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Blaszczak E, Pasquier E, Le Dez G, Odrzywolski A, Lazarewicz N, Brossard A, Fornal E, Moskalek P, Wysocki R, Rabut G. Dissecting Ubiquitylation and DNA Damage Response Pathways in the Yeast Saccharomyces cerevisiae Using a Proteome-Wide Approach. Mol Cell Proteomics 2024; 23:100695. [PMID: 38101750 PMCID: PMC10803944 DOI: 10.1016/j.mcpro.2023.100695] [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: 06/26/2023] [Revised: 11/26/2023] [Accepted: 12/12/2023] [Indexed: 12/17/2023] Open
Abstract
In response to genotoxic stress, cells evolved with a complex signaling network referred to as the DNA damage response (DDR). It is now well established that the DDR depends upon various posttranslational modifications; among them, ubiquitylation plays a key regulatory role. Here, we profiled ubiquitylation in response to the DNA alkylating agent methyl methanesulfonate (MMS) in the budding yeast Saccharomyces cerevisiae using quantitative proteomics. To discover new proteins ubiquitylated upon DNA replication stress, we used stable isotope labeling by amino acids in cell culture, followed by an enrichment of ubiquitylated peptides and LC-MS/MS. In total, we identified 1853 ubiquitylated proteins, including 473 proteins that appeared upregulated more than 2-fold in response to MMS treatment. This enabled us to localize 519 ubiquitylation sites potentially regulated upon MMS in 435 proteins. We demonstrated that the overexpression of some of these proteins renders the cells sensitive to MMS. We also assayed the abundance change upon MMS treatment of a selection of yeast nuclear proteins. Several of them were differentially regulated upon MMS treatment. These findings corroborate the important role of ubiquitin-proteasome-mediated degradation in regulating the DDR.
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Affiliation(s)
- Ewa Blaszczak
- Department of Genetics and Cell Physiology, Faculty of Biological Sciences, University of Wroclaw, Wroclaw, Poland; Department of Biochemistry and Molecular Biology, Faculty of Medical Sciences, Medical University of Lublin, Lublin, Poland.
| | - Emeline Pasquier
- Univ Rennes, CNRS, INSERM, Institute of Genetics and Development of Rennes (IGDR), UMR 6290, U1305, Rennes, France
| | - Gaëlle Le Dez
- Univ Rennes, CNRS, INSERM, Institute of Genetics and Development of Rennes (IGDR), UMR 6290, U1305, Rennes, France
| | - Adrian Odrzywolski
- Department of Biochemistry and Molecular Biology, Faculty of Medical Sciences, Medical University of Lublin, Lublin, Poland
| | - Natalia Lazarewicz
- Department of Genetics and Cell Physiology, Faculty of Biological Sciences, University of Wroclaw, Wroclaw, Poland; Univ Rennes, CNRS, INSERM, Institute of Genetics and Development of Rennes (IGDR), UMR 6290, U1305, Rennes, France
| | - Audrey Brossard
- Univ Rennes, CNRS, INSERM, Institute of Genetics and Development of Rennes (IGDR), UMR 6290, U1305, Rennes, France
| | - Emilia Fornal
- Department of Bioanalytics, Faculty of Biomedicine, Medical University of Lublin, Lublin, Poland
| | - Piotr Moskalek
- Department of Genetics and Cell Physiology, Faculty of Biological Sciences, University of Wroclaw, Wroclaw, Poland
| | - Robert Wysocki
- Department of Genetics and Cell Physiology, Faculty of Biological Sciences, University of Wroclaw, Wroclaw, Poland.
| | - Gwenaël Rabut
- Univ Rennes, CNRS, INSERM, Institute of Genetics and Development of Rennes (IGDR), UMR 6290, U1305, Rennes, France.
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Lehner MH, Walker J, Temcinaite K, Herlihy A, Taschner M, Berger AC, Corbett AH, Dirac Svejstrup AB, Svejstrup JQ. Yeast Smy2 and its human homologs GIGYF1 and -2 regulate Cdc48/VCP function during transcription stress. Cell Rep 2022; 41:111536. [PMID: 36288698 PMCID: PMC9638028 DOI: 10.1016/j.celrep.2022.111536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 06/09/2022] [Accepted: 09/29/2022] [Indexed: 12/02/2022] Open
Abstract
The "last resort" pathway results in ubiquitylation and degradation of RNA polymerase II in response to transcription stress and is governed by factors such as Def1 in yeast. Here, we show that the SMY2 gene acts as a multi-copy suppressor of DEF1 deletion and functions at multiple steps of the last resort pathway. We also provide genetic and biochemical evidence from disparate cellular processes that Smy2 works more broadly as a hitherto overlooked regulator of Cdc48 function. Similarly, the Smy2 homologs GIGYF1 and -2 affect the transcription stress response in human cells and regulate the function of the Cdc48 homolog VCP/p97, presently being explored as a target for cancer therapy. Indeed, we show that the apoptosis-inducing effect of VCP inhibitors NMS-873 and CB-5083 is GIGYF1/2 dependent.
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Affiliation(s)
- Michelle Harreman Lehner
- Mechanisms of Transcription Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Jane Walker
- Mechanisms of Transcription Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Kotryna Temcinaite
- Mechanisms of Transcription Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Anna Herlihy
- Mechanisms of Transcription Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Michael Taschner
- Mechanisms of Transcription Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Adam C Berger
- Department of Biology, RRC 1021, Emory University, 1510 Clifton Road, NE, Atlanta 30322, GA, USA
| | - Anita H Corbett
- Department of Biology, RRC 1021, Emory University, 1510 Clifton Road, NE, Atlanta 30322, GA, USA
| | - A Barbara Dirac Svejstrup
- Mechanisms of Transcription Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK; Department of Cellular and Molecular Medicine, Panum Institute, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen N, Denmark
| | - Jesper Q Svejstrup
- Mechanisms of Transcription Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK; Department of Cellular and Molecular Medicine, Panum Institute, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen N, Denmark.
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3
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Radzinski M, Oppenheim T, Metanis N, Reichmann D. The Cys Sense: Thiol Redox Switches Mediate Life Cycles of Cellular Proteins. Biomolecules 2021; 11:469. [PMID: 33809923 PMCID: PMC8004198 DOI: 10.3390/biom11030469] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Revised: 03/15/2021] [Accepted: 03/16/2021] [Indexed: 12/14/2022] Open
Abstract
Protein homeostasis is an essential component of proper cellular function; however, sustaining protein health is a challenging task, especially during the aerobic lifestyle. Natural cellular oxidants may be involved in cell signaling and antibacterial defense; however, imbalanced levels can lead to protein misfolding, cell damage, and death. This merges together the processes of protein homeostasis and redox regulation. At the heart of this process are redox-regulated proteins or thiol-based switches, which carefully mediate various steps of protein homeostasis across folding, localization, quality control, and degradation pathways. In this review, we discuss the "redox code" of the proteostasis network, which shapes protein health during cell growth and aging. We describe the sources and types of thiol modifications and elaborate on diverse strategies of evolving antioxidant proteins in proteostasis networks during oxidative stress conditions. We also highlight the involvement of cysteines in protein degradation across varying levels, showcasing the importance of cysteine thiols in proteostasis at large. The individual examples and mechanisms raised open the door for extensive future research exploring the interplay between the redox and protein homeostasis systems. Understanding this interplay will enable us to re-write the redox code of cells and use it for biotechnological and therapeutic purposes.
