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Liu C, Yu M, Wang M, Yang S, Fu Y, Zhang L, Zhu C, Zhang H. PCAF-mediated acetylation of METTL3 impairs mRNA translation efficiency in response to oxidative stress. SCIENCE CHINA. LIFE SCIENCES 2024:10.1007/s11427-023-2535-x. [PMID: 39096338 DOI: 10.1007/s11427-023-2535-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 01/08/2024] [Accepted: 08/01/2024] [Indexed: 08/05/2024]
Abstract
METTL3 methylates RNA and regulates the fate of mRNA through its methyltransferase activity. METTL3 enhances RNA translation independently of its catalytic activity. However, the underlying mechanism is still elusive. Here, we report that METTL3 is both interacted with and acetylated at lysine 177 by the acetyltransferase PCAF and deacetylated by SIRT3. Neither the methyltransferase activity nor the stability of METTL3 is affected by its acetylation at K177. Importantly, acetylation of METTL3 blocks its interaction with EIF3H, a subunit of the translation initiation factor, thereby reducing mRNA translation efficiency. Interestingly, acetylation of METTL3 responds to oxidative stress. Mechanistically, oxidative stress enhances the interaction of PCAF with METTL3, increases METTL3 acetylation, and suppresses the interaction of METTL3 with EIF3H, thereby decreasing the translation efficiency of ribosomes and inhibiting cell proliferation. Altogether, we suggest a mechanism by which oxidative stress regulates RNA translation efficiency by the modulation of METTL3 acetylation mediated by PCAF.
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Affiliation(s)
- Cheng Liu
- Program for Cancer and Cell Biology, Department of Human Anatomy, Histology and Embryology, School of Basic Medical Sciences, Peking University International Cancer Institute, and State Key Laboratory of Molecular Oncology, Peking University Health Science Center, Beijing, 100191, China
| | - Miao Yu
- Program for Cancer and Cell Biology, Department of Human Anatomy, Histology and Embryology, School of Basic Medical Sciences, Peking University International Cancer Institute, and State Key Laboratory of Molecular Oncology, Peking University Health Science Center, Beijing, 100191, China
| | - Mengyuan Wang
- Program for Cancer and Cell Biology, Department of Human Anatomy, Histology and Embryology, School of Basic Medical Sciences, Peking University International Cancer Institute, and State Key Laboratory of Molecular Oncology, Peking University Health Science Center, Beijing, 100191, China
| | - Siyuan Yang
- Program for Cancer and Cell Biology, Department of Human Anatomy, Histology and Embryology, School of Basic Medical Sciences, Peking University International Cancer Institute, and State Key Laboratory of Molecular Oncology, Peking University Health Science Center, Beijing, 100191, China
| | - Yenan Fu
- Program for Cancer and Cell Biology, Department of Human Anatomy, Histology and Embryology, School of Basic Medical Sciences, Peking University International Cancer Institute, and State Key Laboratory of Molecular Oncology, Peking University Health Science Center, Beijing, 100191, China
| | - Lei Zhang
- Program for Cancer and Cell Biology, Department of Human Anatomy, Histology and Embryology, School of Basic Medical Sciences, Peking University International Cancer Institute, and State Key Laboratory of Molecular Oncology, Peking University Health Science Center, Beijing, 100191, China
| | - Chaoyang Zhu
- Department of General Surgery and Urological Surgery, Huaihe Hospital, Henan University, Kaifeng, 100084, China.
| | - Hongquan Zhang
- Program for Cancer and Cell Biology, Department of Human Anatomy, Histology and Embryology, School of Basic Medical Sciences, Peking University International Cancer Institute, and State Key Laboratory of Molecular Oncology, Peking University Health Science Center, Beijing, 100191, China.
- Department of Human Anatomy, Histology, and Embryology, Shenzhen University School of Medicine, Shenzhen, 518055, China.
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Tang M, Xia W, Song F, Liu C, Wang X, Zhou H, Mai K, He G. Loss of Gcn2 exacerbates gossypol induced oxidative stress, apoptosis and inflammation in zebrafish. FISH & SHELLFISH IMMUNOLOGY 2024; 151:109727. [PMID: 38936520 DOI: 10.1016/j.fsi.2024.109727] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2024] [Revised: 06/22/2024] [Accepted: 06/24/2024] [Indexed: 06/29/2024]
Abstract
Gossypol, a naturally occurring compound found in cottonseed meal, shows promising therapeutic potential for human diseases. However, within the aquaculture industry, it is considered an antinutritional factor. The incorporation of cottonseed meal into fish feed introduces gossypol, which induces intracellular stresses and hinders overall health of farmed fish. The aim of this study is to determine the role of General control nonderepressible 2 (gcn2), a sensor for intracellular stresses in gossypol-induced stress responses in fish. In the present study, we established two gcn2 knockout zebrafish lines. A feeding trial was conducted to assess the growth-inhibitory effect of gossypol in both wild type and gcn2 knockout zebrafish. The results showed that in the absence of gcn2, zebrafish exhibited increased oxidative stress and apoptosis when exposed to gossypol, resulting in higher mortality rates. In feeding trial, dietary gossypol intensified liver inflammation in gcn2-/- zebrafish, diminishing their growth and feed conversion. Remarkably, administering the antioxidant N-acetylcysteine (NAC) was effective in reversing the gossypol induced oxidative stress and apoptosis, thereby increasing the gossypol tolerance of gcn2-/- zebrafish. Exposure to gossypol induces more severe mitochondrial stress in gcn2-/- zebrafish, thereby inducing metabolic disorders. These results reveal that gcn2 plays a protective role in reducing gossypol-induced oxidative stress and apoptosis, attenuating inflammation responses, and enhancing the survivability of zebrafish in gossypol-challenged conditions. Therefore, maintaining appropriate activation of Gcn2 may be beneficial for fish fed diets containing gossypol.
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Affiliation(s)
- Mingjun Tang
- Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao, 266003, China; Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266003, China
| | - Weiyi Xia
- Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao, 266003, China; Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266003, China
| | - Fei Song
- School of Life Sciences, South China Normal University, Guangzhou, 510631, China
| | - Chengdong Liu
- Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao, 266003, China; Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266003, China.
| | - Xuan Wang
- Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao, 266003, China; Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266003, China
| | - Huihui Zhou
- Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao, 266003, China; Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266003, China
| | - Kangsen Mai
- Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao, 266003, China; Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266003, China
| | - Gen He
- Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao, 266003, China; Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266003, China; Key Laboratory of Aquaculture Nutrition and Feeds, Ministry of Agriculture, Ocean University of China, Qingdao, 266003, China
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3
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Sinha NK, McKenney C, Yeow ZY, Li JJ, Nam KH, Yaron-Barir TM, Johnson JL, Huntsman EM, Cantley LC, Ordureau A, Regot S, Green R. The ribotoxic stress response drives UV-mediated cell death. Cell 2024; 187:3652-3670.e40. [PMID: 38843833 PMCID: PMC11246228 DOI: 10.1016/j.cell.2024.05.018] [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: 08/03/2023] [Revised: 03/03/2024] [Accepted: 05/09/2024] [Indexed: 06/13/2024]
Abstract
While ultraviolet (UV) radiation damages DNA, eliciting the DNA damage response (DDR), it also damages RNA, triggering transcriptome-wide ribosomal collisions and eliciting a ribotoxic stress response (RSR). However, the relative contributions, timing, and regulation of these pathways in determining cell fate is unclear. Here we use time-resolved phosphoproteomic, chemical-genetic, single-cell imaging, and biochemical approaches to create a chronological atlas of signaling events activated in cells responding to UV damage. We discover that UV-induced apoptosis is mediated by the RSR kinase ZAK and not through the DDR. We identify two negative-feedback modules that regulate ZAK-mediated apoptosis: (1) GCN2 activation limits ribosomal collisions and attenuates ZAK-mediated RSR and (2) ZAK activity leads to phosphodegron autophosphorylation and its subsequent degradation. These events tune ZAK's activity to collision levels to establish regimes of homeostasis, tolerance, and death, revealing its key role as the cellular sentinel for nucleic acid damage.
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Affiliation(s)
- Niladri K Sinha
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA
| | - Connor McKenney
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Biochemistry, Cellular and Molecular Biology Graduate Program, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Zhong Y Yeow
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Jeffrey J Li
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Ki Hong Nam
- Cell Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Tomer M Yaron-Barir
- Meyer Cancer Center, Weill Cornell Medicine, New York, NY 10021, USA; Englander Institute for Precision Medicine, Institute for Computational Biomedicine, Weill Cornell Medicine, New York, NY 10021, USA; Columbia University Vagelos College of Physicians and Surgeons, New York, NY 10032, USA
| | - Jared L Johnson
- Meyer Cancer Center, Weill Cornell Medicine, New York, NY 10021, USA; Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA; Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02215, USA
| | - Emily M Huntsman
- Meyer Cancer Center, Weill Cornell Medicine, New York, NY 10021, USA
| | - Lewis C Cantley
- Meyer Cancer Center, Weill Cornell Medicine, New York, NY 10021, USA; Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA; Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02215, USA
| | - Alban Ordureau
- Cell Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA.
| | - Sergi Regot
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
| | - Rachel Green
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA.
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4
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Lu HJ, Koju N, Sheng R. Mammalian integrated stress responses in stressed organelles and their functions. Acta Pharmacol Sin 2024; 45:1095-1114. [PMID: 38267546 PMCID: PMC11130345 DOI: 10.1038/s41401-023-01225-0] [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: 06/29/2023] [Accepted: 12/30/2023] [Indexed: 01/26/2024] Open
Abstract
The integrated stress response (ISR) triggered in response to various cellular stress enables mammalian cells to effectively cope with diverse stressful conditions while maintaining their normal functions. Four kinases (PERK, PKR, GCN2, and HRI) of ISR regulate ISR signaling and intracellular protein translation via mediating the phosphorylation of eukaryotic translation initiation factor 2 α (eIF2α) at Ser51. Early ISR creates an opportunity for cells to repair themselves and restore homeostasis. This effect, however, is reversed in the late stages of ISR. Currently, some studies have shown the non-negligible impact of ISR on diseases such as ischemic diseases, cognitive impairment, metabolic syndrome, cancer, vanishing white matter, etc. Hence, artificial regulation of ISR and its signaling with ISR modulators becomes a promising therapeutic strategy for relieving disease symptoms and improving clinical outcomes. Here, we provide an overview of the essential mechanisms of ISR and describe the ISR-related pathways in organelles including mitochondria, endoplasmic reticulum, Golgi apparatus, and lysosomes. Meanwhile, the regulatory effects of ISR modulators and their potential application in various diseases are also enumerated.
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Affiliation(s)
- Hao-Jun Lu
- Department of Pharmacology and Laboratory of Aging and Nervous Diseases, Jiangsu Key Laboratory of Neuropsychiatric Diseases, College of Pharmaceutical Sciences of Soochow University, Suzhou, 215123, China
| | - Nirmala Koju
- Department of Pharmacology and Laboratory of Aging and Nervous Diseases, Jiangsu Key Laboratory of Neuropsychiatric Diseases, College of Pharmaceutical Sciences of Soochow University, Suzhou, 215123, China
| | - Rui Sheng
- Department of Pharmacology and Laboratory of Aging and Nervous Diseases, Jiangsu Key Laboratory of Neuropsychiatric Diseases, College of Pharmaceutical Sciences of Soochow University, Suzhou, 215123, China.
