTORC1) and 2 (mTORC2), which are governed by different upstream regulators and have distinct cellular actions. Mutations in genes encoding for mTOR regulators result in a collection of neurodevelopmental disorders known as mTORopathies. While these disorders can affect multiple organs, neuropsychiatric conditions such as epilepsy, intellectual disability, and autism spectrum disorder have a major impact on quality of life. The neuropsychiatric aspects of mTORopathies have been particularly challenging to treat in a clinical setting. Current therapeutic approaches center on rapamycin and its analogs, drugs that are administered systemically to inhibit mTOR activity. While these drugs show some clinical efficacy, adverse side effects, incomplete suppression of mTOR targets, and lack of specificity for mTORC1 or mTORC2 may limit their utility. An increased understanding of the neurobiology of mTOR and the underlying molecular, cellular, and circuit mechanisms of mTOR-related disorders will facilitate the development of improved therapeutics. Animal models of mTORopathies have helped unravel the consequences of mTOR pathway mutations in specific brain cell types and developmental stages, revealing an array of disease-related phenotypes. In this review, we discuss current progress and potential future directions for the therapeutic treatment of mTORopathies with a focus on findings from genetic mouse models.
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Affiliation(s)
- Vasiliki Karalis
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California, USA
| | - Helen S Bateup
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California, USA
- Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, California, USA
- Chan Zuckerberg Biohub, San Francisco, California, USA
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4
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Pang AP, Wang H, Zhang F, Hu X, Wu FG, Zhou Z, Wang W, Lu Z, Lin F. High-dose rapamycin exerts a temporary impact on T. reesei RUT-C30 through gene trFKBP12. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:77. [PMID: 33771193 PMCID: PMC8004424 DOI: 10.1186/s13068-021-01926-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Accepted: 03/11/2021] [Indexed: 05/15/2023]
Abstract
BACKGROUND Knowledge with respect to regulatory systems for cellulase production is prerequisite for exploitation of such regulatory networks to increase cellulase production, improve fermentation efficiency and reduce the relevant production cost. The target of rapamycin (TOR) signaling pathway is considered as a central signaling hub coordinating eukaryotic cell growth and metabolism with environmental inputs. However, how and to what extent the TOR signaling pathway and rapamycin are involved in cellulase production remain elusive. RESULT At the early fermentation stage, high-dose rapamycin (100 μM) caused a temporary inhibition effect on cellulase production, cell growth and sporulation of Trichoderma reesei RUT-C30 independently of the carbon sources, and specifically caused a tentative morphology defect in RUT-C30 grown on cellulose. On the contrary, the lipid content of T. reesei RUT-C30 was not affected by rapamycin. Accordingly, the transcriptional levels of genes involved in the cellulase production were downregulated notably with the addition of rapamycin. Although the mRNA levels of the putative rapamycin receptor trFKBP12 was upregulated significantly by rapamycin, gene trTOR (the downstream effector of the rapamycin-FKBP12 complex) and genes associated with the TOR signaling pathways were not changed markedly. With the deletion of gene trFKBP12, there is no impact of rapamycin on cellulase production, indicating that trFKBP12 mediates the observed temporary inhibition effect of rapamycin. CONCLUSION Our study shows for the first time that only high-concentration rapamycin induced a transient impact on T. reesei RUT-C30 at its early cultivation stage, demonstrating T. reesei RUT-C30 is highly resistant to rapamycin, probably due to that trTOR and its related signaling pathways were not that sensitive to rapamycin. This temporary influence of rapamycin was facilitated by gene trFKBP12. These findings add to our knowledge on the roles of rapamycin and the TOR signaling pathways play in T. reesei.
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Affiliation(s)
- Ai-Ping Pang
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
| | - Haiyan Wang
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
| | - Funing Zhang
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
| | - Xin Hu
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
| | - Fu-Gen Wu
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
| | - Zhihua Zhou
- Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Wei Wang
- State Key Lab of Bioreactor Engineering, New World Institute of Biotechnology, East China University of Science and Technology, Shanghai, China
| | - Zuhong Lu
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
| | - Fengming Lin
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China
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5
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Abstract
The mechanistic target of rapamycin complex 1 (mTORC1) controls cell growth and metabolism in response to various environmental inputs, especially amino acids. In fact, the activity of mTORC1 is highly sensitive to changes in amino acid levels. Over past decades, a variety of proteins have been identified as participating in the mTORC1 pathway regulated by amino acids. Classically, the Rag guanosine triphosphatases (GTPases), which reside on the lysosome, transmit amino acid availability to the mTORC1 pathway and recruit mTORC1 to the lysosome upon amino acid sufficiency. Recently, several sensors of leucine, arginine, and S-adenosylmethionine for the amino acid-stimulated mTORC1 pathway have been coming to light. Characterization of these sensors is requisite for understanding how cells adjust amino acid sensing pathways to their different needs. In this review, we summarize recent advances in amino acid sensing mechanisms that regulate mTORC1 activity and highlight these identified sensors that accurately transmit specific amino acid signals to the mTORC1 pathway.
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Affiliation(s)
- Xiu-Zhi Li
- State Key Laboratory of Agricultural Microbiology, College of Animal Sciences and Technology, Huazhong Agricultural University, Wuhan 430070, China.,The Cooperative Innovation Center for Sustainable Pig Production, Wuhan 430070, China.,Hubei Provincial Engineering Laboratory for Pig Precision Feeding and Feed Safety Technology, Wuhan 430070, China
| | - Xiang-Hua Yan
- State Key Laboratory of Agricultural Microbiology, College of Animal Sciences and Technology, Huazhong Agricultural University, Wuhan 430070, China.,The Cooperative Innovation Center for Sustainable Pig Production, Wuhan 430070, China.,Hubei Provincial Engineering Laboratory for Pig Precision Feeding and Feed Safety Technology, Wuhan 430070, China
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6
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Xiong F, Liu M, Zhuo F, Yin H, Deng K, Feng S, Liu Y, Luo X, Feng L, Zhang S, Li Z, Ren M. Host-induced gene silencing of BcTOR in Botrytis cinerea enhances plant resistance to grey mould. MOLECULAR PLANT PATHOLOGY 2019; 20:1722-1739. [PMID: 31622007 PMCID: PMC6859489 DOI: 10.1111/mpp.12873] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Botrytis cinerea is the causal agent of grey mould for more than 200 plant species, including economically important vegetables, fruits and crops, which leads to economic losses worldwide. Target of rapamycin (TOR) acts a master regulator to control cell growth and proliferation by integrating nutrient, energy and growth factors in eukaryotic species, but little is known about whether TOR can function as a practicable target in the control of plant fungal pathogens. Here, we characterize TOR signalling of B. cinerea in the regulation of growth and pathogenicity as well as its potential value in genetic engineering for crop protection by bioinformatics analysis, pharmacological assays, biochemistry and genetics approaches. The results show that conserved TOR signalling occurs, and a functional FK506-binding protein 12 kD (FKBP12) mediates the interaction between rapamycin and B. cinerea TOR (BcTOR). RNA sequencing (RNA-Seq) analysis revealed that BcTOR displayed conserved functions, particularly in controlling growth and metabolism. Furthermore, pathogenicity assay showed that BcTOR inhibition efficiently reduces the infection of B. cinerea in plant leaves of Arabidopsis and potato or tomato fruits. Additionally, transgenic plants expressing double-stranded RNA of BcTOR through the host-induced gene silencing method could produce abundant small RNAs targeting BcTOR, and significantly block the occurrence of grey mould in potato and tomato. Taken together, our results suggest that BcTOR is an efficient target for genetic engineering in control of grey mould, and also a potential and promising target applied in the biocontrol of plant fungal pathogens.
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Affiliation(s)
- Fangjie Xiong
- School of Life SciencesChongqing UniversityChongqing401331China
- Key Laboratory of Plant Hormone and Developmental Regulation of ChongqingChongqing401331China
| | - Mei Liu
- School of Life SciencesChongqing UniversityChongqing401331China
- Key Laboratory of Plant Hormone and Developmental Regulation of ChongqingChongqing401331China
| | - Fengping Zhuo
- School of Life SciencesChongqing UniversityChongqing401331China
- Key Laboratory of Plant Hormone and Developmental Regulation of ChongqingChongqing401331China
- School of Chemistry and Chemical EngineeringChongqing University of Science and TechnologyChongqing401331China
| | - Huan Yin
- School of Life SciencesChongqing UniversityChongqing401331China
- Key Laboratory of Plant Hormone and Developmental Regulation of ChongqingChongqing401331China
| | - Kexuan Deng
- School of Life SciencesChongqing UniversityChongqing401331China
- Key Laboratory of Plant Hormone and Developmental Regulation of ChongqingChongqing401331China
| | - Shun Feng
- School of Life SciencesChongqing UniversityChongqing401331China
- Key Laboratory of Plant Hormone and Developmental Regulation of ChongqingChongqing401331China
| | - Yudong Liu
- School of Life SciencesChongqing UniversityChongqing401331China
- Key Laboratory of Plant Hormone and Developmental Regulation of ChongqingChongqing401331China
| | - Xiumei Luo
- School of Life SciencesChongqing UniversityChongqing401331China
- Key Laboratory of Plant Hormone and Developmental Regulation of ChongqingChongqing401331China
| | - Li Feng
- School of Life SciencesChongqing UniversityChongqing401331China
- Key Laboratory of Plant Hormone and Developmental Regulation of ChongqingChongqing401331China
| | - Shumin Zhang
- School of Life SciencesChongqing UniversityChongqing401331China
- Key Laboratory of Plant Hormone and Developmental Regulation of ChongqingChongqing401331China
| | - Zhengguo Li
- School of Life SciencesChongqing UniversityChongqing401331China
- Key Laboratory of Plant Hormone and Developmental Regulation of ChongqingChongqing401331China
| | - Maozhi Ren
- School of Life SciencesChongqing UniversityChongqing401331China
- Key Laboratory of Plant Hormone and Developmental Regulation of ChongqingChongqing401331China
- Institute of Urban AgricultureChinese Academy of Agricultural Sciences/National Chengdu Agricultural Science and Technology CenterChengdu610000China
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7
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Livi GP. Halcyon days of TOR: Reflections on the multiple independent discovery of the yeast and mammalian TOR proteins. Gene 2019; 692:145-155. [DOI: 10.1016/j.gene.2018.12.046] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 12/13/2018] [Accepted: 12/20/2018] [Indexed: 12/24/2022]
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8
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Beyens M, Vandamme T, Peeters M, Van Camp G, Op de Beeck K. Resistance to targeted treatment of gastroenteropancreatic neuroendocrine tumors. Endocr Relat Cancer 2019; 26:R109-R130. [PMID: 32022503 DOI: 10.1530/erc-18-0420] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The mammalian target of rapamycin (mTOR) is part of the phosphoinositide-3-kinase (PI3K)/protein kinase B (Akt)/mTOR signaling. The PI3K/Akt/mTOR pathway has a pivotal role in the oncogenesis of neuroendocrine tumors (NETs). In addition, vascular endothelial growth factor (VEGF) and platelet-derived growth factor (PDGF) drive angiogenesis in NETs and therefore contributes to neuroendocrine tumor development. Hence, mTOR and angiogenesis inhibitors have been developed. Everolimus, a first-generation mTOR inhibitor, has shown significant survival benefit in advanced gastroenteropancreatic NETs. Sunitinib, a pan-tyrosine kinase inhibitor that targets the VEGF receptor, has proven to increase progression-free survival in advanced pancreatic NETs. Nevertheless, primary and acquired resistance to rapalogs and sunitinib has limited the clinical benefit for NET patients. Despite the identification of multiple molecular mechanisms of resistance, no predictive biomarker has made it to the clinic. This review is focused on the mTOR signaling and angiogenesis in NET, the molecular mechanisms of primary and acquired resistance to everolimus and sunitinib and how to overcome this resistance by alternative drug compounds.