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Affiliation(s)
- Meytal Radzinski
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Safra Campus Givat Ram, The Hebrew University of Jerusalem, Jerusalem 91904, Israel; (M.R.); (T.O.)
| | - Tal Oppenheim
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Safra Campus Givat Ram, The Hebrew University of Jerusalem, Jerusalem 91904, Israel; (M.R.); (T.O.)
| | - Norman Metanis
- Institute of Chemistry, Safra Campus Givat Ram, The Hebrew University of Jerusalem, Jerusalem 91904, Israel;
| | - Dana Reichmann
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Safra Campus Givat Ram, The Hebrew University of Jerusalem, Jerusalem 91904, Israel; (M.R.); (T.O.)
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4
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Sienski G, Narayan P, Bonner JM, Kory N, Boland S, Arczewska AA, Ralvenius WT, Akay L, Lockshin E, He L, Milo B, Graziosi A, Baru V, Lewis CA, Kellis M, Sabatini DM, Tsai LH, Lindquist S. APOE4 disrupts intracellular lipid homeostasis in human iPSC-derived glia. Sci Transl Med 2021; 13:eaaz4564. [PMID: 33658354 PMCID: PMC8218593 DOI: 10.1126/scitranslmed.aaz4564] [Citation(s) in RCA: 130] [Impact Index Per Article: 43.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Revised: 05/27/2020] [Accepted: 11/05/2020] [Indexed: 12/11/2022]
Abstract
The E4 allele of the apolipoprotein E gene (APOE) has been established as a genetic risk factor for many diseases including cardiovascular diseases and Alzheimer's disease (AD), yet its mechanism of action remains poorly understood. APOE is a lipid transport protein, and the dysregulation of lipids has recently emerged as a key feature of several neurodegenerative diseases including AD. However, it is unclear how APOE4 perturbs the intracellular lipid state. Here, we report that APOE4, but not APOE3, disrupted the cellular lipidomes of human induced pluripotent stem cell (iPSC)-derived astrocytes generated from fibroblasts of APOE4 or APOE3 carriers, and of yeast expressing human APOE isoforms. We combined lipidomics and unbiased genome-wide screens in yeast with functional and genetic characterization to demonstrate that human APOE4 induced altered lipid homeostasis. These changes resulted in increased unsaturation of fatty acids and accumulation of intracellular lipid droplets both in yeast and in APOE4-expressing human iPSC-derived astrocytes. We then identified genetic and chemical modulators of this lipid disruption. We showed that supplementation of the culture medium with choline (a soluble phospholipid precursor) restored the cellular lipidome to its basal state in APOE4-expressing human iPSC-derived astrocytes and in yeast expressing human APOE4 Our study illuminates key molecular disruptions in lipid metabolism that may contribute to the disease risk linked to the APOE4 genotype. Our study suggests that manipulating lipid metabolism could be a therapeutic approach to help alleviate the consequences of carrying the APOE4 allele.
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Affiliation(s)
- Grzegorz Sienski
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
| | - Priyanka Narayan
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
- Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, MIT, Cambridge, MA 02139, USA
- Genetics and Biochemistry Branch, NIDDK, National Institutes of Health, Bethesda, MD 20814, USA
| | - Julia Maeve Bonner
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
- Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, MIT, Cambridge, MA 02139, USA
| | - Nora Kory
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
| | - Sebastian Boland
- Department of Molecular Metabolism, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA
| | - Aleksandra A Arczewska
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02138, USA
| | - William T Ralvenius
- Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, MIT, Cambridge, MA 02139, USA
| | - Leyla Akay
- Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, MIT, Cambridge, MA 02139, USA
| | - Elana Lockshin
- Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, MIT, Cambridge, MA 02139, USA
| | - Liang He
- Duke University, Durham, NC 27708, USA
| | - Blerta Milo
- Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, MIT, Cambridge, MA 02139, USA
| | - Agnese Graziosi
- Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, MIT, Cambridge, MA 02139, USA
| | - Valeriya Baru
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
| | - Caroline A Lewis
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
| | - Manolis Kellis
- Broad Institute of Harvard and Massachusetts Institute of Technology, Cambridge, MA 02142, USA
- Computer Science and Artificial Intelligence Laboratory, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - David M Sabatini
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
- Broad Institute of Harvard and Massachusetts Institute of Technology, Cambridge, MA 02142, USA
- Massachusetts Institute of Technology, Cambridge, MA 02142, USA
- Howard Hughes Medical Institute, Cambridge, MA 02139, USA
- Koch Institute for Integrative Cancer Research and Massachusetts Institute of Technology, Department of Biology, Cambridge, MA 02139, USA
| | - Li-Huei Tsai
- Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, MIT, Cambridge, MA 02139, USA.
- Broad Institute of Harvard and Massachusetts Institute of Technology, Cambridge, MA 02142, USA
| | - Susan Lindquist
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
- Massachusetts Institute of Technology, Cambridge, MA 02142, USA
- Howard Hughes Medical Institute, Cambridge, MA 02139, USA
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5
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Stuparević I, Novačić A, Rahmouni AR, Fernandez A, Lamb N, Primig M. Regulation of the conserved 3'-5' exoribonuclease EXOSC10/Rrp6 during cell division, development and cancer. Biol Rev Camb Philos Soc 2021; 96:1092-1113. [PMID: 33599082 DOI: 10.1111/brv.12693] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 02/02/2021] [Accepted: 02/03/2021] [Indexed: 01/31/2023]
Abstract
The conserved 3'-5' exoribonuclease EXOSC10/Rrp6 processes and degrades RNA, regulates gene expression and participates in DNA double-strand break repair and control of telomere maintenance via degradation of the telomerase RNA component. EXOSC10/Rrp6 is part of the multimeric nuclear RNA exosome and interacts with numerous proteins. Previous clinical, genetic, biochemical and genomic studies revealed the protein's essential functions in cell division and differentiation, its RNA substrates and its relevance to autoimmune disorders and oncology. However, little is known about the regulatory mechanisms that control the transcription, translation and stability of EXOSC10/Rrp6 during cell growth, development and disease and how these mechanisms evolved from yeast to human. Herein, we provide an overview of the RNA- and protein expression profiles of EXOSC10/Rrp6 during cell division, development and nutritional stress, and we summarize interaction networks and post-translational modifications across species. Additionally, we discuss how known and predicted protein interactions and post-translational modifications influence the stability of EXOSC10/Rrp6. Finally, we explore the idea that different EXOSC10/Rrp6 alleles, which potentially alter cellular protein levels or affect protein function, might influence human development and disease progression. In this review we interpret information from the literature together with genomic data from knowledgebases to inspire future work on the regulation of this essential protein's stability in normal and malignant cells.