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5
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Ferruzo PYM, Boell VK, Russo LC, Oliveira CC, Forti FL. DUSP3 modulates IRES-dependent translation of mRNAs through dephosphorylation of the HNRNPC protein in cells under genotoxic stimulus. Biol Cell 2024; 116:e2300128. [PMID: 38538536 DOI: 10.1111/boc.202300128] [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: 03/02/2024] [Accepted: 03/06/2024] [Indexed: 05/09/2024]
Abstract
BACKGROUND INFORMATION The dual-specificity phosphatase 3 (DUSP3) regulates cell cycle progression, proliferation, senescence, and DNA repair pathways under genotoxic stress. This phosphatase interacts with HNRNPC protein suggesting an involvement in the regulation of HNRNPC-ribonucleoprotein complex stability. In this work, we investigate the impact of DUSP3 depletion on functions of HNRNPC aiming to suggest new roles for this enzyme. RESULTS The DUSP3 knockdown results in the tyrosine hyperphosphorylation state of HNRNPC increasing its RNA binding ability. HNRNPC is present in the cytoplasm where it interacts with IRES trans-acting factors (ITAF) complex, which recruits the 40S ribosome on mRNA during protein synthesis, thus facilitating the translation of mRNAs containing IRES sequence in response to specific stimuli. In accordance with that, we found that DUSP3 is present in the 40S, monosomes and polysomes interacting with HNRNPC, just like other previously identified DUSP3 substrates/interacting partners such as PABP and NCL proteins. By downregulating DUSP3, Tyr-phosphorylated HNRNPC preferentially binds to IRES-containing mRNAs within ITAF complexes preferentially in synchronized or stressed cells, as evidenced by the higher levels of proteins such as c-MYC and XIAP, but not their mRNAs such as measured by qPCR. Under DUSP3 absence, this increased phosphorylated-HNRNPC/RNA interaction reduces HNRNPC-p53 binding in presence of RNAs releasing p53 for specialized cellular responses. Similarly, to HNRNPC, PABP physically interacts with DUSP3 in an RNA-dependent manner. CONCLUSIONS AND SIGNIFICANCE Overall, DUSP3 can modulate cellular responses to genotoxic stimuli at the translational level by maintaining the stability of HNRNPC-ITAF complexes and regulating the intensity and specificity of RNA interactions with RRM-domain proteins.
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Affiliation(s)
- Pault Y M Ferruzo
- Laboratory of Signaling in Biomolecular Systems, Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo, Brazil
| | - Viktor K Boell
- Laboratory of Signaling in Biomolecular Systems, Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo, Brazil
| | - Lilian C Russo
- Laboratory of Genome Instability, Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo, Brazil
| | - Carla C Oliveira
- Laboratory of Post-transcriptional Control of Gene Expression, Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo, Brazil
| | - Fabio L Forti
- Laboratory of Signaling in Biomolecular Systems, Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo, Brazil
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6
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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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7
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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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8
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Podmanicky O, Gao F, Munro B, Jennings MJ, Boczonadi V, Hathazi D, Mueller JS, Horvath R. Mitochondrial aminoacyl-tRNA synthetases trigger unique compensatory mechanisms in neurons. Hum Mol Genet 2024; 33:435-447. [PMID: 37975900 PMCID: PMC10877469 DOI: 10.1093/hmg/ddad196] [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: 08/10/2023] [Revised: 10/05/2023] [Accepted: 11/10/2023] [Indexed: 11/19/2023] Open
Abstract
Mitochondrial aminoacyl-tRNA synthetase (mt-ARS) mutations cause severe, progressive, and often lethal diseases with highly heterogeneous and tissue-specific clinical manifestations. This study investigates the molecular mechanisms triggered by three different mt-ARS defects caused by biallelic mutations in AARS2, EARS2, and RARS2, using an in vitro model of human neuronal cells. We report distinct molecular mechanisms of mitochondrial dysfunction among the mt-ARS defects studied. Our findings highlight the ability of proliferating neuronal progenitor cells (iNPCs) to compensate for mitochondrial translation defects and maintain balanced levels of oxidative phosphorylation (OXPHOS) components, which becomes more challenging in mature neurons. Mutant iNPCs exhibit unique compensatory mechanisms, involving specific branches of the integrated stress response, which may be gene-specific or related to the severity of the mitochondrial translation defect. RNA sequencing revealed distinct transcriptomic profiles showing dysregulation of neuronal differentiation and protein translation. This study provides valuable insights into the tissue-specific compensatory mechanisms potentially underlying the phenotypes of patients with mt-ARS defects. Our novel in vitro model may more accurately represent the neurological presentation of patients and offer an improved platform for future investigations and therapeutic development.
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Affiliation(s)
- Oliver Podmanicky
- Department of Clinical Neurosciences, John Van Geest Centre for Brain Repair, University of Cambridge, Ed Adrian Building, Robinson Way, Cambridge, CB2 0PY, United Kingdom
| | - Fei Gao
- Department of Clinical Neurosciences, John Van Geest Centre for Brain Repair, University of Cambridge, Ed Adrian Building, Robinson Way, Cambridge, CB2 0PY, United Kingdom
| | - Benjamin Munro
- Department of Clinical Neurosciences, John Van Geest Centre for Brain Repair, University of Cambridge, Ed Adrian Building, Robinson Way, Cambridge, CB2 0PY, United Kingdom
| | - Matthew J Jennings
- Department of Clinical Neurosciences, John Van Geest Centre for Brain Repair, University of Cambridge, Ed Adrian Building, Robinson Way, Cambridge, CB2 0PY, United Kingdom
- Department of Neurology, Columbia University, 630 West 168 St, New York, NY 10032, United States
| | - Veronika Boczonadi
- Biosciences Institute, International Centre for Life, Faculty of Medical Sciences, Newcastle University, Central Parkway, Newcastle upon Tyne, NE1 3BZ, United Kingdom
| | - Denisa Hathazi
- Department of Clinical Neurosciences, John Van Geest Centre for Brain Repair, University of Cambridge, Ed Adrian Building, Robinson Way, Cambridge, CB2 0PY, United Kingdom
| | - Juliane S Mueller
- Department of Clinical Neurosciences, John Van Geest Centre for Brain Repair, University of Cambridge, Ed Adrian Building, Robinson Way, Cambridge, CB2 0PY, United Kingdom
- Dubowitz Neuromuscular Centre, Department of Neuropathology, Institute of Neurology, Queen Square, London, WC1N 3BG, United Kingdom
| | - Rita Horvath
- Department of Clinical Neurosciences, John Van Geest Centre for Brain Repair, University of Cambridge, Ed Adrian Building, Robinson Way, Cambridge, CB2 0PY, United Kingdom
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9
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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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10
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Boone M, Zappa F. Signaling plasticity in the integrated stress response. Front Cell Dev Biol 2023; 11:1271141. [PMID: 38143923 PMCID: PMC10740175 DOI: 10.3389/fcell.2023.1271141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Accepted: 11/29/2023] [Indexed: 12/26/2023] Open
Abstract
The Integrated Stress Response (ISR) is an essential homeostatic signaling network that controls the cell's biosynthetic capacity. Four ISR sensor kinases detect multiple stressors and relay this information to downstream effectors by phosphorylating a common node: the alpha subunit of the eukaryotic initiation factor eIF2. As a result, general protein synthesis is repressed while select transcripts are preferentially translated, thus remodeling the proteome and transcriptome. Mounting evidence supports a view of the ISR as a dynamic signaling network with multiple modulators and feedback regulatory features that vary across cell and tissue types. Here, we discuss updated views on ISR sensor kinase mechanisms, how the subcellular localization of ISR components impacts signaling, and highlight ISR signaling differences across cells and tissues. Finally, we consider crosstalk between the ISR and other signaling pathways as a determinant of cell health.
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11
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Abstract
Heat stress is described as the cumulative detrimental effect caused by an imbalance between heat production within the body and heat dissipation. When cattle are exposed to heat stress with skin surface temperatures exceeding 35 °C, gene networks within and across cells respond to environmental heat loads with both intra and extracellular signals that coordinate cellular and whole-animal metabolism changes to store heat and rapidly increase evaporative heat loss. In this study, we examined evidence from genes known to be associated with heat tolerance (Hsp70, HSF1, HspB8, SOD1, PRLH, ATP1A1, MTOR, and EIF2AK4). This information could serve as valuable resource material for breeding programs aimed at increasing the thermotolerance of cattle.
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Affiliation(s)
- LuLan Zeng
- College of Life Sciences, Northwest A&F University, Yangling, China
| | - Kaixing Qu
- Yunnan Academy of Grassland and Animal Science, Kunming, China
| | - Jicai Zhang
- Yunnan Academy of Grassland and Animal Science, Kunming, China
| | - Bizhi Huang
- Yunnan Academy of Grassland and Animal Science, Kunming, China
| | - Chuzhao Lei
- Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Yangling, China
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12
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van der Woude M, Davó-Martínez C, Thijssen K, Vermeulen W, Lans H. Recovery of protein synthesis to assay DNA repair activity in transcribed genes in living cells and tissues. Nucleic Acids Res 2023; 51:e93. [PMID: 37522336 PMCID: PMC10570043 DOI: 10.1093/nar/gkad642] [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: 01/24/2023] [Revised: 06/19/2023] [Accepted: 07/25/2023] [Indexed: 08/01/2023] Open
Abstract
Transcription-coupled nucleotide excision repair (TC-NER) is an important DNA repair mechanism that protects against the negative effects of transcription-blocking DNA lesions. Hereditary TC-NER deficiencies cause pleiotropic and often severe neurodegenerative and progeroid symptoms. While multiple assays have been developed to determine TC-NER activity for clinical and research purposes, monitoring TC-NER is hampered by the low frequency of repair events occurring in transcribed DNA. 'Recovery of RNA Synthesis' is widely used as indirect TC-NER assay based on the notion that lesion-blocked transcription only resumes after successful TC-NER. Here, we show that measuring novel synthesis of a protein after its compound-induced degradation prior to DNA damage induction is an equally effective but more versatile manner to indirectly monitor DNA repair activity in transcribed genes. This 'Recovery of Protein Synthesis' (RPS) assay can be adapted to various degradable proteins and readouts, including imaging and immunoblotting. Moreover, RPS allows real-time monitoring of TC-NER activity in various living cells types and even in differentiated tissues of living organisms. To illustrate its utility, we show that DNA repair in transcribed genes declines in aging muscle tissue of C. elegans. Therefore, the RPS assay constitutes an important novel clinical and research tool to investigate transcription-coupled DNA repair.
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Affiliation(s)
- Melanie van der Woude
- Department of Molecular Genetics, Erasmus MC Cancer Institute, Erasmus University Medical Center, 3015 GD, Rotterdam, The Netherlands
| | - Carlota Davó-Martínez
- Department of Molecular Genetics, Erasmus MC Cancer Institute, Erasmus University Medical Center, 3015 GD, Rotterdam, The Netherlands
| | - Karen L Thijssen
- Department of Molecular Genetics, Erasmus MC Cancer Institute, Erasmus University Medical Center, 3015 GD, Rotterdam, The Netherlands
| | - Wim Vermeulen
- Department of Molecular Genetics, Erasmus MC Cancer Institute, Erasmus University Medical Center, 3015 GD, Rotterdam, The Netherlands
| | - Hannes Lans
- Department of Molecular Genetics, Erasmus MC Cancer Institute, Erasmus University Medical Center, 3015 GD, Rotterdam, The Netherlands
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13
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Mukhopadhyay S, Amodeo ME, Lee ASY. eIF3d controls the persistent integrated stress response. Mol Cell 2023; 83:3303-3313.e6. [PMID: 37683648 PMCID: PMC10528100 DOI: 10.1016/j.molcel.2023.08.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 05/26/2023] [Accepted: 08/09/2023] [Indexed: 09/10/2023]
Abstract
Cells respond to intrinsic and extrinsic stresses by reducing global protein synthesis and activating gene programs necessary for survival. Here, we show that the integrated stress response (ISR) is driven by the non-canonical cap-binding protein eIF3d that acts as a critical effector to control core stress response orchestrators, the translation factor eIF2α and the transcription factor ATF4. We find that during persistent stress, eIF3d activates the translation of the kinase GCN2, inducing eIF2α phosphorylation and inhibiting general protein synthesis. In parallel, eIF3d upregulates the m6A demethylase ALKBH5 to drive 5' UTR-specific demethylation of stress response genes, including ATF4. Ultimately, this cascade converges on ATF4 expression by increasing mRNA engagement of translation machinery and enhancing ribosome bypass of upstream open reading frames (uORFs). Our results reveal that eIF3d acts in a life-or-death decision point during chronic stress and uncover a synergistic signaling mechanism in which translational cascades complement transcriptional amplification to control essential cellular processes.