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Affiliation(s)
- Matthias Beyens
- Center of Medical Genetics, University of Antwerp and Antwerp University Hospital, Antwerp, Belgium
- Center for Oncological Research, University of Antwerp, Antwerp, Belgium
| | - Timon Vandamme
- Center of Medical Genetics, University of Antwerp and Antwerp University Hospital, Antwerp, Belgium
- Center for Oncological Research, University of Antwerp, Antwerp, Belgium
- Section of Endocrinology, Department of Internal Medicine, Erasmus Medical Center, Rotterdam, the Netherlands
| | - Marc Peeters
- Center of Medical Genetics, University of Antwerp and Antwerp University Hospital, Antwerp, Belgium
| | - Guy Van Camp
- Center of Medical Genetics, University of Antwerp and Antwerp University Hospital, Antwerp, Belgium
- Center for Oncological Research, University of Antwerp, Antwerp, Belgium
| | - Ken Op de Beeck
- Center of Medical Genetics, University of Antwerp and Antwerp University Hospital, Antwerp, Belgium
- Center for Oncological Research, University of Antwerp, Antwerp, Belgium
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9
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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: 737] [Impact Index Per Article: 122.8] [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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10
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Waseem M, Ahmad F, Habib S, Gao Y, Li Z. Genome-wide identification of FK506-binding domain protein gene family, its characterization, and expression analysis in tomato (Solanum lycopersicum L.). Gene 2018; 678:143-154. [DOI: 10.1016/j.gene.2018.08.021] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2018] [Revised: 07/16/2018] [Accepted: 08/04/2018] [Indexed: 11/26/2022]
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11
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Stynen B, Abd-Rabbo D, Kowarzyk J, Miller-Fleming L, Aulakh SK, Garneau P, Ralser M, Michnick SW. Changes of Cell Biochemical States Are Revealed in Protein Homomeric Complex Dynamics. Cell 2018; 175:1418-1429.e9. [PMID: 30454649 PMCID: PMC6242466 DOI: 10.1016/j.cell.2018.09.050] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Revised: 09/04/2018] [Accepted: 09/24/2018] [Indexed: 01/22/2023]
Abstract
We report here a simple and global strategy to map out gene functions and target pathways of drugs, toxins, or other small molecules based on "homomer dynamics" protein-fragment complementation assays (hdPCA). hdPCA measures changes in self-association (homomerization) of over 3,500 yeast proteins in yeast grown under different conditions. hdPCA complements genetic interaction measurements while eliminating the confounding effects of gene ablation. We demonstrate that hdPCA accurately predicts the effects of two longevity and health span-affecting drugs, the immunosuppressant rapamycin and the type 2 diabetes drug metformin, on cellular pathways. We also discovered an unsuspected global cellular response to metformin that resembles iron deficiency and includes a change in protein-bound iron levels. This discovery opens a new avenue to investigate molecular mechanisms for the prevention or treatment of diabetes, cancers, and other chronic diseases of aging.
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Affiliation(s)
- Bram Stynen
- Département de Biochimie, Université de Montréal, C.P. 6128, Succursale Centre-ville, Montréal, QC H3C 3J7, Canada
| | - Diala Abd-Rabbo
- Département de Biochimie, Université de Montréal, C.P. 6128, Succursale Centre-ville, Montréal, QC H3C 3J7, Canada; Centre Robert-Cedergren, Bio-Informatique et Génomique, Université de Montréal, C.P. 6128, Succursale centre-ville, Montréal, QC H3C 3J7, Canada
| | - Jacqueline Kowarzyk
- Département de Biochimie, Université de Montréal, C.P. 6128, Succursale Centre-ville, Montréal, QC H3C 3J7, Canada
| | - Leonor Miller-Fleming
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 1GA, UK
| | - Simran Kaur Aulakh
- Molecular Biology of Metabolism Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Philippe Garneau
- Département de Biochimie, Université de Montréal, C.P. 6128, Succursale Centre-ville, Montréal, QC H3C 3J7, Canada
| | - Markus Ralser
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 1GA, UK; Molecular Biology of Metabolism Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK; Department of Biochemistry, Charité University Medicine, Berlin, Germany
| | - Stephen W Michnick
- Département de Biochimie, Université de Montréal, C.P. 6128, Succursale Centre-ville, Montréal, QC H3C 3J7, Canada; Centre Robert-Cedergren, Bio-Informatique et Génomique, Université de Montréal, C.P. 6128, Succursale centre-ville, Montréal, QC H3C 3J7, Canada.
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12
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Laribee RN. Transcriptional and Epigenetic Regulation by the Mechanistic Target of Rapamycin Complex 1 Pathway. J Mol Biol 2018; 430:4874-4890. [PMID: 30359581 DOI: 10.1016/j.jmb.2018.10.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Revised: 10/09/2018] [Accepted: 10/15/2018] [Indexed: 11/28/2022]
Abstract
Nutrient availability impacts health such that nutrient excess states can dysregulate epigenetic and transcriptional pathways to cause many diseases. Increasing evidence implicates aberrant regulation of nutrient signaling cascades as one means of communicating nutrient information to the epigenetic and transcriptional regulatory machinery. One such signaling cascade, the mechanistic target of rapamycin complex 1 (mTORC1), is conserved from yeast to man, and it is deregulated in diverse disease states. The catalytic subunit of the mTORC1 kinase complex (Tor1 or Tor2 in budding yeast and mTor in mammals) phosphorylates several downstream effectors regulating transcriptional and translational responses controlling growth and proliferation. Delineating mechanisms of cytoplasmic nutrient mTORC1 activation continues to be a major research focus. However, Tor kinases not only localize to the cytoplasm but also are found in the nucleus where they selectively bind and regulate genes controlling cellular metabolism and anabolism. The nuclear mTORC1 functions are now beginning to be defined, and they suggest that mTORC1 has a critical role in regulating the complex transcriptional activities required for ribosomal biogenesis. The mTORC1 pathway also interacts with epigenetic regulators required for modifying chromatin structure and function to control gene expression. Because altered nutrient states exert both individual and transgenerational phenotypic changes, mTORC1 signaling to chromatin effectors may have a significant role in mediating the effects of diet and nutrients on the epigenome. This article will discuss the recent inroads into the function of nuclear mTORC1 and its role in epigenetic and transcriptional regulation.
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Affiliation(s)
- R Nicholas Laribee
- Department of Pathology and Laboratory Medicine, and Center for Cancer Research, University of Tennessee Health Science Center, 19 South Manassas, Cancer Research Building Rm 318, Memphis, TN 38163, USA.
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13
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Ryskalin L, Limanaqi F, Frati A, Busceti CL, Fornai F. mTOR-Related Brain Dysfunctions in Neuropsychiatric Disorders. Int J Mol Sci 2018; 19:ijms19082226. [PMID: 30061532 PMCID: PMC6121884 DOI: 10.3390/ijms19082226] [Citation(s) in RCA: 77] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Revised: 07/26/2018] [Accepted: 07/27/2018] [Indexed: 12/12/2022] Open
Abstract
The mammalian target of rapamycin (mTOR) is an ubiquitously expressed serine-threonine kinase, which senses and integrates several intracellular and environmental cues to orchestrate major processes such as cell growth and metabolism. Altered mTOR signalling is associated with brain malformation and neurological disorders. Emerging evidence indicates that even subtle defects in the mTOR pathway may produce severe effects, which are evident as neurological and psychiatric disorders. On the other hand, administration of mTOR inhibitors may be beneficial for a variety of neuropsychiatric alterations encompassing neurodegeneration, brain tumors, brain ischemia, epilepsy, autism, mood disorders, drugs of abuse, and schizophrenia. mTOR has been widely implicated in synaptic plasticity and autophagy activation. This review addresses the role of mTOR-dependent autophagy dysfunction in a variety of neuropsychiatric disorders, to focus mainly on psychiatric syndromes including schizophrenia and drug addiction. For instance, amphetamines-induced addiction fairly overlaps with some neuropsychiatric disorders including neurodegeneration and schizophrenia. For this reason, in the present review, a special emphasis is placed on the role of mTOR on methamphetamine-induced brain alterations.
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Affiliation(s)
- Larisa Ryskalin
- Human Anatomy, Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Via Roma 55, 56126 Pisa, Italy.
| | - Fiona Limanaqi
- Human Anatomy, Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Via Roma 55, 56126 Pisa, Italy.
| | | | | | - Francesco Fornai
- Human Anatomy, Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Via Roma 55, 56126 Pisa, Italy.
