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Park J, Desai H, Liboy-Lugo JM, Gu S, Jowhar Z, Xu A, Floor SN. IGHMBP2 deletion suppresses translation and activates the integrated stress response. Life Sci Alliance 2024; 7:e202302554. [PMID: 38803225 PMCID: PMC11109757 DOI: 10.26508/lsa.202302554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 05/01/2024] [Accepted: 05/02/2024] [Indexed: 05/29/2024] Open
Abstract
IGHMBP2 is a nonessential, superfamily 1 DNA/RNA helicase that is mutated in patients with rare neuromuscular diseases SMARD1 and CMT2S. IGHMBP2 is implicated in translational and transcriptional regulation via biochemical association with ribosomal proteins, pre-rRNA processing factors, and tRNA-related species. To uncover the cellular consequences of perturbing IGHMBP2, we generated full and partial IGHMBP2 deletion K562 cell lines. Using polysome profiling and a nascent protein synthesis assay, we found that IGHMBP2 deletion modestly reduces global translation. We performed Ribo-seq and RNA-seq and identified diverse gene expression changes due to IGHMBP2 deletion, including ATF4 up-regulation. With recent studies showing the integrated stress response (ISR) can contribute to tRNA metabolism-linked neuropathies, we asked whether perturbing IGHMBP2 promotes ISR activation. We generated ATF4 reporter cell lines and found IGHMBP2 knockout cells demonstrate basal, chronic ISR activation. Our work expands upon the impact of IGHMBP2 in translation and elucidates molecular mechanisms that may link mutant IGHMBP2 to severe clinical phenotypes.
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Affiliation(s)
- Jesslyn Park
- https://ror.org/043mz5j54 Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA, USA
- https://ror.org/043mz5j54 Tetrad Graduate Program, University of California, San Francisco, San Francisco, CA, USA
| | - Hetvee Desai
- https://ror.org/043mz5j54 Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA, USA
| | - José M Liboy-Lugo
- https://ror.org/043mz5j54 Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA, USA
- https://ror.org/043mz5j54 Tetrad Graduate Program, University of California, San Francisco, San Francisco, CA, USA
| | - Sohyun Gu
- https://ror.org/043mz5j54 Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA, USA
| | - Ziad Jowhar
- https://ror.org/043mz5j54 Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA, USA
- https://ror.org/043mz5j54 Biomedical Sciences Graduate Program, University of California, San Francisco, San Francisco, CA, USA
| | - Albert Xu
- https://ror.org/043mz5j54 Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA, USA
- https://ror.org/043mz5j54 Biomedical Sciences Graduate Program, University of California, San Francisco, San Francisco, CA, USA
| | - Stephen N Floor
- https://ror.org/043mz5j54 Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA, USA
- https://ror.org/043mz5j54 Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, CA, USA
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2
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Fulton TL, Wansbrough MR, Mirth CK, Piper MDW. Short-term fasting of a single amino acid extends lifespan. GeroScience 2024; 46:3607-3615. [PMID: 38305939 PMCID: PMC11229437 DOI: 10.1007/s11357-024-01078-3] [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: 08/14/2023] [Accepted: 01/16/2024] [Indexed: 02/03/2024] Open
Abstract
Diet and health are strongly linked, though the strict changes in diet required to improve health outcomes are usually difficult to sustain. We sought to understand whether short-term bouts of amino acid-specific modifications to the diet of Drosophila melanogaster could mimic the lifespan and stress resistance benefits of dietary restriction, without the requirement for drastic reductions in food intake. We found that flies that were transiently fed diets lacking the essential amino acid isoleucine, but otherwise nutritionally complete, exhibited enhanced nicotine tolerance, indicating elevated detoxification capacity. The protection from isoleucine deprivation increased with the duration of exposure, up to a maximum at 7-day isoleucine deprivation for flies 2, 3, or 4 weeks of age, and a 5-day deprivation when flies were 5 weeks of age. Because of these beneficial effects on toxin resistance, we intermittently deprived flies of isoleucine during the first 6 weeks of adulthood and monitored the effect on lifespan. Lifespan was significantly extended when flies experienced short-term isoleucine deprivation at 3 and 5 weeks of age, regardless of whether they were also deprived at 1 week. These results indicate that short-term bouts of isoleucine deprivation can extend lifespan and highlight its cumulative and time-dependent benefits. Interestingly, we found that isoleucine-deprived flies lost their protection against nicotine within 3 days of returning to fully fed conditions. Therefore, the mechanisms underlying lifespan extension may involve transient damage clearance during the bouts of isoleucine deprivation rather than sustained enhanced detoxification capacity. These data highlight a new time-restricted, nutritionally precise method to extend life in Drosophila melanogaster and point to a more manageable dietary method to combat ageing.
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Affiliation(s)
- Tahlia L Fulton
- School of Biological Sciences, Monash University, Melbourne, VIC, 3800, Australia
| | - Mia R Wansbrough
- School of Biological Sciences, Monash University, Melbourne, VIC, 3800, Australia
| | - Christen K Mirth
- School of Biological Sciences, Monash University, Melbourne, VIC, 3800, Australia
| | - Matthew D W Piper
- School of Biological Sciences, Monash University, Melbourne, VIC, 3800, Australia.
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3
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Gibbs VJ, Lin YH, Ghuge AA, Anderson RA, Schiemann AH, Conaglen L, Sansom BJM, da Silva RC, Sattlegger E. GCN2 in Viral Defence and the Subversive Tactics Employed by Viruses. J Mol Biol 2024; 436:168594. [PMID: 38724002 DOI: 10.1016/j.jmb.2024.168594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Revised: 05/01/2024] [Accepted: 05/01/2024] [Indexed: 06/10/2024]
Abstract
The recent SARS-CoV-2 pandemic and associated COVID19 disease illustrates the important role of viral defence mechanisms in ensuring survival and recovery of the host or patient. Viruses absolutely depend on the host's protein synthesis machinery to replicate, meaning that impeding translation is a powerful way to counteract viruses. One major approach used by cells to obstruct protein synthesis is to phosphorylate the alpha subunit of eukaryotic translation initiation factor 2 (eIF2α). Mammals possess four different eIF2α-kinases: PKR, HRI, PEK/PERK, and GCN2. While PKR is currently considered the principal eIF2α-kinase involved in viral defence, the other eIF2α-kinases have also been found to play significant roles. Unsurprisingly, viruses have developed mechanisms to counteract the actions of eIF2α-kinases, or even to exploit them to their benefit. While some of these virulence factors are specific to one eIF2α-kinase, such as GCN2, others target all eIF2α-kinases. This review critically evaluates the current knowledge of viral mechanisms targeting the eIF2α-kinase GCN2. A detailed and in-depth understanding of the molecular mechanisms by which viruses evade host defence mechanisms will help to inform the development of powerful anti-viral measures.
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Affiliation(s)
- Victoria J Gibbs
- School of Food Technology and Natural Sciences, Massey University, Palmerston North, New Zealand
| | - Yu H Lin
- School of Food Technology and Natural Sciences, Massey University, Palmerston North, New Zealand
| | - Aditi A Ghuge
- School of Food Technology and Natural Sciences, Massey University, Palmerston North, New Zealand
| | - Reuben A Anderson
- School of Food Technology and Natural Sciences, Massey University, Palmerston North, New Zealand
| | - Anja H Schiemann
- School of Food Technology and Natural Sciences, Massey University, Palmerston North, New Zealand
| | - Layla Conaglen
- School of Food Technology and Natural Sciences, Massey University, Palmerston North, New Zealand
| | - Bianca J M Sansom
- School of Natural Sciences, Massey University, Auckland, New Zealand
| | - Richard C da Silva
- School of Natural Sciences, Massey University, Auckland, New Zealand; Genome Biology and Epigenetics, Department of Biology, Utrecht University, Utrecht, the Netherlands
| | - Evelyn Sattlegger
- School of Food Technology and Natural Sciences, Massey University, Palmerston North, New Zealand; School of Natural Sciences, Massey University, Auckland, New Zealand; Maurice Wilkins Centre for Molecular BioDiscovery, Palmerston North, New Zealand.
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4
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Liao K, Liu K, Wang Z, Zhao K, Mei Y. TRIM2 promotes metabolic adaptation to glutamine deprivation via enhancement of CPT1A activity. FEBS J 2024. [PMID: 38949993 DOI: 10.1111/febs.17218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2024] [Revised: 05/14/2024] [Accepted: 06/20/2024] [Indexed: 07/03/2024]
Abstract
Cancer cells undergo metabolic adaptation to promote their survival and growth under energy stress conditions, yet the underlying mechanisms remain largely unclear. Here, we report that tripartite motif-containing protein 2 (TRIM2) is upregulated in response to glutamine deprivation by the transcription factor cyclic AMP-dependent transcription factor (ATF4). TRIM2 is shown to specifically interact with carnitine O-palmitoyltransferase 1 (CPT1A), a rate-limiting enzyme of fatty acid oxidation. Via this interaction, TRIM2 enhances the enzymatic activity of CPT1A, thereby regulating intracellular lipid levels and protecting cells from glutamine deprivation-induced apoptosis. Furthermore, TRIM2 is able to promote both in vitro cell proliferation and in vivo xenograft tumor growth via CPT1A. Together, these findings establish TRIM2 as an important regulator of the metabolic adaptation of cancer cells to glutamine deprivation and implicate TRIM2 as a potential therapeutic target for cancer.
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Affiliation(s)
- Kaimin Liao
- Center for Advanced Interdisciplinary Science and Biomedicine of IHM, School of Basic Medical Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| | - Kaiyue Liu
- Center for Advanced Interdisciplinary Science and Biomedicine of IHM, School of Basic Medical Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| | - Zhongyu Wang
- Center for Advanced Interdisciplinary Science and Biomedicine of IHM, School of Basic Medical Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| | - Kailiang Zhao
- Center for Advanced Interdisciplinary Science and Biomedicine of IHM, School of Basic Medical Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| | - Yide Mei
- Center for Advanced Interdisciplinary Science and Biomedicine of IHM, School of Basic Medical Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
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5
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Li X, Yang Y, Bai X, Wang X, Tan H, Chen Y, Zhu Y, Liu Q, Wu MN, Li Y. A brain-derived insulin signal encodes protein satiety for nutrient-specific feeding inhibition. Cell Rep 2024; 43:114282. [PMID: 38795342 PMCID: PMC11220824 DOI: 10.1016/j.celrep.2024.114282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Revised: 04/08/2024] [Accepted: 05/10/2024] [Indexed: 05/27/2024] Open
Abstract
The suppressive effect of insulin on food intake has been documented for decades. However, whether insulin signals can encode a certain type of nutrients to regulate nutrient-specific feeding behavior remains elusive. Here, we show that in female Drosophila, a pair of dopaminergic neurons, tritocerebrum 1-dopaminergic neurons (T1-DANs), are directly activated by a protein-intake-induced insulin signal from insulin-producing cells (IPCs). Intriguingly, opto-activating IPCs elicits feeding inhibition for both protein and sugar, while silencing T1-DANs blocks this inhibition only for protein food. Elevating insulin signaling in T1-DANs or opto-activating these neurons is sufficient to mimic protein satiety. Furthermore, this signal is conveyed to local neurons of the protocerebral bridge (PB-LNs) and specifically suppresses protein intake. Therefore, our findings reveal that a brain-derived insulin signal encodes protein satiety and suppresses feeding behavior in a nutrient-specific manner, shedding light on the functional specificity of brain insulin signals in regulating behaviors.
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Affiliation(s)
- Xiaoyu Li
- Institute of Biophysics, State Key Laboratory of Brain and Cognitive Science, Center for Excellence in Biomacromolecules, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yang Yang
- Institute of Biophysics, State Key Laboratory of Brain and Cognitive Science, Center for Excellence in Biomacromolecules, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiaobing Bai
- Institute of Biophysics, State Key Laboratory of Brain and Cognitive Science, Center for Excellence in Biomacromolecules, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China; Sino-Danish Center for Education and Research, Beijing 100190, China
| | - Xiaotong Wang
- Institute of Biophysics, State Key Laboratory of Brain and Cognitive Science, Center for Excellence in Biomacromolecules, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Houqi Tan
- Institute of Biophysics, State Key Laboratory of Brain and Cognitive Science, Center for Excellence in Biomacromolecules, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yanbo Chen
- Institute of Biophysics, State Key Laboratory of Brain and Cognitive Science, Center for Excellence in Biomacromolecules, Chinese Academy of Sciences, Beijing 100101, China
| | - Yan Zhu
- Institute of Biophysics, State Key Laboratory of Brain and Cognitive Science, Center for Excellence in Biomacromolecules, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China; Sino-Danish Center for Education and Research, Beijing 100190, China
| | - Qili Liu
- Department of Anatomy, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Mark N Wu
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Yan Li
- Institute of Biophysics, State Key Laboratory of Brain and Cognitive Science, Center for Excellence in Biomacromolecules, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China; Sino-Danish Center for Education and Research, Beijing 100190, China.
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6
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Yin JZ, Keszei AFA, Houliston S, Filandr F, Beenstock J, Daou S, Kitaygorodsky J, Schriemer DC, Mazhab-Jafari MT, Gingras AC, Sicheri F. The HisRS-like domain of GCN2 is a pseudoenzyme that can bind uncharged tRNA. Structure 2024; 32:795-811.e6. [PMID: 38531363 DOI: 10.1016/j.str.2024.02.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 01/09/2024] [Accepted: 02/28/2024] [Indexed: 03/28/2024]
Abstract
GCN2 is a stress response kinase that phosphorylates the translation initiation factor eIF2α to inhibit general protein synthesis when activated by uncharged tRNA and stalled ribosomes. The presence of a HisRS-like domain in GCN2, normally associated with tRNA aminoacylation, led to the hypothesis that eIF2α kinase activity is regulated by the direct binding of this domain to uncharged tRNA. Here we solved the structure of the HisRS-like domain in the context of full-length GCN2 by cryoEM. Structure and function analysis shows the HisRS-like domain of GCN2 has lost histidine and ATP binding but retains tRNA binding abilities. Hydrogen deuterium exchange mass spectrometry, site-directed mutagenesis and computational docking experiments support a tRNA binding model that is partially shifted from that employed by bona fide HisRS enzymes. These results demonstrate that the HisRS-like domain of GCN2 is a pseudoenzyme and advance our understanding of GCN2 regulation and function.
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Affiliation(s)
- Jay Z Yin
- Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, ON M5G 1X5, Canada; Department of Biochemistry, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Alexander F A Keszei
- Princess Margaret Cancer Centre, University Health Network, University of Toronto, Toronto, ON M5G 1L7, Canada
| | - Scott Houliston
- Princess Margaret Cancer Centre, University Health Network, University of Toronto, Toronto, ON M5G 1L7, Canada; Structural Genomics Consortium, University of Toronto, Toronto, ON M5G 1L7, Canada
| | - Frantisek Filandr
- Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Jonah Beenstock
- Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, ON M5G 1X5, Canada
| | - Salima Daou
- Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, ON M5G 1X5, Canada
| | - Julia Kitaygorodsky
- Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, ON M5G 1X5, Canada; Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - David C Schriemer
- Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Mohammad T Mazhab-Jafari
- Princess Margaret Cancer Centre, University Health Network, University of Toronto, Toronto, ON M5G 1L7, Canada
| | - Anne-Claude Gingras
- Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, ON M5G 1X5, Canada; Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Frank Sicheri
- Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, ON M5G 1X5, Canada; Department of Biochemistry, University of Toronto, Toronto, ON M5S 1A8, Canada; Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5S 1A8, Canada.