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Affiliation(s)
- Shaoni Mukhopadhyay
- Department of Cell Biology, Harvard Medical School, Boston, MA 02215, USA; Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, MA 02215, USA
| | - Maria E Amodeo
- Department of Cell Biology, Harvard Medical School, Boston, MA 02215, USA; Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, MA 02215, USA
| | - Amy S Y Lee
- Department of Cell Biology, Harvard Medical School, Boston, MA 02215, USA; Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, MA 02215, USA.
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14
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Wang S, Sun S. Translation dysregulation in neurodegenerative diseases: a focus on ALS. Mol Neurodegener 2023; 18:58. [PMID: 37626421 PMCID: PMC10464328 DOI: 10.1186/s13024-023-00642-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Accepted: 07/21/2023] [Indexed: 08/27/2023] Open
Abstract
RNA translation is tightly controlled in eukaryotic cells to regulate gene expression and maintain proteome homeostasis. RNA binding proteins, translation factors, and cell signaling pathways all modulate the translation process. Defective translation is involved in multiple neurological diseases including amyotrophic lateral sclerosis (ALS). ALS is a progressive neurodegenerative disorder and poses a major public health challenge worldwide. Over the past few years, tremendous advances have been made in the understanding of the genetics and pathogenesis of ALS. Dysfunction of RNA metabolisms, including RNA translation, has been closely associated with ALS. Here, we first introduce the general mechanisms of translational regulation under physiological and stress conditions and review well-known examples of translation defects in neurodegenerative diseases. We then focus on ALS-linked genes and discuss the recent progress on how translation is affected by various mutant genes and the repeat expansion-mediated non-canonical translation in ALS.
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Affiliation(s)
- Shaopeng Wang
- Department of Physiology and Brain Science Institute, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Shuying Sun
- Department of Physiology and Brain Science Institute, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA.
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA.
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA.
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15
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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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16
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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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17
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Bahamondes Lorca VA, Wu S. Ultraviolet Light, Unfolded Protein Response and Autophagy †. Photochem Photobiol 2023; 99:498-508. [PMID: 36591940 DOI: 10.1111/php.13777] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Accepted: 12/22/2022] [Indexed: 01/03/2023]
Abstract
The endoplasmic reticulum (ER) plays an important role in the regulation of protein synthesis. Alterations in the folding capacity of the ER induce stress, which activates three ER sensors that mediate the unfolded protein response (UPR). Components of the pathways regulated by these sensors have been shown to regulate autophagy. The last corresponds to a mechanism of self-eating and recycling important for proper cell maintenance. Ultraviolet radiation (UV) is an external damaging stimulus that is known for inducing oxidative stress, and DNA, lipid and protein damage. Many controversies exist regarding the role of UV-inducing ER stress or autophagy. However, a connection between the three of them has not been addressed. In this review, we will discuss the contradictory theories regarding the relationships between UV radiation with the induction of ER stress and autophagy, as well as hypothetic connections between UV, ER stress and autophagy.
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Affiliation(s)
- Verónica A Bahamondes Lorca
- Edison Biotechnology Institute, Ohio University, Athens, OH.,Departamento de Tecnología Médica, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Shiyong Wu
- Edison Biotechnology Institute, Ohio University, Athens, OH.,Department of Chemistry and Biochemistry, Ohio University, Athens, OH
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18
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Brownsword MJ, Locker N. A little less aggregation a little more replication: Viral manipulation of stress granules. WILEY INTERDISCIPLINARY REVIEWS. RNA 2023; 14:e1741. [PMID: 35709333 PMCID: PMC10078398 DOI: 10.1002/wrna.1741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 04/29/2022] [Accepted: 05/05/2022] [Indexed: 01/31/2023]
Abstract
Recent exciting studies have uncovered how membrane-less organelles, also known as biocondensates, are providing cells with rapid response pathways, allowing them to re-organize their cellular contents and adapt to stressful conditions. Their assembly is driven by the phase separation of their RNAs and intrinsically disordered protein components into condensed foci. Among these, stress granules (SGs) are dynamic cytoplasmic biocondensates that form in response to many stresses, including activation of the integrated stress response or viral infections. SGs sit at the crossroads between antiviral signaling and translation because they concentrate signaling proteins and components of the innate immune response, in addition to translation machinery and stalled mRNAs. Consequently, they have been proposed to contribute to antiviral activities, and therefore are targeted by viral countermeasures. Equally, SGs components can be commandeered by viruses for their own efficient replication. Phase separation processes are an important component of the viral life cycle, for example, driving the assembly of replication factories or inclusion bodies. Therefore, in this review, we will outline the recent understanding of this complex interplay and tug of war between viruses, SGs, and their components. This article is categorized under: RNA in Disease and Development > RNA in Disease Translation > Regulation RNA Interactions with Proteins and Other Molecules > RNA-Protein Complexes.
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Affiliation(s)
- Matthew J. Brownsword
- Faculty of Health and Medical Sciences, School of Biosciences and MedicineUniversity of SurreyGuildfordSurreyUK
| | - Nicolas Locker
- Faculty of Health and Medical Sciences, School of Biosciences and MedicineUniversity of SurreyGuildfordSurreyUK
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19
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Urano Y, Osaki S, Chiba R, Noguchi N. Integrated stress response is involved in the 24(S)-hydroxycholesterol-induced unconventional cell death mechanism. Cell Death Dis 2022; 8:406. [PMID: 36195595 PMCID: PMC9532424 DOI: 10.1038/s41420-022-01197-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2022] [Revised: 09/14/2022] [Accepted: 09/21/2022] [Indexed: 01/11/2023]
Abstract
Perturbation of proteostasis triggers the adaptive responses that contribute to the homeostatic pro-survival response, whereas disruption of proteostasis can ultimately lead to cell death. Brain-specific oxysterol-i.e., 24(S)-hydroxycholesterol (24S-OHC)-has been shown to cause cytotoxicity when esterified by acyl-CoA:cholesterol acyltransferase 1 (ACAT1) in the endoplasmic reticulum (ER). Here, we show that the accumulation of 24S-OHC esters caused phosphorylation of eukaryotic translation initiator factor 2α (eIF2α), dissociation of polysomes, and formation of stress granules (SG), resulting in robust downregulation of global protein de novo synthesis in human neuroblastoma SH-SY5Y cells. We also found that integrated stress response (ISR) activation through PERK and GCN2 activation induced by 24S-OHC treatment caused eIF2α phosphorylation. 24S-OHC-inducible SG formation and cell death were suppressed by inhibition of ISR. These results show that ACAT1-mediated 24S-OHC esterification induced ISR and formation of SG, which play crucial roles in 24S-OHC-inducible protein synthesis inhibition and unconventional cell death.
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Affiliation(s)
- Yasuomi Urano
- Department of Medical Life Systems, Faculty of Life and Medical Sciences, Doshisha University, Kyoto, 610-0394, Japan.
| | - Shoya Osaki
- Department of Medical Life Systems, Faculty of Life and Medical Sciences, Doshisha University, Kyoto, 610-0394, Japan
| | - Ren Chiba
- Department of Medical Life Systems, Faculty of Life and Medical Sciences, Doshisha University, Kyoto, 610-0394, Japan
| | - Noriko Noguchi
- Department of Medical Life Systems, Faculty of Life and Medical Sciences, Doshisha University, Kyoto, 610-0394, Japan.
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20
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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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21
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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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22
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Krause LJ, Herrera MG, Winklhofer KF. The Role of Ubiquitin in Regulating Stress Granule Dynamics. Front Physiol 2022; 13:910759. [PMID: 35694405 PMCID: PMC9174786 DOI: 10.3389/fphys.2022.910759] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 05/09/2022] [Indexed: 11/30/2022] Open
Abstract
Stress granules (SGs) are dynamic, reversible biomolecular condensates, which assemble in the cytoplasm of eukaryotic cells under various stress conditions. Formation of SGs typically occurs upon stress-induced translational arrest and polysome disassembly. The increase in cytoplasmic mRNAs triggers the formation of a protein-RNA network that undergoes liquid-liquid phase separation when a critical interaction threshold has been reached. This adaptive stress response allows a transient shutdown of several cellular processes until the stress is removed. During the recovery from stress, SGs disassemble to re-establish cellular activities. Persistent stress and disease-related mutations in SG components favor the formation of aberrant SGs that are impaired in disassembly and prone to aggregation. Recently, posttranslational modifications of SG components have been identified as major regulators of SG dynamics. Here, we summarize new insights into the role of ubiquitination in affecting SG dynamics and clearance and discuss implications for neurodegenerative diseases linked to aberrant SG formation.
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Affiliation(s)
- Laura J. Krause
- Department of Molecular Cell Biology, Institute of Biochemistry and Pathobiochemistry, Ruhr University Bochum, Bochum, Germany
- RESOLV Cluster of Excellence, Ruhr University Bochum, Bochum, Germany
| | - Maria G. Herrera
- Department of Molecular Cell Biology, Institute of Biochemistry and Pathobiochemistry, Ruhr University Bochum, Bochum, Germany
| | - Konstanze F. Winklhofer
- Department of Molecular Cell Biology, Institute of Biochemistry and Pathobiochemistry, Ruhr University Bochum, Bochum, Germany
- RESOLV Cluster of Excellence, Ruhr University Bochum, Bochum, Germany
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23
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Hsu JCC, Laurent-Rolle M, Pawlak JB, Xia H, Kunte A, Hee JS, Lim J, Harris LD, Wood JM, Evans GB, Shi PY, Grove TL, Almo SC, Cresswell P. Viperin triggers ribosome collision-dependent translation inhibition to restrict viral replication. Mol Cell 2022; 82:1631-1642.e6. [PMID: 35316659 PMCID: PMC9081181 DOI: 10.1016/j.molcel.2022.02.031] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 01/06/2022] [Accepted: 02/23/2022] [Indexed: 12/31/2022]
Abstract
Innate immune responses induce hundreds of interferon-stimulated genes (ISGs). Viperin, a member of the radical S-adenosyl methionine (SAM) superfamily of enzymes, is the product of one such ISG that restricts the replication of a broad spectrum of viruses. Here, we report a previously unknown antiviral mechanism in which viperin activates a ribosome collision-dependent pathway that inhibits both cellular and viral RNA translation. We found that the radical SAM activity of viperin is required for translation inhibition and that this is mediated by viperin's enzymatic product, 3'-deoxy-3',4'-didehydro-CTP (ddhCTP). Viperin triggers ribosome collisions and activates the MAPKKK ZAK pathway that in turn activates the GCN2 arm of the integrated stress response pathway to inhibit translation. The study illustrates the importance of translational repression in the antiviral response and identifies viperin as a translation regulator in innate immunity.
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Affiliation(s)
- Jack Chun-Chieh Hsu
- Department of Immunobiology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Maudry Laurent-Rolle
- Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06520, USA; Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, CT 06520, USA
| | - Joanna B Pawlak
- Department of Immunobiology, Yale University School of Medicine, New Haven, CT 06520, USA; Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Hongjie Xia
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Amit Kunte
- Department of Immunobiology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Jia Shee Hee
- Department of Immunobiology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Jaechul Lim
- Department of Immunobiology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Lawrence D Harris
- The Ferrier Research Institute, Victoria University of Wellington, Wellington 6012, New Zealand; The Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland 1010, New Zealand
| | - James M Wood
- The Ferrier Research Institute, Victoria University of Wellington, Wellington 6012, New Zealand; The Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland 1010, New Zealand
| | - Gary B Evans
- The Ferrier Research Institute, Victoria University of Wellington, Wellington 6012, New Zealand; The Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland 1010, New Zealand
| | - Pei-Yong Shi
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555, USA; Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, TX 77555, USA; Sealy Institute for Vaccine Sciences, University of Texas Medical Branch, Galveston, TX 77555, USA; Sealy Institute for Drug Discovery, Galveston, TX 77555, USA
| | - Tyler L Grove
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Steven C Almo
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Peter Cresswell
- Department of Immunobiology, Yale University School of Medicine, New Haven, CT 06520, USA; Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06520, USA.