- I.R.C.C.S. Neuromed, Via Atinense 18, 86077 Isernia, Italy.
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14
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Johnson SC. Nutrient Sensing, Signaling and Ageing: The Role of IGF-1 and mTOR in Ageing and Age-Related Disease. Subcell Biochem 2018; 90:49-97. [PMID: 30779006 DOI: 10.1007/978-981-13-2835-0_3] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Nutrient signaling through insulin/IGF-1 was the first pathway demonstrated to regulate ageing and age-related disease in model organisms. Pharmacological or dietary interventions targeting nutrient signaling pathways have been shown to robustly attenuate ageing in many organisms. Caloric restriction, the most widely studied longevity promoting intervention, works through multiple nutrient signaling pathways, while inhibition of mTOR through treatment with rapamycin reproducibly delays ageing and disease through specific inhibition of the mTOR complexes. Although the benefits of reduced insulin/IGF-1 in lifespan and health are well documented in model organisms, defining the precise role of the IGF-1 in human ageing and age-related disease has proven more difficult. Association studies provide some insight but also reveal paradoxes. Low serum IGF-1 predicts longevity, but IGF-1 decreases with age and IGF-1 therapy benefits some of age-related pathologies. Circulating IGF-1 has been associated both positively and negatively with risk of age-related diseases in humans, and in some cases both activation and inhibition of IGF-1 signaling have provided benefit in animal models of the same diseases. Interventions designed modulate the nutrient sensing signaling pathways positively or negatively are already available for clinical use, highlighting the need for a clear understanding of the role of nutrient signaling in ageing and age-related disease. This chapter examines data from model organisms and human genetic association studies, with a special emphasis on IGF-1 and mTOR, and discusses potential models for resolving the paradoxes surrounding IGF-1 data.
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Affiliation(s)
- Simon C Johnson
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA, USA.
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15
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Hu K, Guo S, Yan G, Yuan W, Zheng Y, Jiang Y. Ubiquitin regulates TORC1 in yeast Saccharomyces cerevisiae. Mol Microbiol 2016; 100:303-14. [PMID: 26700129 DOI: 10.1111/mmi.13319] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/20/2015] [Indexed: 12/01/2022]
Abstract
In the yeast Saccharomyces cerevisiae the TOR complex 1 (TORC1) controls many growth-related cellular processes and is essential for cell growth and proliferation. Macrolide antibiotic rapamycin, in complex with a cytosol protein named FKBP12, specifically inhibits TORC1, causing growth arrest. The FKBP12-rapamycin complex interferes with TORC1 function by binding to the FRB domain of the TOR proteins. In an attempt to understand the role of the FRB domain in TOR function, we identified a single point mutation (Tor2(W2041R) ) in the FRB domain of Tor2 that renders yeast cells rapamycin resistant and temperature sensitive. At the permissive temperature, the Tor2 mutant protein is partially defective for binding with Kog1 and TORC1 is impaired for membrane association. At the restrictive temperature, Kog1 but not the Tor2 mutant protein, is rapidly degraded. Overexpression of ubiquitin stabilizes Kog1 and suppresses the growth defect associated with the tor2 mutant at the nonpremissive temperature. We find that ubiquitin binds non-covalently to Kog1, prevents Kog1 from degradation and stabilizes TORC1. Our data reveal a unique role for ubiquitin in regulation of TORC1 and suggest that Kog1 requires association with the Tor proteins for stabilization.
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Affiliation(s)
- Kejin Hu
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA
| | - Shuguang Guo
- Department of Biology, Henan University, Kaifeng, 475000, China
| | - Gonghong Yan
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA
| | - Wenjie Yuan
- School of Life Science and Biotechnology, Dalian University of Technology, Dalian, 116024, China
| | - Yin Zheng
- Medical and Healthcare Center, Hainan Provincial People's Hospital, Haikou, 570311, China
| | - Yu Jiang
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA
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16
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Szopinska A, Christ E, Planchon S, König H, Evers D, Renaut J. Stuck at work? Quantitative proteomics of environmental wine yeast strains reveals the natural mechanism of overcoming stuck fermentation. Proteomics 2016; 16:593-608. [DOI: 10.1002/pmic.201500225] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Revised: 11/30/2015] [Accepted: 12/30/2015] [Indexed: 11/06/2022]
Affiliation(s)
- Aleksandra Szopinska
- Department ‘Environmental Research and Innovation’; Luxembourg Institute of Science and Technology; Belvaux Grand-duchy of Luxembourg
| | - Eva Christ
- Institute of Microbiology and Wine Research; Johannes Gutenberg University Mainz; Mainz Germany
| | - Sebastien Planchon
- Department ‘Environmental Research and Innovation’; Luxembourg Institute of Science and Technology; Belvaux Grand-duchy of Luxembourg
| | - Helmut König
- Institute of Microbiology and Wine Research; Johannes Gutenberg University Mainz; Mainz Germany
| | - Daniele Evers
- Department ‘Environmental Research and Innovation’; Luxembourg Institute of Science and Technology; Belvaux Grand-duchy of Luxembourg
| | - Jenny Renaut
- Department ‘Environmental Research and Innovation’; Luxembourg Institute of Science and Technology; Belvaux Grand-duchy of Luxembourg
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Deng K, Yu L, Zheng X, Zhang K, Wang W, Dong P, Zhang J, Ren M. Target of Rapamycin Is a Key Player for Auxin Signaling Transduction in Arabidopsis. FRONTIERS IN PLANT SCIENCE 2016; 7:291. [PMID: 27014314 PMCID: PMC4786968 DOI: 10.3389/fpls.2016.00291] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Accepted: 02/23/2016] [Indexed: 05/08/2023]
Abstract
Target of rapamycin (TOR), a master sensor for growth factors and nutrition availability in eukaryotic species, is a specific target protein of rapamycin. Rapamycin inhibits TOR kinase activity viaFK506 binding protein 12 kDa (FKBP12) in all examined heterotrophic eukaryotic organisms. In Arabidopsis, several independent studies have shown that AtFKBP12 is non-functional under aerobic condition, but one study suggests that AtFKBP12 is functional during anaerobic growth. However, the functions of AtFKBP12 have never been examined in parallel under aerobic and anaerobic growth conditions so far. To this end, we cloned the FKBP12 gene of humans, yeast, and Arabidopsis, respectively. Transgenic plants were generated, and pharmacological examinations were performed in parallel with Arabidopsis under aerobic and anaerobic conditions. ScFKBP12 conferred plants with the strongest sensitivity to rapamycin, followed by HsFKBP12, whereas AtFKBP12 failed to generate rapamycin sensitivity under aerobic condition. Upon submergence, yeast and human FKBP12 can significantly block cotyledon greening while Arabidopsis FKBP12 only retards plant growth in the presence of rapamycin, suggesting that hypoxia stress could partially restore the functions of AtFKBP12 to bridge the interaction between rapamycin and TOR. To further determine if communication between TOR and auxin signaling exists in plants, yeast FKBP12 was introduced into DR5::GUS homozygous plants. The transgenic plants DR5/BP12 were then treated with rapamycin or KU63794 (a new inhibitor of TOR). GUS staining showed that the auxin content of root tips decreased compared to the control. DR5/BP12 plants lost sensitivity to auxin after treatment with rapamycin. Auxin-defective phenotypes, including short primary roots, fewer lateral roots, and loss of gravitropism, occurred in DR5/BP12 plants when seedlings were treated with rapamycin+KU63794. This indicated that the combination of rapamycin and KU63794 can significantly inhibit TOR and auxin signaling in DR5/BP12 plants. These studies demonstrate that TOR is essential for auxin signaling transduction in Arabidopsis.
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Affiliation(s)
- Kexuan Deng
- School of Life Sciences, Chongqing UniversityChongqing, China
| | - Lihua Yu
- School of Life Sciences, Chongqing UniversityChongqing, China
| | - Xianzhe Zheng
- School of Life Sciences, Chongqing UniversityChongqing, China
| | - Kang Zhang
- School of Life Sciences, Chongqing UniversityChongqing, China
| | - Wanjing Wang
- College of Agronomy and Biotechnology, Southwest UniversityChongqing, China
| | - Pan Dong
- School of Life Sciences, Chongqing UniversityChongqing, China
| | - Jiankui Zhang
- College of Agronomy and Biotechnology, Southwest UniversityChongqing, China
| | - Maozhi Ren
- School of Life Sciences, Chongqing UniversityChongqing, China
- *Correspondence: Maozhi Ren
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Xiong F, Dong P, Liu M, Xie G, Wang K, Zhuo F, Feng L, Yang L, Li Z, Ren M. Tomato FK506 Binding Protein 12KD (FKBP12) Mediates the Interaction between Rapamycin and Target of Rapamycin (TOR). FRONTIERS IN PLANT SCIENCE 2016; 7:1746. [PMID: 27917191 PMCID: PMC5114585 DOI: 10.3389/fpls.2016.01746] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Accepted: 11/04/2016] [Indexed: 05/18/2023]
Abstract
Target of Rapamycin (TOR) signaling is an important regulator in multiple organisms including yeast, plants, and animals. However, the TOR signaling in plants is much less understood as compared to that in yeast and animals. TOR kinase can be efficiently suppressed by rapamycin in the presence of functional FK506 Binding Protein 12 KD (FKBP12) in yeast and animals. In most examined higher plants rapamycin fails to inhibit TOR kinase due to the non-functional FKBP12. Here we find that tomato plants showed obvious growth inhibition when treated with rapamycin and the inhibitory phenotype is similar to suppression of TOR causing by active-site TOR inhibitors (asTORis) such as KU63794, AZD8055, and Torin1. The chemical genetic assays using TOR inhibitors and heterologous expressing SlFKBP12 in Arabidopsis indicated that the TOR signaling is functional in tomato. The protein gel shifting and TOR inhibitors combination assays showed that SlFKBP12 can mediate the interaction between rapamycin and TOR. Furthermore, comparative expression profile analysis between treatments with rapamycin and KU63794 identified highly overlapped Differentially Expressed Genes (DEGs) which are involved in many anabolic and catabolic processes, such as photosynthesis, cell wall restructuring, and senescence in tomato. These observations suggest that SlFFBP12 is functional in tomato. The results provided basic information of TOR signaling in tomato, and also some new insights into how TOR controls plant growth and development through reprogramming the transcription profiles.