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Affiliation(s)
- Igor Stuparević
- Laboratory of Biochemistry, Department of Chemistry and Biochemistry, Faculty of Food Technology and Biotechnology, University of Zagreb, Zagreb, 10000, Croatia
| | - Ana Novačić
- Laboratory of Biochemistry, Department of Chemistry and Biochemistry, Faculty of Food Technology and Biotechnology, University of Zagreb, Zagreb, 10000, Croatia
| | - A Rachid Rahmouni
- Centre de Biophysique Moléculaire, UPR4301 du CNRS, Orléans, 45071, France
| | - Anne Fernandez
- Institut de Génétique Humaine, UMR 9002 CNRS, Montpellier, France
| | - Ned Lamb
- Institut de Génétique Humaine, UMR 9002 CNRS, Montpellier, France
| | - Michael Primig
- Univ Rennes, Inserm, EHESP, Irset (Institut de recherche en santé, environnement et travail) - UMR_S 1085, Rennes, 35000, France
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6
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Rajakumar S, Vijayakumar R, Abhishek A, Selvam GS, Nachiappan V. Loss of ERAD bridging factor UBX2 modulates lipid metabolism and leads to ER stress-associated apoptosis during cadmium toxicity in Saccharomyces cerevisiae. Curr Genet 2020; 66:1003-1017. [DOI: 10.1007/s00294-020-01090-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 06/08/2020] [Accepted: 06/22/2020] [Indexed: 12/17/2022]
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7
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Metzger MB, Scales JL, Dunklebarger MF, Loncarek J, Weissman AM. A protein quality control pathway at the mitochondrial outer membrane. eLife 2020; 9:51065. [PMID: 32118579 PMCID: PMC7136024 DOI: 10.7554/elife.51065] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Accepted: 03/01/2020] [Indexed: 12/27/2022] Open
Abstract
Maintaining the essential functions of mitochondria requires mechanisms to recognize and remove misfolded proteins. However, quality control (QC) pathways for misfolded mitochondrial proteins remain poorly defined. Here, we establish temperature-sensitive (ts-) peripheral mitochondrial outer membrane (MOM) proteins as novel model QC substrates in Saccharomyces cerevisiae. The ts- proteins sen2-1HAts and sam35-2HAts are degraded from the MOM by the ubiquitin-proteasome system. Ubiquitination of sen2-1HAts is mediated by the ubiquitin ligase (E3) Ubr1, while sam35-2HAts is ubiquitinated primarily by San1. Mitochondria-associated degradation (MAD) of both substrates requires the SSA family of Hsp70s and the Hsp40 Sis1, providing the first evidence for chaperone involvement in MAD. In addition to a role for the Cdc48-Npl4-Ufd1 AAA-ATPase complex, Doa1 and a mitochondrial pool of the transmembrane Cdc48 adaptor, Ubx2, are implicated in their degradation. This study reveals a unique QC pathway comprised of a combination of cytosolic and mitochondrial factors that distinguish it from other cellular QC pathways.
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Affiliation(s)
- Meredith B Metzger
- Laboratory of Protein Dynamics and Signaling, Center for Cancer Research, National Cancer Institute at Frederick, Frederick, United States
| | - Jessica L Scales
- Laboratory of Protein Dynamics and Signaling, Center for Cancer Research, National Cancer Institute at Frederick, Frederick, United States
| | - Mitchell F Dunklebarger
- Laboratory of Protein Dynamics and Signaling, Center for Cancer Research, National Cancer Institute at Frederick, Frederick, United States
| | - Jadranka Loncarek
- Laboratory of Protein Dynamics and Signaling, Center for Cancer Research, National Cancer Institute at Frederick, Frederick, United States
| | - Allan M Weissman
- Laboratory of Protein Dynamics and Signaling, Center for Cancer Research, National Cancer Institute at Frederick, Frederick, United States
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8
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Sinha A, Israeli R, Cirigliano A, Gihaz S, Trabelcy B, Braus GH, Gerchman Y, Fishman A, Negri R, Rinaldi T, Pick E. The COP9 signalosome mediates the Spt23 regulated fatty acid desaturation and ergosterol biosynthesis. FASEB J 2020; 34:4870-4889. [PMID: 32077151 DOI: 10.1096/fj.201902487r] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 01/02/2020] [Accepted: 01/14/2020] [Indexed: 02/06/2023]
Abstract
The COP9 signalosome (CSN) is a conserved eukaryotic complex, essential for vitality in all multicellular organisms and critical for the turnover of key cellular proteins through catalytic and non-catalytic activities. Saccharomyces cerevisiae is a powerful model organism for studying fundamental aspects of the CSN complex, since it includes a conserved enzymatic core but lacks non-catalytic activities, probably explaining its non-essentiality for life. A previous transcriptomic analysis of an S. cerevisiae strain deleted in the CSN5/RRI1 gene, encoding to the CSN catalytic subunit, revealed a downregulation of genes involved in lipid metabolism. We now show that the S. cerevisiae CSN holocomplex is essential for cellular lipid homeostasis. Defects in CSN assembly or activity lead to decreased quantities of ergosterol and unsaturated fatty acids (UFA); vacuole defects; diminished lipid droplets (LDs) size; and to accumulation of endoplasmic reticulum (ER) stress. The molecular mechanism behind these findings depends on CSN involvement in upregulating mRNA expression of SPT23. Spt23 is a novel activator of lipid desaturation and ergosterol biosynthesis. Our data reveal for the first time a functional link between the CSN holocomplex and Spt23. Moreover, CSN-dependent upregulation of SPT23 transcription is necessary for the fine-tuning of lipid homeostasis and for cellular health.
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Affiliation(s)
- Abhishek Sinha
- Department of Biology and Environment, Faculty of Natural Sciences, University of Haifa, Oranim, Israel
| | - Ran Israeli
- Department of Biology and Environment, Faculty of Natural Sciences, University of Haifa, Oranim, Israel
| | - Angela Cirigliano
- Department of Biology and Biotechnology "Charles Darwin", Sapienza University of Rome, Rome, Italy
| | - Shalev Gihaz
- Department of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Haifa, Israel
| | - Beny Trabelcy
- Department of Biology and Environment, Faculty of Natural Sciences, University of Haifa, Oranim, Israel
| | - Gerhard H Braus
- Department of Molecular Microbiology and Genetics, Institute of Microbiology and Genetics, Goettingen Center for Molecular Biosciences (GZMB), University of Goettingen, Goettingen, Germany
| | - Yoram Gerchman
- Department of Biology and Environment, Faculty of Natural Sciences, University of Haifa, Oranim, Israel
| | - Ayelet Fishman
- Department of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Haifa, Israel
| | - Rodolfo Negri
- Department of Biology and Biotechnology "Charles Darwin", Sapienza University of Rome, Rome, Italy
| | - Teresa Rinaldi
- Department of Biology and Biotechnology "Charles Darwin", Sapienza University of Rome, Rome, Italy
| | - Elah Pick
- Department of Biology and Environment, Faculty of Natural Sciences, University of Haifa, Oranim, Israel
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9
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A Transcriptional Regulatory System of the S. cerevisiae OLE1Gene Responds to Fatty Acid Species and Intracellular Amount, and not Simply Membrane Status. J Lipids 2020. [DOI: 10.1155/2020/3903257] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
We examined the effects of unsaturated fatty acid (UFA) species and their concentration on the expression ofOLE1,which encodes the stearoyl CoA desaturase, inSaccharomyces cerevisiae. We controlled the amount of UFA taken up by the cell by varying the concentration of tergitol in the medium. When cultured with 1 mM fatty acid in 0.1% tergitol, cells took up much more fatty acid than when cultured with the same concentration of fatty acid at 1% tergitol, although the amount incorporated was dependent on UFA species. For each fatty acid tested, we found that the higher uptake (0.1% tergitol condition) had a stronger impact onOLE1regulation. A principal product of the desaturase 16:1∆9, and the nonnative UFA 18:2∆9,12, most strongly repressed the reporter constructOLE1-lacZtranscription, while the other major product of the desaturase, 18:1∆9, and the nonnative UFA 17:1∆10 caused a more diminished response. Based on these results, our initial hypothesis was thatOLE1was regulated in response to membrane fluidity; however, subsequent work does not support that idea; we have found that conditions that affect membrane fluidity such as growth temperature and growth with saturated ortransfatty acid supplementation, do not regulateOLE1in the direction predicted by fluidity changes. We conclude that at least one signal that regulatesOLE1transcriptional expression is most likely based on the fatty acids themselves.
