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Prigent M, Jean-Jacques H, Naquin D, Chédin S, Cuif MH, Legouis R, Kuras L. Sulfur starvation-induced autophagy in Saccharomyces cerevisiae involves SAM-dependent signaling and transcription activator Met4. Nat Commun 2024; 15:6927. [PMID: 39138175 PMCID: PMC11322535 DOI: 10.1038/s41467-024-51309-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Accepted: 08/01/2024] [Indexed: 08/15/2024] Open
Abstract
Autophagy is a key lysosomal degradative mechanism allowing a prosurvival response to stresses, especially nutrient starvation. Here we investigate the mechanism of autophagy induction in response to sulfur starvation in Saccharomyces cerevisiae. We found that sulfur deprivation leads to rapid and widespread transcriptional induction of autophagy-related (ATG) genes in ways not seen under nitrogen starvation. This distinctive response depends mainly on the transcription activator of sulfur metabolism Met4. Consistently, Met4 is essential for autophagy under sulfur starvation. Depletion of either cysteine, methionine or SAM induces autophagy flux. However, only SAM depletion can trigger strong transcriptional induction of ATG genes and a fully functional autophagic response. Furthermore, combined inactivation of Met4 and Atg1 causes a dramatic decrease in cell survival under sulfur starvation, highlighting the interplay between sulfur metabolism and autophagy to maintain cell viability. Thus, we describe a pathway of sulfur starvation-induced autophagy depending on Met4 and involving SAM as signaling sulfur metabolite.
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Affiliation(s)
- Magali Prigent
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Gif-sur-Yvette, France
- INSERM U1280, 91198, Gif-sur-Yvette, France
| | - Hélène Jean-Jacques
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Gif-sur-Yvette, France
| | - Delphine Naquin
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Gif-sur-Yvette, France
| | - Stéphane Chédin
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Gif-sur-Yvette, France
| | - Marie-Hélène Cuif
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Gif-sur-Yvette, France
- INSERM U1280, 91198, Gif-sur-Yvette, France
| | - Renaud Legouis
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Gif-sur-Yvette, France
- INSERM U1280, 91198, Gif-sur-Yvette, France
| | - Laurent Kuras
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Gif-sur-Yvette, France.
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2
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Lauinger L, Andronicos A, Flick K, Yu C, Durairaj G, Huang L, Kaiser P. Cadmium binding by the F-box domain induces p97-mediated SCF complex disassembly to activate stress response programs. Nat Commun 2024; 15:3894. [PMID: 38719837 PMCID: PMC11079001 DOI: 10.1038/s41467-024-48184-6] [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: 07/31/2023] [Accepted: 04/22/2024] [Indexed: 05/12/2024] Open
Abstract
The F-box domain is a highly conserved structural motif that defines the largest class of ubiquitin ligases, Skp1/Cullin1/F-box protein (SCF) complexes. The only known function of the F-box motif is to form the protein interaction surface with Skp1. Here we show that the F-box domain can function as an environmental sensor. We demonstrate that the F-box domain of Met30 is a cadmium sensor that blocks the activity of the SCFMet30 ubiquitin ligase during cadmium stress. Several highly conserved cysteine residues within the Met30 F-box contribute to binding of cadmium with a KD of 8 µM. Binding induces a conformational change that allows for Met30 autoubiquitylation, which in turn leads to recruitment of the segregase Cdc48/p97/VCP followed by active SCFMet30 disassembly. The resulting inactivation of SCFMet30 protects cells from cadmium stress. Our results show that F-box domains participate in regulation of SCF ligases beyond formation of the Skp1 binding interface.
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Affiliation(s)
- Linda Lauinger
- Department of Biological Chemistry, University of California, Irvine, Irvine, CA, 92697, USA.
| | - Anna Andronicos
- Department of Biological Chemistry, University of California, Irvine, Irvine, CA, 92697, USA
| | - Karin Flick
- Department of Biological Chemistry, University of California, Irvine, Irvine, CA, 92697, USA
| | - Clinton Yu
- Department of Physiology and Biophysics, University of California, Irvine, Irvine, CA, 92697, USA
| | - Geetha Durairaj
- Department of Biological Chemistry, University of California, Irvine, Irvine, CA, 92697, USA
| | - Lan Huang
- Department of Physiology and Biophysics, University of California, Irvine, Irvine, CA, 92697, USA
| | - Peter Kaiser
- Department of Biological Chemistry, University of California, Irvine, Irvine, CA, 92697, USA.
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3
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François JM. Progress advances in the production of bio-sourced methionine and its hydroxyl analogues. Biotechnol Adv 2023; 69:108259. [PMID: 37734648 DOI: 10.1016/j.biotechadv.2023.108259] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 08/11/2023] [Accepted: 09/15/2023] [Indexed: 09/23/2023]
Abstract
The essential sulphur-containing amino acid, methionine, is becoming a mass-commodity product with an annual production that exceeded 1,500,000 tons in 2018. This amino acid is today almost exclusively produced by chemical process from fossil resources. The environmental problems caused by this industrial process, and the expected scarcity of oil resources in the coming years, have recently accelerated the development of bioprocesses for producing methionine from renewable carbon feedstock. After a brief description of the chemical process and the techno-economic context that still justify the production of methionine by petrochemical processes, this review will present the current state of the art of biobased alternatives aiming at a sustainable production of this amino acid and its hydroxyl analogues from renewable carbon feedstock. In particular, this review will focus on three bio-based processes, namely a purely fermentative process based on the metabolic engineering of the natural methionine pathway, a mixed process combining the production of the O-acetyl/O-succinyl homoserine intermediate of this pathway by fermentation followed by an enzyme-based conversion of this intermediate into L-methionine and lately, a hybrid process in which the non-natural chemical synthon, 2,4-dihydroxybutyric acid, obtained by fermentation of sugars is converted by chemo-catalysis into hydroxyl methionine analogues. The industrial potential of these three bioprocesses, as well as the major technical and economic obstacles that remain to be overcome to reach industrial maturity are discussed. This review concludes by bringing up the assets of these bioprocesses to meet the challenge of the "green transition", with the accomplishment of the objective "zero carbon" by 2050 and how they can be part of a model of Bioeconomy enhancing local resources.
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Affiliation(s)
- Jean Marie François
- Toulouse Biotechnology Institute, UMR INSA -CNRS5504 and UMR INSA-INRAE 792, 135 avenue de Rangueil, 31077 Toulouse, France; Toulouse White Biotechnology, UMS INRAE-INSA-CNRS, 135 Avenue de Rangueil, 31077 Toulouse, France.
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4
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Swaffer MP, Marinov GK, Zheng H, Fuentes Valenzuela L, Tsui CY, Jones AW, Greenwood J, Kundaje A, Greenleaf WJ, Reyes-Lamothe R, Skotheim JM. RNA polymerase II dynamics and mRNA stability feedback scale mRNA amounts with cell size. Cell 2023; 186:5254-5268.e26. [PMID: 37944513 DOI: 10.1016/j.cell.2023.10.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 07/16/2023] [Accepted: 10/10/2023] [Indexed: 11/12/2023]
Abstract
A fundamental feature of cellular growth is that total protein and RNA amounts increase with cell size to keep concentrations approximately constant. A key component of this is that global transcription rates increase in larger cells. Here, we identify RNA polymerase II (RNAPII) as the limiting factor scaling mRNA transcription with cell size in budding yeast, as transcription is highly sensitive to the dosage of RNAPII but not to other components of the transcriptional machinery. Our experiments support a dynamic equilibrium model where global RNAPII transcription at a given size is set by the mass action recruitment kinetics of unengaged nucleoplasmic RNAPII to the genome. However, this only drives a sub-linear increase in transcription with size, which is then partially compensated for by a decrease in mRNA decay rates as cells enlarge. Thus, limiting RNAPII and feedback on mRNA stability work in concert to scale mRNA amounts with cell size.
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Affiliation(s)
| | - Georgi K Marinov
- Department of Genetics, Stanford University, Stanford, CA 94305, USA
| | - Huan Zheng
- Department of Biology, McGill University, Montreal, QC H3G 0B1, Canada
| | | | - Crystal Yee Tsui
- Department of Biology, Stanford University, Stanford, CA 94305, USA
| | | | | | - Anshul Kundaje
- Department of Genetics, Stanford University, Stanford, CA 94305, USA
| | | | | | - Jan M Skotheim
- Department of Biology, Stanford University, Stanford, CA 94305, USA; Chan Zuckerberg Biohub, San Francisco, CA 94158, USA.
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5
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Church MC, Price A, Li H, Workman JL. The Swi-Snf chromatin remodeling complex mediates gene repression through metabolic control. Nucleic Acids Res 2023; 51:10278-10291. [PMID: 37650639 PMCID: PMC10602859 DOI: 10.1093/nar/gkad711] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 08/02/2023] [Accepted: 08/16/2023] [Indexed: 09/01/2023] Open
Abstract
In eukaryotes, ATP-dependent chromatin remodelers regulate gene expression in response to nutritional and metabolic stimuli. However, altered transcription of metabolic genes may have significant indirect consequences which are currently poorly understood. In this study, we use genetic and molecular approaches to uncover a role for the remodeler Swi-Snf as a critical regulator of metabolism. We find that snfΔ mutants display a cysteine-deficient phenotype, despite growth in nutrient-rich media. This correlates with widespread perturbations in sulfur metabolic gene transcription, including global redistribution of the sulfur-sensing transcription factor Met4. Our findings show how a chromatin remodeler can have a significant impact on a whole metabolic pathway by directly regulating an important gene subset and demonstrate an emerging role for chromatin remodeling complexes as decisive factors in metabolic control.
