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Ohtsuka H, Otsubo Y, Shimasaki T, Yamashita A, Aiba H. ecl family genes: Factors linking starvation and lifespan extension in Schizosaccharomyces pombe. Mol Microbiol 2023; 120:645-657. [PMID: 37525511 DOI: 10.1111/mmi.15134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 07/11/2023] [Accepted: 07/12/2023] [Indexed: 08/02/2023]
Abstract
In the fission yeast Schizosaccharomyces pombe, the duration of survival in the stationary phase, termed the chronological lifespan (CLS), is affected by various environmental factors and the corresponding gene activities. The ecl family genes were identified in the genomic region encoding non-coding RNA as positive regulators of CLS in S. pombe, and subsequently shown to encode relatively short proteins. Several studies revealed that ecl family genes respond to various nutritional starvation conditions via different mechanisms, and they are additionally involved in stress resistance, autophagy, sexual differentiation, and cell cycle control. Recent studies reported that Ecl family proteins strongly suppress target of rapamycin complex 1, which is a conserved eukaryotic nutrient-sensing kinase complex that also regulates longevity in a variety of organisms. In this review, we introduce the regulatory mechanisms of Ecl family proteins and discuss their emerging findings.
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Affiliation(s)
- Hokuto Ohtsuka
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, Japan
| | - Yoko Otsubo
- Interdisciplinary Research Unit, National Institute for Basic Biology, Okazaki, Japan
| | - Takafumi Shimasaki
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, Japan
| | - Akira Yamashita
- Interdisciplinary Research Unit, National Institute for Basic Biology, Okazaki, Japan
| | - Hirofumi Aiba
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, Japan
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Cherkasova V, Iben JR, Pridham KJ, Kessler AC, Maraia RJ. The leucine-NH4+ uptake regulator Any1 limits growth as part of a general amino acid control response to loss of La protein by fission yeast. PLoS One 2021; 16:e0253494. [PMID: 34153074 PMCID: PMC8216550 DOI: 10.1371/journal.pone.0253494] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Accepted: 06/04/2021] [Indexed: 11/19/2022] Open
Abstract
The sla1+ gene of Schizosachharoymces pombe encodes La protein which promotes proper processing of precursor-tRNAs. Deletion of sla1 (sla1Δ) leads to disrupted tRNA processing and sensitivity to target of rapamycin (TOR) inhibition. Consistent with this, media containing NH4+ inhibits leucine uptake and growth of sla1Δ cells. Here, transcriptome analysis reveals that genes upregulated in sla1Δ cells exhibit highly significant overalp with general amino acid control (GAAC) genes in relevant transcriptomes from other studies. Growth in NH4+ media leads to additional induced genes that are part of a core environmental stress response (CESR). The sla1Δ GAAC response adds to evidence linking tRNA homeostasis and broad signaling in S. pombe. We provide evidence that deletion of the Rrp6 subunit of the nuclear exosome selectively dampens a subset of GAAC genes in sla1Δ cells suggesting that nuclear surveillance-mediated signaling occurs in S. pombe. To study the NH4+-effects, we isolated sla1Δ spontaneous revertants (SSR) of the slow growth phenotype and found that GAAC gene expression and rapamycin hypersensitivity were also reversed. Genome sequencing identified a F32V substitution in Any1, a known negative regulator of NH4+-sensitive leucine uptake linked to TOR. We show that 3H-leucine uptake by SSR-any1-F32V cells in NH4+-media is more robust than by sla1Δ cells. Moreover, F32V may alter any1+ function in sla1Δ vs. sla1+ cells in a distinctive way. Thus deletion of La, a tRNA processing factor leads to a GAAC response involving reprogramming of amino acid metabolism, and isolation of the any1-F32V rescuing mutant provides an additional specific link.
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Affiliation(s)
- Vera Cherkasova
- Kelly@DeWitt, Inc, National Library of Medicine, National Institutes of Health, Bethesda, MD, United States of America
| | - James R. Iben
- Molecular Genomics Core, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States of America
| | - Kevin J. Pridham
- Fralin Biomedical Research Institute at Virginia Tech, Roanoke, VA, United States of America
| | - Alan C. Kessler
- Section on Molecular and Cell Biology, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD United States of America
| | - Richard J. Maraia
- Section on Molecular and Cell Biology, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD United States of America
- * E-mail:
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3
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Asano K. Origin of translational control by eIF2α phosphorylation: insights from genome-wide translational profiling studies in fission yeast. Curr Genet 2021; 67:359-368. [PMID: 33420908 PMCID: PMC8140999 DOI: 10.1007/s00294-020-01149-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2020] [Revised: 12/09/2020] [Accepted: 12/14/2020] [Indexed: 01/14/2023]
Abstract
During amino acid limitation, the protein kinase Gcn2 phosphorylates the α subunit of eIF2, thereby regulating mRNA translation. In yeast Saccharomyces cerevisiae and mammals, eIF2α phosphorylation regulates translation of related transcription factors Gcn4 and Atf4 through upstream open reading frames (uORFs) to activate transcription genome wide. However, mammals encode three more eIF2α kinases activated by distinct stimuli. Did the translational control system involving eIF2α phosphorylation evolve from so simple (as found in yeast S. cerevisiae) to complex (as found in humans)? Recent genome-wide translational profiling studies of amino acid starvation response in the fission yeast Schizosaccharomyces pombe provide an unexpected answer to this question.