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10
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Iacovella MG, Bremang M, Basha O, Giacò L, Carotenuto W, Golfieri C, Szakal B, Dal Maschio M, Infantino V, Beznoussenko GV, Joseph CR, Visintin C, Mironov AA, Visintin R, Branzei D, Ferreira-Cerca S, Yeger-Lotem E, De Wulf P. Integrating Rio1 activities discloses its nutrient-activated network in Saccharomyces cerevisiae. Nucleic Acids Res 2019; 46:7586-7611. [PMID: 30011030 PMCID: PMC6125641 DOI: 10.1093/nar/gky618] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Accepted: 06/28/2018] [Indexed: 12/14/2022] Open
Abstract
The Saccharomyces cerevisiae kinase/adenosine triphosphatase Rio1 regulates rDNA transcription and segregation, pre-rRNA processing and small ribosomal subunit maturation. Other roles are unknown. When overexpressed, human ortholog RIOK1 drives tumor growth and metastasis. Likewise, RIOK1 promotes 40S ribosomal subunit biogenesis and has not been characterized globally. We show that Rio1 manages directly and via a series of regulators, an essential signaling network at the protein, chromatin and RNA levels. Rio1 orchestrates growth and division depending on resource availability, in parallel to the nutrient-activated Tor1 kinase. To define the Rio1 network, we identified its physical interactors, profiled its target genes/transcripts, mapped its chromatin-binding sites and integrated our data with yeast’s protein–protein and protein–DNA interaction catalogs using network computation. We experimentally confirmed network components and localized Rio1 also to mitochondria and vacuoles. Via its network, Rio1 commands protein synthesis (ribosomal gene expression, assembly and activity) and turnover (26S proteasome expression), and impinges on metabolic, energy-production and cell-cycle programs. We find that Rio1 activity is conserved to humans and propose that pathological RIOK1 may fuel promiscuous transcription, ribosome production, chromosomal instability, unrestrained metabolism and proliferation; established contributors to cancer. Our study will advance the understanding of numerous processes, here revealed to depend on Rio1 activity.
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Affiliation(s)
- Maria G Iacovella
- Department of Experimental Oncology, European Institute of Oncology, Via Adamello 16, 20139 Milan, Italy
| | - Michael Bremang
- Department of Experimental Oncology, European Institute of Oncology, Via Adamello 16, 20139 Milan, Italy.,Current address: Proteome Sciences Plc, Hamilton House, Mabledon Place, London, United Kingdom
| | - Omer Basha
- Department of Clinical Biochemistry and Pharmacology, Faculty of Health Sciences and the National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, POB 653, Beer-Sheva 84105, Israel
| | - Luciano Giacò
- Department of Experimental Oncology, European Institute of Oncology, Via Adamello 16, 20139 Milan, Italy
| | - Walter Carotenuto
- The FIRC Institute of Molecular Oncology (IFOM), Via Adamello 16, 20139 Milan, Italy
| | - Cristina Golfieri
- Department of Experimental Oncology, European Institute of Oncology, Via Adamello 16, 20139 Milan, Italy
| | - Barnabas Szakal
- The FIRC Institute of Molecular Oncology (IFOM), Via Adamello 16, 20139 Milan, Italy
| | - Marianna Dal Maschio
- Department of Experimental Oncology, European Institute of Oncology, Via Adamello 16, 20139 Milan, Italy
| | - Valentina Infantino
- Department of Experimental Oncology, European Institute of Oncology, Via Adamello 16, 20139 Milan, Italy
| | - Galina V Beznoussenko
- The FIRC Institute of Molecular Oncology (IFOM), Via Adamello 16, 20139 Milan, Italy
| | - Chinnu R Joseph
- The FIRC Institute of Molecular Oncology (IFOM), Via Adamello 16, 20139 Milan, Italy
| | - Clara Visintin
- Department of Experimental Oncology, European Institute of Oncology, Via Adamello 16, 20139 Milan, Italy
| | - Alexander A Mironov
- The FIRC Institute of Molecular Oncology (IFOM), Via Adamello 16, 20139 Milan, Italy
| | - Rosella Visintin
- Department of Experimental Oncology, European Institute of Oncology, Via Adamello 16, 20139 Milan, Italy
| | - Dana Branzei
- The FIRC Institute of Molecular Oncology (IFOM), Via Adamello 16, 20139 Milan, Italy.,Istituto di Genetica Molecolare, Consiglio Nazionale delle Ricerche (CNR), Via Abbiategrasso 207, 27100 Pavia, Italy
| | - Sébastien Ferreira-Cerca
- Lehrstuhl für Biochemie III, Universität Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany
| | - Esti Yeger-Lotem
- Department of Clinical Biochemistry and Pharmacology, Faculty of Health Sciences and the National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, POB 653, Beer-Sheva 84105, Israel
| | - Peter De Wulf
- Department of Experimental Oncology, European Institute of Oncology, Via Adamello 16, 20139 Milan, Italy.,Centre for Integrative Biology (CIBIO), University of Trento, Via Sommarive 9, 38123 Trento, Italy
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11
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Chowdhury A, Ogura T, Esaki M. Two Cdc48 cofactors Ubp3 and Ubx2 regulate mitochondrial morphology and protein turnover. J Biochem 2018; 164:349-358. [PMID: 29924334 DOI: 10.1093/jb/mvy057] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Accepted: 06/13/2018] [Indexed: 12/22/2022] Open
Abstract
Mitochondria continuously undergo coordinated fusion and fission during vegetative growth to keep their homogeneity and to remove damaged components. A cytosolic AAA ATPase, Cdc48, is implicated in the mitochondrial fusion event and turnover of a fusion-responsible GTPase in the mitochondrial outer membrane, Fzo1, suggesting a possible linkage of mitochondrial fusion and Fzo1 turnover. Here, we identified two Cdc48 cofactor proteins, Ubp3 and Ubx2, involving mitochondria regulation. In the absence of UBP3, mitochondrial fragmentation and aggregation were observed. The turnover of Fzo1 was not affected in Δubp3, but instead a deubiquitylase Ubp12 that removes fusion-required polyubiquitin chains from Fzo1 was stabilized. Thus, excess amount of Ubp12 may lead to mitochondrial fragmentation by removal of fusion-competent ubiquitylated Fzo1. In contrast, deletion of UBX2 perturbed disassembly of Fzo1 oligomers and their degradation without alteration of mitochondrial morphology. The UBX2 deletion led to destabilization of Ubp2 that negatively regulates Fzo1 turnover by removing degradation-signalling polyubiquitin chains, suggesting that Ubx2 would directly facilitate Fzo1 degradation. These results indicated that two different Cdc48-cofactor complexes independently regulate mitochondrial fusion and Fzo1 turnover.