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Affiliation(s)
- Michael C Church
- Stowers Institute for Medical Research, Kansas City, MO 64110, USA
| | - Andrew Price
- Stowers Institute for Medical Research, Kansas City, MO 64110, USA
| | - Hua Li
- Stowers Institute for Medical Research, Kansas City, MO 64110, USA
| | - Jerry L Workman
- Stowers Institute for Medical Research, Kansas City, MO 64110, USA
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6
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Ozturk M, Metin M, Altay V, De Filippis L, Ünal BT, Khursheed A, Gul A, Hasanuzzaman M, Nahar K, Kawano T, Caparrós PG. Molecular Biology of Cadmium Toxicity in Saccharomyces cerevisiae. Biol Trace Elem Res 2021; 199:4832-4846. [PMID: 33462792 DOI: 10.1007/s12011-021-02584-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Accepted: 01/08/2021] [Indexed: 02/08/2023]
Abstract
Cadmium (Cd) is a toxic heavy metal mainly originating from industrial activities and causes environmental pollution. To better understand its toxicity and pollution remediation, we must understand the effects of Cd on living beings. Saccharomyces cerevisiae (budding yeast) is an eukaryotic unicellular model organism. It has provided much scientific knowledge about cellular and molecular biology in addition to its economic benefits. Effects associated with copper and zinc, sulfur and selenium metabolism, calcium (Ca2+) balance/signaling, and structure of phospholipids as a result of exposure to cadmium have been evaluated. In yeast as a result of cadmium stress, "mitogen-activated protein kinase," "high osmolarity glycerol," and "cell wall integrity" pathways have been reported to activate different signaling pathways. In addition, abnormalities and changes in protein structure, ribosomes, cell cycle disruption, and reactive oxygen species (ROS) following cadmium cytotoxicity have also been detailed. Moreover, the key OLE1 gene that encodes for delta-9 FA desaturase in relation to cadmium toxicity has been discussed in more detail. Keeping all these studies in mind, an attempt has been made to evaluate published cellular and molecular toxicity data related to Cd stress, and specifically published on S. cerevisiae.
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Affiliation(s)
- Munir Ozturk
- Department of Botany and Centre for Environmental Studies, Ege University, Izmir, Turkey.
| | - Mert Metin
- Graduate School of Environmental Engineering, The University of Kitakyushu, 1-1 Hibikino, Wakamatsu-ku, Kitakyushu, Fukuoka, 808-0135, Japan
| | - Volkan Altay
- Department of Biology, Faculty of Science and Arts, Hatay Mustafa Kemal University, Antakya, Hatay, Turkey
| | - Luigi De Filippis
- School of Life Sciences, University of Technology Sydney, Sydney, 123, Australia
| | - Bengu Turkyilmaz Ünal
- Faculty of Science and Arts, Department of Biotechnology, Nigde Omer Halisdemir University, Nigde, Turkey
| | - Anum Khursheed
- Department of Biochemistry, Faculty of Biological Sciences, Quaid-I-Azam University, Islamabad, Pakistan
| | - Alvina Gul
- Atta-ur-Rahman School of Applied Biosciences, National University of Sciences & Technology, Islamabad, Pakistan
| | - Mirza Hasanuzzaman
- Department of Agronomy, Faculty of Agriculture, Sher-e-Bangla Agricultural University, Dhaka, Bangladesh
| | - Kamuran Nahar
- Department of Agricultural Botany, Faculty of Agriculture, Sher-e-Bangla Agricultural University, Dhaka, Bangladesh
| | - Tomonori Kawano
- Graduate School of Environmental Engineering, The University of Kitakyushu, 1-1 Hibikino, Wakamatsu-ku, Kitakyushu, Fukuoka, 808-0135, Japan
| | - Pedro García Caparrós
- Agronomy Department of Superior School Engineering, University of Almería, Ctra. Sacramento s/n, La Cañadade San Urbano, 04120, Almería, Spain
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7
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Shrivastava M, Feng J, Coles M, Clark B, Islam A, Dumeaux V, Whiteway M. Modulation of the complex regulatory network for methionine biosynthesis in fungi. Genetics 2021; 217:6078591. [PMID: 33724418 DOI: 10.1093/genetics/iyaa049] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Accepted: 12/07/2020] [Indexed: 01/19/2023] Open
Abstract
The assimilation of inorganic sulfate and the synthesis of the sulfur-containing amino acids methionine and cysteine is mediated by a multibranched biosynthetic pathway. We have investigated this circuitry in the fungal pathogen Candida albicans, which is phylogenetically intermediate between the filamentous fungi and Saccharomyces cerevisiae. In S. cerevisiae, this pathway is regulated by a collection of five transcription factors (Met4, Cbf1, Met28, and Met31/Met32), while in the filamentous fungi the pathway is controlled by a single Met4-like factor. We found that in C. albicans, the Met4 ortholog is also a core regulator of methionine biosynthesis, where it functions together with Cbf1. While C. albicans encodes this Met4 protein, a Met4 paralog designated Met28 (Orf19.7046), and a Met31 protein, deletion, and activation constructs suggest that of these proteins only Met4 is actually involved in the regulation of methionine biosynthesis. Both Met28 and Met31 are linked to other functions; Met28 appears essential, and Met32 appears implicated in the regulation of genes of central metabolism. Therefore, while S. cerevisiae and C. albicans share Cbf1 and Met4 as central elements of the methionine biosynthesis control, the other proteins that make up the circuit in S. cerevisiae are not members of the C. albicans control network, and so the S. cerevisiae circuit likely represents a recently evolved arrangement.
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Affiliation(s)
| | - Jinrong Feng
- Medical School, Nantong University, Nangtong, Jiangsu, China
| | - Mark Coles
- Depatment of Biology, Concordia University, Montreal, QC, Canada
| | - Benjamin Clark
- Depatment of Biology, Concordia University, Montreal, QC, Canada
| | - Amjad Islam
- Depatment of Biology, Concordia University, Montreal, QC, Canada
| | - Vanessa Dumeaux
- Depatment of Biology, Concordia University, Montreal, QC, Canada
| | - Malcolm Whiteway
- Depatment of Biology, Concordia University, Montreal, QC, Canada
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8
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Cdc48/Shp1 participates in dissociation of protein complexes to regulate their activity. Curr Genet 2021; 67:263-265. [PMID: 33388824 DOI: 10.1007/s00294-020-01136-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 11/17/2020] [Accepted: 11/19/2020] [Indexed: 10/22/2022]
Abstract
The AAA-ATPase p97/Cdc48 is one of the most abundant proteins in eukaryotes, and owing to its multiple functions, is considered the swiss army knife of cells. Recent findings demonstrate that p97/Cdc48 and its cofactor p47/Shp1 control the heavy metal stress response by active, signal-triggered disassembly of a multisubunit ubiquitin ligase. Here we review this pathway and describe recently achieved mechanistic insight into the role of p47/Shp1 in this process.
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9
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Lauinger L, Flick K, Yen JL, Mathur R, Kaiser P. Cdc48 cofactor Shp1 regulates signal-induced SCF Met30 disassembly. Proc Natl Acad Sci U S A 2020; 117:21319-21327. [PMID: 32817489 PMCID: PMC7474596 DOI: 10.1073/pnas.1922891117] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Organisms can adapt to a broad spectrum of sudden and dramatic changes in their environment. These abrupt changes are often perceived as stress and trigger responses that facilitate survival and eventual adaptation. The ubiquitin-proteasome system (UPS) is involved in most cellular processes. Unsurprisingly, components of the UPS also play crucial roles during various stress response programs. The budding yeast SCFMet30 complex is an essential cullin-RING ubiquitin ligase that connects metabolic and heavy metal stress to cell cycle regulation. Cadmium exposure results in the active dissociation of the F-box protein Met30 from the core ligase, leading to SCFMet30 inactivation. Consequently, SCFMet30 substrate ubiquitylation is blocked and triggers a downstream cascade to activate a specific transcriptional stress response program. Signal-induced dissociation is initiated by autoubiquitylation of Met30 and serves as a recruitment signal for the AAA-ATPase Cdc48/p97, which actively disassembles the complex. Here we show that the UBX cofactor Shp1/p47 is an additional key element for SCFMet30 disassembly during heavy metal stress. Although the cofactor can directly interact with the ATPase, Cdc48 and Shp1 are recruited independently to SCFMet30 during cadmium stress. An intact UBX domain is crucial for effective SCFMet30 disassembly, and a concentration threshold of Shp1 recruited to SCFMet30 needs to be exceeded to initiate Met30 dissociation. The latter is likely related to Shp1-mediated control of Cdc48 ATPase activity. This study identifies Shp1 as the crucial Cdc48 cofactor for signal-induced selective disassembly of a multisubunit protein complex to modulate activity.
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Affiliation(s)
- Linda Lauinger
- Department of Biological Chemistry, School of Medicine, University of California, Irvine, CA 92697-1700
| | - Karin Flick
- Department of Biological Chemistry, School of Medicine, University of California, Irvine, CA 92697-1700
| | - James L Yen
- Department of Biological Chemistry, School of Medicine, University of California, Irvine, CA 92697-1700
| | - Radhika Mathur
- Department of Biological Chemistry, School of Medicine, University of California, Irvine, CA 92697-1700
| | - Peter Kaiser
- Department of Biological Chemistry, School of Medicine, University of California, Irvine, CA 92697-1700
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10
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Methionine Dependence of Cancer. Biomolecules 2020; 10:biom10040568. [PMID: 32276408 PMCID: PMC7226524 DOI: 10.3390/biom10040568] [Citation(s) in RCA: 86] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Revised: 04/02/2020] [Accepted: 04/06/2020] [Indexed: 12/25/2022] Open
Abstract
Tumorigenesis is accompanied by the reprogramming of cellular metabolism. The shift from oxidative phosphorylation to predominantly glycolytic pathways to support rapid growth is well known and is often referred to as the Warburg effect. However, other metabolic changes and acquired needs that distinguish cancer cells from normal cells have also been discovered. The dependence of cancer cells on exogenous methionine is one of them and is known as methionine dependence or the Hoffman effect. This phenomenon describes the inability of cancer cells to proliferate when methionine is replaced with its metabolic precursor, homocysteine, while proliferation of non-tumor cells is unaffected by these conditions. Surprisingly, cancer cells can readily synthesize methionine from homocysteine, so their dependency on exogenous methionine reflects a general need for altered metabolic flux through pathways linked to methionine. In this review, an overview of the field will be provided and recent discoveries will be discussed.
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11
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Identification of Grafting-Responsive MicroRNAs Associated with Growth Regulation in Pecan [Carya illinoinensis (Wangenh.) K. Koch]. FORESTS 2020. [DOI: 10.3390/f11020196] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Pecan [Carya illinoinensis (Wangenh.) K. Koch] is an economically important nut tree and grafting is often used for clonal propagation of cultivars. However, there is a lack of research on the effects of rootstocks on scions, which are meaningful targets for directed breeding of pecan grafts. MicroRNAs (miRNAs) play an important role in many biological processes, but the mechanism underlying the involvement of miRNAs in grafting-conferred physiological changes is unclear. To identify the grafting-responsive miRNAs that may be involved in the regulation of growth in grafted pecan, six small RNA libraries were constructed from the phloem of two groups of grafts with significantly different growth performance on short and tall rootstocks. A total of 441 conserved miRNAs belonging to 42 miRNA families and 603 novel miRNAs were identified. Among the identified miRNAs, 24 (seven conserved and 17 novel) were significantly differentially expressed by the different grafts, implying that they might be responsive to grafting and potentially involved in the regulation of graft growth. Ninety-five target genes were predicted for the differentially expressed miRNAs; gene annotation was available for 33 of these. Analysis of their targets suggested that the miRNAs may regulate auxin transport, cell activity, and inorganic phosphate (Pi) acquisition, and thereby, mediate pecan graft growth. Use of the recently-published pecan genome enabled identification of a substantial population of miRNAs, which are now available for further research. We also identified the grafting-responsive miRNAs and their potential roles in pecan graft growth, providing a basis for research on long-distance regulation in grafted pecan.