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Affiliation(s)
- Katsura Asano
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS, 66506, USA.
- Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima, Hiroshima, 739-8530, Japan.
- Hiroshima Research Center for Healthy Aging, Hiroshima University, Higashi-Hiroshima, Hiroshima, 739-8530, Japan.
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Jiménez-Saucedo T, Berlanga JJ, Rodríguez-Gabriel M. Translational control of gene expression by eIF2 modulates proteostasis and extends lifespan. Aging (Albany NY) 2021; 13:10989-11009. [PMID: 33901016 PMCID: PMC8109070 DOI: 10.18632/aging.203018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Accepted: 03/31/2021] [Indexed: 01/14/2023]
Abstract
Although the stress response in eukaryotes depends on early events triggered in cells by environmental insults, long-term processes such as aging are also affected. The loss of cellular proteostasis greatly impacts aging, which is regulated by the balancing of protein synthesis and degradation systems. As translation is the input event in proteostasis, we decided to study the role of translational activity on cell lifespan. Our hypothesis was that a reduction on translational activity or specific changes in translation may increase cellular longevity. Using mutant strains of Schizosaccharomyces pombe and various stress conditions, we showed that translational reduction caused by phosphorylation of eukaryotic translation initiation factor 2 (eIF2) during the exponential growth phase enhances chronological lifespan (CLS). Furthermore, through next-generation sequence analysis, we found eIF2α phosphorylation-dependent translational activation of some specific genes, especially those involved in autophagy. This fact, together with the observed regulation of autophagy, points to a conserved mechanism involving general and specific control of translation and autophagy as mediators of the role of eIF2α phosphorylation in aging.
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Affiliation(s)
- Tamara Jiménez-Saucedo
- Centro de Biología Molecular Severo Ochoa (CSIC-UAM), Universidad Autónoma de Madrid, Madrid, Spain
| | - Juan José Berlanga
- Centro de Biología Molecular Severo Ochoa (CSIC-UAM), Universidad Autónoma de Madrid, Madrid, Spain
| | - Miguel Rodríguez-Gabriel
- Centro de Biología Molecular Severo Ochoa (CSIC-UAM), Universidad Autónoma de Madrid, Madrid, Spain
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Rubio A, Ghosh S, Mülleder M, Ralser M, Mata J. Ribosome profiling reveals ribosome stalling on tryptophan codons and ribosome queuing upon oxidative stress in fission yeast. Nucleic Acids Res 2021; 49:383-399. [PMID: 33313903 PMCID: PMC7797079 DOI: 10.1093/nar/gkaa1180] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 11/13/2020] [Accepted: 11/19/2020] [Indexed: 12/11/2022] Open
Abstract
Translational control is essential in response to stress. We investigated the translational programmes launched by the fission yeast Schizosaccharomyces pombe upon five environmental stresses. We also explored the contribution of defence pathways to these programmes: The Integrated Stress Response (ISR), which regulates translation initiation, and the stress-response MAPK pathway. We performed ribosome profiling of cells subjected to each stress, in wild type cells and in cells with the defence pathways inactivated. The transcription factor Fil1, a functional homologue of the yeast Gcn4 and the mammalian Atf4 proteins, was translationally upregulated and required for the response to most stresses. Moreover, many mRNAs encoding proteins required for ribosome biogenesis were translationally downregulated. Thus, several stresses trigger a universal translational response, including reduced ribosome production and a Fil1-mediated transcriptional programme. Surprisingly, ribosomes stalled on tryptophan codons upon oxidative stress, likely due to a decrease in charged tRNA-Tryptophan. Stalling caused ribosome accumulation upstream of tryptophan codons (ribosome queuing/collisions), demonstrating that stalled ribosomes affect translation elongation by other ribosomes. Consistently, tryptophan codon stalling led to reduced translation elongation and contributed to the ISR-mediated inhibition of initiation. We show that different stresses elicit common and specific translational responses, revealing a novel role in Tryptophan-tRNA availability.
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Affiliation(s)
- Angela Rubio
- Department of Biochemistry, University of Cambridge, UK
| | - Sanjay Ghosh
- Department of Biochemistry, University of Cambridge, UK
| | - Michael Mülleder
- The Molecular Biology of Metabolism Laboratory, The Francis Crick Institute, London, UK
| | - Markus Ralser
- The Molecular Biology of Metabolism Laboratory, The Francis Crick Institute, London, UK.,Department of Biochemistry, Charité University Medicine, Berlin, Germany
| | - Juan Mata
- Department of Biochemistry, University of Cambridge, UK
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Chikashige Y, Kato H, Thornton M, Pepper W, Hilgers M, Cecil A, Asano I, Yamada H, Mori C, Brunkow C, Moravek C, Urano T, Singh CR, Asano K. Gcn2 eIF2α kinase mediates combinatorial translational regulation through nucleotide motifs and uORFs in target mRNAs. Nucleic Acids Res 2020; 48:8977-8992. [PMID: 32710633 PMCID: PMC7498311 DOI: 10.1093/nar/gkaa608] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 07/06/2020] [Accepted: 07/24/2020] [Indexed: 12/14/2022] Open
Abstract
The protein kinase Gcn2 is a central transducer of nutritional stress signaling important for stress adaptation by normal cells and the survival of cancer cells. In response to nutrient deprivation, Gcn2 phosphorylates eIF2α, thereby repressing general translation while enhancing translation of specific mRNAs with upstream ORFs (uORFs) situated in their 5'-leader regions. Here we performed genome-wide measurements of mRNA translation during histidine starvation in fission yeast Schizosaccharomyces pombe. Polysome analyses were combined with microarray measurements to identify gene transcripts whose translation was up-regulated in response to the stress in a Gcn2-dependent manner. We determined that translation is reprogrammed to enhance RNA metabolism and chromatin regulation and repress ribosome synthesis. Interestingly, translation of intron-containing mRNAs was up-regulated. The products of the regulated genes include additional eIF2α kinase Hri2 amplifying the stress signaling and Gcn5 histone acetyl transferase and transcription factors, together altering genome-wide transcription. Unique dipeptide-coding uORFs and nucleotide motifs, such as '5'-UGA(C/G)GG-3', are found in 5' leader regions of regulated genes and shown to be responsible for translational control.