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7
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Boon NJ, Oliveira RA, Körner PR, Kochavi A, Mertens S, Malka Y, Voogd R, van der Horst SEM, Huismans MA, Smabers LP, Draper JM, Wessels LFA, Haahr P, Roodhart JML, Schumacher TNM, Snippert HJ, Agami R, Brummelkamp TR. DNA damage induces p53-independent apoptosis through ribosome stalling. Science 2024; 384:785-792. [PMID: 38753784 DOI: 10.1126/science.adh7950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Accepted: 04/11/2024] [Indexed: 05/18/2024]
Abstract
In response to excessive DNA damage, human cells can activate p53 to induce apoptosis. Cells lacking p53 can still undergo apoptosis upon DNA damage, yet the responsible pathways are unknown. We observed that p53-independent apoptosis in response to DNA damage coincided with translation inhibition, which was characterized by ribosome stalling on rare leucine-encoding UUA codons and globally curtailed translation initiation. A genetic screen identified the transfer RNAse SLFN11 and the kinase GCN2 as factors required for UUA stalling and global translation inhibition, respectively. Stalled ribosomes activated a ribotoxic stress signal conveyed by the ribosome sensor ZAKα to the apoptosis machinery. These results provide an explanation for the frequent inactivation of SLFN11 in chemotherapy-unresponsive tumors and highlight ribosome stalling as a signaling event affecting cell fate in response to DNA damage.
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Affiliation(s)
- Nicolaas J Boon
- Oncode Institute, Utrecht, Netherlands
- Division of Biochemistry, Netherlands Cancer Institute, Amsterdam, Netherlands
| | - Rafaela A Oliveira
- Oncode Institute, Utrecht, Netherlands
- Division of Biochemistry, Netherlands Cancer Institute, Amsterdam, Netherlands
| | - Pierré-René Körner
- Oncode Institute, Utrecht, Netherlands
- Division of Oncogenomics, Netherlands Cancer Institute, Amsterdam, Netherlands
| | - Adva Kochavi
- Oncode Institute, Utrecht, Netherlands
- Division of Oncogenomics, Netherlands Cancer Institute, Amsterdam, Netherlands
| | - Sander Mertens
- Oncode Institute, Utrecht, Netherlands
- Center for Molecular Medicine, University Medical Center Utrecht, Utrecht, Netherlands
| | - Yuval Malka
- Oncode Institute, Utrecht, Netherlands
- Division of Oncogenomics, Netherlands Cancer Institute, Amsterdam, Netherlands
| | - Rhianne Voogd
- Department of Molecular Oncology and Immunology, Netherlands Cancer Institute, Amsterdam, Netherlands
| | - Suzanne E M van der Horst
- Oncode Institute, Utrecht, Netherlands
- Center for Molecular Medicine, University Medical Center Utrecht, Utrecht, Netherlands
| | - Maarten A Huismans
- Oncode Institute, Utrecht, Netherlands
- Center for Molecular Medicine, University Medical Center Utrecht, Utrecht, Netherlands
| | - Lidwien P Smabers
- Department of Medical Oncology, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands
| | - Jonne M Draper
- Division of Biochemistry, Netherlands Cancer Institute, Amsterdam, Netherlands
| | - Lodewyk F A Wessels
- Oncode Institute, Utrecht, Netherlands
- Division of Molecular Carcinogenesis, Netherlands Cancer Institute, Amsterdam, Netherlands
| | - Peter Haahr
- Oncode Institute, Utrecht, Netherlands
- Division of Biochemistry, Netherlands Cancer Institute, Amsterdam, Netherlands
- Center for Gene Expression, Department of Cellular and Molecular Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jeanine M L Roodhart
- Department of Medical Oncology, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands
| | - Ton N M Schumacher
- Oncode Institute, Utrecht, Netherlands
- Department of Molecular Oncology and Immunology, Netherlands Cancer Institute, Amsterdam, Netherlands
| | - Hugo J Snippert
- Oncode Institute, Utrecht, Netherlands
- Center for Molecular Medicine, University Medical Center Utrecht, Utrecht, Netherlands
| | - Reuven Agami
- Oncode Institute, Utrecht, Netherlands
- Division of Oncogenomics, Netherlands Cancer Institute, Amsterdam, Netherlands
| | - Thijn R Brummelkamp
- Oncode Institute, Utrecht, Netherlands
- Division of Biochemistry, Netherlands Cancer Institute, Amsterdam, Netherlands
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8
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Mir DA, Ma Z, Horrocks J, Rogers AN. Stress-induced Eukaryotic Translational Regulatory Mechanisms. ARXIV 2024:arXiv:2405.01664v1. [PMID: 38745702 PMCID: PMC11092689] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
The eukaryotic protein synthesis process entails intricate stages governed by diverse mechanisms to tightly regulate translation. Translational regulation during stress is pivotal for maintaining cellular homeostasis, ensuring the accurate expression of essential proteins crucial for survival. This selective translational control mechanism is integral to cellular adaptation and resilience under adverse conditions. This review manuscript explores various mechanisms involved in selective translational regulation, focusing on mRNA-specific and global regulatory processes. Key aspects of translational control include translation initiation, which is often a rate-limiting step, and involves the formation of the eIF4F complex and recruitment of mRNA to ribosomes. Regulation of translation initiation factors, such as eIF4E, eIF4E2, and eIF2, through phosphorylation and interactions with binding proteins, modulates translation efficiency under stress conditions. This review also highlights the control of translation initiation through factors like the eIF4F complex and the ternary complex and also underscores the importance of eIF2α phosphorylation in stress granule formation and cellular stress responses. Additionally, the impact of amino acid deprivation, mTOR signaling, and ribosome biogenesis on translation regulation and cellular adaptation to stress is also discussed. Understanding the intricate mechanisms of translational regulation during stress provides insights into cellular adaptation mechanisms and potential therapeutic targets for various diseases, offering valuable avenues for addressing conditions associated with dysregulated protein synthesis.
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Affiliation(s)
- Dilawar Ahmad Mir
- Kathryn W. Davis Center for Regenerative Biology and Aging, Mount Desert Island Biological Laboratory, Bar Harbor, ME
| | - Zhengxin Ma
- Kathryn W. Davis Center for Regenerative Biology and Aging, Mount Desert Island Biological Laboratory, Bar Harbor, ME
| | - Jordan Horrocks
- Kathryn W. Davis Center for Regenerative Biology and Aging, Mount Desert Island Biological Laboratory, Bar Harbor, ME
| | - Aric N Rogers
- Kathryn W. Davis Center for Regenerative Biology and Aging, Mount Desert Island Biological Laboratory, Bar Harbor, ME
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9
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Nanjaraj Urs AN, Lasehinde V, Kim L, McDonald E, Yan LL, Zaher HS. Inability to rescue stalled ribosomes results in overactivation of the integrated stress response. J Biol Chem 2024; 300:107290. [PMID: 38636664 PMCID: PMC11106528 DOI: 10.1016/j.jbc.2024.107290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2024] [Revised: 04/07/2024] [Accepted: 04/09/2024] [Indexed: 04/20/2024] Open
Abstract
Endogenous and exogenous chemical agents are known to compromise the integrity of RNA and cause ribosome stalling and collisions. Recent studies have shown that collided ribosomes serve as sensors for multiple processes, including ribosome quality control (RQC) and the integrated stress response (ISR). Since RQC and the ISR have distinct downstream consequences, it is of great importance that organisms activate the appropriate process. We previously showed that RQC is robustly activated in response to collisions and suppresses the ISR activation. However, the molecular mechanics behind this apparent competition were not immediately clear. Here we show that Hel2 does not physically compete with factors of the ISR, but instead its ribosomal-protein ubiquitination activity, and downstream resolution of collided ribosomes, is responsible for suppressing the ISR. Introducing a mutation in the RING domain of Hel2-which inhibits its ubiquitination activity and downstream RQC but imparts higher affinity of the factor for collided ribosomes-resulted in increased activation of the ISR upon MMS-induced alkylation stress. Similarly, mutating Hel2's lysine targets in uS10, which is responsible for RQC activation, resulted in increased Gcn4 target induction. Remarkably, the entire process of RQC appears to be limited by the action of Hel2, as the overexpression of this one factor dramatically suppressed the activation of the ISR. Collectively, our data suggest that cells evolved Hel2 to bind collided ribosomes with a relatively high affinity but kept its concentration relatively low, ensuring that it gets exhausted under stress conditions that cannot be resolved by quality control processes.
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Affiliation(s)
| | - Victor Lasehinde
- Department of Biology, Washington University in St Louis, St Louis, Missouri, USA
| | - Lucas Kim
- Department of Biology, Washington University in St Louis, St Louis, Missouri, USA
| | - Elesa McDonald
- Department of Biology, Washington University in St Louis, St Louis, Missouri, USA
| | - Liewei L Yan
- Department of Biology, Washington University in St Louis, St Louis, Missouri, USA
| | - Hani S Zaher
- Department of Biology, Washington University in St Louis, St Louis, Missouri, USA.
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10
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Ryoo HD. The integrated stress response in metabolic adaptation. J Biol Chem 2024; 300:107151. [PMID: 38462161 PMCID: PMC10998230 DOI: 10.1016/j.jbc.2024.107151] [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: 11/15/2023] [Revised: 02/28/2024] [Accepted: 03/03/2024] [Indexed: 03/12/2024] Open
Abstract
The integrated stress response (ISR) refers to signaling pathways initiated by stress-activated eIF2α kinases. Distinct eIF2α kinases respond to different stress signals, including amino acid deprivation and mitochondrial stress. Such stress-induced eIF2α phosphorylation attenuates general mRNA translation and, at the same time, stimulates the preferential translation of specific downstream factors to orchestrate an adaptive gene expression program. In recent years, there have been significant new advances in our understanding of ISR during metabolic stress adaptation. Here, I discuss those advances, reviewing among others the ISR activation mechanisms in response to amino acid deprivation and mitochondrial stress. In addition, I review how ISR regulates the amino acid metabolic pathways and how changes in the ISR impact the physiology and pathology of various disease models.
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Affiliation(s)
- Hyung Don Ryoo
- Department of Cell Biology, New York University Grossman School of Medicine, New York, New York, USA.
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11
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Mariner BL, Rodriguez AS, Heath OC, McCormick MA. Induction of proteasomal activity in mammalian cells by lifespan-extending tRNA synthetase inhibitors. GeroScience 2024; 46:1755-1773. [PMID: 37749371 PMCID: PMC10828360 DOI: 10.1007/s11357-023-00938-8] [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: 05/08/2023] [Accepted: 09/04/2023] [Indexed: 09/27/2023] Open
Abstract
We have recently shown that multiple tRNA synthetase inhibitors can greatly increase lifespan in multiple models by acting through the conserved transcription factor ATF4. Here, we show that these compounds, and several others of the same class, can greatly upregulate mammalian ATF4 in cells in vitro, in a dose dependent manner. Further, RNASeq analysis of these cells pointed toward changes in protein turnover. In subsequent experiments here we show that multiple tRNA synthetase inhibitors can greatly upregulate activity of the ubiquitin proteasome system (UPS) in cells in an ATF4-dependent manner. The UPS plays an important role in the turnover of many damaged or dysfunctional proteins in an organism. Increasing UPS activity has been shown to enhance the survival of Huntington's disease cell models, but there are few known pharmacological enhancers of the UPS. Additionally, we see separate ATF4 dependent upregulation of macroautophagy upon treatment with tRNA synthetase inhibitors. Protein degradation is an essential cellular process linked to many important human diseases of aging such as Alzheimer's disease and Huntington's disease. These drugs' ability to enhance proteostasis more broadly could have wide-ranging implications in the treatment of important age-related neurodegenerative diseases.
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Affiliation(s)
- Blaise L Mariner
- Department of Biochemistry and Molecular Biology, School of Medicine, University of New Mexico Health Sciences Center, Albuquerque, NM, 87131, USA
- Center for Biomedical Engineering, University of New Mexico, Albuquerque, NM, 87131, USA
- Autophagy, Inflammation and Metabolism Center of Biomedical Research Excellence, Albuquerque, NM, 87131, USA
| | - Antonio S Rodriguez
- Department of Biochemistry and Molecular Biology, School of Medicine, University of New Mexico Health Sciences Center, Albuquerque, NM, 87131, USA
| | - Olivia C Heath
- Department of Biochemistry and Molecular Biology, School of Medicine, University of New Mexico Health Sciences Center, Albuquerque, NM, 87131, USA
| | - Mark A McCormick
- Department of Biochemistry and Molecular Biology, School of Medicine, University of New Mexico Health Sciences Center, Albuquerque, NM, 87131, USA.
- Autophagy, Inflammation and Metabolism Center of Biomedical Research Excellence, Albuquerque, NM, 87131, USA.
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12
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Tang H, Kang R, Liu J, Tang D. ATF4 in cellular stress, ferroptosis, and cancer. Arch Toxicol 2024; 98:1025-1041. [PMID: 38383612 DOI: 10.1007/s00204-024-03681-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Accepted: 01/15/2024] [Indexed: 02/23/2024]
Abstract
Activating transcription factor 4 (ATF4), a member of the ATF/cAMP response element-binding (CREB) family, plays a critical role as a stress-induced transcription factor. It orchestrates cellular responses, particularly in the management of endoplasmic reticulum stress, amino acid deprivation, and oxidative challenges. ATF4's primary function lies in regulating gene expression to ensure cell survival during stressful conditions. However, when considering its involvement in ferroptosis, characterized by severe lipid peroxidation and pronounced endoplasmic reticulum stress, the ATF4 pathway can either inhibit or promote ferroptosis. This intricate relationship underscores the complexity of cellular responses to varying stress levels. Understanding the connections between ATF4, ferroptosis, and endoplasmic reticulum stress holds promise for innovative cancer therapies, especially in addressing apoptosis-resistant cells. In this review, we provide an overview of ATF4, including its structure, modifications, and functions, and delve into its dual role in both ferroptosis and cancer.
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Affiliation(s)
- Hu Tang
- DAMP Laboratory, Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, 510150, Guangdong, China
| | - Rui Kang
- Department of Surgery, UT Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Jiao Liu
- DAMP Laboratory, Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, 510150, Guangdong, China.
| | - Daolin Tang
- Department of Surgery, UT Southwestern Medical Center, Dallas, TX, 75390, USA.
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13
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Tatara Y, Kasai S, Kokubu D, Tsujita T, Mimura J, Itoh K. Emerging Role of GCN1 in Disease and Homeostasis. Int J Mol Sci 2024; 25:2998. [PMID: 38474243 PMCID: PMC10931611 DOI: 10.3390/ijms25052998] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Revised: 02/29/2024] [Accepted: 03/02/2024] [Indexed: 03/14/2024] Open
Abstract
GCN1 is recognized as a factor that is essential for the activation of GCN2, which is a sensor of amino acid starvation. This function is evolutionarily conserved from yeast to higher eukaryotes. However, recent studies have revealed non-canonical functions of GCN1 that are independent of GCN2, such as its participation in cell proliferation, apoptosis, and the immune response, beyond the borders of species. Although it is known that GCN1 and GCN2 interact with ribosomes to accomplish amino acid starvation sensing, recent studies have reported that GCN1 binds to disomes (i.e., ribosomes that collide each other), thereby regulating both the co-translational quality control and stress response. We propose that GCN1 regulates ribosome-mediated signaling by dynamically changing its partners among RWD domain-possessing proteins via unknown mechanisms. We recently demonstrated that GCN1 is essential for cell proliferation and whole-body energy regulation in mice. However, the manner in which ribosome-initiated signaling via GCN1 is related to various physiological functions warrants clarification. GCN1-mediated mechanisms and its interaction with other quality control and stress response signals should be important for proteostasis during aging and neurodegenerative diseases, and may be targeted for drug development.