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Traynor AM, Sheridan KJ, Jones GW, Calera JA, Doyle S. Involvement of Sulfur in the Biosynthesis of Essential Metabolites in Pathogenic Fungi of Animals, Particularly Aspergillus spp.: Molecular and Therapeutic Implications. Front Microbiol 2019; 10:2859. [PMID: 31921039 PMCID: PMC6923255 DOI: 10.3389/fmicb.2019.02859] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Accepted: 11/25/2019] [Indexed: 12/13/2022] Open
Abstract
Fungal sulfur uptake is required for incorporation into the sidechains of the amino acids cysteine and methionine, and is also essential for the biosynthesis of the antioxidant glutathione (GSH), S-adenosylmethionine (SAM), the key source of methyl groups in cellular transmethylation reactions, and S-adenosylhomocysteine (SAH). Biosynthesis of redox-active gliotoxin in the opportunistic fungal pathogen Aspergillus fumigatus has been elucidated over the past 10 years. Some fungi which produce gliotoxin-like molecular species have undergone unexpected molecular rewiring to accommodate this high-risk biosynthetic process. Specific disruption of gliotoxin biosynthesis, via deletion of gliK, which encodes a γ-glutamyl cyclotransferase, leads to elevated intracellular antioxidant, ergothioneine (EGT), levels, and confirms crosstalk between the biosynthesis of both sulfur-containing moieties. Gliotoxin is ultimately formed by gliotoxin oxidoreductase GliT-mediated oxidation of dithiol gliotoxin (DTG). In fact, DTG is a substrate for both GliT and a bis-thiomethyltransferase, GtmA. GtmA converts DTG to bisdethiobis(methylthio)gliotoxin (BmGT), using 2 mol SAM and resultant SAH must be re-converted to SAM via the action of the Methyl/Met cycle. In the absence of GliT, DTG fluxes via GtmA to BmGT, which results in both SAM depletion and SAH overproduction. Thus, the negative regulation of gliotoxin biosynthesis via GtmA must be counter-balanced by GliT activity to avoid Methyl/Met cycle dysregulation, SAM depletion and trans consequences on global cellular biochemistry in A. fumigatus. DTG also possesses potent Zn2+ chelation properties which positions this sulfur-containing metabolite as a putative component of the Zn2+ homeostasis system within fungi. EGT plays an essential role in high-level redox homeostasis and its presence requires significant consideration in future oxidative stress studies in pathogenic filamentous fungi. In certain filamentous fungi, sulfur is additionally indirectly required for the formation of EGT and the disulfide-bridge containing non-ribosomal peptide, gliotoxin, and related epipolythiodioxopiperazines. Ultimately, interference with emerging sulfur metabolite functionality may represent a new strategy for antifungal drug development.
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Affiliation(s)
- Aimee M Traynor
- Department of Biology, Maynooth University, Maynooth, Ireland
| | | | - Gary W Jones
- Centre for Biomedical Science Research, School of Clinical and Applied Sciences, Leeds Beckett University, Leeds, United Kingdom
| | - José A Calera
- Instituto de Biología Funcional y Genómica (IBFG-CSIC), Universidad de Salamanca, Salamanca, Spain.,Departamento de Microbiología y Genética, Universidad de Salamanca, Salamanca, Spain
| | - Sean Doyle
- Department of Biology, Maynooth University, Maynooth, Ireland
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13
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Junker K, Chailyan A, Hesselbart A, Forster J, Wendland J. Multi-omics characterization of the necrotrophic mycoparasite Saccharomycopsis schoenii. PLoS Pathog 2019; 15:e1007692. [PMID: 31071195 PMCID: PMC6508603 DOI: 10.1371/journal.ppat.1007692] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Accepted: 03/10/2019] [Indexed: 12/14/2022] Open
Abstract
Pathogenic yeasts and fungi are an increasing global healthcare burden, but discovery of novel antifungal agents is slow. The mycoparasitic yeast Saccharomycopsis schoenii was recently demonstrated to be able to kill the emerging multi-drug resistant yeast pathogen Candida auris. However, the molecular mechanisms involved in the predatory activity of S. schoenii have not been explored. To this end, we de novo sequenced, assembled and annotated a draft genome of S. schoenii. Using proteomics, we confirmed that Saccharomycopsis yeasts have reassigned the CTG codon and translate CTG into serine instead of leucine. Further, we confirmed an absence of all genes from the sulfate assimilation pathway in the genome of S. schoenii, and detected the expansion of several gene families, including aspartic proteases. Using Saccharomyces cerevisiae as a model prey cell, we honed in on the timing and nutritional conditions under which S. schoenii kills prey cells. We found that a general nutrition limitation, not a specific methionine deficiency, triggered predatory activity. Nevertheless, by means of genome-wide transcriptome analysis we observed dramatic responses to methionine deprivation, which were alleviated when S. cerevisiae was available as prey, and therefore postulate that S. schoenii acquired methionine from its prey cells. During predation, both proteomic and transcriptomic analyses revealed that S. schoenii highly upregulated and translated aspartic protease genes, probably used to break down prey cell walls. With these fundamental insights into the predatory behavior of S. schoenii, we open up for further exploitation of this yeast as a biocontrol yeast and/or source for novel antifungal agents.
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Affiliation(s)
- Klara Junker
- Yeast & Fermentation, Carlsberg Research Laboratory, Copenhagen, Denmark
| | - Anna Chailyan
- Yeast & Fermentation, Carlsberg Research Laboratory, Copenhagen, Denmark
| | - Ana Hesselbart
- Yeast & Fermentation, Carlsberg Research Laboratory, Copenhagen, Denmark
| | - Jochen Forster
- Yeast & Fermentation, Carlsberg Research Laboratory, Copenhagen, Denmark
| | - Jürgen Wendland
- Yeast & Fermentation, Carlsberg Research Laboratory, Copenhagen, Denmark
- Functional Yeast Genomics, Vrije Universiteit Brussel, Brussels, Belgium
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14
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Karpov DS, Spasskaya DS, Nadolinskaia NI, Tutyaeva VV, Lysov YP, Karpov VL. Deregulation of the 19S proteasome complex increases yeast resistance to 4-NQO and oxidative stress via upregulation of Rpn4- and proteasome-dependent stress responsive genes. FEMS Yeast Res 2019; 19:5281435. [DOI: 10.1093/femsyr/foz002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Accepted: 01/05/2019] [Indexed: 01/07/2023] Open
Affiliation(s)
- Dmitry S Karpov
- Department of Intracellular proteolysis regulation, Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Vavilov str. 32, Moscow 119991, Russia
- Laboratory of Medicinal Proteomics, Orekhovich Institute of Biomedical Chemistry, Pogodinskaya str. 10, Moscow 119121, Russia
| | - Daria S Spasskaya
- Department of Intracellular proteolysis regulation, Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Vavilov str. 32, Moscow 119991, Russia
| | - Nonna I Nadolinskaia
- Department of Intracellular proteolysis regulation, Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Vavilov str. 32, Moscow 119991, Russia
| | - Vera V Tutyaeva
- Department of Intracellular proteolysis regulation, Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Vavilov str. 32, Moscow 119991, Russia
| | - Yuriy P Lysov
- Department of Intracellular proteolysis regulation, Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Vavilov str. 32, Moscow 119991, Russia
| | - Vadim L Karpov
- Department of Intracellular proteolysis regulation, Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Vavilov str. 32, Moscow 119991, Russia
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15
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Regulatory Networks Governing Methionine Catabolism into Volatile Organic Sulfur-Containing Compounds in Clonostachys rosea. Appl Environ Microbiol 2018; 84:AEM.01840-18. [PMID: 30217835 DOI: 10.1128/aem.01840-18] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Accepted: 09/04/2018] [Indexed: 11/20/2022] Open
Abstract
Adaptation to environmental perturbations requires living systems to coordinately regulate signaling pathways, gene expression, and metabolism. To better understand the mechanisms underlying adaptation, the regulatory nodes within networks must be elucidated. Here, ARO8-2 (which encodes an aminotransferase), PDC (which encodes a decarboxylase), and STR3 (which encodes a demethiolase) were identified as key genes involved in the catabolism of methionine in the mycoparasitic fungus Clonostachys rosea, isolated from Tuber melanosporum ascocarps. Exogenous Met induced the transcription of ARO8-2 and PDC but repressed the transcription of STR3, which is controlled by the putative MSN2 and GLN3 binding sites responding to nitrogen catabolite repression. Met and its structural derivatives function as glutamine synthetase inhibitors, resulting in the downregulation of STR3 expression. The putative GLN3 binding site was necessary for STR3 downregulation. In Saccharomyces cerevisiae, Met and its structural derivatives also triggered downregulation of demethiolase gene expression. Altogether, the results indicated that exogenous Met triggered nitrogen catabolite repression, which stimulated the Ehrlich pathway and negatively regulated the demethiolation pathway via the methionine sulfoximine-responsive regulatory pathway. This finding revealed the regulatory nodes within the networks controlling the catabolism of Met into volatile organic sulfur-containing compounds, thereby enhancing our understanding of adaptation.IMPORTANCE Methionine shuttles organic nitrogen and plays a central role in nitrogen metabolism. Exogenous Met strongly induces the expression of ARO8-2 and PDC, represses the expression of STR3, and generates volatile organic sulfur-containing compounds via the Ehrlich and demethiolation pathways. In this study, we used genetic, bioinformatic, and metabolite-based analyses to confirm that transcriptional control of the aminotransferase gene ARO8-2, the decarboxylase gene PDC, and the demethiolase gene STR3 modulates Met catabolism into volatile organic sulfur-containing compounds. Importantly, we found that, in addition to the Ehrlich pathway, the demethiolation pathway was regulated by a nitrogen catabolite repression-sensitive regulatory pathway that controlled the transcription of genes required to catabolize poor nitrogen sources. This work significantly advances our understanding of nitrogen catabolite repression-sensitive transcriptional regulation of sulfur-containing amino acid catabolism and provides a basis for engineering Met catabolism pathways for the production of fuel and valuable flavor alcohols.