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Affiliation(s)
- Abhijit Chowdhury
- Department of Molecular Cell Biology, Institute of Molecular Embryology and Genetics, Kumamoto University, Honjo 2-2-1, Chuo-ku, Kumamoto, Japan.,Program for Leading Graduate Schools "HIGO Program", Kumamoto University, Honjo 1-1-1, Chuo-ku, Kumamoto, Japan
| | - Teru Ogura
- Department of Molecular Cell Biology, Institute of Molecular Embryology and Genetics, Kumamoto University, Honjo 2-2-1, Chuo-ku, Kumamoto, Japan.,Program for Leading Graduate Schools "HIGO Program", Kumamoto University, Honjo 1-1-1, Chuo-ku, Kumamoto, Japan.,Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, Honcho 4-1-8, Kawaguchi-shi, Saitama, Japan
| | - Masatoshi Esaki
- Department of Molecular Cell Biology, Institute of Molecular Embryology and Genetics, Kumamoto University, Honjo 2-2-1, Chuo-ku, Kumamoto, Japan.,Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, Honcho 4-1-8, Kawaguchi-shi, Saitama, Japan
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12
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Romero AM, Jordá T, Rozès N, Martínez-Pastor MT, Puig S. Regulation of yeast fatty acid desaturase in response to iron deficiency. Biochim Biophys Acta Mol Cell Biol Lipids 2018; 1863:657-668. [PMID: 29627385 DOI: 10.1016/j.bbalip.2018.03.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Revised: 03/12/2018] [Accepted: 03/27/2018] [Indexed: 10/17/2022]
Abstract
Unsaturated fatty acids (UFA) are essential components of phospholipids that greatly contribute to the biophysical properties of cellular membranes. Biosynthesis of UFAs relies on a conserved family of iron-dependent fatty acid desaturases, whose representative in the model yeast Saccharomyces cerevisiae is Ole1. OLE1 expression is tightly regulated to adapt UFA biosynthesis and lipid bilayer properties to changes in temperature, and in UFA or oxygen availability. Despite iron deficiency being the most extended nutritional disorder worldwide, very little is known about the mechanisms and the biological relevance of fatty acid desaturases regulation in response to iron starvation. In this report, we show that endoplasmic reticulum-anchored transcription factor Mga2 activates OLE1 transcription in response to nutritional and genetic iron deficiencies. Cells lacking MGA2 display low UFA levels and do not grow under iron-limited conditions, unless UFAs are supplemented or OLE1 is overexpressed. The proteasome, E3 ubiquitin ligase Rsp5 and the Cdc48Npl4/Ufd1 complex are required for OLE1 activation during iron depletion. Interestingly, Mga2 also activates the transcription of its own mRNA in response to iron deficiency, hypoxia, low temperature and low UFAs. MGA2 up-regulation contributes to increase OLE1 expression in these situations. These results reveal the mechanism of OLE1 regulation when iron is scarce and identify the MGA2 auto-regulation as a potential activation strategy in multiple stresses.
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Affiliation(s)
- Antonia María Romero
- Departamento de Biotecnología, Instituto de Agroquímica y Tecnología de Alimentos (IATA), Consejo Superior de Investigaciones Científicas (CSIC), Paterna, Valencia, Spain
| | - Tania Jordá
- Departamento de Biotecnología, Instituto de Agroquímica y Tecnología de Alimentos (IATA), Consejo Superior de Investigaciones Científicas (CSIC), Paterna, Valencia, Spain
| | - Nicolas Rozès
- Departament de Bioquímica i Biotecnología, Facultat d'Enologia, Universitat Rovira i Virgili, Tarragona, Spain
| | | | - Sergi Puig
- Departamento de Biotecnología, Instituto de Agroquímica y Tecnología de Alimentos (IATA), Consejo Superior de Investigaciones Científicas (CSIC), Paterna, Valencia, Spain.
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13
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Tsuchiya H, Burana D, Ohtake F, Arai N, Kaiho A, Komada M, Tanaka K, Saeki Y. Ub-ProT reveals global length and composition of protein ubiquitylation in cells. Nat Commun 2018; 9:524. [PMID: 29410401 PMCID: PMC5802829 DOI: 10.1038/s41467-018-02869-x] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 01/02/2018] [Indexed: 01/09/2023] Open
Abstract
Protein ubiquitylation regulates diverse cellular processes via distinct ubiquitin chains that differ by linkage type and length. However, a comprehensive method for measuring these properties has not been developed. Here we describe a method for assessing the length of substrate-attached polyubiquitin chains, "ubiquitin chain protection from trypsinization (Ub-ProT)." Using Ub-ProT, we found that most ubiquitylated substrates in yeast-soluble lysate are attached to chains of up to seven ubiquitin molecules. Inactivation of the ubiquitin-selective chaperone Cdc48 caused a dramatic increase in chain lengths on substrate proteins, suggesting that Cdc48 complex terminates chain elongation by substrate extraction. In mammalian cells, we found that ligand-activated epidermal growth factor receptor (EGFR) is rapidly modified with K63-linked tetra- to hexa-ubiquitin chains following EGF treatment in human cells. Thus, the Ub-ProT method can contribute to our understanding of mechanisms regulating physiological ubiquitin chain lengths and composition.
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Affiliation(s)
- Hikaru Tsuchiya
- Laboratory of Protein Metabolism, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo, 156-8506, Japan
| | - Daocharad Burana
- Laboratory of Protein Metabolism, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo, 156-8506, Japan.,Cell Biology Center, Institute of Innovative Research, Tokyo Institute of Technology, 4259-B16 Nagatsuta, Midori, Yokohama, 226-8501, Japan
| | - Fumiaki Ohtake
- Laboratory of Protein Metabolism, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo, 156-8506, Japan
| | - Naoko Arai
- Laboratory of Protein Metabolism, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo, 156-8506, Japan
| | - Ai Kaiho
- Laboratory of Protein Metabolism, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo, 156-8506, Japan
| | - Masayuki Komada
- Cell Biology Center, Institute of Innovative Research, Tokyo Institute of Technology, 4259-B16 Nagatsuta, Midori, Yokohama, 226-8501, Japan
| | - Keiji Tanaka
- Laboratory of Protein Metabolism, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo, 156-8506, Japan.
| | - Yasushi Saeki
- Laboratory of Protein Metabolism, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo, 156-8506, Japan.
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14
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Chymkowitch P, Enserink JM. Regulation of tRNA synthesis by posttranslational modifications of RNA polymerase III subunits. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2017; 1861:310-319. [PMID: 29127063 DOI: 10.1016/j.bbagrm.2017.11.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 11/05/2017] [Accepted: 11/06/2017] [Indexed: 12/18/2022]
Abstract
RNA polymerase III (RNAPIII) transcribes tRNA genes, 5S RNA as well as a number of other non-coding RNAs. Because transcription by RNAPIII is an energy-demanding process, its activity is tightly linked to the stress levels and nutrient status of the cell. Multiple signaling pathways control RNAPIII activity in response to environmental cues, but exactly how these pathways regulate RNAPIII is still poorly understood. One major target of these pathways is the transcriptional repressor Maf1, which inhibits RNAPIII activity under conditions that are detrimental to cell growth. However, recent studies have found that the cell can also directly regulate the RNAPIII machinery through phosphorylation and sumoylation of RNAPIII subunits. In this review we summarize post-translational modifications of RNAPIII subunits that mainly have been identified in large-scale proteomics studies, and we highlight several examples to discuss their relevance for regulation of RNAPIII.