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Affiliation(s)
- Yota Tatara
- Department of Stress Response Science, Biomedical Research Center, Hirosaki University Graduate School of Medicine, 5 Zaifu-cho, Hirosaki 036-8562, Aomori, Japan
| | - Shuya Kasai
- Department of Stress Response Science, Biomedical Research Center, Hirosaki University Graduate School of Medicine, 5 Zaifu-cho, Hirosaki 036-8562, Aomori, Japan
| | - Daichi Kokubu
- Diet and Well-Being Research Institute, KAGOME, Co., Ltd., 17 Nishitomiyama, Nasushiobara 329-2762, Tochigi, Japan
- Department of Vegetable Life Science, Hirosaki University Graduate School of Medicine, 5 Zaifu-cho, Hirosaki 036-8562, Aomori, Japan
| | - Tadayuki Tsujita
- Laboratory of Biochemistry, Department of Applied Biochemistry and Food Science, Faculty of Agriculture, Saga University, 1 Honjo-machi, Saga City 840-8502, Saga, Japan;
| | - Junsei Mimura
- Department of Stress Response Science, Biomedical Research Center, Hirosaki University Graduate School of Medicine, 5 Zaifu-cho, Hirosaki 036-8562, Aomori, Japan
| | - Ken Itoh
- Department of Stress Response Science, Biomedical Research Center, Hirosaki University Graduate School of Medicine, 5 Zaifu-cho, Hirosaki 036-8562, Aomori, Japan
- Department of Vegetable Life Science, Hirosaki University Graduate School of Medicine, 5 Zaifu-cho, Hirosaki 036-8562, Aomori, Japan
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14
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Misra J, Carlson KR, Spandau DF, Wek RC. Multiple mechanisms activate GCN2 eIF2 kinase in response to diverse stress conditions. Nucleic Acids Res 2024; 52:1830-1846. [PMID: 38281137 PMCID: PMC10899773 DOI: 10.1093/nar/gkae006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Revised: 12/22/2023] [Accepted: 01/02/2024] [Indexed: 01/30/2024] Open
Abstract
Diverse environmental insults induce the integrated stress response (ISR), which features eIF2 phosphorylation and translational control that serves to restore protein homeostasis. The eIF2 kinase GCN2 is a first responder in the ISR that is activated by amino acid depletion and other stresses not directly related to nutrients. Two mechanisms are suggested to trigger an ordered process of GCN2 activation during stress: GCN2 monitoring stress via accumulating uncharged tRNAs or by stalled and colliding ribosomes. Our results suggest that while ribosomal collisions are indeed essential for GCN2 activation in response to translational elongation inhibitors, conditions that trigger deacylation of tRNAs activate GCN2 via its direct association with affected tRNAs. Both mechanisms require the GCN2 regulatory domain related to histidyl tRNA synthetases. GCN2 activation by UV irradiation features lowered amino acids and increased uncharged tRNAs and UV-induced ribosome collisions are suggested to be dispensable. We conclude that there are multiple mechanisms that activate GCN2 during diverse stresses.
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Affiliation(s)
- Jagannath Misra
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, 635 Barnhill Drive, MS4067 Indianapolis, Indiana 46202, USA
| | - Kenneth R Carlson
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, 635 Barnhill Drive, MS4067 Indianapolis, Indiana 46202, USA
| | - Dan F Spandau
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, 635 Barnhill Drive, MS4067 Indianapolis, Indiana 46202, USA
- Department of Dermatology, Indiana University School of Medicine, 635 Barnhill Drive, MS4067 Indianapolis, Indiana 46202, USA
- Richard L. Roudebush Veterans Administration Medical Center, Indiana University School of Medicine, 635 Barnhill Drive, MS4067 Indianapolis, Indiana 46202, USA
| | - Ronald C Wek
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, 635 Barnhill Drive, MS4067 Indianapolis, Indiana 46202, USA
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15
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Zhang H, Ling J. Serine mistranslation induces the integrated stress response without accumulation of uncharged tRNAs. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.04.578812. [PMID: 38370842 PMCID: PMC10871240 DOI: 10.1101/2024.02.04.578812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/20/2024]
Abstract
Aminoacyl-tRNA synthetases (aaRSs) are essential enzymes that support robust and accurate protein synthesis. A rapidly expanding number of studies show that mutations in aaRSs lead to multiple human diseases, including neurological disorders and cancer. Much remains unknown about how aaRS mutations impact human health. In particular, how aminoacylation errors affect stress responses and fitness in eukaryotic cells remains poorly understood. The integrated stress response (ISR) is an adaptive mechanism in response to multiple stresses. However, chronic activation of the ISR contributes to the development of multiple diseases (e.g., neuropathies). Here we show that Ser misincorporation into Ala and Thr codons, resulting from aaRS editing defects or mutations in tRNAs, constitutively active the ISR. Such activation does not appear to depend on the accumulation of uncharged tRNAs, implicating that Ser mistranslation may lead to ribosome stalling and collision.
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Affiliation(s)
- Hong Zhang
- Department of Cell Biology and Molecular Genetics, The University of Maryland, College Park, MD 20742, USA
| | - Jiqiang Ling
- Department of Cell Biology and Molecular Genetics, The University of Maryland, College Park, MD 20742, USA
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16
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Paul PK, Umarvaish S, Bajaj S, S. RF, Mohan H, Annaert W, Chaudhary V. Maintenance of proteostasis by Drosophila Rer1 is essential for competitive cell survival and Myc-driven overgrowth. PLoS Genet 2024; 20:e1011171. [PMID: 38408084 PMCID: PMC10919865 DOI: 10.1371/journal.pgen.1011171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 03/07/2024] [Accepted: 02/05/2024] [Indexed: 02/28/2024] Open
Abstract
Defects in protein homeostasis can induce proteotoxic stress, affecting cellular fitness and, consequently, overall tissue health. In various growing tissues, cell competition based mechanisms facilitate detection and elimination of these compromised, often referred to as 'loser', cells by the healthier neighbors. The precise connection between proteotoxic stress and competitive cell survival remains largely elusive. Here, we reveal the function of an endoplasmic reticulum (ER) and Golgi localized protein Rer1 in the regulation of protein homeostasis in the developing Drosophila wing epithelium. Our results show that loss of Rer1 leads to proteotoxic stress and PERK-mediated phosphorylation of eukaryotic initiation factor 2α. Clonal analysis showed that rer1 mutant cells are identified as losers and eliminated through cell competition. Interestingly, we find that Rer1 levels are upregulated upon Myc-overexpression that causes overgrowth, albeit under high proteotoxic stress. Our results suggest that increased levels of Rer1 provide cytoprotection to Myc-overexpressing cells by alleviating the proteotoxic stress and thereby supporting Myc-driven overgrowth. In summary, these observations demonstrate that Rer1 acts as a novel regulator of proteostasis in Drosophila and reveal its role in competitive cell survival.
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Affiliation(s)
- Pranab Kumar Paul
- Cell and developmental signaling laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research Bhopal, Bhopal, Madhya Pradesh, India
| | - Shruti Umarvaish
- Cell and developmental signaling laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research Bhopal, Bhopal, Madhya Pradesh, India
| | - Shivani Bajaj
- Cell and developmental signaling laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research Bhopal, Bhopal, Madhya Pradesh, India
| | - Rishana Farin S.
- Cell and developmental signaling laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research Bhopal, Bhopal, Madhya Pradesh, India
| | - Hrudya Mohan
- Cell and developmental signaling laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research Bhopal, Bhopal, Madhya Pradesh, India
| | - Wim Annaert
- Laboratory for Membrane Trafficking, VIB-Center for Brain and Disease Research, KU Leuven, Leuven, Belgium, and Department of Neurosciences, KU Leuven, Gasthuisberg, Leuven, Belgium
| | - Varun Chaudhary
- Cell and developmental signaling laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research Bhopal, Bhopal, Madhya Pradesh, India
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17
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Dolliver SM, Galbraith C, Khaperskyy DA. Human Betacoronavirus OC43 Interferes with the Integrated Stress Response Pathway in Infected Cells. Viruses 2024; 16:212. [PMID: 38399988 PMCID: PMC10893100 DOI: 10.3390/v16020212] [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] [Revised: 01/20/2024] [Accepted: 01/29/2024] [Indexed: 02/25/2024] Open
Abstract
Viruses evolve many strategies to ensure the efficient synthesis of their proteins. One such strategy is the inhibition of the integrated stress response-the mechanism through which infected cells arrest translation through the phosphorylation of the alpha subunit of the eukaryotic translation initiation factor 2 (eIF2α). We have recently shown that the human common cold betacoronavirus OC43 actively inhibits eIF2α phosphorylation in response to sodium arsenite, a potent inducer of oxidative stress. In this work, we examined the modulation of integrated stress responses by OC43 and demonstrated that the negative feedback regulator of eIF2α phosphorylation GADD34 is strongly induced in infected cells. However, the upregulation of GADD34 expression induced by OC43 was independent from the activation of the integrated stress response and was not required for the inhibition of eIF2α phosphorylation in virus-infected cells. Our work reveals a complex interplay between the common cold coronavirus and the integrated stress response, in which efficient viral protein synthesis is ensured by the inhibition of eIF2α phosphorylation but the GADD34 negative feedback loop is disrupted.
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Affiliation(s)
| | | | - Denys A. Khaperskyy
- Department of Microbiology and Immunology, Faculty of Medicine, Dalhousie University, Halifax, NS B3H 4R2, Canada
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18
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Li JJ, Xin N, Yang C, Tavizon LA, Hong R, Moore TI, Tharyan RG, Antebi A, Kim HE. Unveiling the Intercompartmental Signaling Axis: Mitochondrial to ER Stress Response (MERSR) and its Impact on Proteostasis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.07.556674. [PMID: 38187690 PMCID: PMC10769184 DOI: 10.1101/2023.09.07.556674] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2024]
Abstract
Maintaining protein homeostasis is essential for cellular health. During times of proteotoxic stress, cells deploy unique defense mechanisms to achieve resolution. Our previous research uncovered a cross-compartmental Mitochondrial to Cytosolic Stress Response (MCSR), a unique stress response activated by the perturbation of mitochondrial proteostasis, which ultimately results in the improvement of proteostasis in the cytosol. Here, we found that this signaling axis also influences the unfolded protein response of the endoplasmic reticulum (UPR ER ), suggesting the presence of a Mitochondria to ER Stress Response (MERSR). During MERSR, the IRE1 branch of UPR ER is inhibited, introducing a previously unknown regulatory component of MCSR. Moreover, proteostasis is enhanced through the upregulation of the PERK-eIF2a signaling pathway, increasing phosphorylation of eIF2a and improving the ER's capacity to manage greater proteostasis load. MERSR activation in both poly-glutamine (poly-Q) and amyloid-beta (Aβ) C. elegans disease models also led to improvement in both aggregate burden and overall disease outcome. These findings shed light on the coordination between the mitochondria and the ER in maintaining cellular proteostasis and provides further evidence for the importance of intercompartmental signaling.
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19
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Ge MK, Zhang C, Zhang N, He P, Cai HY, Li S, Wu S, Chu XL, Zhang YX, Ma HM, Xia L, Yang S, Yu JX, Yao SY, Zhou XL, Su B, Chen GQ, Shen SM. The tRNA-GCN2-FBXO22-axis-mediated mTOR ubiquitination senses amino acid insufficiency. Cell Metab 2023; 35:2216-2230.e8. [PMID: 37979583 DOI: 10.1016/j.cmet.2023.10.016] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 07/26/2023] [Accepted: 10/26/2023] [Indexed: 11/20/2023]
Abstract
Mammalian target of rapamycin complex 1 (mTORC1) monitors cellular amino acid changes for function, but the molecular mediators of this process remain to be fully defined. Here, we report that depletion of cellular amino acids, either alone or in combination, leads to the ubiquitination of mTOR, which inhibits mTORC1 kinase activity by preventing substrate recruitment. Mechanistically, amino acid depletion causes accumulation of uncharged tRNAs, thereby stimulating GCN2 to phosphorylate FBXO22, which in turn accrues in the cytoplasm and ubiquitinates mTOR at Lys2066 in a K27-linked manner. Accordingly, mutation of mTOR Lys2066 abolished mTOR ubiquitination in response to amino acid depletion, rendering mTOR insensitive to amino acid starvation both in vitro and in vivo. Collectively, these data reveal a novel mechanism of amino acid sensing by mTORC1 via a previously unknown GCN2-FBXO22-mTOR pathway that is uniquely controlled by uncharged tRNAs.
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Affiliation(s)
- Meng-Kai Ge
- Institute of Aging & Tissue Regeneration, State Key Laboratory of Systems Medicine for Cancer and Stress and Cancer Research Unit of Chinese Academy of Medical Sciences (No. 2019RU043), Ren-Ji Hospital, Shanghai Jiao Tong University School of Medicine (SJTU-SM), Shanghai 200127, China; Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, SJTU-SM, Shanghai 200025, China
| | - Cheng Zhang
- Institute of Aging & Tissue Regeneration, State Key Laboratory of Systems Medicine for Cancer and Stress and Cancer Research Unit of Chinese Academy of Medical Sciences (No. 2019RU043), Ren-Ji Hospital, Shanghai Jiao Tong University School of Medicine (SJTU-SM), Shanghai 200127, China
| | - Na Zhang
- Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, SJTU-SM, Shanghai 200025, China
| | - Ping He
- Institute of Aging & Tissue Regeneration, State Key Laboratory of Systems Medicine for Cancer and Stress and Cancer Research Unit of Chinese Academy of Medical Sciences (No. 2019RU043), Ren-Ji Hospital, Shanghai Jiao Tong University School of Medicine (SJTU-SM), Shanghai 200127, China
| | - Hai-Yan Cai
- Department of Hematology, Shanghai East Hospital, Tongji University School of Medicine, Shanghai 200120, China
| | - Song Li
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, SJTU-SM, Shanghai 200025, China
| | - Shuai Wu
- Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, SJTU-SM, Shanghai 200025, China
| | - Xi-Li Chu
- Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, SJTU-SM, Shanghai 200025, China
| | - Yu-Xue Zhang
- Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, SJTU-SM, Shanghai 200025, China
| | - Hong-Ming Ma
- Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, SJTU-SM, Shanghai 200025, China
| | - Li Xia
- Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, SJTU-SM, Shanghai 200025, China
| | - Shuo Yang
- Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, SJTU-SM, Shanghai 200025, China
| | - Jian-Xiu Yu
- Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, SJTU-SM, Shanghai 200025, China
| | - Shi-Ying Yao
- State Key Laboratory of Molecular Biology, Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai 200031, China
| | - Xiao-Long Zhou
- State Key Laboratory of Molecular Biology, Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai 200031, China
| | - Bing Su
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, SJTU-SM, Shanghai 200025, China.
| | - Guo-Qiang Chen
- Institute of Aging & Tissue Regeneration, State Key Laboratory of Systems Medicine for Cancer and Stress and Cancer Research Unit of Chinese Academy of Medical Sciences (No. 2019RU043), Ren-Ji Hospital, Shanghai Jiao Tong University School of Medicine (SJTU-SM), Shanghai 200127, China; Hainan Academy of Medical Sciences, Hainan Medical University, Hainan 571199, China.
| | - Shao-Ming Shen
- Institute of Aging & Tissue Regeneration, State Key Laboratory of Systems Medicine for Cancer and Stress and Cancer Research Unit of Chinese Academy of Medical Sciences (No. 2019RU043), Ren-Ji Hospital, Shanghai Jiao Tong University School of Medicine (SJTU-SM), Shanghai 200127, China; Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, SJTU-SM, Shanghai 200025, China.
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20
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Li T, Zeng Z, Fan C, Xiong W. Role of stress granules in tumorigenesis and cancer therapy. Biochim Biophys Acta Rev Cancer 2023; 1878:189006. [PMID: 37913942 DOI: 10.1016/j.bbcan.2023.189006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2023] [Revised: 09/24/2023] [Accepted: 10/16/2023] [Indexed: 11/03/2023]
Abstract
Stress granules (SGs) are membrane-less organelles that cell forms via liquid-liquid phase separation (LLPS) under stress conditions such as oxidative stress, ER stress, heat shock and hypoxia. SG assembly is a stress-responsive mechanism by regulating gene expression and cellular signaling pathways. Cancer cells face various stress conditions in tumor microenvironment during tumorigenesis, while SGs contribute to hallmarks of cancer including proliferation, invasion, migration, avoiding apoptosis, metabolism reprogramming and immune evasion. Here, we review the connection between SGs and cancer development, the limitation of SGs on current cancer therapy and promising cancer therapeutic strategies targeting SGs in the future.