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Affiliation(s)
- Yuji Chikashige
- Advanced ICT Research Institute, National Institute of Information and Communications Technology, Kobe, Hyogo 651-2492, Japan
| | - Hiroaki Kato
- Department of Biochemistry, Shimane University School of Medicine, Izumo, Shimane 693-8501, Japan
| | - Mackenzie Thornton
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Whitney Pepper
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Madelyn Hilgers
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Ariana Cecil
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Izumi Asano
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Haana Yamada
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
- Department of Advanced Transdisciplinary Sciences, Faculty of Advanced Life Science, Hokkaido University, Sapporo, Hokkaido 060-0810, Japan
| | - Chie Mori
- Advanced ICT Research Institute, National Institute of Information and Communications Technology, Kobe, Hyogo 651-2492, Japan
| | - Cheyenne Brunkow
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Carter Moravek
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Takeshi Urano
- Department of Biochemistry, Shimane University School of Medicine, Izumo, Shimane 693-8501, Japan
| | - Chingakham Ranjit Singh
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Katsura Asano
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
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7
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Guedes SFF, Neves BG, Bezerra DS, Souza GHMF, Lima-Neto ABM, Guedes MIF, Duarte S, Rodrigues LKA. Saliva proteomics from children with caries at different severity stages. Oral Dis 2020; 26:1219-1229. [PMID: 32285988 DOI: 10.1111/odi.13352] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 03/18/2020] [Accepted: 03/27/2020] [Indexed: 12/11/2022]
Abstract
OBJECTIVE To perform a comparative analysis of saliva protein profile of patients with early childhood caries at different levels of severity and caries-free individuals. MATERIALS AND METHODS Stimulated saliva samples were collected from 126 children (2-6 years old), classified according to the ICDAS II, and divided into 3 groups (n = 42): caries-free (CF), enamel caries (EC), and dentine caries (DC). Samples were digested and analyzed by nanoUPLC coupled with a mass spectrometry. Data analyses were conducted with Progenesis QI for Proteomics Software v2.0. Gene Ontology (GO) terms and protein-protein interaction analysis were obtained. RESULTS A total of 306 proteins (≈6 peptides) were identified. Among them, 122 were differentially expressed in comparisons among children with different caries status. Out of the 122 proteins, the proteins E2AK4 and SH3L2 were exclusively present in groups CF and EC, respectively, and 8 proteins (HAUS4, CAH1, IL36A, IL36G, AIMP1, KLHL8, KLH13, and SAA1) were considered caries-related proteins when compared to caries-free children; they were up-regulated proteins in the caries groups (EC and DC). CONCLUSION The identification of exclusive proteins for caries-free or carious-related conditions may help in understanding the mechanisms of caries and predicting risk as well as advancing in caries control or anti-caries approaches.
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Affiliation(s)
- Sarah F F Guedes
- Faculty of Pharmacy, Dentistry and Nursing, Postgraduate Program in Dentistry, Federal University of Ceará, Fortaleza, Brazil
| | - Beatriz G Neves
- School of Dentistry, Federal University of Ceará, Sobral, Brazil
| | | | - Gustavo H M F Souza
- MS Applications Development Laboratory, Waters Corporation, São Paulo, Brazil
| | - Abelardo B M Lima-Neto
- Laboratory of Biotechnology and Molecular Biology, State University of Ceará, Fortaleza, Brazil
| | - Maria Izabel F Guedes
- Laboratory of Biotechnology and Molecular Biology, State University of Ceará, Fortaleza, Brazil
| | - Simone Duarte
- Department of Cariology, Operative Dentistry and Dental Public Health, School of Dentistry, Indiana University - Purdue University Indianapolis, Indianapolis, IN, USA
| | - Lidiany K A Rodrigues
- Faculty of Pharmacy, Dentistry and Nursing, Postgraduate Program in Dentistry, Federal University of Ceará, Fortaleza, Brazil
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8
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De Zoysa T, Phizicky EM. Hypomodified tRNA in evolutionarily distant yeasts can trigger rapid tRNA decay to activate the general amino acid control response, but with different consequences. PLoS Genet 2020; 16:e1008893. [PMID: 32841241 PMCID: PMC7473580 DOI: 10.1371/journal.pgen.1008893] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 09/04/2020] [Accepted: 07/22/2020] [Indexed: 12/14/2022] Open
Abstract
All tRNAs are extensively modified, and modification deficiency often results in growth defects in the budding yeast Saccharomyces cerevisiae and neurological or other disorders in humans. In S. cerevisiae, lack of any of several tRNA body modifications results in rapid tRNA decay (RTD) of certain mature tRNAs by the 5'-3' exonucleases Rat1 and Xrn1. As tRNA quality control decay mechanisms are not extensively studied in other eukaryotes, we studied trm8Δ mutants in the evolutionarily distant fission yeast Schizosaccharomyces pombe, which lack 7-methylguanosine at G46 (m7G46) of their tRNAs. We report here that S. pombe trm8Δ mutants are temperature sensitive primarily due to decay of tRNATyr(GUA) and that spontaneous mutations in the RAT1 ortholog dhp1+ restored temperature resistance and prevented tRNA decay, demonstrating conservation of the RTD pathway. We also report for