1
|
Hao W, Li Y, Guo H, Chen J, Pi F. Co-metabolism of Na +/K + ion regulated physiological enhancement on selenium-accumulation in Saccharomyces yeasts. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2024; 104:4136-4144. [PMID: 38258891 DOI: 10.1002/jsfa.13295] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Revised: 01/02/2024] [Accepted: 01/10/2024] [Indexed: 01/24/2024]
Abstract
BACKGROUND Selenium is an important nutritional supplement that mainly exists naturally in soil as inorganic selenium. Saccharomyces cerevisiae cells are excellent medium for converting inorganic selenium in nature into organic selenium. RESULTS Under the co-stimulation of sodium selenite (Na2SeO3) and potassium selenite (K2SeO3), the activity of selenophosphate synthetase (SPS) was improved up to about five folds more than conventional Na2SeO3 group with the total selenite salts content of 30 mg/L. Transcriptome analysis first revealed that due to the sharing pathway between sodium ion (Na+) and potassium ion (K+), the K+ largely regulates the metabolisms of amino acid and glutathione under the accumulation of selenite salt. Furthermore, K+ could improve the tolerance performance and selenium-biotransformation yields of Saccharomyces cerevisiae cells under Na2SeO3 salt stimulation. CONCLUSION The important role of K+ in regulating the intracellular selenium accumulation especially in terms of amino acid metabolism and glutathione, suggested a new direction for the development of selenium-enrichment supplements with Saccharomyces cerevisiae cell factory. © 2024 Society of Chemical Industry.
Collapse
Affiliation(s)
- Wenhui Hao
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi, P. R. China
- Collaborative Innovation Center of Food Safety and Quality Control, Jiangnan University, Wuxi, P. R. China
| | - Ying Li
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi, P. R. China
- Collaborative Innovation Center of Food Safety and Quality Control, Jiangnan University, Wuxi, P. R. China
| | - Hanlin Guo
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi, P. R. China
- Collaborative Innovation Center of Food Safety and Quality Control, Jiangnan University, Wuxi, P. R. China
| | - Jian Chen
- Shandong Jiucifang Biotechnology, Co. Ltd, Zibo, P. R. China
| | - Fuwei Pi
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi, P. R. China
- Collaborative Innovation Center of Food Safety and Quality Control, Jiangnan University, Wuxi, P. R. China
- Shandong Jiucifang Biotechnology, Co. Ltd, Zibo, P. R. China
| |
Collapse
|
2
|
Balasco Serrão VH, Minari K, Pereira HD, Thiemann OH. Bacterial selenocysteine synthase structure revealed by single-particle cryoEM. Curr Res Struct Biol 2024; 7:100143. [PMID: 38681238 PMCID: PMC11047290 DOI: 10.1016/j.crstbi.2024.100143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Revised: 03/31/2024] [Accepted: 04/09/2024] [Indexed: 05/01/2024] Open
Abstract
The 21st amino acid, selenocysteine (Sec), is synthesized on its dedicated transfer RNA (tRNASec). In bacteria, Sec is synthesized from Ser-tRNA[Ser]Sec by Selenocysteine Synthase (SelA), which is a pivotal enzyme in the biosynthesis of Sec. The structural characterization of bacterial SelA is of paramount importance to decipher its catalytic mechanism and its role in the regulation of the Sec-synthesis pathway. Here, we present a comprehensive single-particle cryo-electron microscopy (SPA cryoEM) structure of the bacterial SelA with an overall resolution of 2.69 Å. Using recombinant Escherichia coli SelA, we purified and prepared samples for single-particle cryoEM. The structural insights from SelA, combined with previous in vivo and in vitro knowledge, underscore the indispensable role of decamerization in SelA's function. Moreover, our structural analysis corroborates previous results that show that SelA adopts a pentamer of dimers configuration, and the active site architecture, substrate binding pocket, and key K295 catalytic residue are identified and described in detail. The differences in protein architecture and substrate coordination between the bacterial enzyme and its counterparts offer compelling structural evidence supporting the independent molecular evolution of the bacterial and archaea/eukarya Ser-Sec biosynthesis present in the natural world.