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Affiliation(s)
- Tiansheng Li
- NHC Key Laboratory of Carcinogenesis and Hunan Key Laboratory of Cancer Metabolism, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, Hunan, China; Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Cancer Research Institute, Central South University, Changsha, Hunan, China
| | - Zhaoyang Zeng
- NHC Key Laboratory of Carcinogenesis and Hunan Key Laboratory of Cancer Metabolism, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, Hunan, China; Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Cancer Research Institute, Central South University, Changsha, Hunan, China
| | - Chunmei Fan
- NHC Key Laboratory of Carcinogenesis and Hunan Key Laboratory of Cancer Metabolism, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, Hunan, China; Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Cancer Research Institute, Central South University, Changsha, Hunan, China; Department of Histology and Embryology, Xiangya School of Medicine, Central South University, Changsha, Hunan, China.
| | - Wei Xiong
- NHC Key Laboratory of Carcinogenesis and Hunan Key Laboratory of Cancer Metabolism, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, Hunan, China; Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Cancer Research Institute, Central South University, Changsha, Hunan, China.
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21
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Kahlhofer J, Teis D. The human LAT1-4F2hc (SLC7A5-SLC3A2) transporter complex: Physiological and pathophysiological implications. Basic Clin Pharmacol Toxicol 2023; 133:459-472. [PMID: 36460306 DOI: 10.1111/bcpt.13821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 11/24/2022] [Accepted: 11/28/2022] [Indexed: 12/04/2022]
Abstract
LAT1 and 4F2hc form a heterodimeric membrane protein complex, which functions as one of the best characterized amino acid transporters. Since LAT1-4F2hc is required for the efficient uptake of essential amino acids and hormones, it promotes cellular growth, in part, by stimulating mTORC1 (mechanistic target of rapamycin complex 1) signalling and by repressing the integrated stress response (ISR). Gain or loss of LAT1-4F2hc function is associated with cancer, diabetes, and immunological and neurological diseases. Hence, LAT1-4F2hc represents an attractive drug target for disease treatment. Specific targeting of LAT1-4F2hc will be facilitated by the increasingly detailed understanding of its molecular architecture, which provides important concepts for its function and regulation. Here, we summarize (i) structural insights that help to explain how LAT1 and 4F2hc assemble to transport amino acids across membranes, (ii) the role of LAT1-4F2hc in key metabolic signalling pathways, and (iii) how derailing these processes could contribute to diseases.
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Affiliation(s)
- Jennifer Kahlhofer
- Institute for Cell Biology, Biocenter, Medical University Innsbruck, Innsbruck, Austria
| | - David Teis
- Institute for Cell Biology, Biocenter, Medical University Innsbruck, Innsbruck, Austria
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22
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Zhang H, Murphy P, Yu J, Lee S, Tsai FTF, van Hoof A, Ling J. Coordination between aminoacylation and editing to protect against proteotoxicity. Nucleic Acids Res 2023; 51:10606-10618. [PMID: 37742077 PMCID: PMC10602869 DOI: 10.1093/nar/gkad778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Revised: 08/13/2023] [Accepted: 09/14/2023] [Indexed: 09/25/2023] Open
Abstract
Aminoacyl-tRNA synthetases (aaRSs) are essential enzymes that ligate amino acids to tRNAs, and often require editing to ensure accurate protein synthesis. Recessive mutations in aaRSs cause various neurological disorders in humans, yet the underlying mechanism remains poorly understood. Pathogenic aaRS mutations frequently cause protein destabilization and aminoacylation deficiency. In this study, we report that combined aminoacylation and editing defects cause severe proteotoxicity. We show that the ths1-C268A mutation in yeast threonyl-tRNA synthetase (ThrRS) abolishes editing and causes heat sensitivity. Surprisingly, experimental evolution of the mutant results in intragenic mutations that restore heat resistance but not editing. ths1-C268A destabilizes ThrRS and decreases overall Thr-tRNAThr synthesis, while the suppressor mutations in the evolved strains improve aminoacylation. We further show that deficiency in either ThrRS aminoacylation or editing is insufficient to cause heat sensitivity, and that ths1-C268A impairs ribosome-associated quality control. Our results suggest that aminoacylation deficiency predisposes cells to proteotoxic stress.
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Affiliation(s)
- Hong Zhang
- Department of Cell Biology and Molecular Genetics, The University of Maryland, College Park, MD 20742, USA
| | - Parker Murphy
- Department of Cell Biology and Molecular Genetics, The University of Maryland, College Park, MD 20742, USA
| | - Jason Yu
- Department of Cell Biology and Molecular Genetics, The University of Maryland, College Park, MD 20742, USA
| | - Sukyeong Lee
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA
- Advanced Technology Core for Macromolecular X-ray Crystallography, Baylor College of Medicine, Houston, TX 77030, USA
| | - Francis T F Tsai
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA
- Advanced Technology Core for Macromolecular X-ray Crystallography, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Ambro van Hoof
- Department of Microbiology and Molecular Genetics, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Jiqiang Ling
- Department of Cell Biology and Molecular Genetics, The University of Maryland, College Park, MD 20742, USA
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23
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Webber CJ, Murphy CN, Rondón-Ortiz AN, van der Spek SJF, Kelly EX, Lampl NM, Chiesa G, Khalil AS, Emili A, Wolozin B. Human herpesvirus 8 ORF57 protein is able to reduce TDP-43 pathology: network analysis identifies interacting pathways. Hum Mol Genet 2023; 32:2966-2980. [PMID: 37522762 PMCID: PMC10549787 DOI: 10.1093/hmg/ddad122] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2023] [Revised: 07/25/2023] [Accepted: 07/26/2023] [Indexed: 08/01/2023] Open
Abstract
Aggregation of TAR DNA-binding protein 43 kDa (TDP-43) is thought to drive the pathophysiology of amyotrophic lateral sclerosis and some frontotemporal dementias. TDP-43 is normally a nuclear protein that in neurons translocates to the cytoplasm and can form insoluble aggregates upon activation of the integrated stress response (ISR). Viruses evolved to control the ISR. In the case of Herpesvirus 8, the protein ORF57 acts to bind protein kinase R, inhibit phosphorylation of eIF2α and reduce activation of the ISR. We hypothesized that ORF57 might also possess the ability to inhibit aggregation of TDP-43. ORF57 was expressed in the neuronal SH-SY5Y line and its effects on TDP-43 aggregation characterized. We report that ORF57 inhibits TDP-43 aggregation by 55% and elicits a 2.45-fold increase in the rate of dispersion of existing TDP-43 granules. These changes were associated with a 50% decrease in cell death. Proteomic studies were carried out to identify the protein interaction network of ORF57. We observed that ORF57 directly binds to TDP-43 as well as interacts with many components of the ISR, including elements of the proteostasis machinery known to reduce TDP-43 aggregation. We propose that viral proteins designed to inhibit a chronic ISR can be engineered to remove aggregated proteins and dampen a chronic ISR.
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Affiliation(s)
- Chelsea J Webber
- Departments of Pharmacology, Physiology and Biophysics, Boston University, Boston, MA 02215, USA
| | - Caroline N Murphy
- Departments of Pharmacology, Physiology and Biophysics, Boston University, Boston, MA 02215, USA
| | - Alejandro N Rondón-Ortiz
- Departments of Pharmacology, Physiology and Biophysics, Boston University, Boston, MA 02215, USA
- Center for Network Systems Biology, Boston University, Boston, MA 02215, USA
- Department of Biology, Boston University, Boston, MA 02215, USA
| | - Sophie J F van der Spek
- Departments of Pharmacology, Physiology and Biophysics, Boston University, Boston, MA 02215, USA
| | - Elena X Kelly
- Departments of Pharmacology, Physiology and Biophysics, Boston University, Boston, MA 02215, USA
| | - Noah M Lampl
- Center for Network Systems Biology, Boston University, Boston, MA 02215, USA
| | - Giulio Chiesa
- Biological Design Center, Boston University, Boston, MA 02215, USA
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA
| | - Ahmad S Khalil
- Biological Design Center, Boston University, Boston, MA 02215, USA
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA 02115, USA
| | - Andrew Emili
- Center for Network Systems Biology, Boston University, Boston, MA 02215, USA
- Department of Biochemistry, Boston University, Boston, MA 02115, USA
- Department of Biochemistry, Oregon Health Sciences University, Portland, OR 97239, USA
| | - Benjamin Wolozin
- Departments of Pharmacology, Physiology and Biophysics, Boston University, Boston, MA 02215, USA
- Center for Systems Neuroscience, Boston University, Boston, MA 02115, USA
- Center for Neurophotonics, Boston University, Boston, MA 02115, USA
- Department of Neurology, Boston University, Boston, MA 02115, USA
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24
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Majerciak V, Zhou T, Kruhlak M, Zheng ZM. RNA helicase DDX6 and scaffold protein GW182 in P-bodies promote biogenesis of stress granules. Nucleic Acids Res 2023; 51:9337-9355. [PMID: 37427791 PMCID: PMC10516652 DOI: 10.1093/nar/gkad585] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 06/05/2023] [Accepted: 07/07/2023] [Indexed: 07/11/2023] Open
Abstract
Two prominent cytoplasmic RNA granules, ubiquitous RNA-processing bodies (PB) and inducible stress granules (SG), regulate mRNA translation and are intimately related. In this study, we found that arsenite (ARS)-induced SG formed in a stepwise process is topologically and mechanically linked to PB. Two essential PB components, GW182 and DDX6, are repurposed under stress to play direct but distinguishable roles in SG biogenesis. By providing scaffolding activities, GW182 promotes the aggregation of SG components to form SG bodies. DEAD-box helicase DDX6 is also essential for the proper assembly and separation of PB from SG. DDX6 deficiency results in the formation of irregularly shaped 'hybrid' PB/SG granules with accumulated components of both PB and SG. Wild-type DDX6, but not its helicase mutant E247A, can rescue the separation of PB from SG in DDX6KO cells, indicating a requirement of DDX6 helicase activity for this process. DDX6 activity in biogenesis of both PB and SG in the cells under stress is further modulated by its interaction with two protein partners, CNOT1 and 4E-T, of which knockdown affects the formation of both PB and also SG. Together, these data highlight a new functional paradigm between PB and SG biogenesis during the stress.
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Affiliation(s)
- Vladimir Majerciak
- Tumor Virus RNA Biology Section, HIV Dynamics and Replication Program, National Cancer Institute, National Institutes of Health, Frederick, MD 21702, USA
| | - Tongqing Zhou
- Structural Biology Section, Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Michael J Kruhlak
- CCR Confocal Microscopy Core Facility, Laboratory of Cancer Biology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Zhi-Ming Zheng
- Tumor Virus RNA Biology Section, HIV Dynamics and Replication Program, National Cancer Institute, National Institutes of Health, Frederick, MD 21702, USA
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25
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Livneh I, Cohen-Kaplan V, Fabre B, Abramovitch I, Lulu C, Nataraj NB, Lazar I, Ziv T, Yarden Y, Zohar Y, Gottlieb E, Ciechanover A. Regulation of nucleo-cytosolic 26S proteasome translocation by aromatic amino acids via mTOR is essential for cell survival under stress. Mol Cell 2023; 83:3333-3346.e5. [PMID: 37738964 DOI: 10.1016/j.molcel.2023.08.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 07/12/2023] [Accepted: 08/14/2023] [Indexed: 09/24/2023]
Abstract
The proteasome is responsible for removal of ubiquitinated proteins. Although several aspects of its regulation (e.g., assembly, composition, and post-translational modifications) have been unraveled, studying its adaptive compartmentalization in response to stress is just starting to emerge. We found that following amino acid starvation, the proteasome is translocated from its large nuclear pool to the cytoplasm-a response regulated by newly identified mTOR-agonistic amino acids-Tyr, Trp, and Phe (YWF). YWF relay their signal upstream of mTOR through Sestrin3 by disrupting its interaction with the GATOR2 complex. The triad activates mTOR toward its downstream substrates p62 and transcription factor EB (TFEB), affecting both proteasomal and autophagic activities. Proteasome translocation stimulates cytosolic proteolysis which replenishes amino acids, thus enabling cell survival. In contrast, nuclear sequestration of the proteasome following mTOR activation by YWF inhibits this proteolytic adaptive mechanism, leading to cell death, which establishes this newly identified pathway as a key stress-coping mechanism.
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Affiliation(s)
- Ido Livneh
- The Rappaport Faculty of Medicine and Integrated Cancer Center, Technion-Israel Institute of Technology, Haifa 3109601, Israel; Institute of Pathology, Rambam Health Care Campus, Haifa 3109601, Israel.
| | - Victoria Cohen-Kaplan
- The Rappaport Faculty of Medicine and Integrated Cancer Center, Technion-Israel Institute of Technology, Haifa 3109601, Israel
| | - Bertrand Fabre
- The Rappaport Faculty of Medicine and Integrated Cancer Center, Technion-Israel Institute of Technology, Haifa 3109601, Israel
| | - Ifat Abramovitch
- The Rappaport Faculty of Medicine and Integrated Cancer Center, Technion-Israel Institute of Technology, Haifa 3109601, Israel
| | - Chen Lulu
- The Rappaport Faculty of Medicine and Integrated Cancer Center, Technion-Israel Institute of Technology, Haifa 3109601, Israel
| | | | - Ikrame Lazar
- The Rappaport Faculty of Medicine and Integrated Cancer Center, Technion-Israel Institute of Technology, Haifa 3109601, Israel
| | - Tamar Ziv
- Smoler Proteomic Center, Technion-Israel Institute of Technology, Haifa 3200003, Israel
| | - Yosef Yarden
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Yaniv Zohar
- The Rappaport Faculty of Medicine and Integrated Cancer Center, Technion-Israel Institute of Technology, Haifa 3109601, Israel; Institute of Pathology, Rambam Health Care Campus, Haifa 3109601, Israel
| | - Eyal Gottlieb
- The Rappaport Faculty of Medicine and Integrated Cancer Center, Technion-Israel Institute of Technology, Haifa 3109601, Israel
| | - Aaron Ciechanover
- The Rappaport Faculty of Medicine and Integrated Cancer Center, Technion-Israel Institute of Technology, Haifa 3109601, Israel.
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26
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Loxha L, Ibrahim NK, Stasche AS, Cinar B, Dolgner T, Niessen J, Schreek S, Fehlhaber B, Forster M, Stanulla M, Hinze L. GSK3α Regulates Temporally Dynamic Changes in Ribosomal Proteins upon Amino Acid Starvation in Cancer Cells. Int J Mol Sci 2023; 24:13260. [PMID: 37686063 PMCID: PMC10488213 DOI: 10.3390/ijms241713260] [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: 06/29/2023] [Revised: 08/15/2023] [Accepted: 08/18/2023] [Indexed: 09/10/2023] Open
Abstract
Amino acid availability is crucial for cancer cells' survivability. Leukemia and colorectal cancer cells have been shown to resist asparagine depletion by utilizing GSK3-dependent proteasomal degradation, termed the Wnt-dependent stabilization of proteins (Wnt/STOP), to replenish their amino acid pool. The inhibition of GSK3α halts the sourcing of amino acids, which subsequently leads to cancer cell vulnerability toward asparaginase therapy. However, resistance toward GSK3α-mediated protein breakdown can occur, whose underlying mechanism is poorly understood. Here, we set out to define the mechanisms driving dependence toward this degradation machinery upon asparagine starvation in cancer cells. We show the independence of known stress response pathways including the integrated stress response mediated with GCN2. Additionally, we demonstrate the independence of changes in cell cycle progression and expression levels of the asparagine-synthesizing enzyme ASNS. Instead, RNA sequencing revealed that GSK3α inhibition and asparagine starvation leads to the temporally dynamic downregulation of distinct ribosomal proteins, which have been shown to display anti-proliferative functions. Using a CRISPR/Cas9 viability screen, we demonstrate that the downregulation of these specific ribosomal proteins can rescue cell death upon GSK3α inhibition and asparagine starvation. Thus, our findings suggest the vital role of the previously unrecognized regulation of ribosomal proteins in bridging GSK3α activity and tolerance of asparagine starvation.