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Affiliation(s)
- Fangjie Xiong
- School of Life Sciences, Chongqing UniversityChongqing, China
| | - Pan Dong
- School of Life Sciences, Chongqing UniversityChongqing, China
| | - Mei Liu
- School of Life Sciences, Chongqing UniversityChongqing, China
| | - Gengxin Xie
- Center of Space Exploration, Ministry of EducationChongqing, China
| | - Kai Wang
- School of Life Sciences, Chongqing UniversityChongqing, China
| | - Fengping Zhuo
- School of Life Sciences, Chongqing UniversityChongqing, China
| | - Li Feng
- School of Life Sciences, Chongqing UniversityChongqing, China
| | - Lu Yang
- School of Life Sciences, Chongqing UniversityChongqing, China
| | - Zhengguo Li
- School of Life Sciences, Chongqing UniversityChongqing, China
- *Correspondence: Zhengguo Li
| | - Maozhi Ren
- School of Life Sciences, Chongqing UniversityChongqing, China
- Center of Space Exploration, Ministry of EducationChongqing, China
- Maozhi Ren
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19
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Reamtong O, Srimuang K, Saralamba N, Sangvanich P, Day NP, White NJ, Imwong M. Protein profiling of mefloquine resistant Plasmodium falciparum using mass spectrometry-based proteomics. INTERNATIONAL JOURNAL OF MASS SPECTROMETRY 2015; 391:82-92. [PMID: 26869851 PMCID: PMC4708064 DOI: 10.1016/j.ijms.2015.09.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Revised: 09/07/2015] [Accepted: 09/16/2015] [Indexed: 05/30/2023]
Abstract
Malaria is a mosquito borne infectious disease caused by protozoa of genus Plasmodium. There are five species of Plasmodium that are found to infect humans. Plasmodium falciparum can cause severe malaria leading to higher morbidity and mortality of malaria than the other four species. Antimalarial resistance is the major obstacle to control malaria. Mefloquine was used in combination with Artesunate for uncomplicated P. falciparum in South East Asia and it has developed and established mefloquine resistance in this region. Here, gel-enhanced liquid chromatography/tandem mass spectrometry (GeLC-MS/MS)-based proteomics and label-free quantification were used to explore the protein profiles of mefloquine-sensitive and -induced resistant P. falciparum. A Thai P. falciparum isolate (S066) was used as a model in this research. Our data revealed for the first time that 69 proteins exhibited at least 2-fold differences in their expression levels between the two parasite lines. Of these, 36 were up-regulated and 33 were down-regulated in the mefloquine-resistant line compared with the mefloquine-sensitive line. These findings are consistent with those of past studies, where the multidrug resistance protein Pgh1 showed an up-regulation pattern consistent with that expected from its average 3-copy pfmdr1 gene number. Pgh1 and eight other up-regulated proteins (i.e., histo-aspartyl protease protein, exportin 1, eukaryotic translation initiation factor 3 subunit 8, peptidyl-prolyl cis-trans isomerase, serine rich protein homologue, exported protein 1, ATP synthase beta chain and phospholipid scramblase 1) were further validated for their expression levels using reverse transcriptase quantitative real-time PCR. The data support the up-regulation status in the mefloquine-resistant parasite line of all the candidate genes referred to above. Therefore, GeLC-MS/MS-based proteomics combined with label-free quantification is a reliable approach for exploring mefloquine resistance biomarkers in P. falciparum. Identification of these proteins leads to better understanding of mefloquine resistant mechanisms in malaria parasites.
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Affiliation(s)
- Onrapak Reamtong
- Department of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand
| | - Krongkan Srimuang
- Department of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand
| | - Naowarat Saralamba
- Department of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand
| | - Polkit Sangvanich
- Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
| | - Nicholas P.J. Day
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine, Churchill Hospital, University of Oxford, Oxford, United Kingdom
| | - Nicholas J. White
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine, Churchill Hospital, University of Oxford, Oxford, United Kingdom
| | - Mallika Imwong
- Department of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand
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20
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Nath PR, Isakov N. Insights into peptidyl-prolyl cis–trans isomerase structure and function in immunocytes. Immunol Lett 2015; 163:120-31. [DOI: 10.1016/j.imlet.2014.11.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2014] [Revised: 10/27/2014] [Accepted: 11/03/2014] [Indexed: 12/30/2022]
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21
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Bruntz RC, Lindsley CW, Brown HA. Phospholipase D signaling pathways and phosphatidic acid as therapeutic targets in cancer. Pharmacol Rev 2014; 66:1033-79. [PMID: 25244928 PMCID: PMC4180337 DOI: 10.1124/pr.114.009217] [Citation(s) in RCA: 184] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Phospholipase D is a ubiquitous class of enzymes that generates phosphatidic acid as an intracellular signaling species. The phospholipase D superfamily plays a central role in a variety of functions in prokaryotes, viruses, yeast, fungi, plants, and eukaryotic species. In mammalian cells, the pathways modulating catalytic activity involve a variety of cellular signaling components, including G protein-coupled receptors, receptor tyrosine kinases, polyphosphatidylinositol lipids, Ras/Rho/ADP-ribosylation factor GTPases, and conventional isoforms of protein kinase C, among others. Recent findings have shown that phosphatidic acid generated by phospholipase D plays roles in numerous essential cellular functions, such as vesicular trafficking, exocytosis, autophagy, regulation of cellular metabolism, and tumorigenesis. Many of these cellular events are modulated by the actions of phosphatidic acid, and identification of two targets (mammalian target of rapamycin and Akt kinase) has especially highlighted a role for phospholipase D in the regulation of cellular metabolism. Phospholipase D is a regulator of intercellular signaling and metabolic pathways, particularly in cells that are under stress conditions. This review provides a comprehensive overview of the regulation of phospholipase D activity and its modulation of cellular signaling pathways and functions.
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Affiliation(s)
- Ronald C Bruntz
- Department of Pharmacology (R.C.B., C.W.L., H.A.B.) and Vanderbilt Center for Neuroscience Drug Discovery (C.W.L.), Vanderbilt University Medical Center; Department of Chemistry, Vanderbilt Institute of Chemical Biology (C.W.L., H.A.B.); Vanderbilt Specialized Chemistry for Accelerated Probe Development (C.W.L.); and Department of Biochemistry, Vanderbilt-Ingram Cancer Center (H.A.B.), Vanderbilt University, Nashville, Tennessee
| | - Craig W Lindsley
- Department of Pharmacology (R.C.B., C.W.L., H.A.B.) and Vanderbilt Center for Neuroscience Drug Discovery (C.W.L.), Vanderbilt University Medical Center; Department of Chemistry, Vanderbilt Institute of Chemical Biology (C.W.L., H.A.B.); Vanderbilt Specialized Chemistry for Accelerated Probe Development (C.W.L.); and Department of Biochemistry, Vanderbilt-Ingram Cancer Center (H.A.B.), Vanderbilt University, Nashville, Tennessee
| | - H Alex Brown
- Department of Pharmacology (R.C.B., C.W.L., H.A.B.) and Vanderbilt Center for Neuroscience Drug Discovery (C.W.L.), Vanderbilt University Medical Center; Department of Chemistry, Vanderbilt Institute of Chemical Biology (C.W.L., H.A.B.); Vanderbilt Specialized Chemistry for Accelerated Probe Development (C.W.L.); and Department of Biochemistry, Vanderbilt-Ingram Cancer Center (H.A.B.), Vanderbilt University, Nashville, Tennessee
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22
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Santulli G, Totary-Jain H. Tailoring mTOR-based therapy: molecular evidence and clinical challenges. Pharmacogenomics 2014; 14:1517-26. [PMID: 24024901 DOI: 10.2217/pgs.13.143] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The mTOR signaling pathway integrates inputs from a variety of upstream stimuli to regulate diverse cellular processes including proliferation, growth, survival, motility, autophagy, protein synthesis and metabolism. The mTOR pathway is dysregulated in a number of human pathologies including cancer, diabetes, obesity, autoimmune disorders, neurological disease and aging. Ongoing clinical trials testing mTOR-targeted treatments number in the hundreds and underscore its therapeutic potential. To date mTOR inhibitors are clinically approved to prevent organ rejection, to inhibit restenosis after angioplasty, and to treat several advanced cancers. In this review we discuss the continuously evolving field of mTOR pharmacogenomics, as well as highlight the emerging efforts in identifying diagnostic and prognostic markers, including miRNAs, in order to assess successful therapeutic responses.
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Affiliation(s)
- Gaetano Santulli
- Department of Physiology & Cellular Biophysics, The Clyde & Helen Wu Center for Molecular Cardiology, Columbia University Medical Center, New York, NY 10032, USA
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23
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Rallis C, López-Maury L, Georgescu T, Pancaldi V, Bähler J. Systematic screen for mutants resistant to TORC1 inhibition in fission yeast reveals genes involved in cellular ageing and growth. Biol Open 2014; 3:161-71. [PMID: 24463365 PMCID: PMC3925319 DOI: 10.1242/bio.20147245] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Target of rapamycin complex 1 (TORC1), which controls growth in response to nutrients, promotes ageing in multiple organisms. The fission yeast Schizosaccharomyces pombe emerges as a valuable genetic model system to study TORC1 function and cellular ageing. Here we exploited the combinatorial action of rapamycin and caffeine, which inhibit fission yeast growth in a TORC1-dependent manner. We screened a deletion library, comprising ∼84% of all non-essential fission yeast genes, for drug-resistant mutants. This screen identified 33 genes encoding functions such as transcription, kinases, mitochondrial respiration, biosynthesis, intra-cellular trafficking, and stress response. Among the corresponding mutants, 5 showed shortened and 21 showed increased maximal chronological lifespans; 15 of the latter mutants showed no further lifespan increase with rapamycin and might thus represent key targets downstream of TORC1. We pursued the long-lived sck2 mutant with additional functional analyses, revealing that the Sck2p kinase functions within the TORC1 network and is required for normal cell growth, global protein translation, and ribosomal S6 protein phosphorylation in a nutrient-dependent manner. Notably, slow cell growth was associated with all long-lived mutants while oxidative-stress resistance was not.