the first time evidence linking the RTD and the general amino acid control (GAAC) pathways, which we show in both S. pombe and S. cerevisiae. In S. pombe trm8Δ mutants, spontaneous GAAC mutations restored temperature resistance and tRNA levels, and the trm8Δ temperature sensitivity was precisely linked to GAAC activation due to tRNATyr(GUA) decay. Similarly, in the well-studied S. cerevisiae trm8Δ trm4Δ RTD mutant, temperature sensitivity was closely linked to GAAC activation due to tRNAVal(AAC) decay; however, in S. cerevisiae, GAAC mutations increased tRNA loss and exacerbated temperature sensitivity. A similar exacerbated growth defect occurred upon GAAC mutation in S. cerevisiae trm8Δ and other single modification mutants that triggered RTD. Thus, these results demonstrate a conserved GAAC activation coincident with RTD in S. pombe and S. cerevisiae, but an opposite impact of the GAAC response in the two organisms. We speculate that the RTD pathway and its regulation of the GAAC pathway is widely conserved in eukaryotes, extending to other mutants affecting tRNA body modifications.
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Affiliation(s)
- Thareendra De Zoysa
- Department of Biochemistry and Biophysics, Center for RNA Biology, University of Rochester School of Medicine, Rochester, NY, United States of America
| | - Eric M. Phizicky
- Department of Biochemistry and Biophysics, Center for RNA Biology, University of Rochester School of Medicine, Rochester, NY, United States of America
- * E-mail:
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9
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Yılmazer M, Kartal B, Tarhan Ç, Özarabacı I, Akçaalan S, Özkan E, Karaer Uzuner S, Arıcan E, Palabıyık B. A Genome-Wide Screen for Wortmannin-Resistant Mutants in Schizosaccharomyces pombe: The Phosphorylation-Impaired Mutants Are Resistant to Signaling Defect. DNA Cell Biol 2019; 38:1427-1436. [PMID: 31657618 DOI: 10.1089/dna.2019.5003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Complex human diseases such as metabolic disorders, cancer, neurodegenerative diseases, and mitochondrial dysfunctions arise from the biochemical or genetic defects in various cellular processes. Therefore, it is important to understand which metabolic processes are affected by which cellular impairment. Because genome-wide screening of mutant collections (haploid/diploid deletion library) provides important clues for the understanding of conserved biological processes and for finding potential target genes, we screened the haploid mutant collection of Schizosaccharomyces pombe with wortmannin that inhibits phosphatidylinositol-3-kinase signaling. Using genome-wide screening, we determined that 52 mutants were resistant to this chemical. When 52 genes that are deleted in these mutants were grouped in 41 different biological processes, we found that 37 of them have human orthologues and 4 genes were associated with human metabolic disorders. In addition, when we examined the pathways in which these 52 genes function, we determined that 9 genes were related to phosphorylation process. These results might provide new insights for better understanding of certain human diseases.
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Affiliation(s)
- Merve Yılmazer
- Department of Molecular Biology and Genetics, Faculty of Science, Istanbul University, Istanbul, Turkey
| | - Burcu Kartal
- Department of Molecular Biology and Genetics, Institute of Graduate Studies in Sciences, Istanbul University, Istanbul, Turkey
| | - Çağatay Tarhan
- Department of Molecular Biology and Genetics, Faculty of Science, Istanbul University, Istanbul, Turkey
| | - Ilayda Özarabacı
- Department of Molecular Biology and Genetics, Institute of Graduate Studies in Sciences, Istanbul University, Istanbul, Turkey
| | - Sedef Akçaalan
- Department of Molecular Biology and Genetics, Institute of Graduate Studies in Sciences, Istanbul University, Istanbul, Turkey
| | - Egemen Özkan
- Department of Molecular Biology and Genetics, Institute of Graduate Studies in Sciences, Istanbul University, Istanbul, Turkey
| | - Semian Karaer Uzuner
- Department of Molecular Biology and Genetics, Faculty of Science, Istanbul University, Istanbul, Turkey
| | - Ercan Arıcan
- Department of Molecular Biology and Genetics, Faculty of Science, Istanbul University, Istanbul, Turkey
| | - Bedia Palabıyık
- Department of Molecular Biology and Genetics, Faculty of Science, Istanbul University, Istanbul, Turkey
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10
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Leipheimer J, Bloom ALM, Panepinto JC. Protein Kinases at the Intersection of Translation and Virulence. Front Cell Infect Microbiol 2019; 9:318. [PMID: 31572689 PMCID: PMC6749009 DOI: 10.3389/fcimb.2019.00318] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Accepted: 08/26/2019] [Indexed: 12/14/2022] Open
Abstract
As free living organisms, fungi are challenged with a variety of environmental insults that threaten their cellular processes. In some cases, these challenges mimic conditions present within mammals, resulting in the accidental selection of virulence factors over evolutionary time. Be it within a host or the soil, fungi must contend with environmental challenges through the production of stress effector proteins while maintaining factors required for viability in any condition. Initiation and upkeep of this balancing act is mainly under the control of kinases that affect the propensity and selectivity of protein translation. This review will focus on kinases in pathogenic fungi that facilitate a virulence phenotype through translational control.