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Affiliation(s)
- Lorent Loxha
- Department of Pediatric Hematology and Oncology, Hannover Medical School, 30625 Hannover, Germany; (L.L.); (N.K.I.); (A.S.S.); (B.C.); (T.D.); (J.N.); (S.S.); (B.F.); (M.S.)
| | - Nurul Khalida Ibrahim
- Department of Pediatric Hematology and Oncology, Hannover Medical School, 30625 Hannover, Germany; (L.L.); (N.K.I.); (A.S.S.); (B.C.); (T.D.); (J.N.); (S.S.); (B.F.); (M.S.)
| | - Anna Sophie Stasche
- Department of Pediatric Hematology and Oncology, Hannover Medical School, 30625 Hannover, Germany; (L.L.); (N.K.I.); (A.S.S.); (B.C.); (T.D.); (J.N.); (S.S.); (B.F.); (M.S.)
| | - Büsra Cinar
- Department of Pediatric Hematology and Oncology, Hannover Medical School, 30625 Hannover, Germany; (L.L.); (N.K.I.); (A.S.S.); (B.C.); (T.D.); (J.N.); (S.S.); (B.F.); (M.S.)
| | - Tim Dolgner
- Department of Pediatric Hematology and Oncology, Hannover Medical School, 30625 Hannover, Germany; (L.L.); (N.K.I.); (A.S.S.); (B.C.); (T.D.); (J.N.); (S.S.); (B.F.); (M.S.)
| | - Julia Niessen
- Department of Pediatric Hematology and Oncology, Hannover Medical School, 30625 Hannover, Germany; (L.L.); (N.K.I.); (A.S.S.); (B.C.); (T.D.); (J.N.); (S.S.); (B.F.); (M.S.)
| | - Sabine Schreek
- Department of Pediatric Hematology and Oncology, Hannover Medical School, 30625 Hannover, Germany; (L.L.); (N.K.I.); (A.S.S.); (B.C.); (T.D.); (J.N.); (S.S.); (B.F.); (M.S.)
| | - Beate Fehlhaber
- Department of Pediatric Hematology and Oncology, Hannover Medical School, 30625 Hannover, Germany; (L.L.); (N.K.I.); (A.S.S.); (B.C.); (T.D.); (J.N.); (S.S.); (B.F.); (M.S.)
| | - Michael Forster
- Institute of Clinical Molecular Biology, Kiel University, 24105 Kiel, Germany;
| | - Martin Stanulla
- Department of Pediatric Hematology and Oncology, Hannover Medical School, 30625 Hannover, Germany; (L.L.); (N.K.I.); (A.S.S.); (B.C.); (T.D.); (J.N.); (S.S.); (B.F.); (M.S.)
| | - Laura Hinze
- Department of Pediatric Hematology and Oncology, Hannover Medical School, 30625 Hannover, Germany; (L.L.); (N.K.I.); (A.S.S.); (B.C.); (T.D.); (J.N.); (S.S.); (B.F.); (M.S.)
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27
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Lamichhane PP, Samir P. Cellular Stress: Modulator of Regulated Cell Death. BIOLOGY 2023; 12:1172. [PMID: 37759572 PMCID: PMC10525759 DOI: 10.3390/biology12091172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 08/22/2023] [Accepted: 08/22/2023] [Indexed: 09/29/2023]
Abstract
Cellular stress response activates a complex program of an adaptive response called integrated stress response (ISR) that can allow a cell to survive in the presence of stressors. ISR reprograms gene expression to increase the transcription and translation of stress response genes while repressing the translation of most proteins to reduce the metabolic burden. In some cases, ISR activation can lead to the assembly of a cytoplasmic membraneless compartment called stress granules (SGs). ISR and SGs can inhibit apoptosis, pyroptosis, and necroptosis, suggesting that they guard against uncontrolled regulated cell death (RCD) to promote organismal homeostasis. However, ISR and SGs also allow cancer cells to survive in stressful environments, including hypoxia and during chemotherapy. Therefore, there is a great need to understand the molecular mechanism of the crosstalk between ISR and RCD. This is an active area of research and is expected to be relevant to a range of human diseases. In this review, we provided an overview of the interplay between different cellular stress responses and RCD pathways and their modulation in health and disease.
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Affiliation(s)
| | - Parimal Samir
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555, USA
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28
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Lines CL, McGrath MJ, Dorwart T, Conn CS. The integrated stress response in cancer progression: a force for plasticity and resistance. Front Oncol 2023; 13:1206561. [PMID: 37601686 PMCID: PMC10435748 DOI: 10.3389/fonc.2023.1206561] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Accepted: 06/07/2023] [Indexed: 08/22/2023] Open
Abstract
During their quest for growth, adaptation, and survival, cancer cells create a favorable environment through the manipulation of normal cellular mechanisms. They increase anabolic processes, including protein synthesis, to facilitate uncontrolled proliferation and deplete the tumor microenvironment of resources. As a dynamic adaptation to the self-imposed oncogenic stress, cancer cells promptly hijack translational control to alter gene expression. Rewiring the cellular proteome shifts the phenotypic balance between growth and adaptation to promote therapeutic resistance and cancer cell survival. The integrated stress response (ISR) is a key translational program activated by oncogenic stress that is utilized to fine-tune protein synthesis and adjust to environmental barriers. Here, we focus on the role of ISR signaling for driving cancer progression. We highlight mechanisms of regulation for distinct mRNA translation downstream of the ISR, expand on oncogenic signaling utilizing the ISR in response to environmental stresses, and pinpoint the impact this has for cancer cell plasticity during resistance to therapy. There is an ongoing need for innovative drug targets in cancer treatment, and modulating ISR activity may provide a unique avenue for clinical benefit.
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Affiliation(s)
| | | | | | - Crystal S. Conn
- Department of Radiation Oncology, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, United States
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29
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Hurtig JE, van Hoof A. An unknown essential function of tRNA splicing endonuclease is linked to the integrated stress response and intron debranching. Genetics 2023; 224:iyad044. [PMID: 36943791 PMCID: PMC10213494 DOI: 10.1093/genetics/iyad044] [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: 10/31/2022] [Revised: 10/31/2022] [Accepted: 03/09/2023] [Indexed: 03/23/2023] Open
Abstract
tRNA splicing endonuclease (TSEN) has a well-characterized role in transfer RNA (tRNA) splicing but also other functions. For yeast TSEN, these other functions include degradation of a subset of mRNAs that encode mitochondrial proteins and an unknown essential function. In this study, we use yeast genetics to characterize the unknown tRNA-independent function(s) of TSEN. Using a high-copy suppressor screen, we found that sen2 mutants can be suppressed by overexpression of SEN54. This effect was seen both for tRNA-dependent and tRNA-independent functions indicating that SEN54 is a general suppressor of sen2, likely through structural stabilization. A spontaneous suppressor screen identified mutations in the intron-debranching enzyme, Dbr1, as tRNA splicing-independent suppressors. Transcriptome analysis showed that sen2 mutation activates the Gcn4 stress response. These Gcn4 target transcripts decreased considerably in the sen2 dbr1 double mutant. We propose that Dbr1 and TSEN may compete for a shared substrate, which TSEN normally processes into an essential RNA, while Dbr1 initiates its degradation. These data provide further insight into the essential function(s) of TSEN. Importantly, single amino acid mutations in TSEN cause the generally fatal neuronal disease pontocerebellar hypoplasia (PCH). The mechanism by which defects in TSEN cause this disease is unknown, and our results reveal new possible mechanisms.
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Affiliation(s)
- Jennifer E Hurtig
- Microbiology and Molecular Genetics, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Ambro van Hoof
- Microbiology and Molecular Genetics, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA
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30
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Gupta R, Hinnebusch AG. Differential requirements for P stalk components in activating yeast protein kinase Gcn2 by stalled ribosomes during stress. Proc Natl Acad Sci U S A 2023; 120:e2300521120. [PMID: 37043534 PMCID: PMC10120022 DOI: 10.1073/pnas.2300521120] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 03/13/2023] [Indexed: 04/13/2023] Open
Abstract
The General Amino Acid Control is a conserved response to amino acid starvation involving activation of protein kinase Gcn2, which phosphorylates eukaryotic initiation factor 2 (eIF2α) with attendant inhibition of global protein synthesis and increased translation of yeast transcriptional activator GCN4. Gcn2 can be activated by either amino acid starvation or conditions that stall elongating ribosomes without reducing aminoacylation of tRNA, but it is unclear whether distinct molecular mechanisms operate in these two circumstances. We identified three regimes that activate Gcn2 in yeast cells by starvation-independent (SI) ribosome-stalling: treatment with tigecycline, eliminating the sole gene encoding tRNAArgUCC, and depletion of translation termination factor eRF1. We further demonstrated requirements for the tRNA- and ribosome-binding domains of Gcn2, the positive effector proteins Gcn1/Gcn20, and the tethering of at least one of two distinct P1/P2 heterodimers to the uL10 subunit of the ribosomal P stalk, for detectable activation by SI-ribosome stalling. Remarkably, no tethered P1/P2 proteins were required for strong Gcn2 activation elicited by starvation for histidine or branched-chain amino acids isoleucine/valine. These results indicate that Gcn2 activation has different requirements for the P stalk depending on how ribosomes are stalled. We propose that accumulation of deacylated tRNAs in amino acid-starved cells can functionally substitute for the P stalk in binding to the histidyl-tRNA synthetase-like domain of Gcn2 for eIF2α kinase activation by ribosomes stalled with A sites devoid of the eEF1A∙GTP∙aminoacyl-tRNA ternary complex.
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Affiliation(s)
- Ritu Gupta
- Section on Nutrient Control of Gene Expression, Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD20892
| | - Alan G. Hinnebusch
- Section on Nutrient Control of Gene Expression, Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD20892
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31
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Weber SL, Hustedt K, Schnepel N, Visscher C, Muscher-Banse AS. Modulation of GCN2/eIF2α/ATF4 Pathway in the Liver and Induction of FGF21 in Young Goats Fed a Protein- and/or Phosphorus-Reduced Diet. Int J Mol Sci 2023; 24:ijms24087153. [PMID: 37108315 PMCID: PMC10138370 DOI: 10.3390/ijms24087153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 04/08/2023] [Accepted: 04/10/2023] [Indexed: 04/29/2023] Open
Abstract
Mammals respond to amino acid (AA) deficiency by initiating an AA response pathway (AAR) that involves the activation of general control nonderepressible 2 (GCN2), phosphorylation of eukaryotic translation initiation factor 2α (eIF2α), and activation of transcription factor 4 (ATF4). In this study, the effects of protein (N) and/or phosphorus (P) restriction on the GCN2/eIF2α/ATF4 pathway in the liver and the induction of fibroblast growth factor 21 (FGF21) in young goats were investigated. An N-reduced diet resulted in a decrease in circulating essential AA (EAA) and an increase in non-essential AA (NEAA), as well as an increase in hepatic mRNA expression of GCN2 and ATF4 and protein expression of GCN2. Dietary N restriction robustly increased both hepatic FGF21 mRNA expression and circulating FGF21 levels. Accordingly, numerous significant correlations demonstrated the effects of the AA profile on the AAR pathway and confirmed an association. Furthermore, activation of the AAR pathway depended on the sufficient availability of P. When dietary P was restricted, the GCN2/eIF2α/ATF4 pathway was not initiated, and no increase in FGF21 was observed. These results illustrate how the AAR pathway responds to N- and/or P-reduced diets in ruminants, thus demonstrating the complexity of dietary component changes.
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Affiliation(s)
- Sarah L Weber
- Institute for Physiology and Cell Biology, University of Veterinary Medicine Hannover, 30173 Hannover, Germany
| | - Karin Hustedt
- Institute for Physiology and Cell Biology, University of Veterinary Medicine Hannover, 30173 Hannover, Germany
| | - Nadine Schnepel
- Institute for Physiology and Cell Biology, University of Veterinary Medicine Hannover, 30173 Hannover, Germany
| | - Christian Visscher
- Institute for Animal Nutrition, University of Veterinary Medicine Hannover, 30173 Hannover, Germany
| | - Alexandra S Muscher-Banse
- Institute for Physiology and Cell Biology, University of Veterinary Medicine Hannover, 30173 Hannover, Germany
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32
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Carlson KR, Georgiadis MM, Tameire F, Staschke KA, Wek RC. Activation of Gcn2 by small molecules designed to be inhibitors. J Biol Chem 2023; 299:104595. [PMID: 36898579 PMCID: PMC10124904 DOI: 10.1016/j.jbc.2023.104595] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Accepted: 03/06/2023] [Indexed: 03/10/2023] Open
Abstract
The integrated stress response (ISR) is an important mechanism by which cells confer protection against environmental stresses. Central to the ISR is a collection of related protein kinases that monitor stress conditions, such as Gcn2 (EIF2AK4) that recognizes nutrient limitations, inducing phosphorylation of eukaryotic translation initiation factor 2 (eIF2). Gcn2 phosphorylation of eIF2 lowers bulk protein synthesis, conserving energy and nutrients, coincident with preferential translation of stress-adaptive gene transcripts, such as that encoding the Atf4 transcriptional regulator. While Gcn2 is central for cell protection to nutrient stress and its depletion in humans leads to pulmonary disorders, Gcn2 can also contribute to the progression of cancers and facilitate neurological disorders during chronic stress. Consequently, specific ATP-competitive inhibitors of Gcn2 protein kinase have been developed. In this study, we report that one such Gcn2 inhibitor, Gcn2iB, can activate Gcn2, and we probe the mechanism by which this activation occurs. Low concentrations of Gcn2iB increase Gcn2 phosphorylation of eIF2 and enhance Atf4 expression and activity. Of importance, Gcn2iB can activate Gcn2 mutants devoid of functional regulatory domains or with certain kinase domain substitutions derived from Gcn2-deficient human patients. Other ATP-competitive inhibitors can also activate Gcn2, although there are differences in their mechanisms of activation. These results provide a cautionary note about the pharmacodynamics of eIF2 kinase inhibitors in therapeutic applications. Compounds designed to be kinase inhibitors that instead directly activate Gcn2, even loss of function variants, may provide tools to alleviate deficiencies in Gcn2 and other regulators of the ISR.
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Affiliation(s)
- Kenneth R Carlson
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Millie M Georgiadis
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana, USA; Indiana University Melvin and Bren Simon Comprehensive Cancer Center, Indianapolis, Indiana, USA
| | | | - Kirk A Staschke
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana, USA; Indiana University Melvin and Bren Simon Comprehensive Cancer Center, Indianapolis, Indiana, USA
| | - Ronald C Wek
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana, USA; Indiana University Melvin and Bren Simon Comprehensive Cancer Center, Indianapolis, Indiana, USA.