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Jain S, Sekonyela R, Knox BP, Palmer JM, Huttenlocher A, Kabbage M, Keller NP. Selenate sensitivity of a laeA mutant is restored by overexpression of the bZIP protein MetR in Aspergillus fumigatus. Fungal Genet Biol 2018; 117:1-10. [PMID: 29753128 PMCID: PMC6064392 DOI: 10.1016/j.fgb.2018.05.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2018] [Revised: 05/07/2018] [Accepted: 05/08/2018] [Indexed: 02/06/2023]
Abstract
LaeA is a conserved global regulator of secondary metabolism and development in filamentous fungi. Examination of Aspergillus fumigatus transcriptome data of laeA deletion mutants have been fruitful in identifying genes and molecules contributing to the laeA mutant phenotype. One of the genes significantly down regulated in A. fumigatus ΔlaeA is metR, encoding a bZIP DNA binding protein required for sulfur and methionine metabolism in fungi. LaeA and MetR deletion mutants exhibit several similarities including down regulation of sulfur assimilation and methionine metabolism genes and ability to grow on the toxic sulfur analog, sodium selenate. However, unlike ΔmetR, ΔlaeA strains are able to grow on sulfur, sulfite, and cysteine. To examine if any parameter of the ΔlaeA phenotype is due to decreased metR expression, an over-expression allele (OE::metR) was placed in a ΔlaeA background. The OE::metR allele could not significantly restore expression of MetR regulated genes in ΔlaeA but did restore sensitivity to sodium selenate. In A. nidulans a second bZIP protein, MetZ, also regulates sulfur and methionine metabolism genes. However, addition of an OE::metZ construct to the A. fumigatus ΔlaeA OE::metR strain still was unable to rescue the ΔlaeA phenotype to wildtype with regards gliotoxin synthesis and virulence in a zebrafish aspergillosis model.
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Affiliation(s)
- Sachin Jain
- Department of Plant Pathology, University of Wisconsin-Madison, Madison, WI 53706, United States
| | - Relebohile Sekonyela
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI 53706, United States
| | - Benjamin P Knox
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI 53706, United States
| | - Jonathan M Palmer
- Department of Plant Pathology, University of Wisconsin-Madison, Madison, WI 53706, United States
| | - Anna Huttenlocher
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI 53706, United States
| | - Mehdi Kabbage
- Department of Plant Pathology, University of Wisconsin-Madison, Madison, WI 53706, United States
| | - Nancy P Keller
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI 53706, United States; Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI 53706, United States.
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17
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Mishra R, Upadhyay A, Prajapati VK, Mishra A. Proteasome-mediated proteostasis: Novel medicinal and pharmacological strategies for diseases. Med Res Rev 2018; 38:1916-1973. [DOI: 10.1002/med.21502] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2017] [Revised: 03/13/2018] [Accepted: 04/04/2018] [Indexed: 02/06/2023]
Affiliation(s)
- Ribhav Mishra
- Cellular and Molecular Neurobiology Unit; Indian Institute of Technology Jodhpur; Rajasthan India
| | - Arun Upadhyay
- Cellular and Molecular Neurobiology Unit; Indian Institute of Technology Jodhpur; Rajasthan India
| | - Vijay Kumar Prajapati
- Department of Biochemistry; School of Life Sciences; Central University of Rajasthan; Rajasthan India
| | - Amit Mishra
- Cellular and Molecular Neurobiology Unit; Indian Institute of Technology Jodhpur; Rajasthan India
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18
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Weidberg H, Amon A. MitoCPR-A surveillance pathway that protects mitochondria in response to protein import stress. Science 2018; 360:eaan4146. [PMID: 29650645 PMCID: PMC6528467 DOI: 10.1126/science.aan4146] [Citation(s) in RCA: 215] [Impact Index Per Article: 35.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2017] [Revised: 12/19/2017] [Accepted: 02/19/2018] [Indexed: 12/13/2022]
Abstract
Mitochondrial functions are essential for cell viability and rely on protein import into the organelle. Various disease and stress conditions can lead to mitochondrial import defects. We found that inhibition of mitochondrial import in budding yeast activated a surveillance mechanism, mitoCPR, that improved mitochondrial import and protected mitochondria during import stress. mitoCPR induced expression of Cis1, which associated with the mitochondrial translocase to reduce the accumulation of mitochondrial precursor proteins at the mitochondrial translocase. Clearance of precursor proteins depended on the Cis1-interacting AAA+ adenosine triphosphatase Msp1 and the proteasome, suggesting that Cis1 facilitates degradation of unimported proteins. mitoCPR was required for maintaining mitochondrial functions when protein import was compromised, demonstrating the importance of mitoCPR in protecting the mitochondrial compartment.
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Affiliation(s)
- Hilla Weidberg
- David H. Koch Institute for Integrative Cancer Research, Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
| | - Angelika Amon
- David H. Koch Institute for Integrative Cancer Research, Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
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19
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Mathur R, Yen JL, Kaiser P. Skp1 Independent Function of Cdc53/Cul1 in F-box Protein Homeostasis. PLoS Genet 2015; 11:e1005727. [PMID: 26656496 PMCID: PMC4675558 DOI: 10.1371/journal.pgen.1005727] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Accepted: 11/14/2015] [Indexed: 11/24/2022] Open
Abstract
Abundance of substrate receptor subunits of Cullin-RING ubiquitin ligases (CRLs) is tightly controlled to maintain the full repertoire of CRLs. Unbalanced levels can lead to sequestration of CRL core components by a few overabundant substrate receptors. Numerous diseases, including cancer, have been associated with misregulation of substrate receptor components, particularly for the largest class of CRLs, the SCF ligases. One relevant mechanism that controls abundance of their substrate receptors, the F-box proteins, is autocatalytic ubiquitylation by intact SCF complex followed by proteasome-mediated degradation. Here we describe an additional pathway for regulation of F-box proteins on the example of yeast Met30. This ubiquitylation and degradation pathway acts on Met30 that is dissociated from Skp1. Unexpectedly, this pathway required the cullin component Cdc53/Cul1 but was independent of the other central SCF component Skp1. We demonstrated that this non-canonical degradation pathway is critical for chromosome stability and effective defense against heavy metal stress. More importantly, our results assign important biological functions to a sub-complex of cullin-RING ligases that comprises Cdc53/Rbx1/Cdc34, but is independent of Skp1. Protein ubiquitylation is the covalent attachment of the small protein ubiquitin onto other proteins and is a key regulatory pathway for most biological processes. The central components of the ubiquitylation process are the E3 ligases, which recognize substrate proteins. The best-studied E3 complexes are the SCF ligases, which are composed of 3 core components—Cdc53, Skp1, Rbx1—that assemble to the functional ligase complex by binding to one of the multiple substrate adaptors—the F-box proteins. Maintaining a balanced repertoire of diverse SCF complexes that represent the entire cellular panel of substrate adapters is challenging. Depending on the cell type, hundreds of different F-box proteins can compete for the single binding site on the common SCF core complex. Rapid degradation of F-box proteins helps in maintaining a critical level of unoccupied Cdc53/Skp1/Rbx1 core, complexes and alterations in levels of F-box proteins has been linked to diseases including cancer. Studying the yeast F-box protein Met30 as a model, we have uncovered a novel mechanism for degradation of F-box proteins. This pathway targets free F-box proteins and requires part of the SCF core. These findings add an additional layer to our understanding of regulation of multisubunit E3 ligase.
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Affiliation(s)
- Radhika Mathur
- Department of Biological Chemistry, College of Medicine, University of California Irvine, Irvine, California, United States of America
| | - James L. Yen
- Department of Biological Chemistry, College of Medicine, University of California Irvine, Irvine, California, United States of America
| | - Peter Kaiser
- Department of Biological Chemistry, College of Medicine, University of California Irvine, Irvine, California, United States of America
- * E-mail:
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20
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Nakatsukasa K, Okumura F, Kamura T. Proteolytic regulation of metabolic enzymes by E3 ubiquitin ligase complexes: lessons from yeast. Crit Rev Biochem Mol Biol 2015; 50:489-502. [PMID: 26362128 DOI: 10.3109/10409238.2015.1081869] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Eukaryotic organisms use diverse mechanisms to control metabolic rates in response to changes in the internal and/or external environment. Fine metabolic control is a highly responsive, energy-saving process that is mediated by allosteric inhibition/activation and/or reversible modification of preexisting metabolic enzymes. In contrast, coarse metabolic control is a relatively long-term and expensive process that involves modulating the level of metabolic enzymes. Coarse metabolic control can be achieved through the degradation of metabolic enzymes by the ubiquitin-proteasome system (UPS), in which substrates are specifically ubiquitinated by an E3 ubiquitin ligase and targeted for proteasomal degradation. Here, we review select multi-protein E3 ligase complexes that directly regulate metabolic enzymes in Saccharomyces cerevisiae. The first part of the review focuses on the endoplasmic reticulum (ER) membrane-associated Hrd1 and Doa10 E3 ligase complexes. In addition to their primary roles in the ER-associated degradation pathway that eliminates misfolded proteins, recent quantitative proteomic analyses identified native substrates of Hrd1 and Doa10 in the sterol synthesis pathway. The second part focuses on the SCF (Skp1-Cul1-F-box protein) complex, an abundant prototypical multi-protein E3 ligase complex. While the best-known roles of the SCF complex are in the regulation of the cell cycle and transcription, accumulating evidence indicates that the SCF complex also modulates carbon metabolism pathways. The increasing number of metabolic enzymes whose stability is directly regulated by the UPS underscores the importance of the proteolytic regulation of metabolic processes for the acclimation of cells to environmental changes.