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Affiliation(s)
- Jay Leipheimer
- Department of Microbiology and Immunology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, United States
| | - Amanda L M Bloom
- Department of Microbiology and Immunology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, United States
| | - John C Panepinto
- Department of Microbiology and Immunology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, United States
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11
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Boye E, Grallert B. eIF2α phosphorylation and the regulation of translation. Curr Genet 2019; 66:293-297. [PMID: 31485739 DOI: 10.1007/s00294-019-01026-1] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2019] [Revised: 08/13/2019] [Accepted: 08/16/2019] [Indexed: 12/27/2022]
Abstract
We discuss novel insight into the role and consequences of the phosphorylation of the translation initiation factor eIF2α in the context of stress responses and cell-cycle regulation. eIF2α is centrally located to regulate translation and its phosphorylation in response to different environmental challenges is one of the best characterized stress-response pathways. In addition to its role in stress management, eIF2α phosphorylation is also linked to cell-cycle progression and memory consolidation in the nervous system. The best known consequences of eIF2α phosphorylation are downregulation of global translation and stimulation of translation of some mRNAs. However, recent evidence shows that (i) eIF2α phosphorylation is not always required for the downregulation of global translation after exposure to stress and (ii) eIF2α phosphorylation does not necessarily lead to the downregulation of global translation. These results suggest that the textbook view of eIF2α phosphorylation needs to be revised and that there must be additional regulatory mechanisms at play.
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Affiliation(s)
- Erik Boye
- Department of Radiation Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway
| | - Beáta Grallert
- Department of Radiation Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway.
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12
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Wang P, Xu Y, Zhang J, Shi L, Lei T, Hou Y, Lu Z, Zhao Y. The amino acid sensor general control nonderepressible 2 (GCN2) controls T H9 cells and allergic airway inflammation. J Allergy Clin Immunol 2019; 144:1091-1105. [PMID: 31121187 DOI: 10.1016/j.jaci.2019.04.028] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 04/11/2019] [Accepted: 04/17/2019] [Indexed: 12/20/2022]
Abstract
BACKGROUND TH9 cells have emerged as important mediators of allergic airway inflammation. There is evidence that general control nonderepressible 2 (GCN2) affects the immune response under some stress conditions. However, whether GCN2 regulates CD4+ T-cell differentiation during allergic inflammation remains unknown. OBJECTIVE We sought to clarify the regulatory roles of GCN2 in CD4+ T-cell subset differentiation and its significance in patients with allergic airway inflammation. METHODS The effects of GCN2 in differentiation of TH cell subsets were detected by using the in vitro induction system. GCN2 knockout mice, ovalbumin-induced allergic airway inflammation, and adoptive transfer mouse models were used to determine the significance of GCN2 in TH9 differentiation and allergic airway inflammation in vivo. RNA sequencing, real-time PCR, Western blotting, and other molecular approaches were used to identify the molecular mechanisms relevant to regulation of GCN2 in TH9 cell differentiation. RESULTS GCN2 deficiency significantly inhibited differentiation of TH9 cells but not TH1, TH2, and regulatory T cells. GCN2 knockout mice and recombination-activating gene 2 knockout (Rag2KO) mice that received adoptively transferred GCN2-deficient CD4+ T cells exhibited reduced TH9 differentiation and less severe allergic airway inflammation. Furthermore, the isolated GCN2-deficient TH9 cells also mediated less severe allergic airway inflammation on adoptive transfer. Mechanistically, GCN2 deficiency inhibits TH9 cell differentiation through a hypoxia-inducible factor 1α-dependent glycolytic pathway. CONCLUSION Our results reveal a novel role of GCN2 in TH9 cell differentiation. Our findings indicate that new strategies to inhibit GCN2 activity might provide novel approaches to attenuate allergic airway inflammation.
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Affiliation(s)
- Peng Wang
- State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China; University of Chinese Academy of Sciences, Beijing, China; Department of Immunology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, China
| | - Yana Xu
- State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China; University of Chinese Academy of Sciences, Beijing, China
| | - Jiayu Zhang
- State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China; University of Chinese Academy of Sciences, Beijing, China
| | - Lu Shi
- State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Tong Lei
- University of Chinese Academy of Sciences, Beijing, China
| | - Yangxiao Hou
- State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China; University of Chinese Academy of Sciences, Beijing, China
| | - Zhongbing Lu
- University of Chinese Academy of Sciences, Beijing, China.
| | - Yong Zhao
- State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China; University of Chinese Academy of Sciences, Beijing, China; Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, China.