Collapse
Affiliation(s)
- Vitor Hugo Balasco Serrão
- Biomolecular Cryoelectron Microscopy Facility, University of California - Santa Cruz, Santa Cruz, CA, 95064, United States
- Department of Chemistry and Biochemistry, University of California - Santa Cruz, Santa Cruz, CA, 95064, United States
| | - Karine Minari
- Biomolecular Engineering Department, Jack Baskin School of Engineering, University of California - Santa Cruz, Santa Cruz, CA, 95064, United States
| | - Humberto D'Muniz Pereira
- Physics Institute of Sao Carlos, University of Sao Paulo, Trabalhador Sao Carlense Av., 400, São Carlos, SP, CEP 13566-590, Brazil
| | - Otavio Henrique Thiemann
- Physics Institute of Sao Carlos, University of Sao Paulo, Trabalhador Sao Carlense Av., 400, São Carlos, SP, CEP 13566-590, Brazil
| |
Collapse
|
3
|
Crespo L, Sede Lucena B, Martínez FG, Mozzi F, Pescuma M. Selenium bioactive compounds produced by beneficial microbes. ADVANCES IN APPLIED MICROBIOLOGY 2024; 126:63-92. [PMID: 38637107 DOI: 10.1016/bs.aambs.2024.02.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/20/2024]
Abstract
Selenium (Se) is an essential trace element present as selenocysteine (SeCys) in selenoproteins, which have an important role in thyroid metabolism and the redox system in humans. Se deficiency affects between 500 and 1000 million people worldwide. Increasing Se intake can prevent from bacterial and viral infections. Se deficiency has been associated with cancer, Alzheimer, Parkinson, decreased thyroid function, and male infertility. Se intake depends on the food consumed which is directly related to the amount of Se in the soil as well as on its availability. Se is unevenly distributed on the earth's crust, being scarce in some regions and in excess in others. The easiest way to counteract the symptoms of Se deficiency is to enhance the Se status of the human diet. Se salts are the most toxic form of Se, while Se amino acids and Se-nanoparticles (SeNPs) are the least toxic and most bio-available forms. Some bacteria transform Se salts into these Se species. Generally accepted as safe selenized microorganisms can be directly used in the manufacture of selenized fermented and/or probiotic foods. On the other hand, plant growth-promoting bacteria and/or the SeNPs produced by them can be used to promote plant growth and produce crops enriched with Se. In this chapter we discuss bacterial Se metabolism, the effect of Se on human health, the applications of SeNPs and Se-enriched bacteria, as well as their effect on food fortification. Different strategies to counteract Se deficiency by enriching foods using sustainable strategies and their possible implications for improving human health are discussed.
Collapse
Affiliation(s)
- L Crespo
- Centro de Referencia para Lactobacilos (CERELA)-CONICET, San Miguel de Tucumán, Argentina
| | - B Sede Lucena
- Centro de Investigación y Extensión Forestal Andino Patagónico (CIEFAP), Esquel, Chubut, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - F G Martínez
- Centro de Referencia para Lactobacilos (CERELA)-CONICET, San Miguel de Tucumán, Argentina
| | - F Mozzi
- Centro de Referencia para Lactobacilos (CERELA)-CONICET, San Miguel de Tucumán, Argentina
| | - M Pescuma
- Centro de Investigación y Extensión Forestal Andino Patagónico (CIEFAP), Esquel, Chubut, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina.