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Affiliation(s)
- Kunio Nakatsukasa
- a Division of Biological Sciences , Graduate School of Science, Nagoya University , Nagoya , Aichi , Japan
| | - Fumihiko Okumura
- a Division of Biological Sciences , Graduate School of Science, Nagoya University , Nagoya , Aichi , Japan
| | - Takumi Kamura
- a Division of Biological Sciences , Graduate School of Science, Nagoya University , Nagoya , Aichi , Japan
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21
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Noble J, Sanchez I, Blondin B. Identification of new Saccharomyces cerevisiae variants of the MET2 and SKP2 genes controlling the sulfur assimilation pathway and the production of undesirable sulfur compounds during alcoholic fermentation. Microb Cell Fact 2015; 14:68. [PMID: 25947166 PMCID: PMC4432976 DOI: 10.1186/s12934-015-0245-1] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Accepted: 04/13/2015] [Indexed: 11/10/2022] Open
Abstract
Background Wine yeasts can produce undesirable sulfur compounds during alcoholic fermentation, such as SO2 and H2S, in variable amounts depending mostly on the yeast strain but also on the conditions. However, although sulfur metabolism has been widely studied, some of the genetic determinants of differences in sulfite and/or sulfide production between wine yeast strains remain to be identified. In this study, we used an integrated approach to decipher the genetic determinants of variation in the production of undesirable sulfur compounds. Results We examined the kinetics of SO2 production by two parental strains, one high and one low sulfite producer. These strains displayed similar production profiles but only the high-sulfite producer strain continued to produce SO2 in the stationary phase. Transcriptomic analysis revealed that the low-sulfite producer strain overexpressed genes of the sulfur assimilation pathway, which is the mark of a lower flux through the pathway consistent with a lower intracellular concentration in cysteine. A QTL mapping strategy then enabled us to identify MET2 and SKP2 as the genes responsible for these phenotypic differences between strains and we identified new variants of these genes in the low-sulfite producer strain. MET2 influences the availability of a metabolic intermediate, O-acetylhomoserine, whereas SKP2 affects the activity of a key enzyme of the sulfur assimilation branch of the pathway, the APS kinase, encoded by MET14. Furthermore, these genes also affected the production of propanol and acetaldehyde. These pleiotropic effects are probably linked to the influence of these genes on interconnected pathways and to the chemical reactivity of sulfite with other metabolites. Conclusions This study provides new insight into the regulation of sulfur metabolism in wine yeasts and identifies variants of MET2 and SKP2 genes, that control the activity of both branches of the sulfur amino acid synthesis pathway and modulate sulfite/sulfide production and other related phenotypes. These results provide novel targets for the improvement of wine yeast strains. Electronic supplementary material The online version of this article (doi:10.1186/s12934-015-0245-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jessica Noble
- Lallemand SAS, Blagnac, 31700, France. .,Institut Coopératif du Vin, Lattes, 34970, France.
| | - Isabelle Sanchez
- INRA, UMR1083 Sciences pour l'Oenologie, Montpellier, 34060, France. .,Supagro, UMR1083 Sciences pour l'Oenologie, Montpellier, 34060, France. .,UM1, UMR1083 Sciences pour l'Oenologie, Montpellier, 34060, France.
| | - Bruno Blondin
- INRA, UMR1083 Sciences pour l'Oenologie, Montpellier, 34060, France. .,Supagro, UMR1083 Sciences pour l'Oenologie, Montpellier, 34060, France. .,UM1, UMR1083 Sciences pour l'Oenologie, Montpellier, 34060, France.
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22
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The Aspergillus nidulans metZ gene encodes a transcription factor involved in regulation of sulfur metabolism in this fungus and other Eurotiales. Curr Genet 2014; 61:115-25. [PMID: 25391366 DOI: 10.1007/s00294-014-0459-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2014] [Revised: 10/24/2014] [Accepted: 10/29/2014] [Indexed: 10/24/2022]
Abstract
In Aspergillus nidulans, expression of sulfur metabolism genes is activated by the MetR transcription factor containing a basic region and leucine zipper domain (bZIP). Here we identified and characterized MetZ, a new transcriptional regulator in A. nidulans and other Eurotiales. It contains a bZIP domain similar to the corresponding region in MetR and this similarity suggests that MetZ could potentially complement the MetR deficiency. The metR and metZ genes are interrupted by unusually long introns. Transcription of metZ, unlike that of metR, is controlled by the sulfur metabolite repression system (SMR) dependent on the MetR protein. Overexpression of metZ from a MetR-independent promoter in a ΔmetR background activates transcription of genes encoding sulfate permease, homocysteine synthase and methionine permease, partially complementing the phenotype of the ΔmetR mutation. Thus, MetZ appears to be a second transcription factor involved in regulation of sulfur metabolism genes.
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23
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Ouni I, Flick K, Kaiser P. Ubiquitin and transcription: The SCF/Met4 pathway, a (protein-) complex issue. Transcription 2014; 2:135-139. [PMID: 21826284 DOI: 10.4161/trns.2.3.15903] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2011] [Revised: 04/20/2011] [Accepted: 04/20/2011] [Indexed: 02/06/2023] Open
Abstract
Ubiquitylation has emerged as an omnipresent factor at all levels of transcriptional regulation. A recent study that describes the yeast transcriptional activator Met4 as a functional component of the very same ubiquitin ligase that regulates its own activity highlights the close relation between transcription and the ubiquitin proteasome system.
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Affiliation(s)
- Ikram Ouni
- Department of Biological Chemistry; School of Medicine; University of California Irvine; Irvine, CA USA
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24
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A design principle underlying the paradoxical roles of E3 ubiquitin ligases. Sci Rep 2014; 4:5573. [PMID: 24994517 PMCID: PMC5381699 DOI: 10.1038/srep05573] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Accepted: 06/16/2014] [Indexed: 12/25/2022] Open
Abstract
E3 ubiquitin ligases are important cellular components that determine the specificity of proteolysis in the ubiquitin-proteasome system. However, an increasing number of studies have indicated that E3 ubiquitin ligases also participate in transcription. Intrigued by the apparently paradoxical functions of E3 ubiquitin ligases in both proteolysis and transcriptional activation, we investigated the underlying design principles using mathematical modeling. We found that the antagonistic functions integrated in E3 ubiquitin ligases can prevent any undesirable sustained activation of downstream genes when E3 ubiquitin ligases are destabilized by unexpected perturbations. Interestingly, this design principle of the system is similar to the operational principle of a safety interlock device in engineering systems, which prevents a system from abnormal operation unless stability is guaranteed.
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25
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Shobayashi M, Fujii T, Iefuji H. Effects of AccumulatedS-Adenosylmethionine on Growth of Yeast Cells. Biosci Biotechnol Biochem 2014; 71:1595-7. [PMID: 17587699 DOI: 10.1271/bbb.70100] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
S-adenosylmethionine (SAM) accumulated in cultured yeast cells and affected growth in two ways. High levels of intracellular SAM in yeast inhibited early growth, but increased growth in medium without sources of nitrogen and sulfur. Accumulated SAM in the yeast cells was recycled as a nutritional source depending on the sulfur and nitrogen contents of the medium.
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Sadhu MJ, Moresco JJ, Zimmer AD, Yates JR, Rine J. Multiple inputs control sulfur-containing amino acid synthesis in Saccharomyces cerevisiae. Mol Biol Cell 2014; 25:1653-65. [PMID: 24648496 PMCID: PMC4019496 DOI: 10.1091/mbc.e13-12-0755] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Genes in Saccharomyces cerevisiae involved in sulfur-containing amino acid synthesis are transcriptionally induced by either cysteine or S-adenosyl-methionine deficiency, as well as defects in phosphatidylcholine synthesis. Met30p, a regulator of these genes, changes physically in inducing conditions, which may mediate its regulatory activity. In Saccharomyces cerevisiae, transcription of the MET regulon, which encodes the proteins involved in the synthesis of the sulfur-containing amino acids methionine and cysteine, is repressed by the presence of either methionine or cysteine in the environment. This repression is accomplished by ubiquitination of the transcription factor Met4, which is carried out by the SCF(Met30) E3 ubiquitin ligase. Mutants defective in MET regulon repression reveal that loss of Cho2, which is required for the methylation of phosphatidylethanolamine to produce phosphatidylcholine, leads to induction of the MET regulon. This induction is due to reduced cysteine synthesis caused by the Cho2 defects, uncovering an important link between phospholipid synthesis and cysteine synthesis. Antimorphic mutants in S-adenosyl-methionine (SAM) synthetase genes also induce the MET regulon. This effect is due, at least in part, to SAM deficiency controlling the MET regulon independently of SAM's contribution to cysteine synthesis. Finally, the Met30 protein is found in two distinct forms whose relative abundance is controlled by the availability of sulfur-containing amino acids. This modification could be involved in the nutritional control of SCF(Met30) activity toward Met4.
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Affiliation(s)
- Meru J Sadhu
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720California Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley, CA 94720
| | - James J Moresco
- Department of Chemical Physiology, Scripps Research Institute, La Jolla, CA 92037
| | - Anjali D Zimmer
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720
| | - John R Yates
- Department of Chemical Physiology, Scripps Research Institute, La Jolla, CA 92037
| | - Jasper Rine
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720California Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley, CA 94720
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Zhao S, Zhao X, Zou H, Fu J, Du G, Zhou J, Chen J. Comparative proteomic analysis of Saccharomyces cerevisiae under different nitrogen sources. J Proteomics 2014; 101:102-12. [PMID: 24530623 DOI: 10.1016/j.jprot.2014.01.031] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2013] [Revised: 11/28/2013] [Accepted: 01/24/2014] [Indexed: 11/15/2022]
Abstract
In cultures containing multiple sources of nitrogen, Saccharomyces cerevisiae exhibits a sequential use of nitrogen sources through a mechanism known as nitrogen catabolite repression (NCR). To identify proteins differentially expressed due to NCR, proteomic analysis of S. cerevisiae S288C under different nitrogen source conditions was performed using two-dimensional gel electrophoresis (2-DE), revealing 169 candidate protein spots. Among these 169 protein spots, 121 were identified by matrix assisted laser desorption ionization-time of flight/time of flight mass spectrometry (MALDI-TOF/TOF). The identified proteins were closely associated with four main biological processes through Gene Ontology (GO) categorical analysis. The identification of the potential proteins and cellular processes related to NCR offer a global overview of changes elicited by different nitrogen sources, providing clues into how yeast adapt to different nutritional conditions. Moreover, by comparing our proteomic data with corresponding mRNA data, proteins regulated at the transcriptional and post-transcriptional level could be distinguished. Biological significance In S. cerevisiae, different nitrogen sources provide different growth characteristics and generate different metabolites. The nitrogen catabolite repression (NCR) process plays an important role for S. cerevisiae in the ordinal utilization of different nitrogen sources. NCR process can result in significant shift of global metabolic networks. Previous works on NCR primarily focused on transcriptomic level. The results obtained in this study provided a global atlas of the proteome changes triggered by different nitrogen sources and would facilitate the understanding of mechanisms for how yeast could adapt to different nutritional conditions.