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13
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Parzych K, Saavedra-García P, Valbuena GN, Al-Sadah HA, Robinson ME, Penfold L, Kuzeva DM, Ruiz-Tellez A, Loaiza S, Holzmann V, Caputo V, Johnson DC, Kaiser MF, Karadimitris A, Lam EWF, Chevet E, Feldhahn N, Keun HC, Auner HW. The coordinated action of VCP/p97 and GCN2 regulates cancer cell metabolism and proteostasis during nutrient limitation. Oncogene 2019; 38:3216-3231. [PMID: 30626938 PMCID: PMC6756015 DOI: 10.1038/s41388-018-0651-z] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Revised: 12/05/2018] [Accepted: 12/07/2018] [Indexed: 12/30/2022]
Abstract
VCP/p97 regulates numerous cellular functions by mediating protein degradation through its segregase activity. Its key role in governing protein homoeostasis has made VCP/p97 an appealing anticancer drug target. Here, we provide evidence that VCP/p97 acts as a regulator of cellular metabolism. We found that VCP/p97 was tied to multiple metabolic processes on the gene expression level in a diverse range of cancer cell lines and in patient-derived multiple myeloma cells. Cellular VCP/p97 dependency to maintain proteostasis was increased under conditions of glucose and glutamine limitation in a range of cancer cell lines from different tissues. Moreover, glutamine depletion led to increased VCP/p97 expression, whereas VCP/p97 inhibition perturbed metabolic processes and intracellular amino acid turnover. GCN2, an amino acid-sensing kinase, attenuated stress signalling and cell death triggered by VCP/p97 inhibition and nutrient shortages and modulated ERK activation, autophagy, and glycolytic metabolite turnover. Together, our data point to an interconnected role of VCP/p97 and GCN2 in maintaining cancer cell metabolic and protein homoeostasis.
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Affiliation(s)
- Katarzyna Parzych
- Cancer Cell Protein Metabolism Group, Centre for Haematology, Department of Medicine, Imperial College London, London, UK
| | - Paula Saavedra-García
- Cancer Cell Protein Metabolism Group, Centre for Haematology, Department of Medicine, Imperial College London, London, UK
| | - Gabriel N Valbuena
- Division of Cancer, Department of Surgery and Cancer, Imperial College London, Hammersmith Hospital, London, UK
| | - Hibah A Al-Sadah
- Cancer Cell Protein Metabolism Group, Centre for Haematology, Department of Medicine, Imperial College London, London, UK
| | - Mark E Robinson
- Centre for Haematology, Department of Medicine, Imperial College London, London, UK
| | - Lucy Penfold
- Cancer Cell Protein Metabolism Group, Centre for Haematology, Department of Medicine, Imperial College London, London, UK
| | - Desislava M Kuzeva
- Cancer Cell Protein Metabolism Group, Centre for Haematology, Department of Medicine, Imperial College London, London, UK
| | - Angie Ruiz-Tellez
- Cancer Cell Protein Metabolism Group, Centre for Haematology, Department of Medicine, Imperial College London, London, UK
| | - Sandra Loaiza
- Cancer Cell Protein Metabolism Group, Centre for Haematology, Department of Medicine, Imperial College London, London, UK
| | - Viktoria Holzmann
- Cancer Cell Protein Metabolism Group, Centre for Haematology, Department of Medicine, Imperial College London, London, UK
| | - Valentina Caputo
- Centre for Haematology, Department of Medicine, Imperial College London, London, UK
| | - David C Johnson
- Division of Molecular Pathfology, Institute of Cancer Research, Sutton, UK
| | - Martin F Kaiser
- Division of Molecular Pathfology, Institute of Cancer Research, Sutton, UK
| | | | - Eric W-F Lam
- Division of Cancer, Department of Surgery and Cancer, Imperial College London, Hammersmith Hospital, London, UK
| | - Eric Chevet
- INSERM U1242, Chemistry, Oncogenesis, Stress, Signaling, Université de Rennes 1, Rennes, France
- Centre de Lutte Contre le Cancer Eugène Marquis Rennes, Rennes, France
| | - Niklas Feldhahn
- Centre for Haematology, Department of Medicine, Imperial College London, London, UK
| | - Hector C Keun
- Division of Cancer, Department of Surgery and Cancer, Imperial College London, Hammersmith Hospital, London, UK
| | - Holger W Auner
- Cancer Cell Protein Metabolism Group, Centre for Haematology, Department of Medicine, Imperial College London, London, UK.
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14
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General amino acid control in fission yeast is regulated by a nonconserved transcription factor, with functions analogous to Gcn4/Atf4. Proc Natl Acad Sci U S A 2018; 115:E1829-E1838. [PMID: 29432178 DOI: 10.1073/pnas.1713991115] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Eukaryotes respond to amino acid starvation by enhancing the translation of mRNAs encoding b-ZIP family transcription factors (GCN4 in Saccharomyces cerevisiae and ATF4 in mammals), which launch transcriptional programs to counter this stress. This pathway involves phosphorylation of the eIF2 translation factor by Gcn2-protein kinases and is regulated by upstream ORFs (uORFs) in the GCN4/ATF4 5' leaders. Here, we present evidence that the transcription factors that mediate this response are not evolutionarily conserved. Although cells of the fission yeast Schizosaccharomyces pombe respond transcriptionally to amino acid starvation, they lack clear Gcn4 and Atf4 orthologs. We used ribosome profiling to identify mediators of this response in S. pombe, looking for transcription factors that behave like GCN4 We discovered a transcription factor (Fil1) translationally induced by amino acid starvation in a 5' leader and Gcn2-dependent manner. Like Gcn4, Fil1 is required for the transcriptional response to amino acid starvation, and Gcn4 and Fil1 regulate similar genes. Despite their similarities in regulation, function, and targets, Fil1 and Gcn4 belong to different transcription factor families (GATA and b-ZIP, respectively). Thus, the same functions are performed by nonorthologous proteins under similar regulation. These results highlight the plasticity of transcriptional networks, which maintain conserved principles with nonconserved regulators.