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24
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Berger CA, Ward CP, Karchner SI, Nelson RK, Reddy CM, Hahn ME, Tarrant AM. Nematostella vectensis exhibits an enhanced molecular stress response upon co-exposure to highly weathered oil and surface UV radiation. MARINE ENVIRONMENTAL RESEARCH 2022; 175:105569. [PMID: 35248985 DOI: 10.1016/j.marenvres.2022.105569] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 01/24/2022] [Accepted: 01/26/2022] [Indexed: 06/14/2023]
Abstract
Crude oil released into the environment undergoes weathering processes that gradually change its composition and toxicity. Co-exposure to petroleum mixtures and other stressors, including ultraviolet (UV) radiation, may lead to synergistic effects and increased toxicity. Laboratory studies should consider these factors when testing the effects of oil exposure on aquatic organisms. Here, we study transcriptomic responses of the estuarine sea anemone Nematostella vectensis to naturally weathered oil, with or without co-exposure to environmental levels of UV radiation. We find that co-exposure greatly enhances the response. We use bioinformatic analyses to identify molecular pathways implicated in this response, which suggest phototoxicity and oxidative damage as mechanisms for the enhanced stress response. Nematostella's stress response shares similarities with the vertebrate oxidative stress response, implying deep conservation of certain stress pathways in animals. We show that exposure to weathered oil along with surface-level UV exposure has substantial physiological consequences in a model cnidarian.
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Affiliation(s)
- Cory A Berger
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA, 02543, United States; MIT-WHOI Joint Program in Oceanography/Applied Ocean Science & Engineering, Cambridge and Woods Hole, MA, USA.
| | - Collin P Ward
- Department of Marine Chemistry & Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA, 02543, United States
| | - Sibel I Karchner
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA, 02543, United States
| | - Robert K Nelson
- Department of Marine Chemistry & Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA, 02543, United States
| | - Christopher M Reddy
- Department of Marine Chemistry & Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA, 02543, United States
| | - Mark E Hahn
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA, 02543, United States
| | - Ann M Tarrant
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA, 02543, United States.
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25
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Alagar Boopathy LR, Jacob-Tomas S, Alecki C, Vera M. Mechanisms tailoring the expression of heat shock proteins to proteostasis challenges. J Biol Chem 2022; 298:101796. [PMID: 35248532 PMCID: PMC9065632 DOI: 10.1016/j.jbc.2022.101796] [Citation(s) in RCA: 35] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 02/23/2022] [Accepted: 02/25/2022] [Indexed: 12/14/2022] Open
Abstract
All cells possess an internal stress response to cope with environmental and pathophysiological challenges. Upon stress, cells reprogram their molecular functions to activate a survival mechanism known as the heat shock response, which mediates the rapid induction of molecular chaperones such as the heat shock proteins (HSPs). This potent production overcomes the general suppression of gene expression and results in high levels of HSPs to subsequently refold or degrade misfolded proteins. Once the damage or stress is repaired or removed, cells terminate the production of HSPs and resume regular functions. Thus, fulfillment of the stress response requires swift and robust coordination between stress response activation and completion that is determined by the status of the cell. In recent years, single-cell fluorescence microscopy techniques have begun to be used in unravelling HSP-gene expression pathways, from DNA transcription to mRNA degradation. In this review, we will address the molecular mechanisms in different organisms and cell types that coordinate the expression of HSPs with signaling networks that act to reprogram gene transcription, mRNA translation, and decay and ensure protein quality control.
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26
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Holmes MJ, Misra J, Wek RC. Analysis of Translational Control in the Integrated Stress Response by Polysome Profiling. Methods Mol Biol 2022; 2428:157-171. [PMID: 35171479 DOI: 10.1007/978-1-0716-1975-9_10] [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] [Indexed: 06/14/2023]
Abstract
Translational control provides a strategy for rapid optimization of gene expression and restoration of protein homeostasis in response to cellular stresses. An important mechanism for translational control involves phosphorylation of eIF2, which invokes the integrated stress response (ISR). In the ISR, initiation of bulk protein synthesis is lowered coincident with enhanced translation efficiency of select gene transcripts that serve critical functions in stress adaptation. In this chapter, we focus on polysome profiling as a tool for establishing and characterizing translation control induced by eIF2 phosphorylation during environmental stresses. We describe in detail the experimental strategies of polysome profiling for detecting bulk repression of the translational machinery and quantifying translational control of key stress-induced gene transcripts. These experimental strategies can be adjusted to measure individual gene transcripts or genome-wide analyses and can be adapted to measure changes in the levels of ribosome subunits and associated factors invoked by various cellular cues in the ISR.
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Affiliation(s)
- Michael J Holmes
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, USA
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Jagannath Misra
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Ronald C Wek
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, USA.
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27
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Riepe C, Zelin E, Frankino PA, Meacham ZA, Fernandez S, Ingolia NT, Corn JE. Double stranded DNA breaks and genome editing trigger loss of ribosomal protein RPS27A. FEBS J 2021; 289:3101-3114. [PMID: 34914197 PMCID: PMC9295824 DOI: 10.1111/febs.16321] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 11/09/2021] [Accepted: 12/14/2021] [Indexed: 11/03/2022]
Abstract
DNA damage activates a robust transcriptional stress response, but much less is known about how DNA damage impacts translation. The advent of genome editing with Cas9 has intensified interest in understanding cellular responses to DNA damage. Here, we find that DNA double-strand breaks (DSBs), including those induced by Cas9, trigger the loss of ribosomal protein RPS27A from ribosomes via p53-independent proteasomal degradation. Comparisons of Cas9 and dCas9 ribosome profiling and mRNA-seq experiments reveal a global translational response to DSBs that precedes changes in transcript abundance. Our results demonstrate that even a single double-strand break can lead to altered translational output and ribosome remodeling, suggesting caution in interpreting cellular phenotypes measured immediately after genome editing.
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Affiliation(s)
- Celeste Riepe
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California, USA
| | - Elena Zelin
- Innovative Genomics Institute, University of California, Berkeley, Berkeley, California, USA
| | - Phillip A Frankino
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California, USA
| | - Zuriah A Meacham
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California, USA
| | - Samantha Fernandez
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California, USA
| | - Nicholas T Ingolia
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California, USA
| | - Jacob E Corn
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California, USA.,Innovative Genomics Institute, University of California, Berkeley, Berkeley, California, USA.,Department of Biology, ETH, Zürich, Switzerland
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28
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Asadi MR, Rahmanpour D, Moslehian MS, Sabaie H, Hassani M, Ghafouri-Fard S, Taheri M, Rezazadeh M. Stress Granules Involved in Formation, Progression and Metastasis of Cancer: A Scoping Review. Front Cell Dev Biol 2021; 9:745394. [PMID: 34604242 PMCID: PMC8485071 DOI: 10.3389/fcell.2021.745394] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 08/25/2021] [Indexed: 12/15/2022] Open
Abstract
The assembly of stress granules (SGs) is a well-known cellular strategy for reducing stress-related damage and promoting cell survival. SGs have become important players in human health, in addition to their fundamental role in the stress response. The critical role of SGs in cancer cells in formation, progression, and metastasis makes sense. Recent researchers have found that several SG components play a role in tumorigenesis and cancer metastasis via tumor-associated signaling pathways and other mechanisms. Gene-ontology analysis revealed the role of these protein components in the structure of SGs. Involvement in the translation process, regulation of mRNA stability, and action in both the cytoplasm and nucleus are among the main features of SG proteins. The present scoping review aimed to consider all studies on the effect of SGs on cancer formation, proliferation, and metastasis and performed based on a six-stage methodology structure and the PRISMA guideline. A systematic search of seven databases for qualified articles was conducted before July 2021. Publications were screened, and quantitative and qualitative analysis was performed on the extracted data. Go analysis was performed on seventy-one SGs protein components. Remarkably G3BP1, TIA1, TIAR, and YB1 have the largest share among the proteins considered in the studies. Altogether, this scoping review tries to demonstrate and provide a comprehensive summary of the role of SGs in the formation, progression, and metastasis of cancer by reviewing all studies.
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Affiliation(s)
- Mohammad Reza Asadi
- Molecular Medicine Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.,Student Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Dara Rahmanpour
- Student Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran
| | | | - Hani Sabaie
- Student Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran.,Department of Medical Genetics, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mehdi Hassani
- Student Research Committee, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran
| | - Soudeh Ghafouri-Fard
- Department of Medical Genetics, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mohammad Taheri
- Skull Base Research Center, Loghman Hakim Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Maryam Rezazadeh
- Molecular Medicine Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.,Department of Medical Genetics, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
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29
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Lyu X, Yang Q, Zhao F, Liu Y. Codon usage and protein length-dependent feedback from translation elongation regulates translation initiation and elongation speed. Nucleic Acids Res 2021; 49:9404-9423. [PMID: 34417614 PMCID: PMC8450115 DOI: 10.1093/nar/gkab729] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 07/26/2021] [Accepted: 08/17/2021] [Indexed: 12/26/2022] Open
Abstract
Essential cellular functions require efficient production of many large proteins but synthesis of large proteins encounters many obstacles in cells. Translational control is mostly known to be regulated at the initiation step. Whether translation elongation process can feedback to regulate initiation efficiency is unclear. Codon usage bias, a universal feature of all genomes, plays an important role in determining gene expression levels. Here, we discovered that there is a conserved but codon usage-dependent genome-wide negative correlation between protein abundance and CDS length. The codon usage effects on protein expression and ribosome flux on mRNAs are influenced by CDS length; optimal codon usage preferentially promotes production of large proteins. Translation of mRNAs with long CDS and non-optimal codon usage preferentially induces phosphorylation of initiation factor eIF2α, which inhibits translation initiation efficiency. Deletion of the eIF2α kinase CPC-3 (GCN2 homolog) in Neurospora preferentially up-regulates large proteins encoded by non-optimal codons. Surprisingly, CPC-3 also inhibits translation elongation rate in a codon usage and CDS length-dependent manner, resulting in slow elongation rates for long CDS mRNAs. Together, these results revealed a codon usage and CDS length-dependent feedback mechanism from translation elongation to regulate both translation initiation and elongation kinetics.
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Affiliation(s)
- Xueliang Lyu
- Department of Physiology, The University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390, USA.,State Key Laboratory of Agricultural Microbiology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, China
| | - Qian Yang
- Department of Physiology, The University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390, USA
| | - Fangzhou Zhao
- Department of Physiology, The University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390, USA
| | - Yi Liu
- Department of Physiology, The University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390, USA
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30
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English AM, Green KM, Moon SL. A (dis)integrated stress response: Genetic diseases of eIF2α regulators. WILEY INTERDISCIPLINARY REVIEWS-RNA 2021; 13:e1689. [PMID: 34463036 DOI: 10.1002/wrna.1689] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2021] [Revised: 08/03/2021] [Accepted: 08/04/2021] [Indexed: 01/28/2023]
Abstract
The integrated stress response (ISR) is a conserved mechanism by which eukaryotic cells remodel gene expression to adapt to intrinsic and extrinsic stressors rapidly and reversibly. The ISR is initiated when stress-activated protein kinases phosphorylate the major translation initiation factor eukaryotic translation initiation factor 2ɑ (eIF2ɑ), which globally suppresses translation initiation activity and permits the selective translation of stress-induced genes including important transcription factors such as activating transcription factor 4 (ATF4). Translationally repressed messenger RNAs (mRNAs) and noncoding RNAs assemble into cytoplasmic RNA-protein granules and polyadenylated RNAs are concomitantly stabilized. Thus, regulated changes in mRNA translation, stability, and localization to RNA-protein granules contribute to the reprogramming of gene expression that defines the ISR. We discuss fundamental mechanisms of RNA regulation during the ISR and provide an overview of a growing class of genetic disorders associated with mutant alleles of key translation factors in the ISR pathway. This article is categorized under: RNA Interactions with Proteins and Other Molecules > Protein-RNA Interactions: Functional Implications RNA in Disease and Development > RNA in Disease Translation > Translation Regulation RNA in Disease and Development > RNA in Development.