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Affiliation(s)
- Shaohui Zhao
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China; Synergetic Innovation Center of Food Safety and Nutrition, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
| | - Xinrui Zhao
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China; Synergetic Innovation Center of Food Safety and Nutrition, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
| | - Huijun Zou
- Zhejiang Guyuelongshan Shaoxing Wine Company, 13 Yangjiang Road, Shaoxing, Zhejiang 312000, China
| | - Jianwei Fu
- Zhejiang Guyuelongshan Shaoxing Wine Company, 13 Yangjiang Road, Shaoxing, Zhejiang 312000, China
| | - Guocheng Du
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China; Synergetic Innovation Center of Food Safety and Nutrition, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
| | - Jingwen Zhou
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China; Synergetic Innovation Center of Food Safety and Nutrition, 1800 Lihu Road, Wuxi, Jiangsu 214122, China.
| | - Jian Chen
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China; Synergetic Innovation Center of Food Safety and Nutrition, 1800 Lihu Road, Wuxi, Jiangsu 214122, China.
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Fehrmann S, Bottin-Duplus H, Leonidou A, Mollereau E, Barthelaix A, Wei W, Steinmetz LM, Yvert G. Natural sequence variants of yeast environmental sensors confer cell-to-cell expression variability. Mol Syst Biol 2013; 9:695. [PMID: 24104478 PMCID: PMC3817403 DOI: 10.1038/msb.2013.53] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2013] [Accepted: 09/06/2013] [Indexed: 01/29/2023] Open
Abstract
DNA polymorphisms that change cell-to-cell variability in gene expression are identified in a screen for ‘Probabilistic Trait Loci' in yeast. By modifying transmembrane transporter genes, these natural variants modulate intraclonal phenotypic diversification. ![]()
We mapped genetic loci affecting cell–cell variability in gene expression. One variant enhanced both expression of a transporter and variability in a metabolic pathway. A sequence change in another transporter also increased pathway variability. The study invites to apprehend complex traits from a nondeterministic angle.
Living systems may have evolved probabilistic bet hedging strategies that generate cell-to-cell phenotypic diversity in anticipation of environmental catastrophes, as opposed to adaptation via a deterministic response to environmental changes. Evolution of bet hedging assumes that genotypes segregating in natural populations modulate the level of intraclonal diversity, which so far has largely remained hypothetical. Using a fluorescent Pmet17-GFP reporter, we mapped four genetic loci conferring to a wild yeast strain an elevated cell-to-cell variability in the expression of MET17, a gene regulated by the methionine pathway. A frameshift mutation in the Erc1p transmembrane transporter, probably resulting from a release of laboratory strains from negative selection, reduced Pmet17-GFP expression variability. At a second locus, cis-regulatory polymorphisms increased mean expression of the Mup1p methionine permease, causing increased expression variability in trans. These results demonstrate that an expression quantitative trait locus (eQTL) can simultaneously have a deterministic effect in cis and a probabilistic effect in trans. Our observations indicate that the evolution of transmembrane transporter genes can tune intraclonal variation and may therefore be implicated in both reactive and anticipatory strategies of adaptation.
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Affiliation(s)
- Steffen Fehrmann
- Laboratoire de Biologie Moléculaire de la Cellule, Ecole Normale Supérieure de Lyon, CNRS, Université Lyon 1, Lyon, France
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Franciosini A, Lombardi B, Iafrate S, Pecce V, Mele G, Lupacchini L, Rinaldi G, Kondou Y, Gusmaroli G, Aki S, Tsuge T, Deng XW, Matsui M, Vittorioso P, Costantino P, Serino G. The Arabidopsis COP9 SIGNALOSOME INTERACTING F-BOX KELCH 1 protein forms an SCF ubiquitin ligase and regulates hypocotyl elongation. MOLECULAR PLANT 2013; 6:1616-29. [PMID: 23475998 DOI: 10.1093/mp/sst045] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
The regulation of protein turnover by the ubiquitin proteasome system (UPS) is a major posttranslational mechanism in eukaryotes. One of the key components of the UPS, the COP9 signalosome (CSN), regulates 'cullin-ring' E3 ubiquitin ligases. In plants, CSN participates in diverse cellular and developmental processes, ranging from light signaling to cell cycle control. In this work, we isolated a new plant-specific CSN-interacting F-box protein, which we denominated CFK1 (COP9 INTERACTING F-BOX KELCH 1). We show that, in Arabidopsis thaliana, CFK1 is a component of a functional ubiquitin ligase complex. We also show that CFK1 stability is regulated by CSN and by proteasome-dependent proteolysis, and that light induces accumulation of the CFK1 transcript in the hypocotyl. Analysis of CFK1 knockdown, mutant, and overexpressing seedlings indicates that CFK1 promotes hypocotyl elongation by increasing cell size. Reduction of CSN levels enhances the short hypocotyl phenotype of CFK1-depleted seedlings, while complete loss of CSN activity suppresses the long-hypocotyl phenotype of CFK1-overexpressing seedlings. We propose that CFK1 (and its regulation by CSN) is a novel component of the cellular mechanisms controlling hypocotyl elongation.
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Affiliation(s)
- Anna Franciosini
- Dipartimento di Biologia e Biotecnologie, Sapienza Università di Roma, Italy
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Abstract
All living organisms require nutrient minerals for growth and have developed mechanisms to acquire, utilize, and store nutrient minerals effectively. In the aqueous cellular environment, these elements exist as charged ions that, together with protons and hydroxide ions, facilitate biochemical reactions and establish the electrochemical gradients across membranes that drive cellular processes such as transport and ATP synthesis. Metal ions serve as essential enzyme cofactors and perform both structural and signaling roles within cells. However, because these ions can also be toxic, cells have developed sophisticated homeostatic mechanisms to regulate their levels and avoid toxicity. Studies in Saccharomyces cerevisiae have characterized many of the gene products and processes responsible for acquiring, utilizing, storing, and regulating levels of these ions. Findings in this model organism have often allowed the corresponding machinery in humans to be identified and have provided insights into diseases that result from defects in ion homeostasis. This review summarizes our current understanding of how cation balance is achieved and modulated in baker's yeast. Control of intracellular pH is discussed, as well as uptake, storage, and efflux mechanisms for the alkali metal cations, Na(+) and K(+), the divalent cations, Ca(2+) and Mg(2+), and the trace metal ions, Fe(2+), Zn(2+), Cu(2+), and Mn(2+). Signal transduction pathways that are regulated by pH and Ca(2+) are reviewed, as well as the mechanisms that allow cells to maintain appropriate intracellular cation concentrations when challenged by extreme conditions, i.e., either limited availability or toxic levels in the environment.
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31
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Transcriptional profiling of Candida glabrata during phagocytosis by neutrophils and in the infected mouse spleen. Infect Immun 2013; 81:1325-33. [PMID: 23403555 DOI: 10.1128/iai.00851-12] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Expression microarray analysis of Candida glabrata following phagocytosis by human neutrophils was performed, and results were compared with those from C. glabrata incubated under conditions of carbohydrate or nitrogen deprivation. Twenty genes were selected to represent the major cell processes altered by phagocytosis or nutrient deprivation. Quantitative real-time PCR (qRT-PCR) with TaqMan chemistry was used to assess expression of the same genes in spleens of mice infected intravenously with Candida glabrata. The results in spleen closely paralleled gene expression in neutrophils or following carbohydrate deprivation. Fungal cells responded by upregulating alternative energy sources through gluconeogenesis, glyoxylate cycle, and long-chain fatty acid metabolism. Autophagy was likely employed to conserve intracellular resources. Aspartyl protease upregulation occurred and may represent defense against attacks on cell wall integrity. Downregulated genes were in the pathways of protein and ergosterol synthesis. Upregulation of the sterol transport gene AUS1 suggested that murine cholesterol may have been used to replace ergosterol, as has been reported in vitro. C. glabrata isolates in spleens of gp91(phox-/-) knockout mice with reduced oxidative phagocyte defenses were grossly similar although with a reduced level of response. These results are consistent with reported results of other fungi responding to phagocytosis, indicating that a rapid shift in metabolism is required for growth in a carbohydrate-limited intracellular environment.
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32
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Anton F, Dittmar G, Langer T, Escobar-Henriques M. Two deubiquitylases act on mitofusin and regulate mitochondrial fusion along independent pathways. Mol Cell 2013; 49:487-98. [PMID: 23317502 DOI: 10.1016/j.molcel.2012.12.003] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2012] [Revised: 11/02/2012] [Accepted: 12/06/2012] [Indexed: 01/07/2023]
Abstract
Mitofusins, conserved dynamin-related GTPases in the mitochondrial outer membrane, mediate the fusion of mitochondria. Here, we demonstrate that the activity of the mitofusin Fzo1 is regulated by sequential ubiquitylation at conserved lysine residues and by the deubiquitylases Ubp2 and Ubp12. Ubp2 and Ubp12 recognize distinct ubiquitin chains on Fzo1 that have opposing effects on mitochondrial fusion. Ubp2 removes ubiquitin chains that initiate proteolysis of Fzo1 and inhibit fusion. Ubp12 recognizes ubiquitin chains that stabilize Fzo1 and promote mitochondrial fusion. Self-assembly of dynamin-related GTPases is critical for their function. Ubp12 deubiquitylates Fzo1 only after oligomerization. Moreover, ubiquitylation at one monomer activates ubiquitin chain formation on another monomer. Thus, regulation of mitochondrial fusion involves ubiquitylation of mitofusin at distinct lysine residues, intermolecular crosstalk between mitofusin monomers, and two deubiquitylases that act as regulatory and quality control enzymes.
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Affiliation(s)
- Fabian Anton
- Institute for Genetics, Center for Molecular Medicine (CMMC), Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, 50674 Cologne, Germany
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Nishiuchi H, Suehiro M, Sugimoto R, Yamagishi K. Preparation of a γ-glutamylcysteine-enriched yeast extract from a newly developed GSH2-deficient strain. J Biosci Bioeng 2013; 115:50-4. [DOI: 10.1016/j.jbiosc.2012.08.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2012] [Revised: 08/09/2012] [Accepted: 08/11/2012] [Indexed: 10/27/2022]
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34
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Barbosa C, Mendes-Faia A, Mendes-Ferreira A. The nitrogen source impacts major volatile compounds released by Saccharomyces cerevisiae during alcoholic fermentation. Int J Food Microbiol 2012. [DOI: 10.1016/j.ijfoodmicro.2012.10.003] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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35
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Tarutina MG, Dutova TA, Yezhova IE, Nishiuchi H, Sineoky SP. Novel method for screening Saccharomyces cerevisiae mutants with increased sulfur-containing compounds: color-based selection of ade1 or ade2 mutants. J Biosci Bioeng 2012; 114:615-8. [PMID: 22877685 DOI: 10.1016/j.jbiosc.2012.07.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2012] [Revised: 06/28/2012] [Accepted: 07/17/2012] [Indexed: 11/17/2022]
Abstract
We identified Saccharomyces cerevisiae mutants with 100% higher intracellular glutathione using 1-methyl-3-nitro-1-nitrosoguanidine mutagenesis. This method employs visual selection of the most pigmented colonies among met30 strains carrying ade1 and ade2 mutations. Since the method does not involve genetic engineering, the mutants are suitable for use in the food industry.