| |
Collapse
|
4
|
Chaudière J. Biological and Catalytic Properties of Selenoproteins. Int J Mol Sci 2023; 24:10109. [PMID: 37373256 DOI: 10.3390/ijms241210109] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 06/06/2023] [Accepted: 06/08/2023] [Indexed: 06/29/2023] Open
Abstract
Selenocysteine is a catalytic residue at the active site of all selenoenzymes in bacteria and mammals, and it is incorporated into the polypeptide backbone by a co-translational process that relies on the recoding of a UGA termination codon into a serine/selenocysteine codon. The best-characterized selenoproteins from mammalian species and bacteria are discussed with emphasis on their biological function and catalytic mechanisms. A total of 25 genes coding for selenoproteins have been identified in the genome of mammals. Unlike the selenoenzymes of anaerobic bacteria, most mammalian selenoenzymes work as antioxidants and as redox regulators of cell metabolism and functions. Selenoprotein P contains several selenocysteine residues and serves as a selenocysteine reservoir for other selenoproteins in mammals. Although extensively studied, glutathione peroxidases are incompletely understood in terms of local and time-dependent distribution, and regulatory functions. Selenoenzymes take advantage of the nucleophilic reactivity of the selenolate form of selenocysteine. It is used with peroxides and their by-products such as disulfides and sulfoxides, but also with iodine in iodinated phenolic substrates. This results in the formation of Se-X bonds (X = O, S, N, or I) from which a selenenylsulfide intermediate is invariably produced. The initial selenolate group is then recycled by thiol addition. In bacterial glycine reductase and D-proline reductase, an unusual catalytic rupture of selenium-carbon bonds is observed. The exchange of selenium for sulfur in selenoproteins, and information obtained from model reactions, suggest that a generic advantage of selenium compared with sulfur relies on faster kinetics and better reversibility of its oxidation reactions.
Collapse
Affiliation(s)
- Jean Chaudière
- CBMN (CNRS, UMR 5248), University of Bordeaux, 33600 Pessac, France
| |
Collapse
|
5
|
Bang J, Kang D, Jung J, Yoo TJ, Shim MS, Gladyshev VN, Tsuji PA, Hatfield DL, Kim JH, Lee BJ. SEPHS1: Its evolution, function and roles in development and diseases. Arch Biochem Biophys 2022; 730:109426. [PMID: 36202216 PMCID: PMC9648052 DOI: 10.1016/j.abb.2022.109426] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 09/27/2022] [Accepted: 09/29/2022] [Indexed: 11/25/2022]
Abstract
Selenophosphate synthetase (SEPHS) was originally discovered in prokaryotes as an enzyme that catalyzes selenophosphate synthesis using inorganic selenium and ATP as substrates. However, in contrast to prokaryotes, two paralogs, SEPHS1 and SEPHS2, occur in many eukaryotes. Prokaryotic SEPHS, also known as SelD, contains either cysteine (Cys) or selenocysteine (Sec) in the catalytic domain. In eukaryotes, only SEPHS2 carries out selenophosphate synthesis and contains Sec at the active site. However, SEPHS1 contains amino acids other than Sec or Cys at the catalytic position. Phylogenetic analysis of SEPHSs reveals that the ancestral SEPHS contains both selenophosphate synthesis and another unknown activity, and that SEPHS1 lost the selenophosphate synthesis activity. The three-dimensional structure of SEPHS1 suggests that its homodimer is unable to form selenophosphate, but retains ATPase activity to produce ADP and inorganic phosphate. The most prominent function of SEPHS1 is that it is implicated in the regulation of cellular redox homeostasis. Deficiency of SEPHS1 leads to the disturbance in the expression of genes involved in redox homeostasis. Different types of reactive oxygen species (ROS) are accumulated in response to SEPHS deficiency depending on cell or tissue types. The accumulation of ROS causes pleiotropic effects such as growth retardation, apoptosis, DNA damage, and embryonic lethality. SEPHS1 deficiency in mouse embryos affects retinoic signaling and other related signaling pathways depending on the embryonal stage until the embryo dies at E11.5. Dysregulated SEPHS1 is associated with the pathogenesis of various diseases including cancer, Crohn's disease, and osteoarthritis.