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Affiliation(s)
- Pierre Chymkowitch
- Department of Microbiology, Oslo University Hospital, NO-0027 Oslo, Norway.
| | - Jorrit M Enserink
- Department of Molecular Cell Biology, Institute for Cancer Research, the Norwegian Radium Hospital, Montebello, N-0379 Oslo, Norway; Section for Biochemistry and Molecular Biology, Faculty of Mathematics and Natural Sciences, University of Oslo, 0371, Norway.
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15
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Zhang M, Yu Q, Liu Z, Liang C, Zhang B, Li M. UBX domain-containing proteins are involved in lipid homeostasis and stress responses in Pichia pastoris. Int J Biochem Cell Biol 2017; 90:136-144. [PMID: 28807601 DOI: 10.1016/j.biocel.2017.08.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Revised: 08/07/2017] [Accepted: 08/09/2017] [Indexed: 12/12/2022]
Abstract
Ubiquitin regulatory X (UBX) domain-containing proteins constitute a family of proteins and are substrate adaptors of AAA ATPase Cdc48. UBX proteins can bind to the N-terminal region of Cdc48 to perform endoplasmic reticulum associated protein degradation (ERAD). In this study, we identified two UBX domain-containing proteins, Ubx1 and Ubx2, in Pichia pastoris and found that the two proteins could recover the growth defect of Saccharomyces cerevisiae in ubx2Δ. Our results revealed that Ubx1 and Ubx2 play critical roles in synthesis of unsaturated fatty acids by affecting Spt23. In addition, the results demonstrated that both Ubx1 and Ubx2 are involved in lipid droplet formation and protein degradation. Deletion of UBX1 led to increased sensitivity to oxidative stress and disruption of UBX2 impaired cell viability under osmotic stress. The phenotypes of ubx1Δ+UBX2, ubx2Δ+UBX1 and ubx1Δubx2Δ and RNA-seq data suggested that Ubx1 and Ubx2 play different roles in cell functions, and the roles of Ubx1 may be more numerous than Ubx2. In summary, our findings provide new insights into the relationship between lipid homeostasis and cell functions in the oil-producing organism P. pastoris.
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Affiliation(s)
- Meng Zhang
- Ministry of Education Key Laboratory of Molecular Microbiology and Technology, Department of Microbiology, College of Life Science, Nankai University, Tianjin, 300071, PR China.
| | - Qilin Yu
- Ministry of Education Key Laboratory of Molecular Microbiology and Technology, Department of Microbiology, College of Life Science, Nankai University, Tianjin, 300071, PR China.
| | - Zhe Liu
- Ministry of Education Key Laboratory of Molecular Microbiology and Technology, Department of Microbiology, College of Life Science, Nankai University, Tianjin, 300071, PR China.
| | - Chen Liang
- Ministry of Education Key Laboratory of Molecular Microbiology and Technology, Department of Microbiology, College of Life Science, Nankai University, Tianjin, 300071, PR China.
| | - Biao Zhang
- Tianjin Traditional Chinese Medicine University, Tianjin, 300193, PR China.
| | - Mingchun Li
- Ministry of Education Key Laboratory of Molecular Microbiology and Technology, Department of Microbiology, College of Life Science, Nankai University, Tianjin, 300071, PR China.
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16
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Ballweg S, Ernst R. Control of membrane fluidity: the OLE pathway in focus. Biol Chem 2017; 398:215-228. [DOI: 10.1515/hsz-2016-0277] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Accepted: 10/18/2016] [Indexed: 11/15/2022]
Abstract
Abstract
The maintenance of a fluid lipid bilayer is key for membrane integrity and cell viability. We are only beginning to understand how eukaryotic cells sense and maintain the characteristic lipid compositions and bulk membrane properties of their organelles. One of the key factors determining membrane fluidity and phase behavior is the proportion of saturated and unsaturated acyl chains in membrane lipids. Saccharomyces cerevisiae is an ideal model organism to study the regulation of the lipid acyl chain composition via the OLE pathway. The OLE pathway comprises all steps involved in the regulated mobilization of the transcription factors Mga2 and Spt23 from the endoplasmic reticulum (ER), which then drive the expression of OLE1 in the nucleus. OLE1 encodes for the essential Δ9-fatty acid desaturase Ole1 and is crucial for de novo biosynthesis of unsaturated fatty acids (UFAs) that are used as lipid building blocks. This review summarizes our current knowledge of the OLE pathway, the best-characterized, eukaryotic sense-and-control system regulating membrane lipid saturation, and identifies open questions to indicate future directions.
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17
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Pantazopoulou M, Boban M, Foisner R, Ljungdahl PO. Cdc48 and Ubx1 participate in a pathway associated with the inner nuclear membrane that governs Asi1 degradation. J Cell Sci 2016; 129:3770-3780. [PMID: 27566164 DOI: 10.1242/jcs.189332] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Accepted: 08/18/2016] [Indexed: 01/04/2023] Open
Abstract
The nuclear envelope is a barrier comprising outer and inner membranes that separate the cytoplasm from the nucleoplasm. The two membranes have different physical characteristics and protein compositions. The processes governing the stability of inner nuclear membrane (INM) proteins are not well characterized. In Saccharomyces cerevisiae, the INM Asi1-Asi3 complex, principally composed of integral membrane proteins Asi1 and Asi3, is an E3 ubiquitin ligase. In addition to its well-documented function in endoplasmic reticulum (ER)-associated degradation, the Doa10 E3 ubiquitin ligase complex partially localizes to the INM. The Asi1-Asi3 and Doa10 complexes define independent INM-associated degradation (INMAD) pathways that target discrete sets of nuclear substrates for proteasomal degradation. Here, we report that Asi1 is rapidly turned over (t1/2≤30 min). Its turnover depends on ubiquitin-mediated degradation by nucleus-localized proteasomes, exhibiting a clear requirement for the E2 ubiquitin-conjugating enzyme Ubc7, Cue1 and the AAA ATPase Cdc48 and co-factor Ubx1. Asi1 turnover occurs largely independently of the Asi1-Asi3 or Doa10 complexes, indicating that it is subject to quality control at the INM in a manner distinct from that of the characterized INMAD pathways.
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Affiliation(s)
- Marina Pantazopoulou
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm SE-106 91, Sweden
| | - Mirta Boban
- University of Zagreb, School of Medicine, Croatian Institute for Brain Research, Šalata 12, Zagreb 10000, Croatia
| | - Roland Foisner
- Max F. Perutz Laboratories, Department of Medical Biochemistry, Medical University of Vienna, Dr. Bohr-Gasse 9, Vienna A-1030, Austria
| | - Per O Ljungdahl
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm SE-106 91, Sweden
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18
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Control of Formin Distribution and Actin Cable Assembly by the E3 Ubiquitin Ligases Dma1 and Dma2. Genetics 2016; 204:205-20. [PMID: 27449057 DOI: 10.1534/genetics.116.189258] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Accepted: 07/18/2016] [Indexed: 11/18/2022] Open
Abstract
Formins are widespread actin-polymerizing proteins that play pivotal roles in a number of processes, such as cell polarity, morphogenesis, cytokinesis, and cell migration. In agreement with their crucial function, formins are prone to a variety of regulatory mechanisms that include autoinhibition, post-translational modifications, and interaction with formin modulators. Furthermore, activation and function of formins is intimately linked to their ability to interact with membranes. In the budding yeast Saccharomyces cerevisiae, the two formins Bni1 and Bnr1 play both separate and overlapping functions in the organization of the actin cytoskeleton. In addition, they are controlled by both common and different regulatory mechanisms. Here we show that proper localization of both formins requires the redundant E3 ubiquitin ligases Dma1 and Dma2, which were previously involved in spindle positioning and septin organization. In dma1 dma2 double mutants, formin distribution at polarity sites is impaired, thus causing defects in the organization of the actin cable network and hypersensitivity to the actin depolymerizer latrunculin B. Expression of a hyperactive variant of Bni1 (Bni1-V360D) rescues these defects and partially restores proper spindle positioning in the mutant, suggesting that the failure of dma1 dma2 mutant cells to position the spindle is partly due to faulty formin activity. Strikingly, Dma1/2 interact physically with both formins, while their ubiquitin-ligase activity is required for formin function and polarized localization. Thus, ubiquitylation of formin or a formin interactor(s) could promote formin binding to membrane and its ability to nucleate actin. Altogether, our data highlight a novel level of formin regulation that further expands our knowledge of the complex and multilayered controls of these key cytoskeleton organizers.