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Szczerba M, Johnson B, Acciai F, Gogerty C, McCaughan M, Williams J, Kibler KV, Jacobs BL. Canonical cellular stress granules are required for arsenite-induced necroptosis mediated by Z-DNA-binding protein 1. Sci Signal 2023; 16:eabq0837. [PMID: 36917643 PMCID: PMC10561663 DOI: 10.1126/scisignal.abq0837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Accepted: 02/22/2023] [Indexed: 03/15/2023]
Abstract
Cellular stress granules arise in cells subjected to stress and promote cell survival. A cellular protein that localizes to stress granules is Z-DNA-binding protein 1 (ZBP1), which plays a major role in necroptosis, a programmed cell death pathway mediated by the kinase RIPK3. Here, we showed that the stress granule inducer arsenite activated RIPK3-dependent necroptosis. This pathway required ZBP1, which localized to arsenite-induced stress granules. RIPK3 localized to stress granules in the presence of ZBP1, leading to the formation of ZBP1-RIPK3 necrosomes, phosphorylation of the RIPK3 effector MLKL, and execution of necroptosis. Cells that did not form stress granules did not induce necroptosis in response to arsenite. Together, these results show that arsenite induces ZBP1-mediated necroptosis in a manner dependent on stress granule formation.
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Affiliation(s)
- Mateusz Szczerba
- Biodesign Center for Immunotherapy, Vaccines and Virotherapy, Arizona State University, Tempe, AZ 85281, USA
| | - Brian Johnson
- Biodesign Center for Immunotherapy, Vaccines and Virotherapy, Arizona State University, Tempe, AZ 85281, USA
| | - Francesco Acciai
- College of Health Solutions, Arizona State University, Phoenix, AZ 85004, USA
| | - Carolina Gogerty
- Biodesign Center for Immunotherapy, Vaccines and Virotherapy, Arizona State University, Tempe, AZ 85281, USA
- School of Life Sciences, Arizona State University, Tempe, AZ 85281, USA
| | - Megan McCaughan
- Biodesign Center for Immunotherapy, Vaccines and Virotherapy, Arizona State University, Tempe, AZ 85281, USA
- School of Life Sciences, Arizona State University, Tempe, AZ 85281, USA
| | - Jacqueline Williams
- Biodesign Center for Immunotherapy, Vaccines and Virotherapy, Arizona State University, Tempe, AZ 85281, USA
- School of Life Sciences, Arizona State University, Tempe, AZ 85281, USA
| | - Karen V. Kibler
- Biodesign Center for Immunotherapy, Vaccines and Virotherapy, Arizona State University, Tempe, AZ 85281, USA
| | - Bertram L. Jacobs
- Biodesign Center for Immunotherapy, Vaccines and Virotherapy, Arizona State University, Tempe, AZ 85281, USA
- School of Life Sciences, Arizona State University, Tempe, AZ 85281, USA
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Santos-Ribeiro D, Lecocq M, de Beukelaer M, Verleden S, Bouzin C, Ambroise J, Dorfmuller P, Yakoub Y, Huaux F, Quarck R, Karmouty-Quintana H, Ghigna MR, Bignard J, Nadaud S, Soubrier F, Horman S, Perros F, Godinas L, Pilette C. Disruption of GCN2 Pathway Aggravates Vascular and Parenchymal Remodeling during Pulmonary Fibrosis. Am J Respir Cell Mol Biol 2023; 68:326-338. [PMID: 36476191 DOI: 10.1165/rcmb.2021-0541oc] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Pulmonary fibrosis (PF) and pulmonary hypertension (PH) are chronic diseases of the pulmonary parenchyma and circulation, respectively, which may coexist, but underlying mechanisms remain elusive. Mutations in the GCN2 (general control nonderepressible 2) gene (EIF2AK4 [eukaryotic translation initiation factor 2 alpha kinase 4]) were recently associated with pulmonary veno-occlusive disease. The aim of this study is to explore the involvement of the GCN2/eIF2α (eukaryotic initiation factor 2α) pathway in the development of PH during PF, in both human disease and in a laboratory animal model. Lung tissue from patients with PF with or without PH was collected at the time of lung transplantation, and control tissue was obtained from tumor resection surgery. Experimental lung disease was induced in either male wild-type or EIF2AK4-mutated Sprague-Dawley rats, randomly receiving a single intratracheal instillation of bleomycin or saline. Hemodynamic studies and organ collection were performed 3 weeks after instillation. Only significant results (P < 0.05) are presented. In PF lung tissue, GCN2 protein expression was decreased compared with control tissue. GCN2 expression was reduced in CD31+ endothelial cells. In line with human data, GCN2 protein expression was decreased in the lung of bleomycin rats compared with saline. EIF2AK4-mutated rats treated with bleomycin showed increased parenchymal fibrosis (hydroxyproline concentrations) and vascular remodeling (media wall thickness) as well as increased right ventricular systolic pressure compared with wild-type animals. Our data show that GCN2 is dysregulated in both humans and in an animal model of combined PF and PH. The possibility of a causative implication of GCN2 dysregulation in PF and/or PH development should be further studied.
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Affiliation(s)
| | | | | | - Stijn Verleden
- Laboratory of Respiratory Diseases & Thoracic Surgery, Department of Chronic Diseases and Metabolism, and
| | | | | | - Peter Dorfmuller
- Department of Pathology, University of Giessen and Marburg Lung Center, Justus-Liebig University Giessen, German Center for Lung Research, Giessen, Germany
| | - Yousef Yakoub
- Louvain Center for Toxicology and Applied Pharmacology, and
| | - François Huaux
- Louvain Center for Toxicology and Applied Pharmacology, and
| | - Rozenn Quarck
- Clinical Department of Respiratory Diseases, University Hospitals - University of Leuven, Leuven, Belgium
| | - Harry Karmouty-Quintana
- Department of Biochemistry and Molecular Biology and.,Division of Critical Care and.,Division of Pulmonary and Sleep Medicine, Department of Internal Medicine, The University of Texas Health Science Center at Houston, Houston, Texas
| | - Maria-Rosa Ghigna
- Faculté de Médecine, Université Paris-Saclay, Le Kremlin-Bicêtre, France.,Département de Pathologie and.,INSERM UMR_S 999, Hôpital Marie Lannelongue, Le Plessis-Robinson, France
| | | | - Sophie Nadaud
- UMR_S 1166-ICAN, INSERM, Sorbonne Université, Paris, France
| | | | - Sandrine Horman
- Cardiovascular Research Unit, Institute of Experimental and Clinical Research, Catholic University of Louvain, Brussels, Belgium
| | - Frederic Perros
- Faculté de Médecine, Université Paris-Saclay, Le Kremlin-Bicêtre, France.,INSERM UMR_S 999, Hôpital Marie Lannelongue, Le Plessis-Robinson, France.,Assistance Publique-Hôpitaux de Paris, Centre de Référence de l'Hypertension Pulmonaire, Service de Pneumologie et Soins Intensifs Respiratoires, Hôpital Bicêtre, Le Kremlin-Bicêtre, France.,Laboratoire CarMeN, UMR INSERM U1060/INRA U1397, Université Claude Bernard Lyon1, Pierre-Bénite and Bron, France; and
| | - Laurent Godinas
- Clinical Department of Respiratory Diseases, University Hospitals - University of Leuven, Leuven, Belgium
| | - Charles Pilette
- Pneumology, ENT and Dermatology.,Département de Pneumologie, Cliniques Universitaires St-Luc, Brussels, Belgium
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35
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Zhao C, Guo H, Hou Y, Lei T, Wei D, Zhao Y. Multiple Roles of the Stress Sensor GCN2 in Immune Cells. Int J Mol Sci 2023; 24:ijms24054285. [PMID: 36901714 PMCID: PMC10002013 DOI: 10.3390/ijms24054285] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 02/16/2023] [Accepted: 02/17/2023] [Indexed: 02/24/2023] Open
Abstract
The serine/threonine-protein kinase general control nonderepressible 2 (GCN2) is a well-known stress sensor that responds to amino acid starvation and other stresses, making it critical to the maintenance of cellular and organismal homeostasis. More than 20 years of research has revealed the molecular structure/complex, inducers/regulators, intracellular signaling pathways and bio-functions of GCN2 in various biological processes, across an organism's lifespan, and in many diseases. Accumulated studies have demonstrated that the GCN2 kinase is also closely involved in the immune system and in various immune-related diseases, such as GCN2 acts as an important regulatory molecule to control macrophage functional polarization and CD4+ T cell subset differentiation. Herein, we comprehensively summarize the biological functions of GCN2 and discuss its roles in the immune system, including innate and adaptive immune cells. We also discuss the antagonism of GCN2 and mTOR pathways in immune cells. A better understanding of GCN2's functions and signaling pathways in the immune system under physiological, stressful, and pathological situations will be beneficial to the development of potential therapies for many immune-relevant diseases.
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Affiliation(s)
- Chenxu Zhao
- State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Han Guo
- State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yangxiao Hou
- State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Tong Lei
- State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Dong Wei
- State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yong Zhao
- State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- Beijing Institute for Stem Cell and Regenerative Medicine, Beijing 100101, China
- Correspondence: ; Tel.: +86-10-64807302
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36
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Li W, Wang Y. Stress granules: potential therapeutic targets for infectious and inflammatory diseases. Front Immunol 2023; 14:1145346. [PMID: 37205103 PMCID: PMC10185834 DOI: 10.3389/fimmu.2023.1145346] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Accepted: 04/12/2023] [Indexed: 05/21/2023] Open
Abstract
Eukaryotic cells are stimulated by external pressure such as that derived from heat shock, oxidative stress, nutrient deficiencies, or infections, which induce the formation of stress granules (SGs) that facilitates cellular adaptation to environmental pressures. As aggregated products of the translation initiation complex in the cytoplasm, SGs play important roles in cell gene expression and homeostasis. Infection induces SGs formation. Specifically, a pathogen that invades a host cell leverages the host cell translation machinery to complete the pathogen life cycle. In response, the host cell suspends translation, which leads to SGs formation, to resist pathogen invasion. This article reviews the production and function of SGs, the interaction between SGs and pathogens, and the relationship between SGs and pathogen-induced innate immunity to provide directions for further research into anti-infection and anti-inflammatory disease strategies.
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Affiliation(s)
- Wenyuan Li
- Department of Anesthesiology, Renmin Hospital of Wuhan University, Wuhan, Hubei, China
| | - Yao Wang
- Department of Infectious Diseases, Renmin Hospital of Wuhan University, Wuhan, Hubei, China
- *Correspondence: Yao Wang,
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37
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Ranea-Robles P, Pavlova NN, Bender A, Pereyra AS, Ellis JM, Stauffer B, Yu C, Thompson CB, Argmann C, Puchowicz M, Houten SM. A mitochondrial long-chain fatty acid oxidation defect leads to transfer RNA uncharging and activation of the integrated stress response in the mouse heart. Cardiovasc Res 2022; 118:3198-3210. [PMID: 35388887 PMCID: PMC9799058 DOI: 10.1093/cvr/cvac050] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 03/08/2022] [Accepted: 03/23/2022] [Indexed: 01/25/2023] Open
Abstract
AIMS Cardiomyopathy and arrhythmias can be severe presentations in patients with inherited defects of mitochondrial long-chain fatty acid β-oxidation (FAO). The pathophysiological mechanisms that underlie these cardiac abnormalities remain largely unknown. We investigated the molecular adaptations to a FAO deficiency in the heart using the long-chain acyl-CoA dehydrogenase (LCAD) knockout (KO) mouse model. METHODS AND RESULTS We observed enrichment of amino acid metabolic pathways and of ATF4 target genes among the upregulated genes in the LCAD KO heart transcriptome. We also found a prominent activation of the eIF2α/ATF4 axis at the protein level that was independent of the feeding status, in addition to a reduction of cardiac protein synthesis during a short period of food withdrawal. These findings are consistent with an activation of the integrated stress response (ISR) in the LCAD KO mouse heart. Notably, charging of several transfer RNAs (tRNAs), such as tRNAGln was decreased in LCAD KO hearts, reflecting a reduced availability of cardiac amino acids, in particular, glutamine. We replicated the activation of the ISR in the hearts of mice with muscle-specific deletion of carnitine palmitoyltransferase 2. CONCLUSIONS Our results show that perturbations in amino acid metabolism caused by long-chain FAO deficiency impact cardiac metabolic signalling, in particular the ISR. These results may serve as a foundation for investigating the role of the ISR in the cardiac pathology associated with long-chain FAO defects.Translational Perspective: The heart relies mainly on mitochondrial fatty acid β-oxidation (FAO) for its high energy requirements. The heart disease observed in patients with a genetic defect in this pathway highlights the importance of FAO for cardiac health. We show that the consequences of a FAO defect extend beyond cardiac energy homeostasis and include amino acid metabolism and associated signalling pathways such as the integrated stress response.
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Affiliation(s)
- Pablo Ranea-Robles
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, 1425 Madison Avenue, Box 1498, New York, NY 10029, USA
| | - Natalya N Pavlova
- Cancer Biology & Genetics Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Aaron Bender
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, 1425 Madison Avenue, Box 1498, New York, NY 10029, USA
| | - Andrea S Pereyra
- Brody School of Medicine at East Carolina University, Department of Physiology, and East Carolina Diabetes and Obesity Institute, Greenville, NC 27858, USA
| | - Jessica M Ellis
- Brody School of Medicine at East Carolina University, Department of Physiology, and East Carolina Diabetes and Obesity Institute, Greenville, NC 27858, USA
| | - Brandon Stauffer
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, 1425 Madison Avenue, Box 1498, New York, NY 10029, USA
- Mount Sinai Genomics, Inc, Stamford, CT 06902, USA
| | - Chunli Yu
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, 1425 Madison Avenue, Box 1498, New York, NY 10029, USA
- Mount Sinai Genomics, Inc, Stamford, CT 06902, USA
| | - Craig B Thompson
- Cancer Biology & Genetics Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Carmen Argmann
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, 1425 Madison Avenue, Box 1498, New York, NY 10029, USA
| | - Michelle Puchowicz
- Department of Nutrition, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
- Department of Pediatrics, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Sander M Houten
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, 1425 Madison Avenue, Box 1498, New York, NY 10029, USA
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38
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Is bRaQCing bad? New roles for ribosome associated quality control factors in stress granule regulation. Biochem Soc Trans 2022; 50:1715-1724. [DOI: 10.1042/bst20220549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 11/01/2022] [Accepted: 11/21/2022] [Indexed: 12/13/2022]
Abstract
Maintenance of proteostasis is of utmost importance to cellular viability and relies on the coordination of many post-transcriptional processes to respond to stressful stimuli. Stress granules (SGs) are RNA–protein condensates that form after translation initiation is inhibited, such as during the integrated stress response (ISR), and may facilitate cellular adaptation to stress. The ribosome-associated quality control (RQC) pathway is a critical translation monitoring system that recognizes aberrant mRNAs encoding potentially toxic nascent peptides to target them for degradation. Both SG regulation and the RQC pathway are directly associated with translation regulation, thus it is of no surprise recent developments have demonstrated a connection between them. VCP's function in the stress activated RQC pathway, ribosome collisions activating the ISR, and the regulation of the 40S ribosomal subunit by canonical SG proteins during the RQC all connect SGs to the RQC pathway. Because mutations in genes that are involved in both SG and RQC regulation are associated with degenerative and neurological diseases, understanding the coordination and interregulation of SGs and RQC may shed light on disease mechanisms. This minireview will highlight recent advances in understanding how SGs and the RQC pathway interact in health and disease contexts.