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Affiliation(s)
- Alyssa M English
- Department of Human Genetics, Center for RNA Biomedicine, University of Michigan, Ann Arbor, Michigan, USA
| | - Katelyn M Green
- Department of Chemistry, Department of Human Genetics, Center for RNA Biomedicine, University of Michigan, Ann Arbor, Michigan, USA
| | - Stephanie L Moon
- Department of Human Genetics, Center for RNA Biomedicine, University of Michigan, Ann Arbor, Michigan, USA
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31
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Hazell L, Allan F, Emery AM, Templeton MR. Ultraviolet disinfection of Schistosoma mansoni cercariae in water. PLoS Negl Trop Dis 2021; 15:e0009572. [PMID: 34228750 PMCID: PMC8284627 DOI: 10.1371/journal.pntd.0009572] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 07/16/2021] [Accepted: 06/17/2021] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Schistosomiasis is a parasitic disease that is transmitted by skin contact with waterborne schistosome cercariae. Mass drug administration with praziquantel is an effective control method, but it cannot prevent reinfection if contact with cercariae infested water continues. Providing safe water for contact activities such as laundry and bathing can help to reduce transmission. In this study we examine the direct effect of UV light on Schistosoma mansoni cercariae using ultraviolet light-emitting diodes (UV LEDs) and a low-pressure (LP) mercury arc discharge lamp. METHODOLOGY S. mansoni cercariae were exposed to UV light at four peak wavelengths: 255 nm, 265 nm, 285 nm (UV LEDs), and 253.7 nm (LP lamp) using bench scale collimated beam apparatus. The UV fluence ranged from 0-300 mJ/cm2 at each wavelength. Cercariae were studied under a stereo-microscope at 0, 60, and 180 minutes post-exposure and the viability of cercariae was determined by assessing their motility and morphology. CONCLUSION Very high UV fluences were required to kill S. mansoni cercariae, when compared to most other waterborne pathogens. At 265 nm a fluence of 247 mJ/cm2 (95% confidence interval (CI): 234-261 mJ/cm2) was required to achieve a 1-log10 reduction at 0 minutes post-exposure. Cercariae were visibly damaged at lower fluences, and the log reduction increased with time post-exposure at all wavelengths. Fluences of 127 mJ/cm2 (95% CI: 111-146 mJ/cm2) and 99 mJ/cm2 (95% CI: 85-113 mJ/cm2) were required to achieve a 1-log10 reduction at 60 and 180 minutes post-exposure at 265 nm. At 0 minutes post-exposure 285 nm was slightly less effective, but there was no statistical difference between 265 nm and 285 nm after 60 minutes. The least effective wavelengths were 255 nm and 253.7 nm. Due to the high fluences required, UV disinfection is unlikely to be an energy- or cost-efficient water treatment method against schistosome cercariae when compared to other methods such as chlorination, unless it can be demonstrated that UV-damaged cercariae are non-infective using alternative assay methods or there are improvements in UV LED technology.
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Affiliation(s)
- Lucinda Hazell
- Department of Civil and Environmental Engineering, Imperial College London, London, United Kingdom
- * E-mail:
| | - Fiona Allan
- Wolfson Wellcome Biomedical Laboratories, Department of Life Sciences, Natural History Museum, London, United Kingdom
| | - Aidan M. Emery
- Wolfson Wellcome Biomedical Laboratories, Department of Life Sciences, Natural History Museum, London, United Kingdom
| | - Michael R. Templeton
- Department of Civil and Environmental Engineering, Imperial College London, London, United Kingdom
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32
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Alboushi L, Hackett AP, Naeli P, Bakhti M, Jafarnejad SM. Multifaceted control of mRNA translation machinery in cancer. Cell Signal 2021; 84:110037. [PMID: 33975011 DOI: 10.1016/j.cellsig.2021.110037] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Accepted: 05/06/2021] [Indexed: 12/15/2022]
Abstract
The mRNA translation machinery is tightly regulated through several, at times overlapping, mechanisms that modulate its efficiency and accuracy. Due to their fast rate of growth and metabolism, cancer cells require an excessive amount of mRNA translation and protein synthesis. However, unfavorable conditions, such as hypoxia, amino acid starvation, and oxidative stress, which are abundant in cancer, as well as many anti-cancer treatments inhibit mRNA translation. Cancer cells adapt to the various internal and environmental stresses by employing specialised transcript-specific translation to survive and gain a proliferative advantage. We will highlight the major signaling pathways and mechanisms of translation that regulate the global or mRNA-specific translation in response to the intra- or extra-cellular signals and stresses that are key components in the process of tumourigenesis.
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Affiliation(s)
- Lilas Alboushi
- Patrick G. Johnston Centre for Cancer Research, Queen's University Belfast, Belfast, UK
| | - Angela P Hackett
- Patrick G. Johnston Centre for Cancer Research, Queen's University Belfast, Belfast, UK
| | - Parisa Naeli
- Patrick G. Johnston Centre for Cancer Research, Queen's University Belfast, Belfast, UK
| | - Mostafa Bakhti
- Institute of Diabetes and Regeneration Research, Helmholtz Zentrum München, 85764 Neuherberg, Germany
| | - Seyed Mehdi Jafarnejad
- Patrick G. Johnston Centre for Cancer Research, Queen's University Belfast, Belfast, UK.
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33
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Koncha RR, Ramachandran G, Sepuri NBV, Ramaiah KVA. CCCP-induced mitochondrial dysfunction - characterization and analysis of integrated stress response to cellular signaling and homeostasis. FEBS J 2021; 288:5737-5754. [PMID: 33837631 DOI: 10.1111/febs.15868] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 02/26/2021] [Accepted: 04/07/2021] [Indexed: 12/11/2022]
Abstract
Mitochondrial dysfunction mediated by CCCP (carbonyl cyanide m-chlorophenyl hydrazone), an inhibitor of mitochondrial oxidative phosphorylation, evokes the integrated stress response (ISR), which is analyzed here by eIF2α phosphorylation and expression profiles of ATF4 and CHOP proteins. Our findings suggest that the CCCP-induced ISR pathway is mediated by activation of HRI kinase, but not by GCN2, PERK, or PKR. Also, CCCP activates AMPK, a cellular energy sensor, and AKT, a regulator implicated in cell survival, and suppresses phosphorylation of mTORC1 substrates eIF4E-BP1 and S6K. CCCP also downregulates translation and promotes autophagy, leading to noncaspase-mediated cell death in HepG2 cells. All these events are neutralized by NAC, an anti-ROS, suggesting that CCCP-induced mitochondrial dysfunction promotes oxidative stress. ISRIB, an inhibitor of the ISR pathway, mitigates CCCP-induced expression of ATF4 and CHOP, activation of AKT, and autophagy, similar to NAC. However, it fails to reverse CCCP-induced AMPK activation, suggesting that CCCP-induced autophagy is dependent on ISR and independent of AMPK activation. ISRIB restores partly, inhibition in eIF4E-BP1 phosphorylation, promotes eIF2α phosphorylation, albeit slowly, and mitigates suppression of translation accordingly, in CCCP-treated cells. These findings are consistent with the idea that CCCP-induced oxidative stress leading to eIF2α phosphorylation and ATF4 expression, which is known to stimulate genes involved in autophagy, play a pro-survival role together with AKT activation and regulate mTOR-mediated eIF4E-BP1 phosphorylation.
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Affiliation(s)
| | - Gayatri Ramachandran
- Department of Biochemistry, School of Life Sciences, University of Hyderabad, India
| | - Naresh Babu V Sepuri
- Department of Biochemistry, School of Life Sciences, University of Hyderabad, India
| | - Kolluru V A Ramaiah
- Department of Biochemistry, School of Life Sciences, University of Hyderabad, India
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34
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Abstract
There is growing evidence that collisions between ribosomes represent a cellular signal for activating multiple stress pathways, such as ribosome-associated quality control (RQC), the ribotoxic stress response, and the integrated stress response (ISR). Here we illustrate how a single protein can monitor both ribosomes within a disome, by presenting a cryo-electron microscopy structure of a native complex of the ISR protein Gcn1 interacting with both the leading stalled ribosome and the following colliding ribosome. The structure provides insight into the regulation of Gcn2 activation in yeast and has implications for the interplay between the RQC and ISR pathways in eukaryotic cells. The Gcn pathway is conserved in all eukaryotes, including mammals such as humans, where it is a crucial part of the integrated stress response (ISR). Gcn1 serves as an essential effector protein for the kinase Gcn2, which in turn is activated by stalled ribosomes, leading to phosphorylation of eIF2 and a subsequent global repression of translation. The fine-tuning of this adaptive response is performed by the Rbg2/Gir2 complex, a negative regulator of Gcn2. Despite the wealth of available biochemical data, information on structures of Gcn proteins on the ribosome has remained elusive. Here we present a cryo-electron microscopy structure of the yeast Gcn1 protein in complex with stalled and colliding 80S ribosomes. Gcn1 interacts with both 80S ribosomes within the disome, such that the Gcn1 HEAT repeats span from the P-stalk region on the colliding ribosome to the P-stalk and the A-site region of the lead ribosome. The lead ribosome is stalled in a nonrotated state with peptidyl-tRNA in the A-site, uncharged tRNA in the P-site, eIF5A in the E-site, and Rbg2/Gir2 in the A-site factor binding region. By contrast, the colliding ribosome adopts a rotated state with peptidyl-tRNA in a hybrid A/P-site, uncharged-tRNA in the P/E-site, and Mbf1 bound adjacent to the mRNA entry channel on the 40S subunit. Collectively, our findings reveal the interaction mode of the Gcn2-activating protein Gcn1 with colliding ribosomes and provide insight into the regulation of Gcn2 activation. The binding of Gcn1 to a disome has important implications not only for the Gcn2-activated ISR, but also for the general ribosome-associated quality control pathways.
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Hei Z, Wu S, Zheng L, Zhou J, Liu Z, Wang J, Fang P. Crystal structures reveal a novel dimer of the RWD domain of human general control nonderepressible 2. Biochem Biophys Res Commun 2021; 549:164-170. [PMID: 33676185 DOI: 10.1016/j.bbrc.2021.02.111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Accepted: 02/23/2021] [Indexed: 10/22/2022]
Abstract
General control nonderepressible 2 (GCN2) is a serine/threonine protein kinase, detecting a variety of stresses including amino acid starvation, reactive oxygen species, etc. in eukaryotic cells. Activation of GCN2 requires the interaction of the N-terminal RWD domain with the upstream GCN1 protein and the dimerization by the kinase domain. In this study, we determined two crystal structures of the RWD domain of human GCN2 in two different crystal packing modes. These two different crystal structures reveal a same dimer of the RWD domain, which has not been reported in previous studies. We further confirmed this novel dimer interaction in solution using gel filtration experiments, and in human embryonic kidney (HEK) 293 cells using bimolecular fluorescence complementation (BiFC) and co-immunoprecipitation (co-IP) assays. Together, this study discovers a potential protein-protein interface on the RWD domain of human GCN2, and suggests a possible regulation between the interaction of GCN1 and the formation of GCN2 dimer.
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Affiliation(s)
- Zhoufei Hei
- State Key Laboratory of Bioorganic and Natural Products Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, Shanghai, 200032, China
| | - Siqi Wu
- State Key Laboratory of Bioorganic and Natural Products Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, Shanghai, 200032, China
| | - Li Zheng
- State Key Laboratory of Bioorganic and Natural Products Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, Shanghai, 200032, China; School of Chemistry and Materials Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, 1 Sub-lane Xiangshan, Hangzhou, 310024, China
| | - Jintong Zhou
- State Key Laboratory of Bioorganic and Natural Products Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, Shanghai, 200032, China
| | - Zaizhou Liu
- State Key Laboratory of Bioorganic and Natural Products Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, Shanghai, 200032, China
| | - Jing Wang
- State Key Laboratory of Bioorganic and Natural Products Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, Shanghai, 200032, China; School of Chemistry and Materials Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, 1 Sub-lane Xiangshan, Hangzhou, 310024, China
| | - Pengfei Fang
- State Key Laboratory of Bioorganic and Natural Products Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, Shanghai, 200032, China; School of Chemistry and Materials Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, 1 Sub-lane Xiangshan, Hangzhou, 310024, China.