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19
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Covino R, Ballweg S, Stordeur C, Michaelis J, Puth K, Wernig F, Bahrami A, Ernst A, Hummer G, Ernst R. A Eukaryotic Sensor for Membrane Lipid Saturation. Mol Cell 2016; 63:49-59. [DOI: 10.1016/j.molcel.2016.05.015] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Revised: 04/12/2016] [Accepted: 05/11/2016] [Indexed: 12/22/2022]
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20
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Kito K, Okada M, Ishibashi Y, Okada S, Ito T. A strategy for absolute proteome quantification with mass spectrometry by hierarchical use of peptide-concatenated standards. Proteomics 2016; 16:1457-73. [DOI: 10.1002/pmic.201500414] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Revised: 02/18/2016] [Accepted: 03/24/2016] [Indexed: 12/20/2022]
Affiliation(s)
- Keiji Kito
- Department of Life Sciences, School of Agriculture; Meiji University; Kawasaki Japan
| | - Mitsuhiro Okada
- Department of Life Sciences, School of Agriculture; Meiji University; Kawasaki Japan
| | - Yuko Ishibashi
- Department of Life Sciences, School of Agriculture; Meiji University; Kawasaki Japan
| | - Satoshi Okada
- Department of Biochemistry; Kyushu University Graduate School of Medical Science; Fukuoka Japan
| | - Takashi Ito
- Department of Biochemistry; Kyushu University Graduate School of Medical Science; Fukuoka Japan
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21
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Wang CW. Lipid droplet dynamics in budding yeast. Cell Mol Life Sci 2015; 72:2677-95. [PMID: 25894691 PMCID: PMC11113813 DOI: 10.1007/s00018-015-1903-5] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Revised: 04/01/2015] [Accepted: 04/07/2015] [Indexed: 10/23/2022]
Abstract
Eukaryotic cells store excess fatty acids as neutral lipids, predominantly triacylglycerols and sterol esters, in organelles termed lipid droplets (LDs) that bulge out from the endoplasmic reticulum. LDs are highly dynamic and contribute to diverse cellular functions. The catabolism of the storage lipids within LDs is channeled to multiple metabolic pathways, providing molecules for energy production, membrane building blocks, and lipid signaling. LDs have been implicated in a number of protein degradation and pathogen infection processes. LDs may be linked to prevalent human metabolic diseases and have marked potential for biofuel production. The knowledge accumulated on LDs in recent years provides a foundation for diverse, and even unexpected, future research. This review focuses on recent advances in LD research, emphasizing the diverse physiological roles of LDs in the model system of budding yeast.
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Affiliation(s)
- Chao-Wen Wang
- Institute of Plant and Microbial Biology, Academia Sinica, Nankang, Taipei, 11529, Taiwan,
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22
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Mor V, Rella A, Farnoud AM, Singh A, Munshi M, Bryan A, Naseem S, Konopka JB, Ojima I, Bullesbach E, Ashbaugh A, Linke MJ, Cushion M, Collins M, Ananthula HK, Sallans L, Desai PB, Wiederhold NP, Fothergill AW, Kirkpatrick WR, Patterson T, Wong LH, Sinha S, Giaever G, Nislow C, Flaherty P, Pan X, Cesar GV, de Melo Tavares P, Frases S, Miranda K, Rodrigues ML, Luberto C, Nimrichter L, Del Poeta M. Identification of a New Class of Antifungals Targeting the Synthesis of Fungal Sphingolipids. mBio 2015; 6:e00647. [PMID: 26106079 PMCID: PMC4479701 DOI: 10.1128/mbio.00647-15] [Citation(s) in RCA: 106] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
UNLABELLED Recent estimates suggest that >300 million people are afflicted by serious fungal infections worldwide. Current antifungal drugs are static and toxic and/or have a narrow spectrum of activity. Thus, there is an urgent need for the development of new antifungal drugs. The fungal sphingolipid glucosylceramide (GlcCer) is critical in promoting virulence of a variety of human-pathogenic fungi. In this study, we screened a synthetic drug library for compounds that target the synthesis of fungal, but not mammalian, GlcCer and found two compounds [N'-(3-bromo-4-hydroxybenzylidene)-2-methylbenzohydrazide (BHBM) and its derivative, 3-bromo-N'-(3-bromo-4-hydroxybenzylidene) benzohydrazide (D0)] that were highly effective in vitro and in vivo against several pathogenic fungi. BHBM and D0 were well tolerated in animals and are highly synergistic or additive to current antifungals. BHBM and D0 significantly affected fungal cell morphology and resulted in the accumulation of intracellular vesicles. Deep-sequencing analysis of drug-resistant mutants revealed that four protein products, encoded by genes APL5, COS111, MKK1, and STE2, which are involved in vesicular transport and cell cycle progression, are targeted by BHBM. IMPORTANCE Fungal infections are a significant cause of morbidity and mortality worldwide. Current antifungal drugs suffer from various drawbacks, including toxicity, drug resistance, and narrow spectrum of activity. In this study, we have demonstrated that pharmaceutical inhibition of fungal glucosylceramide presents a new opportunity to treat cryptococcosis and various other fungal infections. In addition to being effective against pathogenic fungi, the compounds discovered in this study were well tolerated by animals and additive to current antifungals. These findings suggest that these drugs might pave the way for the development of a new class of antifungals.