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39
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Sadasivan J, Vlok M, Wang X, Nayak A, Andino R, Jan E. Targeting Nup358/RanBP2 by a viral protein disrupts stress granule formation. PLoS Pathog 2022; 18:e1010598. [PMID: 36455064 PMCID: PMC9746944 DOI: 10.1371/journal.ppat.1010598] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 12/13/2022] [Accepted: 11/17/2022] [Indexed: 12/03/2022] Open
Abstract
Viruses have evolved mechanisms to modulate cellular pathways to facilitate infection. One such pathway is the formation of stress granules (SG), which are ribonucleoprotein complexes that assemble during translation inhibition following cellular stress. Inhibition of SG assembly has been observed under numerous virus infections across species, suggesting a conserved fundamental viral strategy. However, the significance of SG modulation during virus infection is not fully understood. The 1A protein encoded by the model dicistrovirus, Cricket paralysis virus (CrPV), is a multifunctional protein that can bind to and degrade Ago-2 in an E3 ubiquitin ligase-dependent manner to block the antiviral RNA interference pathway and inhibit SG formation. Moreover, the R146 residue of 1A is necessary for SG inhibition and CrPV infection in both Drosophila S2 cells and adult flies. Here, we uncoupled CrPV-1A's functions and provide insight into its underlying mechanism for SG inhibition. CrPV-1A mediated inhibition of SGs requires the E3 ubiquitin-ligase binding domain and the R146 residue, but not the Ago-2 binding domain. Wild-type but not mutant CrPV-1A R146A localizes to the nuclear membrane which correlates with nuclear enrichment of poly(A)+ RNA. Transcriptome changes in CrPV-infected cells are dependent on the R146 residue. Finally, Nup358/RanBP2 is targeted and degraded in CrPV-infected cells in an R146-dependent manner and the depletion of Nup358 blocks SG formation. We propose that CrPV utilizes a multiprong strategy whereby the CrPV-1A protein interferes with a nuclear event that contributes to SG inhibition in order to promote infection.
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Affiliation(s)
- Jibin Sadasivan
- Department of Biochemistry and Molecular Biology, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Marli Vlok
- Department of Biochemistry and Molecular Biology, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Xinying Wang
- Department of Biochemistry and Molecular Biology, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Arabinda Nayak
- Department of Microbiology and Immunology, University of California San Francisco, San Francisco, California, United States of America
| | - Raul Andino
- Department of Microbiology and Immunology, University of California San Francisco, San Francisco, California, United States of America
| | - Eric Jan
- Department of Biochemistry and Molecular Biology, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada
- * E-mail:
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40
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Cabral AJ, Costello DC, Farny NG. The enigma of ultraviolet radiation stress granules: Research challenges and new perspectives. Front Mol Biosci 2022; 9:1066650. [DOI: 10.3389/fmolb.2022.1066650] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Accepted: 11/17/2022] [Indexed: 12/02/2022] Open
Abstract
Stress granules (SGs) are non-membrane bound cytoplasmic condensates that form in response to a variety of different stressors. Canonical SGs are thought to have a cytoprotective role, reallocating cellular resources during stress by activation of the integrated stress response (ISR) to inhibit translation and avoid apoptosis. However, different stresses result in compositionally distinct, non-canonical SG formation that is likely pro-apoptotic, though the exact function(s) of both SGs subtypes remain unclear. A unique non-canonical SG subtype is triggered upon exposure to ultraviolet (UV) radiation. While it is generally agreed that UV SGs are bona fide SGs due to their dependence upon the core SG nucleating protein Ras GTPase-activating protein-binding protein 1 (G3BP1), the localization of other key components of UV SGs are unknown or under debate. Further, the dynamics of UV SGs are not known, though unique properties such as cell cycle dependence have been observed. This Perspective compiles the available information on SG subtypes and on UV SGs in particular in an attempt to understand the formation, dynamics, and function of these mysterious stress-specific complexes. We identify key gaps in knowledge related to UV SGs, and examine the unique aspects of their formation. We propose that more thorough knowledge of the distinct properties of UV SGs will lead to new avenues of understanding of the function of SGs, as well as their roles in disease.
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Martin JL, Dawson SJ, Gale JE. An emerging role for stress granules in neurodegenerative disease and hearing loss. Hear Res 2022; 426:108634. [PMID: 36384053 DOI: 10.1016/j.heares.2022.108634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 09/20/2022] [Accepted: 10/11/2022] [Indexed: 11/04/2022]
Abstract
Stress granules (SGs) are membrane-less cytosolic assemblies that form in response to stress (e.g., heat, oxidative stress, hypoxia, viral infection and UV). Composed of mRNA, RNA binding proteins and signalling proteins, SGs minimise stress-related damage and promote cell survival. Recent research has shown that the stress granule response is vital to the cochlea's response to stress. However, emerging evidence suggests stress granule dysfunction plays a key role in the pathophysiology of multiple neurodegenerative diseases, several of which present with hearing loss as a symptom. Hearing loss has been identified as the largest potentially modifiable risk factor for dementia. The underlying reason for the link between hearing loss and dementia remains to be established. However, several possible mechanisms have been proposed including a common pathological mechanism. Here we will review the role of SGs in the pathophysiology of neurodegenerative diseases and explore possible links and emerging evidence that they may play an important role in maintenance of hearing and may be a common mechanism underlying age-related hearing loss and dementia.
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Affiliation(s)
- Jack L Martin
- UCL Ear Institute, 332 Gray's Inn Road, London WC1X 8EE, UK
| | - Sally J Dawson
- UCL Ear Institute, 332 Gray's Inn Road, London WC1X 8EE, UK.
| | - Jonathan E Gale
- UCL Ear Institute, 332 Gray's Inn Road, London WC1X 8EE, UK.
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42
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Fulton TL, Mirth CK, Piper MDW. Restricting a single amino acid cross-protects Drosophila melanogaster from nicotine poisoning through mTORC1 and GCN2 signalling. Open Biol 2022; 12:220319. [PMID: 36514979 PMCID: PMC9748770 DOI: 10.1098/rsob.220319] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Dietary interventions that restrict protein intake have repeatedly been shown to offer beneficial health outcomes to the consumer. Benefits such as increased stress tolerance can be observed when individual amino acids are restricted, thus mimicking dietary protein restriction. Here, we sought to further understand the relationship between dietary amino acids and stress tolerance using Drosophila melanogaster. Using a chemically defined medium for Drosophila, we found that transiently restricting adult flies of a single essential amino acid generally protects against a lethal dose of the naturally occurring insecticide, nicotine. This protection varied with the identity of the focal amino acid and depended on the duration and intensity of its restriction. To understand the molecular basis of these effects, we modified the signalling of two cellular sensors of amino acids, GCN2 and mTORC1, in combination with amino acid restriction. We found that GCN2 was necessary for diets to protect against nicotine, whereas the suppression of mTORC1 was sufficient to induce nicotine resistance. This finding implies that amino acid restriction acts via amino acid signalling to cross-protect against seemingly unrelated stressors. Altogether, our study offers new insights into the physiological responses to restriction of individual amino acids that confer stress tolerance.
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Affiliation(s)
- Tahlia L. Fulton
- School of Biological Sciences, Monash University, Melbourne, VIC 3800, Australia
| | - Christen K. Mirth
- School of Biological Sciences, Monash University, Melbourne, VIC 3800, Australia
| | - Matthew D. W. Piper
- School of Biological Sciences, Monash University, Melbourne, VIC 3800, Australia
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The antitumor activity of a novel GCN2 inhibitor in head and neck squamous cell carcinoma cell lines. Transl Oncol 2022; 27:101592. [PMID: 36436443 PMCID: PMC9694079 DOI: 10.1016/j.tranon.2022.101592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Revised: 11/03/2022] [Accepted: 11/21/2022] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND General control nonderepressible 2 (GCN2) senses amino acid deprivation and activates activating transcription factor 4 (ATF4), which regulates many adaptive genes. We evaluated the impact of AST-0513, a novel GCN2 inhibitor, on the GCN2-ATF4 pathway. Additionally, we evaluated the antitumor effects of AST-0513 in amino acid deprivation in head and neck squamous cell carcinoma (HNSCC) cell lines. METHODS GCN2 expression in HNSCC patient tissues was measured by immunohistochemistry. Five HNSCC cell lines (SNU-1041, SNU-1066, SNU-1076, Detroit-562, FaDu) grown under amino acid deprivation conditions, were treated with AST-0513. After AST-0513 treatment, cell proliferation was measured by CCK-8 assay. Flow cytometry was used to evaluate apoptosis and cell cycle phase. In addition, immunoblotting was performed to evaluate the effect of AST-0513 on the GCN2-ATF4 pathway, cell cycle arrest, and apoptosis. RESULTS We demonstrated that GCN2 was highly expressed in HNSCC patient tissues. AST-0513 inhibited the GCN2-ATF4 pathway in all five HNSCC cell lines. Inhibiting the GCN2-ATF4 pathway during amino acid deprivation reduced HNSCC cell proliferation and prevented adaptation to nutrient stress. Moreover, AST-0513 treatment led to p21 and Cyclin B1 accumulation and G2/M phase cycle arrest. Also, apoptosis was increased, consistent with increased bax expression, increased bcl-xL phosphorylation, and decreased bcl-2 expression. CONCLUSION A novel GCN2 inhibitor, AST-0513, inhibited the GCN2-ATF4 pathway and has antitumor activity that inhibits proliferation and promotes cell cycle arrest and apoptosis. Considering the high expression of GCN2 in HNSCC patients, these results suggest the potential role of GCN2 inhibitor for the treatment of HNSCC.
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44
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Cordova RA, Misra J, Amin PH, Klunk AJ, Damayanti NP, Carlson KR, Elmendorf AJ, Kim HG, Mirek ET, Elzey BD, Miller MJ, Dong XC, Cheng L, Anthony TG, Pili R, Wek RC, Staschke KA. GCN2 eIF2 kinase promotes prostate cancer by maintaining amino acid homeostasis. eLife 2022; 11:e81083. [PMID: 36107759 PMCID: PMC9578714 DOI: 10.7554/elife.81083] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 09/14/2022] [Indexed: 12/15/2022] Open
Abstract
A stress adaptation pathway termed the integrated stress response has been suggested to be active in many cancers including prostate cancer (PCa). Here, we demonstrate that the eIF2 kinase GCN2 is required for sustained growth in androgen-sensitive and castration-resistant models of PCa both in vitro and in vivo, and is active in PCa patient samples. Using RNA-seq transcriptome analysis and a CRISPR-based phenotypic screen, GCN2 was shown to regulate expression of over 60 solute-carrier (SLC) genes, including those involved in amino acid transport and loss of GCN2 function reduces amino acid import and levels. Addition of essential amino acids or expression of 4F2 (SLC3A2) partially restored growth following loss of GCN2, suggesting that GCN2 targeting of SLC transporters is required for amino acid homeostasis needed to sustain tumor growth. A small molecule inhibitor of GCN2 showed robust in vivo efficacy in androgen-sensitive and castration-resistant mouse models of PCa, supporting its therapeutic potential for the treatment of PCa.
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Affiliation(s)
- Ricardo A Cordova
- Department of Biochemistry and Molecular Biology, Indiana University School of MedicineIndianapolisUnited States
- Indiana University Melvin and Bren Simon Comprehensive Cancer CenterIndianapolisUnited States
| | - Jagannath Misra
- Department of Biochemistry and Molecular Biology, Indiana University School of MedicineIndianapolisUnited States
| | - Parth H Amin
- Department of Biochemistry and Molecular Biology, Indiana University School of MedicineIndianapolisUnited States
| | - Anglea J Klunk
- Department of Biochemistry and Molecular Biology, Indiana University School of MedicineIndianapolisUnited States
| | - Nur P Damayanti
- Indiana University Melvin and Bren Simon Comprehensive Cancer CenterIndianapolisUnited States
- Department of Neurological Surgery, Indiana University School of MedicineIndianapolisUnited States
| | - Kenneth R Carlson
- Department of Biochemistry and Molecular Biology, Indiana University School of MedicineIndianapolisUnited States
| | - Andrew J Elmendorf
- Department of Biochemistry and Molecular Biology, Indiana University School of MedicineIndianapolisUnited States
| | - Hyeong-Geug Kim
- Department of Biochemistry and Molecular Biology, Indiana University School of MedicineIndianapolisUnited States
| | - Emily T Mirek
- Department of Nutritional Sciences, Rutgers UniversityNew BrunswickUnited States
| | - Bennet D Elzey
- Department of Comparative Pathology, Purdue UniversityWest LafayetteUnited States
- Department of Urology, Indiana University School of MedicineIndianapolisUnited States
| | - Marcus J Miller
- Department of Medical and Molecular Genetics, Indiana University School of MedicineIndianapolisUnited States
| | - X Charlie Dong
- Department of Biochemistry and Molecular Biology, Indiana University School of MedicineIndianapolisUnited States
| | - Liang Cheng
- Indiana University Melvin and Bren Simon Comprehensive Cancer CenterIndianapolisUnited States
- Department of Urology, Indiana University School of MedicineIndianapolisUnited States
- Department of Pathology and Laboratory Medicine, Indiana University School of MedicineIndianapolisUnited States
| | - Tracy G Anthony
- Department of Nutritional Sciences, Rutgers UniversityNew BrunswickUnited States
| | - Roberto Pili
- Jacobs School of Medicine and Biomedical Sciences, University at BuffaloBuffaloUnited States
| | - Ronald C Wek
- Department of Biochemistry and Molecular Biology, Indiana University School of MedicineIndianapolisUnited States
- Indiana University Melvin and Bren Simon Comprehensive Cancer CenterIndianapolisUnited States
| | - Kirk A Staschke
- Department of Biochemistry and Molecular Biology, Indiana University School of MedicineIndianapolisUnited States
- Indiana University Melvin and Bren Simon Comprehensive Cancer CenterIndianapolisUnited States
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45
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Toboz P, Amiri M, Tabatabaei N, Dufour CR, Kim SH, Fillebeen C, Ayemoba CE, Khoutorsky A, Nairz M, Shao L, Pajcini KV, Kim KW, Giguère V, Oliveira RL, Constante M, Santos MM, Morales CR, Pantopoulos K, Sonenberg N, Pinho S, Tahmasebi S. The amino acid sensor GCN2 controls red blood cell clearance and iron metabolism through regulation of liver macrophages. Proc Natl Acad Sci U S A 2022; 119:e2121251119. [PMID: 35994670 PMCID: PMC9436309 DOI: 10.1073/pnas.2121251119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 07/20/2022] [Indexed: 11/18/2022] Open
Abstract
GCN2 (general control nonderepressible 2) is a serine/threonine-protein kinase that controls messenger RNA translation in response to amino acid availability and ribosome stalling. Here, we show that GCN2 controls erythrocyte clearance and iron recycling during stress. Our data highlight the importance of liver macrophages as the primary cell type mediating these effects. During different stress conditions, such as hemolysis, amino acid deficiency or hypoxia, GCN2 knockout (GCN2-/-) mice displayed resistance to anemia compared with wild-type (GCN2+/+) mice. GCN2-/- liver macrophages exhibited defective erythrophagocytosis and lysosome maturation. Molecular analysis of GCN2-/- cells demonstrated that the ATF4-NRF2 pathway is a critical downstream mediator of GCN2 in regulating red blood cell clearance and iron recycling.