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Affiliation(s)
- Charalampos Rallis
- Department of Genetics, Evolution and Environment, and Institute of Healthy Ageing, Darwin Building, University College London, Gower Street, London WC1E 6BT, UK
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24
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Zhang R, Meng Z, Zhou T, Deng Y, Feng L, Wang Y, Sun G, Guo S, Ren M. ScFKBP12 bridges rapamycin and AtTOR in Arabidopsis. PLANT SIGNALING & BEHAVIOR 2013; 8:e26115. [PMID: 23989449 PMCID: PMC4106506 DOI: 10.4161/psb.26115] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
FKBP12 encodes a prolyl isomerase and highly conserved in eukaryotic species. In yeasts and animals, FKBP12 can interact with rapamycin and FK506 to form rapamycin-FKBP12 and FK506-FKBP12 complex, respectively. In higher plants, FKBP12 protein lost its function to bind rapamycin and FK506. Early studies showed that yeast and human FKBP12 protein can restore the rapamycin sensitivity in Arabidopsis, but the used concentration is 100-1000 folds higher than that in yeast and animals. High concentration of drugs would increase the cost and cause the potential secondary effects on plant growth and development. Here we further discovered that BP12 plants generated in our previous study are hypersensitive to rapamycin at the concentration as low as that is effective in yeast and animals. It is surprising to observe that WT and BP12 plants are not sensitive to FK506 in normal growth condition. These findings advance the current understanding of rapamycin-TOR signaling in plants.
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Affiliation(s)
- Rui Zhang
- Biotechnology Research Institute; Chinese Academy of Agricultural Sciences; Beijing, PR China
| | - Zhigang Meng
- Biotechnology Research Institute; Chinese Academy of Agricultural Sciences; Beijing, PR China
| | - Tao Zhou
- Biotechnology Research Institute; Chinese Academy of Agricultural Sciences; Beijing, PR China
| | - Yong Deng
- Biotechnology Research Institute; Chinese Academy of Agricultural Sciences; Beijing, PR China
| | - Li Feng
- School of Life Sciences; Chongqing University; Chongqing, PR China
| | - Yuan Wang
- Biotechnology Research Institute; Chinese Academy of Agricultural Sciences; Beijing, PR China
| | - Guoqing Sun
- Biotechnology Research Institute; Chinese Academy of Agricultural Sciences; Beijing, PR China
| | - Sandui Guo
- Biotechnology Research Institute; Chinese Academy of Agricultural Sciences; Beijing, PR China
| | - Maozhi Ren
- Biotechnology Research Institute; Chinese Academy of Agricultural Sciences; Beijing, PR China
- School of Life Sciences; Chongqing University; Chongqing, PR China
- Correspondence to: Maozhi Ren,
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25
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Galat A. Functional diversity and pharmacological profiles of the FKBPs and their complexes with small natural ligands. Cell Mol Life Sci 2013; 70:3243-75. [PMID: 23224428 PMCID: PMC11113493 DOI: 10.1007/s00018-012-1206-z] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2012] [Revised: 10/24/2012] [Accepted: 10/25/2012] [Indexed: 12/25/2022]
Abstract
From 5 to 12 FK506-binding proteins (FKBPs) are encoded in the genomes of disparate marine organisms, which appeared at the dawn of evolutionary events giving rise to primordial multicellular organisms with elaborated internal body plan. Fifteen FKBPs, several FKBP-like proteins and some splicing variants of them are expressed in humans. Human FKBP12 and some of its paralogues bind to different macrocyclic antibiotics such as FK506 or rapamycin and their derivatives. FKBP12/(macrocyclic antibiotic) complexes induce diverse pharmacological activities such as immunosuppression in humans, anticancerous actions and as sustainers of quiescence in certain organisms. Since the FKBPs bind to various assemblies of proteins and other intracellular components, their complexes with the immunosuppressive drugs may differentially perturb miscellaneous cellular functions. Sequence-structure relationships and pharmacological profiles of diverse FKBPs and their involvement in crucial intracellular signalization pathways and modulation of cryptic intercellular communication networks were discussed.
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Affiliation(s)
- Andrzej Galat
- Commissariat à l'Energie Atomique, Direction des Sciences du Vivant, Institut de Biologie et de Technologies de Saclay, Service d'Ingénierie Moléculaire des Protéines, Bat. 152, 91191, Gif-sur-Yvette Cedex, France.
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26
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Rallis C, Codlin S, Bähler J. TORC1 signaling inhibition by rapamycin and caffeine affect lifespan, global gene expression, and cell proliferation of fission yeast. Aging Cell 2013; 12:563-73. [PMID: 23551936 PMCID: PMC3798131 DOI: 10.1111/acel.12080] [Citation(s) in RCA: 106] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/11/2013] [Indexed: 01/06/2023] Open
Abstract
Target of rapamycin complex 1 (TORC1) is implicated in growth control and aging from yeast to humans. Fission yeast is emerging as a popular model organism to study TOR signaling, although rapamycin has been thought to not affect cell growth in this organism. Here, we analyzed the effects of rapamycin and caffeine, singly and combined, on multiple cellular processes in fission yeast. The two drugs led to diverse and specific phenotypes that depended on TORC1 inhibition, including prolonged chronological lifespan, inhibition of global translation, inhibition of cell growth and division, and reprograming of global gene expression mimicking nitrogen starvation. Rapamycin and caffeine differentially affected these various TORC1-dependent processes. Combined drug treatment augmented most phenotypes and effectively blocked cell growth. Rapamycin showed a much more subtle effect on global translation than did caffeine, while both drugs were effective in prolonging chronological lifespan. Rapamycin and caffeine did not affect the lifespan via the pH of the growth media. Rapamycin prolonged the lifespan of nongrowing cells only when applied during the growth phase but not when applied after cells had stopped proliferation. The doses of rapamycin and caffeine strongly correlated with growth inhibition and with lifespan extension. This comprehensive analysis will inform future studies into TORC1 function and cellular aging in fission yeast and beyond.
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Affiliation(s)
- Charalampos Rallis
- Department of Genetics Evolution & Environment and Institute of Healthy Ageing University College London Gower Street – Darwin Building London WC1E 6BT UK
| | - Sandra Codlin
- Department of Genetics Evolution & Environment and Institute of Healthy Ageing University College London Gower Street – Darwin Building London WC1E 6BT UK
| | - Jürg Bähler
- Department of Genetics Evolution & Environment and Institute of Healthy Ageing University College London Gower Street – Darwin Building London WC1E 6BT UK
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27
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Peel N, Larijani B, Parker PJ. Localised interventions in cellular processes. BIOCHIMICA ET BIOPHYSICA ACTA 2013; 1834:1364-70. [PMID: 23403146 DOI: 10.1016/j.bbapap.2013.01.044] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2012] [Accepted: 01/30/2013] [Indexed: 12/11/2022]
Abstract
The once linear view of cell regulatory processes is now changing as we begin to overlay spatial and temporal characteristics onto signalling pathways and dynamic membranous events. To better understand the properties of these spatially restricted processes we must refine our targeting of these events with acute localised manipulations. We review here the diverse application of a dimerisation system, which exploits immunosuppressor/immunophilin biology to provide a route to drug-inducible subdomain interventions. This article is part of a Special Issue entitled: Inhibitors of Protein Kinases (2012).
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Affiliation(s)
- Nick Peel
- Protein Phosphorylation Laboratory London Research Institute, London, UK.
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Ikai N, Nakazawa N, Hayashi T, Yanagida M. The reverse, but coordinated, roles of Tor2 (TORC1) and Tor1 (TORC2) kinases for growth, cell cycle and separase-mediated mitosis in Schizosaccharomyces pombe. Open Biol 2013; 1:110007. [PMID: 22645648 PMCID: PMC3352084 DOI: 10.1098/rsob.110007] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2011] [Accepted: 10/20/2011] [Indexed: 11/12/2022] Open
Abstract
Target of rapamycin complexes (TORCs), which are vital for nutrient utilization, contain a catalytic subunit with the phosphatidyl inositol kinase-related kinase (PIKK) motif. TORC1 is required for cell growth, while the functions of TORC2 are less well understood. We show here that the fission yeast Schizosaccharomyces pombe TORC2 has a cell cycle role through determining the proper timing of Cdc2 Tyr15 dephosphorylation and the cell size under limited glucose, whereas TORC1 restrains mitosis and opposes securin–separase, which are essential for chromosome segregation. These results were obtained using the previously isolated TORC1 mutant tor2-L2048S in the phosphatidyl inositol kinase (PIK) domain and a new TORC2 mutant tor1-L2045D, which harbours a mutation in the same site. While mutated TORC1 and TORC2 displayed diminished kinase activity and FKBP12/Fkh1-dependent rapamycin sensitivity, their phenotypes were nearly opposite in mitosis. Premature mitosis and the G2–M delay occurred in TORC1 and TORC2 mutants, respectively. Surprisingly, separase/cut1—securin/cut2 mutants were rescued by TORC1/tor2-L2048S mutation or rapamycin addition or even Fkh1 deletion, whereas these mutants showed synthetic defect with TORC2/tor1-L2045D. TORC1 and TORC2 coordinate growth, mitosis and cell size control, such as Wee1 and Cdc25 do for the entry into mitosis.