Collapse
Affiliation(s)
- Jeyoung Bang
- Interdisciplinary Program in Bioinformatics, College of Natural Sciences, Seoul National University, Seoul, South Korea
| | - Donghyun Kang
- School of Biological Sciences, College of Natural Sciences, Seoul National University, Seoul, South Korea
| | - Jisu Jung
- School of Biological Sciences, College of Natural Sciences, Seoul National University, Seoul, South Korea
| | - Tack-Jin Yoo
- School of Biological Sciences, College of Natural Sciences, Seoul National University, Seoul, South Korea
| | - Myoung Sup Shim
- Department of Ophthalmology, Duke Eye Center, Duke University, Durham, NC, USA
| | - Vadim N Gladyshev
- Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Petra A Tsuji
- Department of Biological Sciences, Towson University, 8000 York Rd., Towson, MD, USA
| | - Dolph L Hatfield
- Mouse Cancer Genetics Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Jin-Hong Kim
- School of Biological Sciences, College of Natural Sciences, Seoul National University, Seoul, South Korea.
| | - Byeong Jae Lee
- Interdisciplinary Program in Bioinformatics, College of Natural Sciences, Seoul National University, Seoul, South Korea; School of Biological Sciences, College of Natural Sciences, Seoul National University, Seoul, South Korea.
| |
Collapse
|
6
|
Manta B, Makarova NE, Mariotti M. The selenophosphate synthetase family: A review. Free Radic Biol Med 2022; 192:63-76. [PMID: 36122644 DOI: 10.1016/j.freeradbiomed.2022.09.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 09/11/2022] [Accepted: 09/12/2022] [Indexed: 11/23/2022]
Abstract
Selenophosphate synthetases use selenium and ATP to synthesize selenophosphate. This is required for biological utilization of selenium, most notably for the synthesis of the non-canonical amino acid selenocysteine (Sec). Therefore, selenophosphate synthetases underlie all functions of selenoproteins, which include redox homeostasis, protein quality control, hormone regulation, metabolism, and many others. This protein family comprises two groups, SelD/SPS2 and SPS1. The SelD/SPS2 group represent true selenophosphate synthetases, enzymes central to selenium metabolism which are present in all Sec-utilizing organisms across the tree of life. Notably, many SelD/SPS2 proteins contain Sec as catalytic residue in their N-terminal flexible selenium-binding loop, while others replace it with cysteine (Cys). The SPS1 group comprises proteins originated through gene duplications of SelD/SPS2 in metazoa in which the Sec/Cys-dependent catalysis was disrupted. SPS1 proteins do not synthesize selenophosphate and are not required for Sec synthesis. They have essential regulatory functions related to redox homeostasis and pyridoxal phosphate, which affect signaling pathways for growth and differentiation. In this review, we summarize the knowledge about the selenophosphate synthetase family acquired through decades of research, encompassing their structure, mechanism, function, and evolution.
Collapse
Affiliation(s)
- Bruno Manta
- Laboratorio de Genómica Microbiana, Institut Pasteur Montevideo, Uruguay, Cátedra de Fisiopatología, Facultad de Odontología, Universidad de la República, Uruguay
| | - Nadezhda E Makarova
- Departament de Genètica, Microbiologia i Estadística, Facultat de Biologia, Universitat de Barcelona (UB), Avinguda Diagonal 643, Barcelona, 08028, Catalonia, Spain
| | - Marco Mariotti
- Departament de Genètica, Microbiologia i Estadística, Facultat de Biologia, Universitat de Barcelona (UB), Avinguda Diagonal 643, Barcelona, 08028, Catalonia, Spain.
| |
Collapse
|
7
|
Wells M, Basu P, Stolz JF. The physiology and evolution of microbial selenium metabolism. Metallomics 2021; 13:6261189. [PMID: 33930157 DOI: 10.1093/mtomcs/mfab024] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 04/21/2021] [Accepted: 04/22/2021] [Indexed: 12/27/2022]
Abstract
Selenium is an essential trace element whose compounds are widely metabolized by organisms from all three domains of life. Moreover, phylogenetic evidence indicates that selenium species, along with iron, molybdenum, tungsten, and nickel, were metabolized by the last universal common ancestor of all cellular lineages, primarily for the synthesis of the 21st amino acid selenocysteine. Thus, selenium metabolism is both environmentally ubiquitous and a physiological adaptation of primordial life. Selenium metabolic reactions comprise reductive transformations both for assimilation into macromolecules and dissimilatory reduction of selenium oxyanions and elemental selenium during anaerobic respiration. This review offers a comprehensive overview of the physiology and evolution of both assimilatory and dissimilatory selenium metabolism in bacteria and archaea, highlighting mechanisms of selenium respiration. This includes a thorough discussion of our current knowledge of the physiology of selenocysteine synthesis and incorporation into proteins in bacteria obtained from structural biology. Additionally, this is the first comprehensive discussion in a review of the incorporation of selenium into the tRNA nucleoside 5-methylaminomethyl-2-selenouridine and as an inorganic cofactor in certain molybdenum hydroxylase enzymes. Throughout, conserved mechanisms and derived features of selenium metabolism in both domains are emphasized and discussed within the context of the global selenium biogeochemical cycle.