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15
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Gao L, Zhu H, Fan H, Liu Z. Chloroquine exacerbates serum withdrawal-induced G 1 phase arrest via an autophagy-independent mechanism. RSC Adv 2017. [DOI: 10.1039/c7ra06737b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Chloroquine exacerbates serum withdrawal-induced G1 phase arrest via an autophagy-independent, but an oxidative stress-dependent mechanism in endothelial cells.
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Affiliation(s)
- Lei Gao
- Research Institute of Heart Failure
- Shanghai East Hospital
- Tongji University School of Medicine
- Shanghai
- China
| | - Hongming Zhu
- Research Institute of Heart Failure
- Shanghai East Hospital
- Tongji University School of Medicine
- Shanghai
- China
| | - Huimin Fan
- Research Institute of Heart Failure
- Shanghai East Hospital
- Tongji University School of Medicine
- Shanghai
- China
| | - Zhongmin Liu
- Research Institute of Heart Failure
- Shanghai East Hospital
- Tongji University School of Medicine
- Shanghai
- China
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16
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Silva RC, Dautel M, Di Genova BM, Amberg DC, Castilho BA, Sattlegger E. The Gcn2 Regulator Yih1 Interacts with the Cyclin Dependent Kinase Cdc28 and Promotes Cell Cycle Progression through G2/M in Budding Yeast. PLoS One 2015; 10:e0131070. [PMID: 26176233 PMCID: PMC4503747 DOI: 10.1371/journal.pone.0131070] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2014] [Accepted: 05/28/2015] [Indexed: 12/01/2022] Open
Abstract
The Saccharomyces cerevisiae protein Yih1, when overexpressed, inhibits the eIF2 alpha kinase Gcn2 by competing for Gcn1 binding. However, deletion of YIH1 has no detectable effect on Gcn2 activity, suggesting that Yih1 is not a general inhibitor of Gcn2, and has no phenotypic defect identified so far. Thus, its physiological role is largely unknown. Here, we show that Yih1 is involved in the cell cycle. Yeast lacking Yih1 displays morphological patterns and DNA content indicative of a delay in the G2/M phases of the cell cycle, and this phenotype is independent of Gcn1 and Gcn2. Accordingly, the levels of phosphorylated eIF2α, which show a cell cycle-dependent fluctuation, are not altered in cells devoid of Yih1. We present several lines of evidence indicating that Yih1 is in a complex with Cdc28. Yih1 pulls down endogenous Cdc28 in vivo and this interaction is enhanced when Cdc28 is active, suggesting that Yih1 modulates the function of Cdc28 in specific stages of the cell cycle. We also demonstrate, by Bimolecular Fluorescence Complementation, that endogenous Yih1 and Cdc28 interact with each other, confirming Yih1 as a bona fide Cdc28 binding partner. Amino acid substitutions within helix H2 of the RWD domain of Yih1 enhance Yih1-Cdc28 association. Overexpression of this mutant, but not of wild type Yih1, leads to a phenotype similar to that of YIH1 deletion, supporting the view that Yih1 is involved through Cdc28 in the regulation of the cell cycle. We further show that IMPACT, the mammalian homologue of Yih1, interacts with CDK1, the mammalian counterpart of Cdc28, indicating that the involvement with the cell cycle is conserved. Together, these data provide insights into the cellular function of Yih1/IMPACT, and provide the basis for future studies on the role of this protein in the cell cycle.
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Affiliation(s)
- Richard C. Silva
- Department of Microbiology, Immunology and Parasitology, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Martina Dautel
- Institute of Natural and Mathematical Sciences, Massey University, Auckland, New Zealand
| | - Bruno M. Di Genova
- Department of Microbiology, Immunology and Parasitology, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - David C. Amberg
- Department of Biochemistry and Molecular Biology, Upstate Medical University, State University of New York, Syracuse, New York, United States of America
| | - Beatriz A. Castilho
- Department of Microbiology, Immunology and Parasitology, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Evelyn Sattlegger
- Institute of Natural and Mathematical Sciences, Massey University, Auckland, New Zealand
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17
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Lehman SL, Cerniglia GJ, Johannes GJ, Ye J, Ryeom S, Koumenis C. Translational Upregulation of an Individual p21Cip1 Transcript Variant by GCN2 Regulates Cell Proliferation and Survival under Nutrient Stress. PLoS Genet 2015; 11:e1005212. [PMID: 26102367 PMCID: PMC4477940 DOI: 10.1371/journal.pgen.1005212] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Accepted: 04/13/2015] [Indexed: 12/20/2022] Open
Abstract
Multiple transcripts encode for the cell cycle inhibitor p21Cip1. These transcripts produce identical proteins but differ in their 5’ untranslated regions (UTRs). Although several stresses that induce p21 have been characterized, the mechanisms regulating the individual transcript variants and their functional significance are unknown. Here we demonstrate through 35S labeling, luciferase reporter assays, and polysome transcript profiling that activation of the Integrated Stress Response (ISR) kinase GCN2 selectively upregulates the translation of a p21 transcript variant containing 5’ upstream open reading frames (uORFs) through phosphorylation of the eukaryotic translation initiation factor eIF2α. Mutational analysis reveals that the uORFs suppress translation under basal conditions, but promote translation under stress. Functionally, ablation of p21 ameliorates G1/S arrest and reduces cell survival in response to GCN2 activation. These findings uncover a novel mechanism of p21 post-transcriptional regulation, offer functional significance for the existence of multiple p21 transcripts, and support a key role for GCN2 in regulating the cell cycle under stress. Cells sense nutrient levels in their environment in order to determine if conditions are favorable to divide. GCN2 is a protein that senses amino acids and responds to amino acid deficiency by suppressing protein synthesis and increasing the expression of genes involved in recovery from nutrient stress. Although GCN2’s role in amino acid sensing is well-characterized, it is not known how it links nutrient availability with the cell cycle. Here, we show that GCN2 induces the cell cycle inhibitor p21Cip1 at the level of protein translation. The induction of p21 is limited to a specific messenger RNA variant that contains upstream open reading frames, and these upstream open reading frames are required for its enhanced translation under stress. Previously, the functional significance of these different p21 variants was unknown. Upregulation of p21 allows cells to halt division and survive under conditions of nutrient stress. Collectively, this work demonstrates a new mechanism of p21 regulation and the connection between GCN2 and the cell cycle.