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Affiliation(s)
- Nobuyasu Ikai
- Okinawa Institute of Science and Technology Promotion Corporation, 1919-1 Tancha, Onna, Okinawa 904-0412, Japan
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29
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Abstract
In metazoans, TOR is an essential protein that functions as a master regulator of cellular growth and proliferation. Over the past decade, there has been an explosion of information about this critical master kinase, ranging from the composition of the TOR protein complex to its ability to act as an integrator of numerous extracellular signals. Unfortunately, this plethora of information has also raised numerous questions regarding TOR function. Currently, the prevailing view is that mammalian TOR (mTOR) exists in at least two molecular complexes, mTORC1 and mTORC2, which are largely defined by the presence of either RAPTOR or RICTOR. However, additional co-factors have been identified for each complex, and their importance in mediating mTOR signals has been incompletely elucidated. Similarly, there are differences in mTOR function that reflect the tissue of origin. In this review, we present an alternative view to mTOR complex formation and function, which envisions mTOR regulation and signal propagation as a reflection of cell type- and basal state-dependent conditions. The re-interpretation of mTOR biology in this framework may facilitate the design of therapies most likely to effectively inhibit this central regulator of cell behavior.
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Affiliation(s)
- Jason D Weber
- Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO, USA
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30
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Titov DV, Liu JO. Identification and validation of protein targets of bioactive small molecules. Bioorg Med Chem 2011; 20:1902-9. [PMID: 22226983 DOI: 10.1016/j.bmc.2011.11.070] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2011] [Revised: 11/22/2011] [Accepted: 11/30/2011] [Indexed: 12/22/2022]
Abstract
Identification and validation of protein targets of bioactive small molecules is an important problem in chemical biology and drug discovery. Currently, no single method is satisfactory for this task. Here, we provide an overview of common methods for target identification and validation that historically were most successful. We have classified for the first time the existing methods into two distinct and complementary types, the 'top-down' and 'bottom-up' approaches. In a typical top-down approach, the cellular phenotype is used as a starting point and the molecular target is approached through systematic narrowing down of possibilities by taking advantage of the detailed existing knowledge of cellular pathways and processes. In contrast, the bottom-up approach entails the direct detection and identification of the molecular targets using affinity-based or genetic methods. A special emphasis is placed on target validation, including correlation analysis and genetic methods, as this area is often ignored despite its importance.
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Affiliation(s)
- Denis V Titov
- Department of Pharmacology, Johns Hopkins University School of Medicine, MD, USA
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31
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Ungar L, Harari Y, Toren A, Kupiec M. Tor complex 1 controls telomere length by affecting the level of Ku. Curr Biol 2011; 21:2115-20. [PMID: 22169538 DOI: 10.1016/j.cub.2011.11.024] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2011] [Revised: 10/25/2011] [Accepted: 11/14/2011] [Indexed: 01/12/2023]
Abstract
Telomeres are specialized DNA-protein structures at the ends of eukaryotic chromosomes. Telomeric DNA is synthesized by telomerase, which is expressed only at the early stages of development [1, 2]. To become malignant, any cell has to be able to replenish telomeres [3]. Thus, understanding how telomere length is monitored has significant medical implications, especially in the fields of aging and cancer. In yeast, telomerase is constitutively active. A large network of genes participates in controlling telomere length [4-8]. Tor1 and Tor2 (targets of rapamycin [9]) are two similar kinases that regulate cell growth [10]. Both can be found as part of the TOR complex 1 (TORC1 [11]), which coordinates the response to nutrient starvation and is sensitive to rapamycin [12]. The rapamycin-insensitive TOR complex 2 (TORC2) contains only Tor2 and regulates actin cytoskeleton polarization [13]. Here we provide evidence for a role of TORC1 in telomere shortening upon starvation in yeast cells. The TORC1 signal is transduced by the Gln3/Gat1/Ure2 pathway, which controls the levels of the Ku heterodimer, a telomere regulator. We discuss the potential implications for the usage of rapamycin as a therapeutic agent against cancer and the effect that calorie restriction may have on telomere length.
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Affiliation(s)
- Lior Ungar
- Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Ramat Aviv 69978, Israel
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32
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Abstract
Cell migration is a fundamental process in a wide array of biological and
pathological responses. It is regulated by complex signal transduction pathways
in response to external cues that couple to growth factor and chemokine
receptors. In recent years, the target of rapamycin (TOR) kinase, as part of
either TOR complex 1 (TORC1) or TOR complex 2 (TORC2), has been shown to be an
important signaling component linking external signals to the cytoskeletal
machinery in a variety of cell types and organisms. Thus, these complexes have
emerged as key regulators of cell migration and chemotaxis.
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Affiliation(s)
- Lunhua Liu
- Laboratory of Cellular and Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
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33
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Bracho-Valdés I, Moreno-Alvarez P, Valencia-Martínez I, Robles-Molina E, Chávez-Vargas L, Vázquez-Prado J. mTORC1- and mTORC2-interacting proteins keep their multifunctional partners focused. IUBMB Life 2011; 63:896-914. [PMID: 21905202 DOI: 10.1002/iub.558] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2011] [Accepted: 07/14/2011] [Indexed: 12/11/2022]
Abstract
The mammalian target of rapamycin, best known as mTOR, is a phylogenetically conserved serine/threonine kinase that controls life-defining cellular processes such as growth, metabolism, survival, and migration under the influence of multiple interacting proteins. Historically, the cellular activities blocked by rapamycin in mammalian cells were considered the only events controlled by mTOR. However, this paradigm changed with the discovery of two signaling complexes differentially sensitive to rapamycin, whose catalytic component is mTOR. The one sensitive to rapamycin, known as mTORC1, promotes protein synthesis in response to growth factors and nutrients via the phosphorylation of p70S6K and 4EBP1; while the other, known as mTORC2, promotes cell migration and survival via the activation of Rho GTPases and the phosphorylation of AKT, respectively. Although mTORC2 kinase activity is not inhibited by rapamycin, hours of incubation with this antibiotic can impede the assembly of this signaling complex. The direct mechanism by which mTORC2 leads to cell migration depends on its interaction with P-Rex1, a Rac-specific guanine nucleotide exchange factor, while additional indirect pathways involve the intervention of PKC or AKT, multifunctional ubiquitous serine/threonine kinases that activate effectors of cell migration upon being phosphorylated by mTORC2 in response to chemotactic signals. These mTORC2 effectors are altered in metastatic cancer. Numerous clinical trials are testing mTOR inhibitors as potential antineoplasic drugs. Here, we briefly review the actions of mTOR with emphasis on the controlling role of mTORC1 and mTORC2-interacting proteins and highlight the mechanisms linked to cell migration.
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Affiliation(s)
- Ismael Bracho-Valdés
- Department of Pharmacology, CINVESTAV-IPN, Av. Instituto Politécnico Nacional 2508.Col. San Pedro Zacatenco, 07000 México D.F., México
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34
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Rakhit R, Edwards SR, Iwamoto M, Wandless TJ. Evaluation of FKBP and DHFR based destabilizing domains in Saccharomyces cerevisiae. Bioorg Med Chem Lett 2011; 21:4965-8. [PMID: 21741238 PMCID: PMC3156383 DOI: 10.1016/j.bmcl.2011.06.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2011] [Revised: 06/01/2011] [Accepted: 06/02/2011] [Indexed: 12/19/2022]
Abstract
Two orthogonal destabilizing domains have been developed based on mutants of human FKBP12 as well as bacterial DHFR and these engineered domains have been used to control protein concentration in a variety of contexts in vitro and in vivo. FKBP12 based destabilizing domains cannot be rescued in the yeast Saccharomyces cerevisiae; ecDHFR based destabilizing domains are not degraded as efficiently in S. cerevisiae as in mammalian cells or Plasmodium, but provide a starting point for the development of domains with increased signal-to-noise in S. cerevisiae.
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Affiliation(s)
- Rishi Rakhit
- Department of Chemical and Systems Biology, Stanford University, CA, United States
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35
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Chang YJ, Shin CS, Han DH, Kim JY, Kim KI, Kwon YM, Huh WK. Genomewide Profiling of Rapamycin Sensitivity in Saccharomyces cerevisiae on Synthetic Medium. Genomics Inform 2010. [DOI: 10.5808/gi.2010.8.4.177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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36
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Ha CW, Huh WK. Rapamycin increases rDNA stability by enhancing association of Sir2 with rDNA in Saccharomyces cerevisiae. Nucleic Acids Res 2010; 39:1336-50. [PMID: 20947565 PMCID: PMC3045593 DOI: 10.1093/nar/gkq895] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The target of rapamycin (TOR) kinase is an evolutionarily conserved key regulator of eukaryotic cell growth and proliferation. Recently, it has been reported that inhibition of TOR signaling pathway can delay aging and extend lifespan in several eukaryotic organisms, but how lifespan extension is mediated by inhibition of TOR signaling is poorly understood. Here we report that rapamycin treatment and nitrogen starvation, both of which cause inactivation of TOR complex 1 (TORC1), lead to enhanced association of Sir2 with ribosomal DNA (rDNA) in Saccharomyces cerevisiae. TORC1 inhibition increases transcriptional silencing of RNA polymerase II-transcribed gene integrated at the rDNA locus and reduces homologous recombination between rDNA repeats that causes formation of toxic extrachromosomal rDNA circles. In addition, TORC1 inhibition induces deacetylation of histones at rDNA. We also found that Pnc1 and Net1 are required for enhancement of association of Sir2 with rDNA under TORC1 inhibition. Taken together, our findings suggest that inhibition of TORC1 signaling stabilizes the rDNA locus by enhancing association of Sir2 with rDNA, thereby leading to extension of replicative lifespan in S. cerevisiae.
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Affiliation(s)
- Cheol Woong Ha
- School of Biological Sciences, Research Center for Functional Cellulomics, Institute of Microbiology, Seoul National University, Seoul 151-747, Republic of Korea
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37
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Inference of the Molecular Mechanism of Action from Genetic Interaction and Gene Expression Data. OMICS-A JOURNAL OF INTEGRATIVE BIOLOGY 2010; 14:357-67. [DOI: 10.1089/omi.2009.0144] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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38
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Biosynthesis of rapamycin and its regulation: past achievements and recent progress. J Antibiot (Tokyo) 2010; 63:434-41. [PMID: 20588302 DOI: 10.1038/ja.2010.71] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Rapamycin and its analogs are clinically important macrolide compounds produced by Streptomyces hygroscopicus. They exhibit antifungal, immunosuppressive, antitumor, neuroprotective and antiaging activities. The core macrolactone ring of rapamycin is biosynthesized by hybrid type I modular polyketide synthase (PKS)/nonribosomal peptide synthetase systems primed with 4,5-dihydrocyclohex-1-ene-carboxylic acid. The linear polyketide chain is condensed with pipecolate by peptide synthetase, followed by cyclization to form the macrolide ring and modified by a series of post-PKS tailoring steps. The aim of this review was to outline past and recent advances in the biosynthesis and regulation of rapamycin, with an emphasis on the distinguished contributions of Professor Demain to the study of rapamycin. In addition, this article describes the biological activities as well as mechanism of action of rapamycin and its derivatives. Recent attempts to improve the productivity of rapamycin and generate diverse rapamycin analogs through mutasynthesis and mutagenesis are also introduced, along with some future perspectives.