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Affiliation(s)
- Visesato Mor
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, New York, USA
| | - Antonella Rella
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, New York, USA
| | - Amir M Farnoud
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, New York, USA
| | - Ashutosh Singh
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, New York, USA
| | - Mansa Munshi
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, New York, USA
| | - Arielle Bryan
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, New York, USA
| | - Shamoon Naseem
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, New York, USA
| | - James B Konopka
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, New York, USA
| | - Iwao Ojima
- Department of Chemistry and Institute of Chemical Biology and Drug Discovery, Stony Brook University, Stony Brook, New York, USA
| | - Erika Bullesbach
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Alan Ashbaugh
- Department of Veterans Affairs Medical Center, Cincinnati, Ohio, USA
| | | | | | - Margaret Collins
- University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | | | - Larry Sallans
- Department of Chemistry, University of Cincinnati, Cincinnati, Ohio, USA
| | - Pankaj B Desai
- Department of Pharmaceutical Sciences, University of Cincinnati, Cincinnati, Ohio, USA
| | - Nathan P Wiederhold
- Department of Pathology, Fungus Testing Laboratory, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA
| | - Annette W Fothergill
- Department of Pathology, Fungus Testing Laboratory, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA
| | - William R Kirkpatrick
- Division of Infectious Diseases, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA
| | - Thomas Patterson
- Division of Infectious Diseases, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA
| | - Lai Hong Wong
- Department of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Colombia, Canada
| | - Sunita Sinha
- Department of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Colombia, Canada
| | - Guri Giaever
- Department of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Colombia, Canada
| | - Corey Nislow
- Department of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Colombia, Canada
| | - Patrick Flaherty
- Department of Biomedical Engineering, Worcester Polytechnic Institute, Worcester, Massachusetts, USA
| | - Xuewen Pan
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas, USA
| | - Gabriele Vargas Cesar
- Instituto de Microbiologia Professor Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Patricia de Melo Tavares
- Instituto de Microbiologia Professor Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Susana Frases
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | | | | | - Chiara Luberto
- Department of Physiology and Biophysics, Stony Brook University, Stony Brook, New York, USA
| | - Leonardo Nimrichter
- Instituto de Microbiologia Professor Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Maurizio Del Poeta
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, New York, USA
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23
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Stordeur C, Puth K, Sáenz JP, Ernst R. Crosstalk of lipid and protein homeostasis to maintain membrane function. Biol Chem 2014; 395:313-26. [DOI: 10.1515/hsz-2013-0235] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Accepted: 10/21/2013] [Indexed: 01/22/2023]
Abstract
Abstract
Biological membranes are a defining feature of cellular life. They serve as selective diffusion barriers, compartmentalize biochemical processes and protect the cellular milieu. We are only beginning to understand the principles underlying their homeostasis and the functional relevance of their complex compositions. Here, we summarize some recent evidences that suggest an intense crosstalk between the pathways of protein quality control and lipid homeostasis. We discuss paradigms of lipid regulation by protein degradation machineries and highlight the intricate connections between lipid droplet morphology, membrane biogenesis and ER-stress.
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Radhakrishnan SK, den Besten W, Deshaies RJ. p97-dependent retrotranslocation and proteolytic processing govern formation of active Nrf1 upon proteasome inhibition. eLife 2014; 3:e01856. [PMID: 24448410 PMCID: PMC3896944 DOI: 10.7554/elife.01856] [Citation(s) in RCA: 155] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Proteasome inhibition elicits an evolutionarily conserved response wherein proteasome subunit mRNAs are upregulated, resulting in recovery (i.e., ‘bounce-back’) of proteasome activity. We previously demonstrated that the transcription factor Nrf1/NFE2L1 mediates this homeostatic response in mammalian cells. We show here that Nrf1 is initially translocated into the lumen of the ER, but is rapidly and efficiently retrotranslocated to the cytosolic side of the membrane in a manner that depends on p97/VCP. Normally, retrotranslocated Nrf1 is degraded promptly by the proteasome and active species do not accumulate. However, in cells with compromised proteasomes, retrotranslocated Nrf1 escapes degradation and is cleaved N-terminal to Leu-104 to yield a fragment that is no longer tethered to the ER membrane. Importantly, this cleavage event is essential for Nrf1-dependent activation of proteasome gene expression upon proteasome inhibition. Our data uncover an unexpected role for p97 in activation of a transcription factor by relocalizing it from the ER lumen to the cytosol. DOI:http://dx.doi.org/10.7554/eLife.01856.001 Cells exposed to high temperatures, infections and other forms of stress often produce oxygen ions and peroxide molecules that can cause damage to proteins and DNA. Cells therefore rely on molecular machines called proteasomes to eliminate damaged proteins, before they cause too much harm. Two related transcription factors—proteins that interact with DNA to ‘switch on’ the expression of genes—are involved in a cell’s responses to stress, but in different ways. Nrf2 switches on genes that limit the damage caused by oxygen ions and peroxide molecules, while Nrf1 switches on the genes that encode the components of the proteasome. As such, Nrf1 helps to restart proteasome activity if it has been shut off—a phenomenon known as ‘bounce-back’. Within a cell, Nrf1 is known to start off embedded within the membranes of a structure called the endoplasmic reticulum. However, it is not clear how activated Nrf1 leaves this membrane and enters the nucleus to interact with the cell’s DNA. Now, Radhakrishnan et al. show that when Nrf1 is produced, most of its length is found inside the endoplasmic reticulum, with only a small piece being anchored in the surrounding membrane. This is unlike previously described transcription factors that associate with the endoplasmic reticulum, which are stuck to the outside of this structure. Radhakrishnan et al. also discovered that the activation of Nrf1 depends on an enzyme called p97 or VCP. This enzyme helps to flip Nrf1 from the inside of the endoplasmic reticulum to its outside surface. In most cells, the proteasome then breaks down this part of Nrf1. However, if the proteasome is inhibited, an unknown enzyme cuts Nrf1 free from the endoplasmic reticulum, allowing it to migrate to the nucleus and promote the production of more proteasome components to counteract the inhibition. Interestingly, drugs that inhibit the proteasome are used to combat cancer because the build-up of damaged proteins is toxic to the cancer cells. By showing that p97 promotes the ‘bounce-back’ of the proteasome, the work of Radhakrishnan et al. suggests that combining existing proteasome inhibitors with drugs that inhibit p97 could eventually lead to new, more effective, therapies for cancer or other diseases. DOI:http://dx.doi.org/10.7554/eLife.01856.002
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Affiliation(s)
- Senthil K Radhakrishnan
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, United States
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The natural diyne-furan fatty acid EV-086 is an inhibitor of fungal delta-9 fatty acid desaturation with efficacy in a model of skin dermatophytosis. Antimicrob Agents Chemother 2013; 58:455-66. [PMID: 24189258 DOI: 10.1128/aac.01443-13] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Human fungal infections represent a therapeutic challenge. Although effective strategies for treatment are available, resistance is spreading, and many therapies have unacceptable side effects. A clear need for novel antifungal targets and molecules is thus emerging. Here, we present the identification and characterization of the plant-derived diyne-furan fatty acid EV-086 as a novel antifungal compound. EV-086 has potent and broad-spectrum activity in vitro against Candida, Aspergillus, and Trichophyton spp., whereas activities against bacteria and human cell lines are very low. Chemical-genetic profiling of Saccharomyces cerevisiae deletion mutants identified lipid metabolic processes and organelle organization and biogenesis as targets of EV-086. Pathway modeling suggested that EV-086 inhibits delta-9 fatty acid desaturation, an essential process in S. cerevisiae, depending on the delta-9 fatty acid desaturase OLE1. Delta-9 unsaturated fatty acids-but not saturated fatty acids-antagonized the EV-086-mediated growth inhibition, and transcription of the OLE1 gene was strongly upregulated in the presence of EV-086. EV-086 increased the ratio of saturated to unsaturated free fatty acids and phosphatidylethanolamine fatty acyl chains, respectively. Furthermore, EV-086 was rapidly taken up into the lipid fraction of the cell and incorporated into phospholipids. Together, these findings demonstrate that EV-086 is an inhibitor of delta-9 fatty acid desaturation and that the mechanism of inhibition might involve an EV-086-phospholipid. Finally, EV-086 showed efficacy in a guinea pig skin dermatophytosis model of topical Trichophyton infection, which demonstrates that delta-9 fatty acid desaturation is a valid antifungal target, at least for dermatophytoses.
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