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Affiliation(s)
- Stacey L. Lehman
- Department of Radiation Oncology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - George J. Cerniglia
- Department of Radiation Oncology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Gregg J. Johannes
- Department of Pathology and Laboratory Medicine, Drexel University College of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Jiangbin Ye
- Department of Radiation Oncology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Sandra Ryeom
- Department of Cancer Biology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Constantinos Koumenis
- Department of Radiation Oncology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- * E-mail:
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18
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Ždralević M, Longo V, Guaragnella N, Giannattasio S, Timperio AM, Zolla L. Differential proteome–metabolome profiling of YCA1-knock-out and wild type cells reveals novel metabolic pathways and cellular processes dependent on the yeast metacaspase. MOLECULAR BIOSYSTEMS 2015; 11:1573-83. [DOI: 10.1039/c4mb00660g] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
A combined proteomic and metabolomic approach revealed new non-apoptotic roles of the metacaspaseYCA1gene inSaccharomyces cerevisiae, highlighting its involvement in the cell metabolism and stress response.
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Affiliation(s)
- Maša Ždralević
- CNR
- Istituto di Biomembrane e Bioenergetica
- 70126 Bari
- Italy
| | - Valentina Longo
- Department of Ecological and Biological Sciences
- University of Tuscia
- Largo dell'Università
- 01100 Viterbo
- Italy
| | | | | | - Anna Maria Timperio
- Department of Ecological and Biological Sciences
- University of Tuscia
- Largo dell'Università
- 01100 Viterbo
- Italy
| | - Lello Zolla
- Department of Ecological and Biological Sciences
- University of Tuscia
- Largo dell'Università
- 01100 Viterbo
- Italy
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19
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Abstract
Gcn2 was first described in budding yeast as a serine/threonine protein kinase involved in the response to amino acid starvation and this is its best characterized role to date. Recent work has revealed new and exciting roles for Gcn2, which affect many aspects of cellular physiology in response to a number of stresses in addition to starvation. Furthermore, the Gcn2 pathway has been implicated in diseases such as cancer and Alzheimer's disease, and therefore elucidating the new roles of Gcn2 seems ever more important.
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20
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Rødland GE, Tvegård T, Boye E, Grallert B. Crosstalk between the Tor and Gcn2 pathways in response to different stresses. Cell Cycle 2013; 13:453-61. [PMID: 24280780 DOI: 10.4161/cc.27270] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Regulating growth and the cell cycle in response to environmental fluctuations is important for all organisms in order to maintain viability. Two major pathways for translational regulation are found in higher eukaryotes: the Tor signaling pathway and those operating through the eIF2α kinases. Studies from several organisms indicate that the two pathways are interlinked, in that Tor complex 1 (TORC1) negatively regulates the Gcn2 kinase. Furthermore, inactivation of TORC1 may be required for activation of Gcn2 in response to stress. Here, we use the model organism Schizosaccharomyces pombe to investigate this crosstalk further. We find that the relationship is more complex than previously thought. First, in response to UV irradiation and oxidative stress, Gcn2 is fully activated in the presence of TORC1 signaling. Second, during amino-acid starvation, activation of Gcn2 is dependent on Tor2 activity, and Gcn2 is required for timely inactivation of the Tor pathway. Our data show that the crosstalk between the two pathways varies with the actual stress applied.
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Affiliation(s)
- Gro Elise Rødland
- Department of Cell Biology; Institute for Cancer Research; Oslo University Hospital; Oslo, Norway
| | - Tonje Tvegård
- Department of Cell Biology; Institute for Cancer Research; Oslo University Hospital; Oslo, Norway
| | - Erik Boye
- Department of Cell Biology; Institute for Cancer Research; Oslo University Hospital; Oslo, Norway; Institute for Molecular Biosciences; University of Oslo; Oslo, Norway
| | - Beáta Grallert
- Department of Cell Biology; Institute for Cancer Research; Oslo University Hospital; Oslo, Norway
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