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39
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Bai X, Jiang Y. Key factors in mTOR regulation. Cell Mol Life Sci 2010; 67:239-53. [PMID: 19823764 PMCID: PMC4780839 DOI: 10.1007/s00018-009-0163-7] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2009] [Revised: 09/22/2009] [Accepted: 09/23/2009] [Indexed: 12/12/2022]
Abstract
Mammalian target of rapamycin (mTOR) is a protein serine/threonine kinase that controls a wide range of growth-related cellular processes. In the past several years, many factors have been identified that are involved in controlling mTOR activity. Those factors in turn are regulated by diverse signaling cascades responsive to changes in intracellular and environmental conditions. The molecular connections between mTOR and its regulators form a complex signaling network that governs cellular metabolism, growth and proliferation. In this review, we discuss some key factors in mTOR regulation and mechanisms by which these factors control mTOR activity.
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Affiliation(s)
- Xiaochun Bai
- Department of Cell Biology, School of Basic Medical Sciences, Southern Medical University, 510515 Guangzhou, China
| | - Yu Jiang
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213 USA
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40
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Chai R, Chen S, Ding J, Grayburn PA. Efficient, glucose responsive and islet-specific transgene expression by a modified rat insulin promoter. Gene Ther 2009; 16:1202-9. [PMID: 19727136 PMCID: PMC2762485 DOI: 10.1038/gt.2009.114] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2009] [Revised: 07/01/2009] [Accepted: 07/01/2009] [Indexed: 12/15/2022]
Abstract
This study was done to improve efficiency and islet specificity of the rat insulin promoter (RIP). Various RIP lengths were prepared and tested in vitro to drive luciferase reporter gene expression in INS1-cells, alpha-cells, acinar cells, ductal cells and fibroblasts. The CMV promoter was used as a positive control. In addition, the DsRed reporter gene was administered in vivo to rat pancreas by ultrasound-targeted microbubble destruction (UTMD). Confocal microscopy was used to detect the presence and distribution of DsRed within the pancreas after UTMD. A modified RIP3.1 promoter, which includes portions of the insulin gene after its transcription start site is fivefold more active in INS-1 cells than the full-length RIP promoter or the CMV promoter. RIP3.1 is regulated by glucose level and various islet transcription factors in vitro, and exhibits activity in alpha-cells, but not in exocrine cells. In vivo delivery of RIP3.1-DsRed resulted in expression of DsRed protein in beta-cells, and to a lesser extent in alpha-cells under normal glucose conditions. No DsRed signal was present in exocrine pancreas under RIP3.1. A modified RIP, RIP3.1, efficiently and specifically directs gene expression to endocrine pancreas.
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Affiliation(s)
- Renjie Chai
- Institute of Metabolic Disease, Baylor University Medical Center, Dallas, Texas, 75246
| | - Shuyuan Chen
- Department of Internal Medicine, Division of Cardiology, Baylor University Medical Center, Baylor Heart and Vascular Institute, 621 N. Hall St, Suite H030, Dallas, Texas, 75226
| | - Jiahuan Ding
- Institute of Metabolic Disease, Baylor University Medical Center, Dallas, Texas, 75246
| | - Paul A Grayburn
- Department of Internal Medicine, Division of Cardiology, Baylor University Medical Center, Baylor Heart and Vascular Institute, 621 N. Hall St, Suite H030, Dallas, Texas, 75226
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41
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Shin CS, Kim SY, Huh WK. TORC1 controls degradation of the transcription factor Stp1, a key effector of the SPS amino-acid-sensing pathway in Saccharomyces cerevisiae. J Cell Sci 2009; 122:2089-99. [PMID: 19494127 DOI: 10.1242/jcs.047191] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
The target of rapamycin (TOR) signaling pathway plays crucial roles in the regulation of eukaryotic cell growth. In Saccharomyces cerevisiae, nitrogen sources in the extracellular environment activate the TOR signaling pathway. However, the precise mechanisms underlying the regulation of TOR activity in response to extracellular nitrogen sources are poorly understood. Here, we report that degradation of Stp1, a transcription factor for amino acid uptake and a key effector of the SPS amino-acid-sensing pathway, is controlled by TOR activity in S. cerevisiae. Using a genome-wide protein localization study, we found that Stp1 disappeared from the nucleus upon inactivation of TOR complex 1 (TORC1) by rapamycin, suggesting the involvement of Stp1 in the TOR signaling pathway. Supporting this notion, a knockout mutant for the STP1 gene was found to be hypersensitive to rapamycin, and overexpression of STP1 conferred resistance to rapamycin. Interestingly, we found that the rapamycin-induced disappearance of Stp1 from the nucleus resulted from Stp1 degradation, which was dependent on the activity of a protein phosphatase 2A (PP2A)-like phosphatase, Sit4, which is a well-known downstream effector of TORC1. Taken together, our findings highlight an intimate connection between the amino-acid-sensing pathway and the rapamycin-sensitive TOR signaling pathway.
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Affiliation(s)
- Chun-Shik Shin
- School of Biological Sciences and Research Center for Functional Cellulomics, Institute of Microbiology, Seoul National University, Seoul 151-747, Republic of Korea
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42
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Hoon S, Smith AM, Wallace IM, Suresh S, Miranda M, Fung E, Proctor M, Shokat KM, Zhang C, Davis RW, Giaever G, St Onge RP, StOnge RP, Nislow C. An integrated platform of genomic assays reveals small-molecule bioactivities. Nat Chem Biol 2008; 4:498-506. [PMID: 18622389 DOI: 10.1038/nchembio.100] [Citation(s) in RCA: 154] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2008] [Accepted: 06/16/2008] [Indexed: 01/27/2023]
Abstract
Bioactive compounds are widely used to modulate protein function and can serve as important leads for drug development. Identifying the in vivo targets of these compounds remains a challenge. Using yeast, we integrated three genome-wide gene-dosage assays to measure the effect of small molecules in vivo. A single TAG microarray was used to resolve the fitness of strains derived from pools of (i) homozygous deletion mutants, (ii) heterozygous deletion mutants and (iii) genomic library transformants. We demonstrated, with eight diverse reference compounds, that integration of these three chemogenomic profiles improves the sensitivity and specificity of small-molecule target identification. We further dissected the mechanism of action of two protein phosphatase inhibitors and in the process developed a framework for the rational design of multidrug combinations to sensitize cells with specific genotypes more effectively. Finally, we applied this platform to 188 novel synthetic chemical compounds and identified both potential targets and structure-activity relationships.
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Affiliation(s)
- Shawn Hoon
- Department of Genetics, Stanford University, Mail Stop-5120, Palo Alto, California 94305, USA
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43
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Hayashi T, Hatanaka M, Nagao K, Nakaseko Y, Kanoh J, Kokubu A, Ebe M, Yanagida M. Rapamycin sensitivity of the Schizosaccharomyces pombe tor2 mutant and organization of two highly phosphorylated TOR complexes by specific and common subunits. Genes Cells 2008; 12:1357-70. [PMID: 18076573 DOI: 10.1111/j.1365-2443.2007.01141.x] [Citation(s) in RCA: 153] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Nutrients are essential for cell growth and division. Screening of Schizosaccharomyces pombe temperature-sensitive strains led to the isolation of a nutrient-insensitive mutant, tor2-287. This mutant produces a nitrogen starvation-induced arrest phenotype in rich media, fails to recover from the arrest, and is hypersensitive to rapamycin. The L2048S substitution mutation in the catalytic domain in close proximity to the adenine base of ATP is unique as it is the sole known genetic cause of rapamycin hypersensitivity. Localization of Tor2 was speckled in the vegetative cytoplasm, and both speckled and membranous in the arrested cell cytoplasm. Using mass spectroscopic analysis, we identified six subunits (Tco89, Bit61, Toc1, Tel2, Tti1 and Cka1) that, in addition to the six previously identified subunits (Tor1, Tor2, Mip1/Raptor, Ste20/Rictor, Sin1/Avo1 and Wat1/Lst8), comprise the TOR complexes (TORCs). All of the subunits so far examined are multiply phosphorylated. Tel2 bound to Tti1 interacts with various phosphatidyl inositol kinase (PIK)-related kinases including Tra1, Tra2 and Rad3, as well as Tor1 and Tor2. Schizosaccharomyces pombe TORCs should thus be functionally redundant and might be broadly regulated through different subunits that are either common or specific to the two TORCs, or even common to various PIK-related kinases. Functional redundancy of the TORCs may explain the rapamycin hypersensitivity of tor2-287.