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Gao B, Gong X, Fang S, Weng W, Wang H, Chu H, Sun Y, Meng C, Tan L, Song C, Qiu X, Liu W, Forlenza M, Ding C, Liao Y. Inhibition of anti-viral stress granule formation by coronavirus endoribonuclease nsp15 ensures efficient virus replication. PLoS Pathog 2021; 17:e1008690. [PMID: 33635931 PMCID: PMC7946191 DOI: 10.1371/journal.ppat.1008690] [Citation(s) in RCA: 78] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Revised: 03/10/2021] [Accepted: 02/01/2021] [Indexed: 12/19/2022] Open
Abstract
Cytoplasmic stress granules (SGs) are generally triggered by stress-induced translation arrest for storing mRNAs. Recently, it has been shown that SGs exert anti-viral functions due to their involvement in protein synthesis shut off and recruitment of innate immune signaling intermediates. The largest RNA viruses, coronaviruses, impose great threat to public safety and animal health; however, the significance of SGs in coronavirus infection is largely unknown. Infectious Bronchitis Virus (IBV) is the first identified coronavirus in 1930s and has been prevalent in poultry farm for many years. In this study, we provided evidence that IBV overcomes the host antiviral response by inhibiting SGs formation via the virus-encoded endoribonuclease nsp15. By immunofluorescence analysis, we observed that IBV infection not only did not trigger SGs formation in approximately 80% of the infected cells, but also impaired the formation of SGs triggered by heat shock, sodium arsenite, or NaCl stimuli. We further demonstrated that the intrinsic endoribonuclease activity of nsp15 was responsible for the interference of SGs formation. In fact, nsp15-defective recombinant IBV (rIBV-nsp15-H238A) greatly induced the formation of SGs, along with accumulation of dsRNA and activation of PKR, whereas wild type IBV failed to do so. Consequently, infection with rIBV-nsp15-H238A strongly triggered transcription of IFN-β which in turn greatly affected rIBV-nsp15-H238A replication. Further analysis showed that SGs function as an antiviral hub, as demonstrated by the attenuated IRF3-IFN response and increased production of IBV in SG-defective cells. Additional evidence includes the aggregation of pattern recognition receptors (PRRs) and signaling intermediates to the IBV-induced SGs. Collectively, our data demonstrate that the endoribonuclease nsp15 of IBV interferes with the formation of antiviral hub SGs by regulating the accumulation of viral dsRNA and by antagonizing the activation of PKR, eventually ensuring productive virus replication. We further demonstrated that nsp15s from PEDV, TGEV, SARS-CoV, and SARS-CoV-2 harbor the conserved function to interfere with the formation of chemically-induced SGs. Thus, we speculate that coronaviruses employ similar nsp15-mediated mechanisms to antagonize the host anti-viral SGs formation to ensure efficient virus replication. Coronavirus encodes the conserved endoribonuclease nsp15, which has been reported to antagonize IFN responses by mediating evasion of recognition by dsRNA sensors. SGs are part of the host cell anti-viral response; not surprisingly, viruses in turn produce an array of antagonists to counteract such host response. Here, we show that IBV prevents the formation of SGs via nsp15, by reducing the accumulation of viral dsRNA, thereby evading the activation of PKR, phosphorylation of eIF2α, and formation of SGs. Depletion of SG scaffold proteins G3BP1/2 decreases IRF3-IFN response and increases the production of IBV. When overexpressed alone, nsp15s from different coronaviruses (IBV, PEDV, TGEV, SARS-CoV, and SARS-CoV-2) interferes with chemically- and physically-induced SGs, probably by targeting essential SGs assembly factors. In this way, coronaviruses antagonize the formation of SGs by nsp15, via reducing the viral dsRNA accumulation and sequestering/depleting critical component of SGs. To our knowledge, this is the first report describing the role of coronavirus nsp15 in the suppression of integral stress response, in crosstalk with anti-innate immune response.
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Affiliation(s)
- Bo Gao
- Department of Avian Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, P. R. China
| | - Xiaoqian Gong
- Department of Avian Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, P. R. China
- Cell Biology and Immunology Group, Department of Animal Sciences, Wageningen University, Wageningen, The Netherlands
| | - Shouguo Fang
- College of Agriculture, College of Animal Sciences, Yangtze University, Jingzhou, P. R. China
| | - Wenlian Weng
- Department of Avian Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, P. R. China
| | - Huan Wang
- Department of Avian Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, P. R. China
| | - Hongyan Chu
- Department of Avian Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, P. R. China
| | - Yingjie Sun
- Department of Avian Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, P. R. China
| | - Chunchun Meng
- Department of Avian Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, P. R. China
| | - Lei Tan
- Department of Avian Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, P. R. China
| | - Cuiping Song
- Department of Avian Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, P. R. China
| | - Xusheng Qiu
- Department of Avian Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, P. R. China
| | - Weiwei Liu
- Department of Avian Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, P. R. China
| | - Maria Forlenza
- Cell Biology and Immunology Group, Department of Animal Sciences, Wageningen University, Wageningen, The Netherlands
| | - Chan Ding
- Department of Avian Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, P. R. China
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, P. R. China
| | - Ying Liao
- Department of Avian Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, P. R. China
- * E-mail:
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Rosche KL, Sidak-Loftis LC, Hurtado J, Fisk EA, Shaw DK. Arthropods Under Pressure: Stress Responses and Immunity at the Pathogen-Vector Interface. Front Immunol 2021; 11:629777. [PMID: 33659000 PMCID: PMC7917218 DOI: 10.3389/fimmu.2020.629777] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Accepted: 12/30/2020] [Indexed: 12/14/2022] Open
Abstract
Understanding what influences the ability of some arthropods to harbor and transmit pathogens may be key for controlling the spread of vector-borne diseases. Arthropod immunity has a central role in dictating vector competence for pathogen acquisition and transmission. Microbial infection elicits immune responses and imparts stress on the host by causing physical damage and nutrient deprivation, which triggers evolutionarily conserved stress response pathways aimed at restoring cellular homeostasis. Recent studies increasingly recognize that eukaryotic stress responses and innate immunity are closely intertwined. Herein, we describe two well-characterized and evolutionarily conserved mechanisms, the Unfolded Protein Response (UPR) and the Integrated Stress Response (ISR), and examine evidence that these stress responses impact immune signaling. We then describe how multiple pathogens, including vector-borne microbes, interface with stress responses in mammals. Owing to the well-conserved nature of the UPR and ISR, we speculate that similar mechanisms may be occurring in arthropod vectors and ultimately impacting vector competence. We conclude this Perspective by positing that novel insights into vector competence will emerge when considering that stress-signaling pathways may be influencing the arthropod immune network.
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Affiliation(s)
- Kristin L Rosche
- Program in Vector-borne Disease, Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA, United States
| | - Lindsay C Sidak-Loftis
- Program in Vector-borne Disease, Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA, United States
| | - Joanna Hurtado
- Program in Vector-borne Disease, Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA, United States
| | - Elizabeth A Fisk
- Program in Vector-borne Disease, Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA, United States
| | - Dana K Shaw
- Program in Vector-borne Disease, Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA, United States
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Abstract
Senescence is a state of long-term cell cycle arrest that arises in cells that have incurred sublethal damage. While senescent cells no longer replicate, they remain metabolically active and further develop unique and stable phenotypes that are not present in proliferating cells. On one hand, senescent cells increase in size, maintain an active mTORC1 complex, and produce and secrete a substantial amount of inflammatory proteins as part of the senescence-associated secretory phenotype (SASP). On the other hand, these progrowth phenotypes contrast with the p53-mediated growth arrest typical of senescent cells that is associated with nucleolar stress and an inhibition of rRNA processing and ribosome biogenesis. In sum, translation in senescent cells paradoxically comprises both a global repression of translation triggered by DNA damage and a select increase in the translation of specific proteins, including SASP factors.
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Mitochondrial stress and GDF15 in the pathophysiology of sepsis. Arch Biochem Biophys 2020; 696:108668. [PMID: 33188737 DOI: 10.1016/j.abb.2020.108668] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 11/02/2020] [Accepted: 11/04/2020] [Indexed: 02/07/2023]
Abstract
Mitochondria are multifunctional organelles that regulate diverse cellular processes. Mitochondrial stress, including stress generated by electron transport chain defects and impaired mitochondrial proteostasis, is intimately involved in various diseases and pathological conditions. Sepsis is a life-threatening condition that occurs when an imbalanced host response to infection leads to organ dysfunction. Metabolic disturbances and impaired immune responses are implicated in the pathogenesis and development of sepsis. Given that mitochondria play central roles in cellular metabolism, mitochondrial stress is predicted to be involved in the pathological mechanism of sepsis. Under mitochondrial stress, cells activate stress response systems to maintain homeostasis. This mitochondrial stress response transcriptionally activates genes involved in cell survival and death. Mitochondrial stress also induces the release of distinctive secretory proteins from cells. Recently, we showed that growth differentiation factor 15 (GDF15) is a major secretory protein induced by mitochondrial dysfunction. In this article, we provide a brief overview of mitochondrial stress response and GDF15, and discuss the potential role of GDF15 in the pathophysiology of sepsis.
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Natural Exogenous Antioxidant Defense against Changes in Human Skin Fibroblast Proteome Disturbed by UVA Radiation. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2020; 2020:3216415. [PMID: 33204393 PMCID: PMC7661135 DOI: 10.1155/2020/3216415] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Accepted: 10/15/2020] [Indexed: 12/16/2022]
Abstract
Daily exposure of the skin to UVA radiation causes oxidative modifications to cellular components and biomolecules. These include proteins involved in the metabolism and cytoprotection of fibroblasts, and their modification can contribute to the disruption of cell function and the development of skin disorders. Therefore, there remains a need for highly active cytoprotective compounds with antioxidant properties. The purpose of this study was to investigate the effect of ascorbic acid on the activity of rutin against UVA-induced changes in the proteome of human fibroblasts. All analyses were carried out on fibroblasts cultured in a three-dimensional system exposed to UVA radiation and incubated with rutin and ascorbic acid. Their proteomic profile was analyzed using nano-HPLC, which revealed 150 proteins whose expression was significantly altered between treatment conditions. UVA radiation led to changes in the expression of 82 proteins. However, some of these changes were mitigated by rutin and ascorbic acid separately (23 and 25 proteins, respectively) and rutin and ascorbic acid together (23 proteins). UVA radiation has led to the upregulation of proteins involved in gene expression, catalytic processes and antioxidant pathways, and downregulation of proteins with binding activity. Nevertheless, rutin and ascorbic acid used separately or together have countered these changes to varying degrees. Moreover, rutin and ascorbic acid stimulated fibroblasts irradiated by UVA to increase the expression of the signalling molecules responsible for the opening of the transmembrane channels. In the context of the results obtained, the observed cytoprotective effect of the cooperation of rutin and ascorbic acid results not only from the overlapping properties of the compounds. The effect of rutin alone is probably inhibited by its limited bioavailability. Therefore, its interaction with ascorbic acid increases membrane penetration and improves the cytoprotective effect on skin fibroblasts.