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Affiliation(s)
- Phoenix Toboz
- Department of Pharmacology and Regenerative Medicine, University of Illinois College of Medicine, Chicago, IL, 60612
| | - Mehdi Amiri
- Department of Biochemistry, McGill University, Montreal, QC, H3A 1A3, Canada
- Rosalind and Morris Goodman Cancer Institute, McGill University, Montreal, QC, H3A 1A3, Canada
| | - Negar Tabatabaei
- Department of Pharmacology and Regenerative Medicine, University of Illinois College of Medicine, Chicago, IL, 60612
| | - Catherine R. Dufour
- Rosalind and Morris Goodman Cancer Institute, McGill University, Montreal, QC, H3A 1A3, Canada
| | - Seung Hyeon Kim
- Department of Pharmacology and Regenerative Medicine, University of Illinois College of Medicine, Chicago, IL, 60612
| | - Carine Fillebeen
- Lady Davis Institute for Medical Research, Jewish General Hospital and Department of Medicine, McGill University, Montreal, QC, H3T 1E2, Canada
| | - Charles E. Ayemoba
- Department of Pharmacology and Regenerative Medicine, University of Illinois College of Medicine, Chicago, IL, 60612
| | - Arkady Khoutorsky
- Department of Anesthesia and Faculty of Dentistry, McGill University, Montreal, QC, H3A 0G1, Canada
| | - Manfred Nairz
- Department of Internal Medicine II, Medical University of Innsbruck, Innsbruck, 6020, Austria
| | - Lijian Shao
- Department of Pharmacology and Regenerative Medicine, University of Illinois College of Medicine, Chicago, IL, 60612
| | - Kostandin V. Pajcini
- Department of Pharmacology and Regenerative Medicine, University of Illinois College of Medicine, Chicago, IL, 60612
| | - Ki-Wook Kim
- Department of Pharmacology and Regenerative Medicine, University of Illinois College of Medicine, Chicago, IL, 60612
| | - Vincent Giguère
- Department of Biochemistry, McGill University, Montreal, QC, H3A 1A3, Canada
- Rosalind and Morris Goodman Cancer Institute, McGill University, Montreal, QC, H3A 1A3, Canada
| | - Regiana L. Oliveira
- Department of Anatomy and Cell Biology, McGill University, Montreal, QC, H3G 1Y6, Canada
| | - Marco Constante
- Nutrition and Microbiome Laboratory, Centre de recherche du CHUM and Department of Medicine, Université de Montréal, Montréal, QC, H3X 0A9, Canada
| | - Manuela M. Santos
- Nutrition and Microbiome Laboratory, Centre de recherche du CHUM and Department of Medicine, Université de Montréal, Montréal, QC, H3X 0A9, Canada
| | - Carlos R. Morales
- Department of Anatomy and Cell Biology, McGill University, Montreal, QC, H3G 1Y6, Canada
| | - Kostas Pantopoulos
- Lady Davis Institute for Medical Research, Jewish General Hospital and Department of Medicine, McGill University, Montreal, QC, H3T 1E2, Canada
| | - Nahum Sonenberg
- Department of Biochemistry, McGill University, Montreal, QC, H3A 1A3, Canada
- Rosalind and Morris Goodman Cancer Institute, McGill University, Montreal, QC, H3A 1A3, Canada
| | - Sandra Pinho
- Department of Pharmacology and Regenerative Medicine, University of Illinois College of Medicine, Chicago, IL, 60612
| | - Soroush Tahmasebi
- Department of Pharmacology and Regenerative Medicine, University of Illinois College of Medicine, Chicago, IL, 60612
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46
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Roman-Trufero M, Auner HW, Edwards CM. Multiple myeloma metabolism - a treasure trove of therapeutic targets? Front Immunol 2022; 13:897862. [PMID: 36072593 PMCID: PMC9441940 DOI: 10.3389/fimmu.2022.897862] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Accepted: 07/18/2022] [Indexed: 11/16/2022] Open
Abstract
Multiple myeloma is an incurable cancer of plasma cells that is predominantly located in the bone marrow. Multiple myeloma cells are characterized by distinctive biological features that are intricately linked to their core function, the assembly and secretion of large amounts of antibodies, and their diverse interactions with the bone marrow microenvironment. Here, we provide a concise and introductory discussion of major metabolic hallmarks of plasma cells and myeloma cells, their roles in myeloma development and progression, and how they could be exploited for therapeutic purposes. We review the role of glucose consumption and catabolism, assess the dependency on glutamine to support key metabolic processes, and consider metabolic adaptations in drug-resistant myeloma cells. Finally, we examine the complex metabolic effects of proteasome inhibitors on myeloma cells and the extracellular matrix, and we explore the complex relationship between myeloma cells and bone marrow adipocytes.
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Affiliation(s)
- Monica Roman-Trufero
- Department of Immunology and Inflammation, Cancer Cell Protein Metabolism, The Hugh and Josseline Langmuir Centre for Myeloma Research, Centre for Haematology, Imperial College London, London, United Kingdom
| | - Holger W. Auner
- Department of Immunology and Inflammation, Cancer Cell Protein Metabolism, The Hugh and Josseline Langmuir Centre for Myeloma Research, Centre for Haematology, Imperial College London, London, United Kingdom
| | - Claire M. Edwards
- Nuffield Department of Surgical Sciences, University of Oxford, Oxford, United Kingdom
- Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, United Kingdom
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47
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Farooq Z, Kusuma F, Burke P, Dufour CR, Lee D, Tabatabaei N, Toboz P, Radovani E, Greenblatt J, Rehman J, Class J, Khoutorsky A, Fonseca BD, Richner JM, Mercier E, Bourque G, Giguère V, Subramaniam AR, Han J, Tahmasebi S. The amino acid sensor GCN2 suppresses Terminal Oligopyrimidine (TOP) mRNA translation via La-related Protein 1 (LARP1). J Biol Chem 2022; 298:102277. [PMID: 35863436 PMCID: PMC9396407 DOI: 10.1016/j.jbc.2022.102277] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Revised: 07/10/2022] [Accepted: 07/11/2022] [Indexed: 11/16/2022] Open
Abstract
La-related protein 1 (LARP1) has been identified as a key translational inhibitor of terminal oligopyrimidine (TOP) mRNAs downstream of the nutrient sensing protein kinase complex, mTORC1. LARP1 exerts this inhibitory effect on TOP mRNA translation by binding to the mRNA cap and the adjacent 5′TOP motif, resulting in the displacement of the cap-binding protein eIF4E from TOP mRNAs. However, the involvement of additional signaling pathway in regulating LARP1-mediated inhibition of TOP mRNA translation is largely unexplored. In the present study, we identify a second nutrient sensing kinase GCN2 that converges on LARP1 to control TOP mRNA translation. Using chromatin-immunoprecipitation followed by massive parallel sequencing (ChIP-seq) analysis of activating transcription factor 4 (ATF4), an effector of GCN2 in nutrient stress conditions, in WT and GCN2 KO mouse embryonic fibroblasts, we determined that LARP1 is a GCN2-dependent transcriptional target of ATF4. Moreover, we identified GCN1, a GCN2 activator, participates in a complex with LARP1 on stalled ribosomes, suggesting a role for GCN1 in LARP1-mediated translation inhibition in response to ribosome stalling. Therefore, our data suggest that the GCN2 pathway controls LARP1 activity via two mechanisms: ATF4-dependent transcriptional induction of LARP1 mRNA and GCN1-mediated recruitment of LARP1 to stalled ribosomes.
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Affiliation(s)
- Zeenat Farooq
- Department of Pharmacology and Regenerative Medicine, University of Illinois College of Medicine, Chicago, IL, USA
| | - Fedho Kusuma
- Soonchunhyang Institute of Medi-bio Science (SIMS), Soonchunhyang University, Cheonan-si, Chungcheongnam-do 31151, Korea
| | - Phillip Burke
- Basic Sciences Division and Computational Biology Section of the Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Catherine R Dufour
- Goodman Cancer Research Centre, McGill University, Montréal, QC, H3A 1A3, Canada
| | - Duckgue Lee
- Soonchunhyang Institute of Medi-bio Science (SIMS), Soonchunhyang University, Cheonan-si, Chungcheongnam-do 31151, Korea
| | - Negar Tabatabaei
- Department of Pharmacology and Regenerative Medicine, University of Illinois College of Medicine, Chicago, IL, USA
| | - Phoenix Toboz
- Department of Pharmacology and Regenerative Medicine, University of Illinois College of Medicine, Chicago, IL, USA
| | - Ernest Radovani
- Donnelly Centre, University of Toronto, Toronto, ON M5S 3E1, Canada
| | - Jack Greenblatt
- Donnelly Centre, University of Toronto, Toronto, ON M5S 3E1, Canada
| | - Jalees Rehman
- Department of Pharmacology and Regenerative Medicine, University of Illinois College of Medicine, Chicago, IL, USA
| | - Jacob Class
- Department of Microbiology and Immunology, University of Illinois College of Medicine, Chicago, IL, USA
| | - Arkady Khoutorsky
- Department of Anesthesia and Faculty of Dentistry, McGill University, Montreal, QC H3A 0G1, Canada
| | | | - Justin M Richner
- Department of Microbiology and Immunology, University of Illinois College of Medicine, Chicago, IL, USA
| | - Eloi Mercier
- Canadian Centre for Computational Genomics, and McGill University and Genome Québec Innovation Center, Montréal, QC H3A 0G1, Canada
| | - Guillaume Bourque
- Canadian Centre for Computational Genomics, and McGill University and Genome Québec Innovation Center, Montréal, QC H3A 0G1, Canada
| | - Vincent Giguère
- Goodman Cancer Research Centre, McGill University, Montréal, QC, H3A 1A3, Canada
| | - Arvind R Subramaniam
- Basic Sciences Division and Computational Biology Section of the Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Jaeseok Han
- Soonchunhyang Institute of Medi-bio Science (SIMS), Soonchunhyang University, Cheonan-si, Chungcheongnam-do 31151, Korea.
| | - Soroush Tahmasebi
- Department of Pharmacology and Regenerative Medicine, University of Illinois College of Medicine, Chicago, IL, USA.
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48
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Srivastava A, Lu J, Gadalla DS, Hendrich O, Grönke S, Partridge L. The Role of GCN2 Kinase in Mediating the Effects of Amino Acids on Longevity and Feeding Behaviour in Drosophila. FRONTIERS IN AGING 2022; 3:944466. [PMID: 35821827 PMCID: PMC9261369 DOI: 10.3389/fragi.2022.944466] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/15/2022] [Accepted: 05/30/2022] [Indexed: 02/03/2023]
Abstract
Restriction of amino acids in the diet can extend lifespan in diverse species ranging from flies to mammals. However, the role of individual amino acids and the underlying molecular mechanisms are only partially understood. The evolutionarily conserved serine/threonine kinase General Control Nonderepressible 2 (GCN2) is a key sensor of amino acid deficiency and has been implicated in the response of lifespan to dietary restriction (DR). Here, we generated a novel Drosophila GCN2 null mutant and analyzed its response to individual amino acid deficiency. We show that GCN2 function is essential for fly development, longevity and feeding behaviour under long-term, but not short-term, deprivation of all individual essential amino acids (EAAs) except for methionine. GCN2 mutants were longer-lived than control flies and showed normal feeding behaviour under methionine restriction. Thus, in flies at least two systems regulate these responses to amino acid deprivation. Methionine deprivation acts via a GCN2-independent mechanism, while all other EAA are sensed by GCN2. Combined deficiency of methionine and a second EAA blocked the response of GCN2 mutants to methionine, suggesting that these two pathways are interconnected. Wild type flies showed a short-term rejection of food lacking individual EAA, followed by a long-term compensatory increase in food uptake. GCN2 mutants also showed a short-term rejection of food deprived of individual EAA, but were unable to mount the compensatory long-term increase in food uptake. Over-expression of the downstream transcription factor ATF4 partially rescued the response of feeding behaviour in GCN2 mutants to amino acid deficiency. Phenotypes of GCN2 mutants induced by leucine and tryptophan, but not isoleucine, deficiency were partially rescued by ATF4 over-expression. The exact function of GCN2 as an amino acid sensor in vivo and the downstream action of its transcription factor effector ATF4 are thus context-specific with respect to the EAA involved.
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Affiliation(s)
| | - Jiongming Lu
- Max Planck Institute for Biology of Ageing, Cologne, Germany
| | | | - Oliver Hendrich
- Max Planck Institute for Biology of Ageing, Cologne, Germany
| | | | - Linda Partridge
- Max Planck Institute for Biology of Ageing, Cologne, Germany.,Department of Genetics, Evolution and Environment, Institute of Healthy Ageing, University College London, London, United Kingdom
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49
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Lokdarshi A, von Arnim AG. Review: Emerging roles of the signaling network of the protein kinase GCN2 in the plant stress response. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2022; 320:111280. [PMID: 35643606 PMCID: PMC9197246 DOI: 10.1016/j.plantsci.2022.111280] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Revised: 03/07/2022] [Accepted: 03/30/2022] [Indexed: 06/15/2023]
Abstract
The pan-eukaryotic protein kinase GCN2 (General Control Nonderepressible2) regulates the translation of mRNAs in response to external and metabolic conditions. Although GCN2 and its substrate, translation initiation factor 2 (eIF2) α, and several partner proteins are substantially conserved in plants, this kinase has assumed novel functions in plants, including in innate immunity and retrograde signaling between the chloroplast and cytosol. How exactly some of the biochemical paradigms of the GCN2 system have diverged in the green plant lineage is only partially resolved. Specifically, conflicting data underscore and cast doubt on whether GCN2 regulates amino acid biosynthesis; also whether phosphorylation of eIF2α can in fact repress global translation or activate mRNA specific translation via upstream open reading frames; and whether GCN2 is controlled in vivo by the level of uncharged tRNA. This review examines the status of research on the eIF2α kinase, GCN2, its function in the response to xenobiotics, pathogens, and abiotic stress conditions, and its rather tenuous role in the translational control of mRNAs.
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Affiliation(s)
- Ansul Lokdarshi
- Department of Biology, Valdosta State University, Valdosta, GA 31698, USA.
| | - Albrecht G von Arnim
- Department of Biochemistry & Cellular and Molecular Biology, The University of Tennessee, Knoxville, TN 37996-1939, USA; UT-ORNL Graduate School of Genome Science and Technology, The University of Tennessee, Knoxville, TN 37996-1939, USA.
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50
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Kosakamoto H, Okamoto N, Aikawa H, Sugiura Y, Suematsu M, Niwa R, Miura M, Obata F. Sensing of the non-essential amino acid tyrosine governs the response to protein restriction in Drosophila. Nat Metab 2022; 4:944-959. [PMID: 35879463 DOI: 10.1038/s42255-022-00608-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Accepted: 06/15/2022] [Indexed: 11/08/2022]
Abstract
The intake of dietary protein regulates growth, metabolism, fecundity and lifespan across various species, which makes amino acid (AA)-sensing vital for adaptation to the nutritional environment. The general control nonderepressible 2 (GCN2)-activating transcription factor 4 (ATF4) pathway and the mechanistic target of rapamycin complex 1 (mTORC1) pathway are involved in AA-sensing. However, it is not fully understood which AAs regulate these two pathways in living animals and how they coordinate responses to protein restriction. Here we show in Drosophila that the non-essential AA tyrosine (Tyr) is a nutritional cue in the fat body necessary and sufficient for promoting adaptive responses to a low-protein diet, which entails reduction of protein synthesis and mTORC1 activity and increased food intake. This adaptation is regulated by dietary Tyr through GCN2-independent induction of ATF4 target genes in the fat body. This study identifies the Tyr-ATF4 axis as a regulator of the physiological response to a low-protein diet and sheds light on the essential function of a non-essential nutrient.
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Affiliation(s)
- Hina Kosakamoto
- Department of Genetics, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
- RIKEN Center for Biosystems and Dynamics Research, Kobe, Japan
- Life Science Center for Survival Dynamics, Tsukuba Advanced Research Alliance (TARA), University of Tsukuba, Tsukuba, Japan
| | - Naoki Okamoto
- Life Science Center for Survival Dynamics, Tsukuba Advanced Research Alliance (TARA), University of Tsukuba, Tsukuba, Japan
| | - Hide Aikawa
- Department of Genetics, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Yuki Sugiura
- Department of Biochemistry, Keio University School of Medicine, Shinjuku-ku, Tokyo, Japan
| | - Makoto Suematsu
- Department of Biochemistry, Keio University School of Medicine, Shinjuku-ku, Tokyo, Japan
| | - Ryusuke Niwa
- Life Science Center for Survival Dynamics, Tsukuba Advanced Research Alliance (TARA), University of Tsukuba, Tsukuba, Japan
| | - Masayuki Miura
- Department of Genetics, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Fumiaki Obata
- Department of Genetics, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan.
- RIKEN Center for Biosystems and Dynamics Research, Kobe, Japan.
- Life Science Center for Survival Dynamics, Tsukuba Advanced Research Alliance (TARA), University of Tsukuba, Tsukuba, Japan.
- Laboratory of Molecular Cell Biology and Development, Graduate School of Biostudies, Kyoto University, Kyoto, Japan.
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