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Affiliation(s)
- Marina G Tarutina
- Russian State Collection of Industrial Microorganisms (VKPM), State Research Institute for Genetics and Selection of Industrial Microorganisms, 1-st Dorozhny proezd 1, 117545 Moscow, Russia
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36
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Regulation of amino acid, nucleotide, and phosphate metabolism in Saccharomyces cerevisiae. Genetics 2012; 190:885-929. [PMID: 22419079 DOI: 10.1534/genetics.111.133306] [Citation(s) in RCA: 348] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Ever since the beginning of biochemical analysis, yeast has been a pioneering model for studying the regulation of eukaryotic metabolism. During the last three decades, the combination of powerful yeast genetics and genome-wide approaches has led to a more integrated view of metabolic regulation. Multiple layers of regulation, from suprapathway control to individual gene responses, have been discovered. Constitutive and dedicated systems that are critical in sensing of the intra- and extracellular environment have been identified, and there is a growing awareness of their involvement in the highly regulated intracellular compartmentalization of proteins and metabolites. This review focuses on recent developments in the field of amino acid, nucleotide, and phosphate metabolism and provides illustrative examples of how yeast cells combine a variety of mechanisms to achieve coordinated regulation of multiple metabolic pathways. Importantly, common schemes have emerged, which reveal mechanisms conserved among various pathways, such as those involved in metabolite sensing and transcriptional regulation by noncoding RNAs or by metabolic intermediates. Thanks to the remarkable sophistication offered by the yeast experimental system, a picture of the intimate connections between the metabolomic and the transcriptome is becoming clear.
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37
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Petti AA, McIsaac RS, Ho-Shing O, Bussemaker HJ, Botstein D. Combinatorial control of diverse metabolic and physiological functions by transcriptional regulators of the yeast sulfur assimilation pathway. Mol Biol Cell 2012; 23:3008-24. [PMID: 22696679 PMCID: PMC3408426 DOI: 10.1091/mbc.e12-03-0233] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2012] [Revised: 06/04/2012] [Accepted: 06/06/2012] [Indexed: 01/03/2023] Open
Abstract
Methionine abundance affects diverse cellular functions, including cell division, redox homeostasis, survival under starvation, and oxidative stress response. Regulation of the methionine biosynthetic pathway involves three DNA-binding proteins-Met31p, Met32p, and Cbf1p. We hypothesized that there exists a "division of labor" among these proteins that facilitates coordination of methionine biosynthesis with diverse biological processes. To explore combinatorial control in this regulatory circuit, we deleted CBF1, MET31, and MET32 individually and in combination in a strain lacking methionine synthase. We followed genome-wide gene expression as these strains were starved for methionine. Using a combination of bioinformatic methods, we found that these regulators control genes involved in biological processes downstream of sulfur assimilation; many of these processes had not previously been documented as methionine dependent. We also found that the different factors have overlapping but distinct functions. In particular, Met31p and Met32p are important in regulating methionine metabolism, whereas p functions as a "generalist" transcription factor that is not specific to methionine metabolism. In addition, Met31p and Met32p appear to regulate iron-sulfur cluster biogenesis through direct and indirect mechanisms and have distinguishable target specificities. Finally, CBF1 deletion sometimes has the opposite effect on gene expression from MET31 and MET32 deletion.
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Affiliation(s)
- Allegra A. Petti
- The Lewis-Sigler Institute for Integrative Genomics, Columbia University, New York, NY 10027
| | - R. Scott McIsaac
- The Lewis-Sigler Institute for Integrative Genomics, Columbia University, New York, NY 10027
- Graduate Program in Quantitative and Computational Biology, Columbia University, New York, NY 10027
| | - Olivia Ho-Shing
- The Lewis-Sigler Institute for Integrative Genomics, Columbia University, New York, NY 10027
| | | | - David Botstein
- The Lewis-Sigler Institute for Integrative Genomics, Columbia University, New York, NY 10027
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544
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38
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McIsaac RS, Petti AA, Bussemaker HJ, Botstein D. Perturbation-based analysis and modeling of combinatorial regulation in the yeast sulfur assimilation pathway. Mol Biol Cell 2012; 23:2993-3007. [PMID: 22696683 PMCID: PMC3408425 DOI: 10.1091/mbc.e12-03-0232] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Here we establish the utility of a recently described perturbative method to study complex regulatory circuits in vivo. By combining rapid modulation of single TFs under physiological conditions with genome-wide expression analysis, we elucidate several novel regulatory features within the pathways of sulfur assimilation and beyond. In yeast, the pathways of sulfur assimilation are combinatorially controlled by five transcriptional regulators (three DNA-binding proteins [Met31p, Met32p, and Cbf1p], an activator [Met4p], and a cofactor [Met28p]) and a ubiquitin ligase subunit (Met30p). This regulatory system exerts combinatorial control not only over sulfur assimilation and methionine biosynthesis, but also on many other physiological functions in the cell. Recently we characterized a gene induction system that, upon the addition of an inducer, results in near-immediate transcription of a gene of interest under physiological conditions. We used this to perturb levels of single transcription factors during steady-state growth in chemostats, which facilitated distinction of direct from indirect effects of individual factors dynamically through quantification of the subsequent changes in genome-wide patterns of gene expression. We were able to show directly that Cbf1p acts sometimes as a repressor and sometimes as an activator. We also found circumstances in which Met31p/Met32p function as repressors, as well as those in which they function as activators. We elucidated and numerically modeled feedback relationships among the regulators, notably feedforward regulation of Met32p (but not Met31p) by Met4p that generates dynamic differences in abundance that can account for the differences in function of these two proteins despite their identical binding sites.
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Affiliation(s)
- R Scott McIsaac
- The Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA.
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39
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A combination of flow cytometry and traditional screening using chemicals to isolate high glutathione-producing yeast mutants. Biosci Biotechnol Biochem 2012; 76:1085-90. [PMID: 22790927 DOI: 10.1271/bbb.110883] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Traditional screening using chemicals or flow cytometry (FCM) alone is not sufficient to isolate the high glutathione (GSH)-producing yeast strains used in food production. Therefore, to improve screening efficiency, we investigated a combination of both methods. A mutated Saccharomyces cerevisiae strain was labeled with 5-chloromethylfluorescein diacetate and sorted by FCM according to emitted fluorescence intensity. Moderate GSH (1%-2%)-producing mutants were isolated, whereas high GSH (>2%)-producing mutants were not. Traditional screening using cerulenin resulted in similar findings, but a combination of both methods resulted in a 40% increase in the screening yield of high GSH-producing mutants. An analysis of model strains indicated that the ratio of high GSH-producing cells in a sample affected the FCM results. By combining FCM with traditional screening using chemicals, we succeeded in isolating high GSH-producing mutants from several parental strains.
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40
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Thorsen M, Jacobson T, Vooijs R, Navarrete C, Bliek T, Schat H, Tamás MJ. Glutathione serves an extracellular defence function to decrease arsenite accumulation and toxicity in yeast. Mol Microbiol 2012; 84:1177-88. [DOI: 10.1111/j.1365-2958.2012.08085.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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41
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Carrillo E, Ben-Ari G, Wildenhain J, Tyers M, Grammentz D, Lee TA. Characterizing the roles of Met31 and Met32 in coordinating Met4-activated transcription in the absence of Met30. Mol Biol Cell 2012; 23:1928-42. [PMID: 22438580 PMCID: PMC3350556 DOI: 10.1091/mbc.e11-06-0532] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
To examine how target gene expression is coordinated among members of a transcription factor family, a simple two-member family (Met31 and Met32) that is essential for regulating sulfur metabolism in budding yeast is examined using both transcriptional and genome-wide binding arrays. Yeast sulfur metabolism is transcriptionally regulated by the activator Met4. Met4 lacks DNA-binding ability and relies on interactions with Met31 and Met32, paralogous proteins that bind the same cis-regulatory element, to activate its targets. Although Met31 and Met32 are redundant for growth in the absence of methionine, studies indicate that Met32 has a prominent role over Met31 when Met30, a negative regulator of Met4 and Met32, is inactive. To characterize different roles of Met31 and Met32 in coordinating Met4-activated transcription, we examined transcription in strains lacking either Met31 or Met32 upon Met4 induction in the absence of Met30. Microarray analysis revealed that transcripts involved in sulfate assimilation and sulfonate metabolism were dramatically decreased in met32Δ cells compared to its wild-type and met31Δ counterparts. Despite this difference, both met31Δ and met32Δ cells used inorganic sulfur compounds and sulfonates as sole sulfur sources in minimal media when Met30 was present. This discrepancy may be explained by differential binding of Met31 to Cbf1-dependent promoters between these two conditions. In the absence of Met30, genome-wide chromatin immunoprecipitation analyses found that Met32 bound all Met4-bound targets, supporting Met32 as the main platform for Met4 recruitment. Finally, Met31 and Met32 levels were differentially regulated, with Met32 levels mimicking the profile for active Met4. These different properties of Met32 likely contribute to its prominent role in Met4-activated transcription when Met30 is absent.
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Affiliation(s)
- Emilio Carrillo
- Department of Biological Sciences, University of Wisconsin-Parkside, Kenosha, WI 53144, USA
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42
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Yao T, Ndoja A. Regulation of gene expression by the ubiquitin-proteasome system. Semin Cell Dev Biol 2012; 23:523-9. [PMID: 22430757 DOI: 10.1016/j.semcdb.2012.02.006] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2011] [Revised: 02/06/2012] [Accepted: 02/10/2012] [Indexed: 12/26/2022]
Abstract
Transcription is the foremost regulatory point during the process of producing a functional protein. Not only specific genes need to be turned on and off according to growth and environmental conditions, the amounts and quality of transcripts produced are fine-tuned to offer optimal responses. As a result, numerous regulatory mechanisms converge to provide temporal and spatial specificity for this process. In the past decade, the ubiquitin-proteasome system (UPS), which is best known as a pathway for intracellular proteolysis, has emerged as another pivotal player in the control of gene expression. There is increasing evidence that the UPS has both proteolytic and non-proteolytic functions in multiple aspects of the transcription process, including initiation, elongation, mRNA processing as well as chromatin dynamics. In this review, we introduce the many interfaces between the UPS and transcription with focuses on the mechanistic understanding of UPS function in each process.