Collapse
Affiliation(s)
- Michael Wells
- Department of Biological Sciences, Duquesne University, Pittsburgh, PA 15282, USA
| | - Partha Basu
- Department of Chemistry and Chemical Biology, Indiana University-Purdue University Indianapolis, Indianapolis, IN 46202, USA
| | - John F Stolz
- Department of Biological Sciences, Duquesne University, Pittsburgh, PA 15282, USA
| |
Collapse
|
8
|
Genome-Driven Discovery of Enzymes with Industrial Implications from the Genus Aneurinibacillus. Microorganisms 2021; 9:microorganisms9030499. [PMID: 33652876 PMCID: PMC7996765 DOI: 10.3390/microorganisms9030499] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 02/19/2021] [Accepted: 02/23/2021] [Indexed: 01/27/2023] Open
Abstract
Bacteria belonging to the genus Aneurinibacillus within the family Paenibacillaceae are Gram-positive, endospore-forming, and rod-shaped bacteria inhabiting diverse environments. Currently, there are eight validly described species of Aneurinibacillus; however, several unclassified species have also been reported. Aneurinibacillus spp. have shown the potential for producing secondary metabolites (SMs) and demonstrated diverse types of enzyme activities. These features make them promising candidates with industrial implications. At present, genomes of 9 unique species from the genus Aneurinibacillus are available, which can be utilized to decipher invaluable information on their biosynthetic potential as well as enzyme activities. In this work, we performed the comparative genome analyses of nine Aneurinibacillus species representing the first such comprehensive study of this genus at the genome level. We focused on discovering the biosynthetic, biodegradation, and heavy metal resistance potential of this under-investigated genus. The results indicate that the genomes of Aneurinibacillus contain SM-producing regions with diverse bioactivities, including antimicrobial and antiviral activities. Several carbohydrate-active enzymes (CAZymes) and genes involved in heavy metal resistance were also identified. Additionally, a broad range of enzyme classes were also identified in the Aneurinibacillus pan-genomes, making this group of bacteria potential candidates for future investigations with industrial applications.
Collapse
|
9
|
da Silva MTA, Silva IRE, Faim LM, Bellini NK, Pereira ML, Lima AL, de Jesus TCL, Costa FC, Watanabe TF, Pereira HD, Valentini SR, Zanelli CF, Borges JC, Dias MVB, da Cunha JPC, Mittra B, Andrews NW, Thiemann OH. Trypanosomatid selenophosphate synthetase structure, function and interaction with selenocysteine lyase. PLoS Negl Trop Dis 2020; 14:e0008091. [PMID: 33017394 PMCID: PMC7595633 DOI: 10.1371/journal.pntd.0008091] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Revised: 10/29/2020] [Accepted: 08/03/2020] [Indexed: 11/19/2022] Open
Abstract
Eukaryotes from the Excavata superphylum have been used as models to study the evolution of cellular molecular processes. Strikingly, human parasites of the Trypanosomatidae family (T. brucei, T. cruzi and L. major) conserve the complex machinery responsible for selenocysteine biosynthesis and incorporation in selenoproteins (SELENOK/SelK, SELENOT/SelT and SELENOTryp/SelTryp), although these proteins do not seem to be essential for parasite viability under laboratory controlled conditions. Selenophosphate synthetase (SEPHS/SPS) plays an indispensable role in selenium metabolism, being responsible for catalyzing the formation of selenophosphate, the biological selenium donor for selenocysteine synthesis. We solved the crystal structure of the L. major selenophosphate synthetase and confirmed that its dimeric organization is functionally important throughout the domains of life. We also demonstrated its interaction with selenocysteine lyase (SCLY) and showed that it is not present in