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Ying S, Khaperskyy DA. UV damage induces G3BP1-dependent stress granule formation that is not driven by mTOR inhibition-mediated translation arrest. J Cell Sci 2020; 133:jcs248310. [PMID: 32989041 PMCID: PMC7648617 DOI: 10.1242/jcs.248310] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Accepted: 09/17/2020] [Indexed: 12/19/2022] Open
Abstract
Translation arrest is a part of the cellular stress response that decreases energy consumption and enables rapid reprioritisation of gene expression. Often translation arrest leads to condensation of untranslated messenger ribonucleoproteins (mRNPs) into stress granules (SGs). Studies into mechanisms of SG formation and functions are complicated because various types of stress cause formation of SGs with different properties and composition. In this work, we focused on the mechanism of SG formation triggered by UV damage. We demonstrate that UV-induced inhibition of translation does not involve inhibition of the mechanistic target of rapamycin (mTOR) signaling or dissociation of the 48S preinitiation complexes. The general control non-derepressible 2 (GCN2; also known as EIF2AK4) kinase contributes to UV-induced SG formation, which is independent of the phosphorylation of the eukaryotic translation initiation factor 2α. Like many other types of SGs, condensation of UV-induced granules requires the Ras-GTPase-activating protein SH3-domain-binding protein 1 (G3BP1). Our work reveals that, in UV-treated cells, the mechanisms of translation arrest and SG formation may be unlinked, resulting in SGs that do not contain the major type of polysome-free preinitiation complexes that accumulate in the cytoplasm.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Shan Ying
- Department of Microbiology and Immunology, Dalhousie University, Halifax, NS B3H 4R2, Canada
| | - Denys A Khaperskyy
- Department of Microbiology and Immunology, Dalhousie University, Halifax, NS B3H 4R2, Canada
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42
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Stress relief for cancer immunotherapy: implications for the ER stress response in tumor immunity. Cancer Immunol Immunother 2020; 70:1165-1175. [PMID: 33104836 DOI: 10.1007/s00262-020-02740-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2020] [Accepted: 10/11/2020] [Indexed: 12/25/2022]
Abstract
The solid tumor microenvironment is replete with factors that present a stress to infiltrating immune cells. Endoplasmic reticulum (ER) stress sensor PKR-like ER kinase (PERK) is primed to sense and respond to the burden of misfolded proteins in the ER lumen induced by cell stressors. PERK has documented roles as a master regulator of acute and chronic responses to cell stress as well as in the regulation of cell metabolism. Here, we provide an overview of the roles of PERK based on what is known and remains to be tested in immune cells in tumors and impacts on tumor control. PERK is one of several ER kinases able to preferentially induce activating transcription factor 4 (ATF4) as a response to cell stress. ATF4 orchestrates the oxidative stress response and governs amino acid metabolism. We discuss the tested role of ATF4 in tumor immunity and provide insight on the dueling protective and deleterious roles that ATF4 may play in the stress of solid tumors.
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Bond S, Lopez-Lloreda C, Gannon PJ, Akay-Espinoza C, Jordan-Sciutto KL. The Integrated Stress Response and Phosphorylated Eukaryotic Initiation Factor 2α in Neurodegeneration. J Neuropathol Exp Neurol 2020; 79:123-143. [PMID: 31913484 DOI: 10.1093/jnen/nlz129] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 11/07/2019] [Indexed: 02/06/2023] Open
Abstract
The proposed molecular mechanisms underlying neurodegenerative pathogenesis are varied, precluding the development of effective therapies for these increasingly prevalent disorders. One of the most consistent observations across neurodegenerative diseases is the phosphorylation of eukaryotic initiation factor 2α (eIF2α). eIF2α is a translation initiation factor, involved in cap-dependent protein translation, which when phosphorylated causes global translation attenuation. eIF2α phosphorylation is mediated by 4 kinases, which, together with their downstream signaling cascades, constitute the integrated stress response (ISR). While the ISR is activated by stresses commonly observed in neurodegeneration, such as oxidative stress, endoplasmic reticulum stress, and inflammation, it is a canonically adaptive signaling cascade. However, chronic activation of the ISR can contribute to neurodegenerative phenotypes such as neuronal death, memory impairments, and protein aggregation via apoptotic induction and other maladaptive outcomes downstream of phospho-eIF2α-mediated translation inhibition, including neuroinflammation and altered amyloidogenic processing, plausibly in a feed-forward manner. This review examines evidence that dysregulated eIF2a phosphorylation acts as a driver of neurodegeneration, including a survey of observations of ISR signaling in human disease, inspection of the overlap between ISR signaling and neurodegenerative phenomenon, and assessment of recent encouraging findings ameliorating neurodegeneration using developing pharmacological agents which target the ISR. In doing so, gaps in the field, including crosstalk of the ISR kinases and consideration of ISR signaling in nonneuronal central nervous system cell types, are highlighted.
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Affiliation(s)
- Sarah Bond
- From the Department of Biochemistry and Biophysics (SB); Department of Neuroscience (CL-L); Department of Pharmacology (PG), Perelman School of Medicine; Department of Basic and Translational Sciences (CA-E); and Department of Basic and Translational Sciences (KLJ-S), School of Dental Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Claudia Lopez-Lloreda
- From the Department of Biochemistry and Biophysics (SB); Department of Neuroscience (CL-L); Department of Pharmacology (PG), Perelman School of Medicine; Department of Basic and Translational Sciences (CA-E); and Department of Basic and Translational Sciences (KLJ-S), School of Dental Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Patrick J Gannon
- From the Department of Biochemistry and Biophysics (SB); Department of Neuroscience (CL-L); Department of Pharmacology (PG), Perelman School of Medicine; Department of Basic and Translational Sciences (CA-E); and Department of Basic and Translational Sciences (KLJ-S), School of Dental Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Cagla Akay-Espinoza
- From the Department of Biochemistry and Biophysics (SB); Department of Neuroscience (CL-L); Department of Pharmacology (PG), Perelman School of Medicine; Department of Basic and Translational Sciences (CA-E); and Department of Basic and Translational Sciences (KLJ-S), School of Dental Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Kelly L Jordan-Sciutto
- From the Department of Biochemistry and Biophysics (SB); Department of Neuroscience (CL-L); Department of Pharmacology (PG), Perelman School of Medicine; Department of Basic and Translational Sciences (CA-E); and Department of Basic and Translational Sciences (KLJ-S), School of Dental Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
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Wu CCC, Peterson A, Zinshteyn B, Regot S, Green R. Ribosome Collisions Trigger General Stress Responses to Regulate Cell Fate. Cell 2020; 182:404-416.e14. [PMID: 32610081 PMCID: PMC7384957 DOI: 10.1016/j.cell.2020.06.006] [Citation(s) in RCA: 232] [Impact Index Per Article: 58.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 05/18/2020] [Accepted: 06/02/2020] [Indexed: 01/01/2023]
Abstract
Problems arising during translation of mRNAs lead to ribosome stalling and collisions that trigger a series of quality control events. However, the global cellular response to ribosome collisions has not been explored. Here, we uncover a function for ribosome collisions in signal transduction. Using translation elongation inhibitors and general cellular stress conditions, including amino acid starvation and UV irradiation, we show that ribosome collisions activate the stress-activated protein kinase (SAPK) and GCN2-mediated stress response pathways. We show that the MAPKKK ZAK functions as the sentinel for ribosome collisions and is required for immediate early activation of both SAPK (p38/JNK) and GCN2 signaling pathways. Selective ribosome profiling and biochemistry demonstrate that although ZAK generally associates with elongating ribosomes on polysomal mRNAs, it specifically auto-phosphorylates on the minimal unit of colliding ribosomes, the disome. Together, these results provide molecular insights into how perturbation of translational homeostasis regulates cell fate.
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Affiliation(s)
- Colin Chih-Chien Wu
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Amy Peterson
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Boris Zinshteyn
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Sergi Regot
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Rachel Green
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
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The structure of human GCN2 reveals a parallel, back-to-back kinase dimer with a plastic DFG activation loop motif. Biochem J 2020; 477:275-284. [PMID: 31868900 DOI: 10.1042/bcj20190196] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Revised: 12/10/2019] [Accepted: 12/23/2019] [Indexed: 11/17/2022]
Abstract
When activated by amino acid starvation, the stress sensing protein kinase GCN2 phosphorylates the eukaryotic initiation factor 2 alpha, inhibiting translation to conserve energy and facilitate cell survival. Amino acid starvation, particularly of tryptophan and arginine, affects immune tolerance by suppressing differentiation and proliferation of T-cells via activation of GCN2 kinase. In addition, the GCN2 pathway mediates cancer survival directly within the context of metabolic stress. Here, we report the first crystal structures of the human GCN2 kinase domain (KD) in complex with two inhibitors of different size, shape, and chemical scaffold. Three novel activation loop conformations representative of different activation states of the kinase are described. In addition, a novel dimerization organization for GCN2 is observed. This arrangement is consistent with the hypothesis that the GCN2 KD forms an antiparallel inactive dimer until uncharged tRNA binds to it and triggers conformational changes that shift the equilibrium to the active parallel dimer.
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46
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Infectious Bronchitis Virus Regulates Cellular Stress Granule Signaling. Viruses 2020; 12:v12050536. [PMID: 32422883 PMCID: PMC7291021 DOI: 10.3390/v12050536] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Revised: 05/12/2020] [Accepted: 05/12/2020] [Indexed: 12/21/2022] Open
Abstract
Viruses must hijack cellular translation machinery to express viral genes. In many cases, this is impeded by cellular stress responses. These stress responses result in the global inhibition of translation and the storage of stalled mRNAs, into RNA-protein aggregates called stress granules. This results in the translational silencing of the majority of mRNAs excluding those beneficial for the cell to resolve the specific stress. For example, the expression of antiviral factors is maintained during viral infection. Here we investigated stress granule regulation by Gammacoronavirus infectious bronchitis virus (IBV), which causes the economically important poultry disease, infectious bronchitis. Interestingly, we found that IBV is able to inhibit multiple cellular stress granule signaling pathways, whilst at the same time, IBV replication also results in the induction of seemingly canonical stress granules in a proportion of infected cells. Moreover, IBV infection uncouples translational repression and stress granule formation and both processes are independent of eIF2α phosphorylation. These results provide novel insights into how IBV modulates cellular translation and antiviral stress signaling.
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Yamazaki H, Kasai S, Mimura J, Ye P, Inose-Maruyama A, Tanji K, Wakabayashi K, Mizuno S, Sugiyama F, Takahashi S, Sato T, Ozaki T, Cavener DR, Yamamoto M, Itoh K. Ribosome binding protein GCN1 regulates the cell cycle and cell proliferation and is essential for the embryonic development of mice. PLoS Genet 2020; 16:e1008693. [PMID: 32324833 PMCID: PMC7179835 DOI: 10.1371/journal.pgen.1008693] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Accepted: 02/22/2020] [Indexed: 12/24/2022] Open
Abstract
Amino acids exert many biological functions, serving as allosteric regulators and neurotransmitters, as constituents in proteins and as nutrients. GCN2-mediated phosphorylation of eukaryotic initiation factor 2 alpha (elF2α) restores homeostasis in response to amino acid starvation (AAS) through the inhibition of the general translation and upregulation of amino acid biosynthetic enzymes and transporters by activating the translation of Gcn4 and ATF4 in yeast and mammals, respectively. GCN1 is a GCN2-binding protein that possesses an RWD binding domain (RWDBD) in its C-terminus. In yeast, Gcn1 is essential for Gcn2 activation by AAS; however, the roles of GCN1 in mammals need to be established. Here, we revealed a novel role of GCN1 that does not depend on AAS by generating two Gcn1 mutant mouse lines: Gcn1-knockout mice (Gcn1 KO mice (Gcn1-/-)) and RWDBD-deleted mutant mice (Gcn1ΔRWDBD mice). Both mutant mice showed growth retardation, which was not observed in the Gcn2 KO mice, such that the Gcn1 KO mice died at the intermediate stage of embryonic development because of severe growth retardation, while the Gcn1ΔRWDBD embryos showed mild growth retardation and died soon after birth, most likely due to respiratory failure. Extension of pregnancy by 24 h through the administration of progesterone to the pregnant mothers rescued the expression of differentiation markers in the lungs and prevented lethality of the Gcn1ΔRWDBD pups, indicating that perinatal lethality of the Gcn1ΔRWDBD embryos was due to simple growth retardation. Similar to the yeast Gcn2/Gcn1 system, AAS- or UV irradiation-induced elF2α phosphorylation was diminished in the Gcn1ΔRWDBD mouse embryonic fibroblasts (MEFs), suggesting that GCN1 RWDBD is responsible for GCN2 activity. In addition, we found reduced cell proliferation and G2/M arrest accompanying a decrease in Cdk1 and Cyclin B1 in the Gcn1ΔRWDBD MEFs. Our results demonstrated, for the first time, that GCN1 is essential for both GCN2-dependent stress response and GCN2-independent cell cycle regulation. The stress response at the translational level is an energetically cost-saving mechanism because translation consumes a considerable amount of energy. Upon exposure to stresses such as that from amino acid starvation (AAS), the translational initiation factor eIF2α is phosphorylated, which represses general translation to save energy. At the same time, eIF2α phosphorylation increases the selective translation of cytoprotective proteins, such as ATF4, that transcriptionally activate the stress response, promoting cell survival. Among four eIF2α kinases, GCN2 responds to AAS and phosphorylates eIF2α. In yeast, Gcn1 is required for Gcn2 activation by AAS, but the roles of GCN1 in mammals remain to be established. Here, we show that GCN1 is involved in GCN2-mediated eIF2α phosphorylation after AAS and UV radiation by generating Gcn1 mutant mice. Interestingly, GCN1 not only regulates the eIF2α-mediated stress response but also the cell cycle and cell proliferation in a GCN2-independent manner. Taking these findings together, we propose that GCN1 integrates cellular information and coordinates the cellular stress response to enhance viability.