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Affiliation(s)
- Tingting Yao
- Colorado State University, Biochemistry and Molecular Biology, 1870 Campus Delivery, Fort Collins, CO 80523, USA.
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43
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McIsaac RS, Silverman SJ, McClean MN, Gibney PA, Macinskas J, Hickman MJ, Petti AA, Botstein D. Fast-acting and nearly gratuitous induction of gene expression and protein depletion in Saccharomyces cerevisiae. Mol Biol Cell 2011; 22:4447-59. [PMID: 21965290 PMCID: PMC3216669 DOI: 10.1091/mbc.e11-05-0466] [Citation(s) in RCA: 96] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
We describe the development and characterization of a system that allows the rapid and specific induction of individual genes in the yeast Saccharomyces cerevisiae without changes in nutrients or temperature. The system is based on the chimeric transcriptional activator Gal4dbd.ER.VP16 (GEV). Upon addition of the hormone β-estradiol, cytoplasmic GEV localizes to the nucleus and binds to promoters containing Gal4p consensus binding sequences to activate transcription. With galactokinase Gal1p and transcriptional activator Gal4p absent, the system is fast-acting, resulting in readily detectable transcription within 5 min after addition of the inducer. β-Estradiol is nearly a gratuitous inducer, as indicated by genome-wide profiling that shows unintended induction (by GEV) of only a few dozen genes. Response to inducer is graded: intermediate concentrations of inducer result in production of intermediate levels of product protein in all cells. We present data illustrating several applications of this system, including a modification of the regulated degron method, which allows rapid and specific degradation of a specific protein upon addition of β-estradiol. These gene induction and protein degradation systems provide important tools for studying the dynamics and functional relationships of genes and their respective regulatory networks.
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Affiliation(s)
- R Scott McIsaac
- The Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA.
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44
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Hickman MJ, Petti AA, Ho-Shing O, Silverman SJ, McIsaac RS, Lee TA, Botstein D. Coordinated regulation of sulfur and phospholipid metabolism reflects the importance of methylation in the growth of yeast. Mol Biol Cell 2011; 22:4192-204. [PMID: 21900497 PMCID: PMC3204079 DOI: 10.1091/mbc.e11-05-0467] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
The sulfur assimilation and phospholipid biosynthesis pathways interact metabolically and transcriptionally. Genetic analysis, genome-wide sequencing, and expression microarrays show that regulators of these pathways, Met4p and Opi1p, control cellular methylation capacity that can limit the growth rate. A yeast strain lacking Met4p, the primary transcriptional regulator of the sulfur assimilation pathway, cannot synthesize methionine. This apparently simple auxotroph did not grow well in rich media containing excess methionine, forming small colonies on yeast extract/peptone/dextrose plates. Faster-growing large colonies were abundant when overnight cultures were plated, suggesting that spontaneous suppressors of the growth defect arise with high frequency. To identify the suppressor mutations, we used genome-wide single-nucleotide polymorphism and standard genetic analyses. The most common suppressors were loss-of-function mutations in OPI1, encoding a transcriptional repressor of phospholipid metabolism. Using a new system that allows rapid and specific degradation of Met4p, we could study the dynamic expression of all genes following loss of Met4p. Experiments using this system with and without Opi1p showed that Met4 activates and Opi1p represses genes that maintain levels of S-adenosylmethionine (SAM), the substrate for most methyltransferase reactions. Cells lacking Met4p grow normally when either SAM is added to the media or one of the SAM synthetase genes is overexpressed. SAM is used as a methyl donor in three Opi1p-regulated reactions to create the abundant membrane phospholipid, phosphatidylcholine. Our results show that rapidly growing cells require significant methylation, likely for the biosynthesis of phospholipids.
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Affiliation(s)
- Mark J Hickman
- Lewis-Sigler Institute for Integrative Genomics and Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA.
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45
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A transcriptional activator is part of an SCF ubiquitin ligase to control degradation of its cofactors. Mol Cell 2011; 40:954-64. [PMID: 21172660 DOI: 10.1016/j.molcel.2010.11.018] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2010] [Revised: 08/11/2010] [Accepted: 09/24/2010] [Indexed: 02/04/2023]
Abstract
Multisubunit protein complexes pose a challenge to the coordinated regulation of individual components. We show how the yeast transactivating factor Met4 functions as a component of the SCF(Met30) ubiquitin ligase to synchronize its own activity with cofactor assembly. Cells maintain Met4 in a dormant state by a regulatory ubiquitin chain assembled by SCF(Met30). Nutritional and heavy-metal stress block Met4 ubiquitylation resulting in Met4 activation, which induces a stress-response program including cell-cycle arrest. Met4 relies on assembly with various cofactors for promoter binding. We report here that the stability of these DNA-binding cofactors is regulated by SCF(Met30). Remarkably, the transcriptional activator Met4 functions as a substrate-specificity factor in the context of SCF(Met30/Met4) to coordinate cofactor degradation with its own activity status. Our results establish an additional layer for substrate recruitment by SCF ubiquitin ligases and provide conceptual insight into coordinated regulation of protein complexes.
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46
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Wysocki R, Tamás MJ. How Saccharomyces cerevisiae copes with toxic metals and metalloids. FEMS Microbiol Rev 2011; 34:925-51. [PMID: 20374295 DOI: 10.1111/j.1574-6976.2010.00217.x] [Citation(s) in RCA: 206] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Toxic metals and metalloids are widespread in nature and can locally reach fairly high concentrations. To ensure cellular protection and survival in such environments, all organisms possess systems to evade toxicity and acquire tolerance. This review provides an overview of the molecular mechanisms that contribute to metal toxicity, detoxification and tolerance acquisition in budding yeast Saccharomyces cerevisiae. We mainly focus on the metals/metalloids arsenic, cadmium, antimony, mercury, chromium and selenium, and emphasize recent findings on sensing and signalling mechanisms and on the regulation of tolerance and detoxification systems that safeguard cellular and genetic integrity.
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Affiliation(s)
- Robert Wysocki
- Institute of Genetics and Microbiology, University of Wroclaw, Wroclaw, Poland
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47
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Physiologically relevant and portable tandem ubiquitin-binding domain stabilizes polyubiquitylated proteins. Proc Natl Acad Sci U S A 2010; 107:19796-801. [PMID: 21041680 DOI: 10.1073/pnas.1010648107] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Ubiquitylation of proteins can be a signal for a variety of cellular processes beyond the classical role in proteolysis. The different signaling functions of ubiquitylation are thought to rely on ubiquitin-binding domains (UBDs). Several distinct UBD families are known, but their functions are not understood in detail, and mechanisms for interpretation and transmission of the ubiquitin signals remain to be discovered. One interesting example of the complexity of ubiquitin signaling is the Saccharomyces cerevisiae transcription factor Met4, which is regulated by a single lysine-48 linked polyubiquitin chain that can directly repress activity of Met4 or induce degradation by the proteasome. Here we show that ubiquitin signaling in Met4 is controlled by its tandem UBD regions, consisting of a previously recognized ubiquitin-interacting motif and a novel ubiquitin-binding region, which lacks homology to known UBDs. The tandem arrangement of UBDs is required to protect ubiquitylated Met4 from degradation and enables direct inactivation of Met4 by ubiquitylation. Interestingly, protection from proteasomes is a portable feature of UBDs because a fusion of the tandem UBDs to the classic proteasome substrate Sic1 stabilized Sic1 in vivo in its ubiquitylated form. Using the well-defined Sic1 in vitro ubiquitylation system we demonstrate that the tandem UBDs inhibit efficient polyubiquitin chain elongation but have no effect on initiation of ubiquitylation. Importantly, we show that the nonproteolytic regulation enabled by the tandem UBDs is critical for ensuring rapid transcriptional responses to nutritional stress, thus demonstrating an important physiological function for tandem ubiquitin-binding domains that protect ubiquitylated proteins from degradation.
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Metabolic changes underlying the higher accumulation of glutathione in Saccharomyces cerevisiae mutants. Appl Microbiol Biotechnol 2010; 89:1029-37. [DOI: 10.1007/s00253-010-2946-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2010] [Revised: 10/01/2010] [Accepted: 10/08/2010] [Indexed: 12/15/2022]
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Novel mutations reveal two important regions in Aspergillus nidulans transcriptional activator MetR. Fungal Genet Biol 2010; 48:104-12. [PMID: 20955810 DOI: 10.1016/j.fgb.2010.10.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2010] [Revised: 10/01/2010] [Accepted: 10/06/2010] [Indexed: 11/23/2022]
Abstract
Expression of the sulfur assimilation pathway in Aspergillus nidulans is under control of sulfur metabolite repression, which is composed of scon genes encoding subunits of ubiquitin ligase and the metR gene coding for a transcriptional activator. In this paper we report three dominant suppressors of methionine requirement isolated from a metB3 diploid strain. All three mutations lead to the substitution of phenylalanine 48 by serine or leucine in the conserved N-terminal region of the MetR protein. Strains carrying the dominant suppressor mutations exhibit increased activities of homocysteine synthase and sulfur assimilation enzymes as well as elevated levels of the corresponding transcripts. These changes are observed even under conditions of methionine repression, which suggests that the mutated MetR protein may be resistant to inactivation or degradation mediated by sulfur metabolite repression. We also found that a mutant impaired in sulfite reductase activity, known until now as sG8, has a frameshift which changes 41 C-terminal amino acids. Therefore, it is now designated metR18. This mutant has elevated levels of MetR-regulated transcripts and of activities of sulfur assimilation enzymes (except sulfite reductase), which can be repressed to the wild type level by exogenous methionine. Thus, metR18 and the three dominant suppressors represent new types of mutations affecting different parts of the A. nidulans MetR protein.
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Yoshida S, Imoto J, Minato T, Oouchi R, Kamada Y, Tomita M, Soga T, Yoshimoto H. A novel mechanism regulates H2S and SO2 production in Saccharomyces cerevisiae. Yeast 2010; 28:109-21. [DOI: 10.1002/yea.1823] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2010] [Accepted: 08/27/2010] [Indexed: 11/06/2022] Open
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