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Affiliation(s)
- Takeshi Hayashi
- The G0 Cell Unit, Okinawa Institute of Science and Technology Promotion Corporation, Suzaki 12-22, Uruma, Okinawa 904-2234, Japan
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44
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Min SK, Kenagy RD, Clowes AW. Induction of vascular atrophy as a novel approach to treating restenosis. A review. J Vasc Surg 2008; 47:662-70. [PMID: 17950562 PMCID: PMC2268652 DOI: 10.1016/j.jvs.2007.07.056] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2007] [Revised: 07/24/2007] [Accepted: 07/28/2007] [Indexed: 01/01/2023]
Abstract
Regardless of the type of arterial reconstruction, luminal narrowing (stenosis or restenosis) develops in approximately one third of the vessels. In the past, the focus of research has been on the mechanisms of stenosis (intimal hyperplasia, pathologic remodeling) and pharmacologic approaches to prevention. An alternative approach is to induce intimal atrophy after luminal narrowing has developed, thus limiting treatment to only those patients that develop a problem. This approach to treat established disease by reducing wall mass through induction of cell death and extracellular matrix removal would be particularly useful for treating stenosis in synthetic bypass grafts or stented vessels, in which intimal hyperplasia is the primary mechanism of stenosis. This approach may be applicable as well to other vascular proliferative disorders, such as pulmonary hypertension and chronic transplant arteriopathy. Proof of principle has been shown in experiments with antibodies to platelet-derived growth factor (PDGF) receptors that cause neointimal regression in baboon polytetrafluoroethylene (PTFE) grafts and with angiotensin-converting enzyme inhibitors that induce medial atrophy in hypertensive arteries. Possible molecular targets could include PDGF receptors, A20, and BMP4. Further studies are needed to determine the utility of such a therapeutic approach to vascular disease.
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Affiliation(s)
- Seung-Kee Min
- Department of Surgery, Seoul National University College of Medicine, Seoul, Korea
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45
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Rubio-Texeira M. Urmylation controls Nil1p and Gln3p-dependent expression of nitrogen-catabolite repressed genes in Saccharomyces cerevisiae. FEBS Lett 2007; 581:541-50. [PMID: 17254574 DOI: 10.1016/j.febslet.2007.01.019] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2006] [Revised: 12/22/2006] [Accepted: 01/09/2007] [Indexed: 11/28/2022]
Abstract
Urm1 is a modifier protein that is conjugated to substrate proteins through thioester formation with the E1-like enzyme, Uba4. Here is shown that the lack of urmylation causes derepression of the GAP1 gene (encoding a nitrogen-regulated broad-spectrum amino acid-scavenging permease) in the presence of rich nitrogen sources, and simultaneous inhibition of the expression of CIT2, a TCA-cycle gene involved in the production of glutamate and glutamine. This effect is dependent on the TORC1- and nutrient-regulated transcriptional factors, Nil1p and Gln3p. Evidence is provided that, in the absence of urmylation, nuclear/cytosolic shuffling of both transcriptional factors is altered, ultimately leading to inability to repress GAP1 gene in the presence of a rich nitrogen source. Altogether, the data presented here indicate an important role of the urmylation pathway in regulating the expression of genes involved in sensing and controlling amino acids levels.
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Affiliation(s)
- Marta Rubio-Texeira
- Whitehead Institute, Massachusetts Institute of Technology, 9 Cambridge Center 653, Cambridge, MA 02142, USA.
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46
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FLIRI HANS, BAUMANN GOETZ, ENZ ALBERT, KALLEN JUERG, LUYTEN MARCEL, MIKOL VINCENT, MOVVA RAO, QUESNIAUX VALERIE, SCHREIER MAX, WALKINSHAW MALCOLM, WENGER ROLAND, ZENKE GERHARD, ZURINI MAURO. Cyclosporins. Ann N Y Acad Sci 2006. [DOI: 10.1111/j.1749-6632.1993.tb17141.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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47
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Abstract
The story of rapamycin is a pharmaceutical fairytale. Discovered as an antifungal activity in a soil sample collected on Easter Island, this macrocyclic lactone and its derivatives are now billion dollar drugs, used in, and being evaluated for, a number of clinical applications. Taking advantage of its antifungal property, the molecular Target Of Rapamycin, TOR, was first described in the budding yeast Saccharomyces cerevisiae. TORs encode large, Ser/Thr protein kinases that reside in two distinct, structurally and functionally conserved, multi-protein complexes. In yeast, these complexes coordinate many different aspects of cell growth. TOR complex 1, TORC1, promotes protein synthesis and other anabolic processes, while inhibiting macroautophagy and other catabolic and stress-response processes. TORC2 primarily regulates cell polarity, although additional readouts of this complex are beginning to be characterized. TORC1 appears to be activated by nutrient cues and inhibited by stresses and rapamycin; however, detailed mechanisms are not known. In contrast, TORC2 is insensitive to rapamycin and physiological regulators of this complex have yet to be defined. Given the unsurpassed resources available to yeast researchers, this simple eukaryote continues to contribute to our understanding of eukaryotic cell growth in general and TOR function in particular.
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Affiliation(s)
- C De Virgilio
- Département de Microbiologie et Médecine Moléculaire, Université de Genève, CMU, Geneva, Switzerland.
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Avruch J, Hara K, Lin Y, Liu M, Long X, Ortiz-Vega S, Yonezawa K. Insulin and amino-acid regulation of mTOR signaling and kinase activity through the Rheb GTPase. Oncogene 2006; 25:6361-72. [PMID: 17041622 DOI: 10.1038/sj.onc.1209882] [Citation(s) in RCA: 245] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Target of Rapamycin (TOR), a giant protein kinase expressed by all eucaryotic cells, controls cell size in response to nutrient signals. In metazoans, cell and organismal growth is controlled by nutrients and the insulin/insulin-like growth factor (IGF) system, and the understanding of how these inputs coordinately regulate TOR signaling has advanced greatly in the past 5 years. In single-cell eucaryotes and Caenorhabditis elegans, TOR is a dominant regulator of overall mRNA translation, whereas in higher metazoans, TOR controls the expression of a smaller fraction of mRNAs that is especially important to cell growth. TOR signals through two physically distinct multiprotein complexes, and the control of cell growth is mediated primarily by TOR complex 1 (TORC1), which contains the polypeptides raptor and LST8. Raptor is the substrate binding element of TORC1, and the ability of raptor to properly present substrates, such as the translational regulators 4E-BP and p70 S6 kinase, to the TOR catalytic domain is essential for their TOR-catalysed phosphorylation, and is inhibited by the Rapamycin/FKBP-12 complex. The dominant proximal regulator of TORC1 signaling and kinase activity is the ras-like small GTPase Rheb. Rheb binds directly to the mTOR catalytic domain, and Rheb-GTP enables TORC1 to attain an active configuration. Insulin/IGF enhances Rheb GTP charging through the ability of activated Akt to inhibit the Rheb-GTPase-activating function of the tuberous sclerosis heterodimer (TSC1/TSC2). Conversely, energy depletion reduces Rheb-GTP charging through the ability of the adenosine monophosphate-activated protein kinase to phosphorylate TSC2 and stimulate its Rheb-GTPase activating function, as well as by HIFalpha-mediated transcriptional responses that act upstream of the TSC1/2 complex. Amino-acid depletion inhibits TORC1 acting predominantly downstream of the TSC complex, by interfering with the ability of Rheb to bind to mTOR. The components of the insulin/IGF pathway to TORC1 are now well established, whereas the elements mediating the more ancient and functionally dominant input of amino acids remain largely unknown.
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Affiliation(s)
- J Avruch
- Diabetes Research Lab, Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA.
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Arvisais EW, Romanelli A, Hou X, Davis JS. AKT-independent phosphorylation of TSC2 and activation of mTOR and ribosomal protein S6 kinase signaling by prostaglandin F2alpha. J Biol Chem 2006; 281:26904-13. [PMID: 16816403 DOI: 10.1074/jbc.m605371200] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Prostaglandin F2alpha (PGF2alpha) is an important mediator of corpus luteum (CL) regression, although the cellular signaling events that mediate this process have not been clearly identified. It is established that PGF2alpha binds to a G-proteincoupled receptor (GPCR) to stimulate protein kinase C (PKC) and Raf-MEK-Erk signaling in luteal cells. The present experiments were performed to determine whether PGF2alpha stimulates the mammalian target of rapamycin (mTOR)/ribosomal protein S6 kinase 1 (S6K1) signaling pathway in steroidogenic luteal cells. We demonstrate that PGF2alpha treatment results in a timeand concentration-dependent stimulation of the phosphorylation and activation of S6K1. The stimulation of S6K1 in response to PGF2alpha treatment was abolished by the mTOR inhibitor rapamycin. Treatment with PGF2alpha did not increase AKT phosphorylation but increased the phosphorylation of Erk and the tumor suppressor protein tuberous sclerosis complex 2 (TSC2), an upstream regulator of mTOR. The effects of PGF2alpha were mimicked by the PKC activator PMA and inhibited by U0126, a MEK1 inhibitor. The activation of mTOR/S6K1 and putative down stream processes involving the translational apparatus (i.e. 4EBP1 phosphorylation, release of 4EBP1 binding in m(7)G cap binding assays, and the phosphorylation and synthesis of S6) were completely sensitive to treatment with rapamycin, implicating mTOR in the actions of PGF2alpha. Taken together, our data suggest that GPCR activation in response to PGF2alpha stimulates the mTOR pathway which increases the translational machinery in luteal cells. The translation of proteins under the control of mTOR may have implications for luteal development and regression and offer new strategies for therapeutic intervention in PGF2alpha-target tissues.
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Affiliation(s)
- Edward W Arvisais
- Olson Center for Women's Health, Department of Obstetrics and Gynecology, University of Nebraska Medical Center, Omaha, Nebraska 68198-3255, USA
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Inoki K, Guan KL. Complexity of the TOR signaling network. Trends Cell Biol 2006; 16:206-12. [PMID: 16516475 DOI: 10.1016/j.tcb.2006.02.002] [Citation(s) in RCA: 127] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2005] [Revised: 01/16/2006] [Accepted: 02/13/2006] [Indexed: 01/10/2023]
Abstract
The target of rapamycin (TOR) is a serine/threonine kinase of the phosphatidylinositol kinase-related kinase family and is highly conserved from yeast to mammals. TOR functions as a central regulator of cell growth and is itself regulated by a wide range of signals, including growth factors, nutrients and stress conditions. Recent studies in eukaryotic cells have identified two distinct TOR complexes, TORC1 and TORC2, which phosphorylate different substrates and have distinct physiological functions. Here, we discuss new findings that have extended the complexity of TOR signaling and the different roles of the TORC complexes in yeast, flies and mammals.
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Affiliation(s)
- Ken Inoki
- Life Sciences Institute, Department of Biological Chemistry, Institute of Gerontology, University of Michigan, Ann Arbor, MI 48109, USA
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