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Affiliation(s)
- Hiromi Yamazaki
- Department of Stress Response Science, Center for Advanced Medical Research, Hirosaki University, Hirosaki, Japan
| | - Shuya Kasai
- Department of Stress Response Science, Center for Advanced Medical Research, Hirosaki University, Hirosaki, Japan
| | - Junsei Mimura
- Department of Stress Response Science, Center for Advanced Medical Research, Hirosaki University, Hirosaki, Japan
| | - Peng Ye
- Department of Stress Response Science, Center for Advanced Medical Research, Hirosaki University, Hirosaki, Japan
| | - Atsushi Inose-Maruyama
- Department of Stress Response Science, Center for Advanced Medical Research, Hirosaki University, Hirosaki, Japan
| | - Kunikazu Tanji
- Department of Neuropathology, Institute of Brain Science Graduate School of Medicine, Hirosaki University, Hirosaki, Japan
| | - Koichi Wakabayashi
- Department of Neuropathology, Institute of Brain Science Graduate School of Medicine, Hirosaki University, Hirosaki, Japan
| | - Seiya Mizuno
- Transborder Medical Research Center and Laboratory Animal Resource Center, University of Tsukuba, Tsukuba, Japan
| | - Fumihiro Sugiyama
- Transborder Medical Research Center and Laboratory Animal Resource Center, University of Tsukuba, Tsukuba, Japan
| | - Satoru Takahashi
- Transborder Medical Research Center and Laboratory Animal Resource Center, University of Tsukuba, Tsukuba, Japan
| | - Tsubasa Sato
- Department of Stress Response Science, Center for Advanced Medical Research, Hirosaki University, Hirosaki, Japan.,Department of Chemistry and Biological Sciences, Faculty of Science and Engineering, Iwate University, Morioka, Japan
| | - Taku Ozaki
- Department of Chemistry and Biological Sciences, Faculty of Science and Engineering, Iwate University, Morioka, Japan
| | - Douglas R Cavener
- Department of Biology, Center for Cellular Dynamics and the Huck Institute of the Life Sciences, Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Masayuki Yamamoto
- Department of Medical Biochemistry, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Ken Itoh
- Department of Stress Response Science, Center for Advanced Medical Research, Hirosaki University, Hirosaki, Japan
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Jaud M, Philippe C, Di Bella D, Tang W, Pyronnet S, Laurell H, Mazzolini L, Rouault-Pierre K, Touriol C. Translational Regulations in Response to Endoplasmic Reticulum Stress in Cancers. Cells 2020; 9:cells9030540. [PMID: 32111004 PMCID: PMC7140484 DOI: 10.3390/cells9030540] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 02/18/2020] [Accepted: 02/24/2020] [Indexed: 12/20/2022] Open
Abstract
During carcinogenesis, almost all the biological processes are modified in one way or another. Among these biological processes affected, anomalies in protein synthesis are common in cancers. Indeed, cancer cells are subjected to a wide range of stresses, which include physical injuries, hypoxia, nutrient starvation, as well as mitotic, oxidative or genotoxic stresses. All of these stresses will cause the accumulation of unfolded proteins in the Endoplasmic Reticulum (ER), which is a major organelle that is involved in protein synthesis, preservation of cellular homeostasis, and adaptation to unfavourable environment. The accumulation of unfolded proteins in the endoplasmic reticulum causes stress triggering an unfolded protein response in order to promote cell survival or to induce apoptosis in case of chronic stress. Transcription and also translational reprogramming are tightly controlled during the unfolded protein response to ensure selective gene expression. The majority of stresses, including ER stress, induce firstly a decrease in global protein synthesis accompanied by the induction of alternative mechanisms for initiating the translation of mRNA, later followed by a translational recovery. After a presentation of ER stress and the UPR response, we will briefly present the different modes of translation initiation, then address the specific translational regulatory mechanisms acting during reticulum stress in cancers and highlight the importance of translational control by ER stress in tumours.
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Affiliation(s)
- Manon Jaud
- Inserm UMR1037, CRCT (Cancer Research Center of Toulouse), F-31037 Toulouse, France; (M.J.); (S.P.); (L.M.)
- Université Toulouse III Paul-Sabatier, F-31000 Toulouse, France;
| | - Céline Philippe
- Barts Cancer Institute, Queen Mary University of London, London E1 4NS, UK; (C.P.); (D.D.B.); (W.T.); (K.R.-P.)
| | - Doriana Di Bella
- Barts Cancer Institute, Queen Mary University of London, London E1 4NS, UK; (C.P.); (D.D.B.); (W.T.); (K.R.-P.)
| | - Weiwei Tang
- Barts Cancer Institute, Queen Mary University of London, London E1 4NS, UK; (C.P.); (D.D.B.); (W.T.); (K.R.-P.)
| | - Stéphane Pyronnet
- Inserm UMR1037, CRCT (Cancer Research Center of Toulouse), F-31037 Toulouse, France; (M.J.); (S.P.); (L.M.)
- Université Toulouse III Paul-Sabatier, F-31000 Toulouse, France;
| | - Henrik Laurell
- Université Toulouse III Paul-Sabatier, F-31000 Toulouse, France;
- Inserm UMR1048, I2MC (Institut des Maladies Métaboliques et Cardiovasculaires), BP 84225, CEDEX 04, 31 432 Toulouse, France
| | - Laurent Mazzolini
- Inserm UMR1037, CRCT (Cancer Research Center of Toulouse), F-31037 Toulouse, France; (M.J.); (S.P.); (L.M.)
- CNRS ERL5294, CRCT, F-31037 Toulouse, France
| | - Kevin Rouault-Pierre
- Barts Cancer Institute, Queen Mary University of London, London E1 4NS, UK; (C.P.); (D.D.B.); (W.T.); (K.R.-P.)
| | - Christian Touriol
- Inserm UMR1037, CRCT (Cancer Research Center of Toulouse), F-31037 Toulouse, France; (M.J.); (S.P.); (L.M.)
- Université Toulouse III Paul-Sabatier, F-31000 Toulouse, France;
- Correspondence:
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49
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Towards a model of GCN2 activation. Biochem Soc Trans 2020; 47:1481-1488. [PMID: 31647517 PMCID: PMC6824675 DOI: 10.1042/bst20190331] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Revised: 09/19/2019] [Accepted: 09/23/2019] [Indexed: 01/06/2023]
Abstract
Cells must be able to sense and adapt to their surroundings to thrive in a dynamic environment. Key to adapting to a low nutrient environment is the Integrated Stress Response (ISR), a short-lived pathway that allows cells to either regain cellular homeostasis or facilitate apoptosis during periods of stress. Central to the ISR is the protein kinase General Control Non-depressible 2 (GCN2), which is responsible for sensing starvation. Upon amino acid deficiency, GCN2 is activated and initiates the ISR by phosphorylating the translation initiation factor eIF2α, stalling protein translation, and activating the transcription factor ATF4, which in turn up-regulates autophagy and biosynthesis pathways. A key outstanding question is how GCN2 is activated from an autoinhibited state. Until recently, a model of activation focussed on the increase of deacylated tRNA associated with amino acid starvation, with deacylated tRNA binding directly to GCN2 and releasing autoinhibition. However, in vivo experiments have pointed towards an alternative, deacylated-tRNA-independent mechanism of activation. Here, we review the various factors that may facilitate GCN2 activation, including recent research showing that the P-stalk complex, a ribosome-associated heteropentameric protein complex, is a potent activator of GCN2.
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50
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Ou HL, Kim CS, Uszkoreit S, Wickström SA, Schumacher B. Somatic Niche Cells Regulate the CEP-1/p53-Mediated DNA Damage Response in Primordial Germ Cells. Dev Cell 2020; 50:167-183.e8. [PMID: 31336098 DOI: 10.1016/j.devcel.2019.06.012] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Revised: 03/13/2019] [Accepted: 06/17/2019] [Indexed: 12/26/2022]
Abstract
Genome integrity in primordial germ cells (PGCs) is a prerequisite for fertility and species maintenance. In C. elegans, PGCs require global-genome nucleotide excision repair (GG-NER) to remove UV-induced DNA lesions. Failure to remove the lesions leads to the activation of the C. elegans p53, CEP-1, resulting in mitotic arrest of the PGCs. We show that the eIF4E2 translation initiation factor IFE-4 in somatic gonad precursor (SGP) niche cells regulates the CEP-1/p53-mediated DNA damage response (DDR) in PGCs. We determine that the IFE-4 translation target EGL-15/FGFR regulates the non-cell-autonomous DDR that is mediated via FGF-like signaling. Using hair follicle stem cells as a paradigm, we demonstrate that the eIF4E2-mediated niche cell regulation of the p53 response in stem cells is highly conserved in mammals. We thus reveal that the somatic niche regulates the CEP-1/p53-mediated DNA damage checkpoint in PGCs. Our data suggest that the somatic niche impacts the stability of heritable genomes.
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Affiliation(s)
- Hui-Ling Ou
- Institute for Genome Stability in Ageing and Disease, Medical Faculty, University of Cologne, Joseph-Stelzmann-Str. 26, 50931 Cologne, Germany; Cologne Excellence Cluster for Cellular Stress Responses in Ageing-Associated Diseases (CECAD), Center for Molecular Medicine Cologne (CMMC), University of Cologne, Joseph-Stelzmann-Str. 26, 50931 Cologne, Germany
| | - Christine S Kim
- Cologne Excellence Cluster for Cellular Stress Responses in Ageing-Associated Diseases (CECAD), Center for Molecular Medicine Cologne (CMMC), University of Cologne, Joseph-Stelzmann-Str. 26, 50931 Cologne, Germany; Paul Gerson Unna Group "Skin Homeostasis and Ageing," Max Planck Institute for Biology of Ageing, Joseph-Stelzmann-Str. 9b, D-50931 Cologne, Germany
| | - Simon Uszkoreit
- Institute for Genome Stability in Ageing and Disease, Medical Faculty, University of Cologne, Joseph-Stelzmann-Str. 26, 50931 Cologne, Germany; Cologne Excellence Cluster for Cellular Stress Responses in Ageing-Associated Diseases (CECAD), Center for Molecular Medicine Cologne (CMMC), University of Cologne, Joseph-Stelzmann-Str. 26, 50931 Cologne, Germany
| | - Sara A Wickström
- Cologne Excellence Cluster for Cellular Stress Responses in Ageing-Associated Diseases (CECAD), Center for Molecular Medicine Cologne (CMMC), University of Cologne, Joseph-Stelzmann-Str. 26, 50931 Cologne, Germany; Paul Gerson Unna Group "Skin Homeostasis and Ageing," Max Planck Institute for Biology of Ageing, Joseph-Stelzmann-Str. 9b, D-50931 Cologne, Germany; Helsinki Institute of Life Science, Biomedicum Helsinki, University of Helsinki, FI-00014 Helsinki, Finland; Wihuri Research Institute, Biomedicum Helsinki, University of Helsinki, FI-00014 Helsinki, Finland
| | - Björn Schumacher
- Institute for Genome Stability in Ageing and Disease, Medical Faculty, University of Cologne, Joseph-Stelzmann-Str. 26, 50931 Cologne, Germany; Cologne Excellence Cluster for Cellular Stress Responses in Ageing-Associated Diseases (CECAD), Center for Molecular Medicine Cologne (CMMC), University of Cologne, Joseph-Stelzmann-Str. 26, 50931 Cologne, Germany.
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