other stable assemblies involved in the selenocysteine pathway, namely the phosphoseryl-tRNASec kinase (PSTK)-Sec-tRNASec synthase (SEPSECS) complex and the tRNASec-specific elongation factor (eEFSec) complex. Endoplasmic reticulum stress with dithiothreitol (DTT) or tunicamycin upon selenophosphate synthetase ablation in procyclic T. brucei cells led to a growth defect. On the other hand, only DTT presented a negative effect in bloodstream T. brucei expressing selenophosphate synthetase-RNAi. Furthermore, selenoprotein T (SELENOT) was dispensable for both forms of the parasite. Together, our data suggest a role for the T. brucei selenophosphate synthetase in the regulation of the parasite’s ER stress response. Selenium is both a toxic compound and a micronutrient. As a micronutrient, it participates in the synthesis of specific proteins, selenoproteins, as the amino acid selenocysteine. The synthesis of selenocysteine is present in organisms ranging from bacteria to humans. The protist parasites of the Trypanosomatidae family, that cause major tropical diseases, conserve the complex machinery responsible for selenocysteine biosynthesis and incorporation in selenoproteins. However, this pathway has been considered dispensable for the parasitic protist cells. This has intrigued us, and lead to question that if maintained in the cell it should be under selective pressure and therefore be necessary. Also, extensive and dynamic protein-protein interactions must happen to deliver selenium-containing intermediates along the pathway in order to warrant efficient usage of biological selenium in the cell. In this study we have investigated the molecular interactions of different proteins involved in selenocysteine synthesis and its putative involvement in the endoplasmic reticulum redox homeostasis.
Collapse
Affiliation(s)
- Marco Túlio Alves da Silva
- Laboratory of Structural Biology, Sao Carlos Institute of Physics, University of São Paulo, São Carlos, SP, Brazil
| | - Ivan Rosa e Silva
- Laboratory of Structural Biology, Sao Carlos Institute of Physics, University of São Paulo, São Carlos, SP, Brazil
| | - Lívia Maria Faim
- Laboratory of Structural Biology, Sao Carlos Institute of Physics, University of São Paulo, São Carlos, SP, Brazil
| | - Natália Karla Bellini
- Laboratory of Structural Biology, Sao Carlos Institute of Physics, University of São Paulo, São Carlos, SP, Brazil
| | - Murilo Leão Pereira
- Laboratory of Structural Biology, Sao Carlos Institute of Physics, University of São Paulo, São Carlos, SP, Brazil
| | - Ana Laura Lima
- Laboratory of Structural Biology, Sao Carlos Institute of Physics, University of São Paulo, São Carlos, SP, Brazil
| | - Teresa Cristina Leandro de Jesus
- Laboratory of Structural Biology, Sao Carlos Institute of Physics, University of São Paulo, São Carlos, SP, Brazil
- Laboratory of Cell Cycle and Center of Toxins, Immune Response and Cell Signaling—CeTICS, Butantan Institute, São Paulo, SP, Brazil
| | - Fernanda Cristina Costa
- Laboratory of Structural Biology, Sao Carlos Institute of Physics, University of São Paulo, São Carlos, SP, Brazil
- London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Tatiana Faria Watanabe
- School of Pharmaceutical Sciences, São Paulo State University (UNESP), Araraquara, SP, Brazil
| | - Humberto D'Muniz Pereira
- Laboratory of Structural Biology, Sao Carlos Institute of Physics, University of São Paulo, São Carlos, SP, Brazil
| | | | | | - Júlio Cesar Borges
- São Carlos Institute of Chemistry, University of São Paulo, São Carlos, SP, Brazil
| | | | - Júlia Pinheiro Chagas da Cunha
- Laboratory of Cell Cycle and Center of Toxins, Immune Response and Cell Signaling—CeTICS, Butantan Institute, São Paulo, SP, Brazil
| | - Bidyottam Mittra
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland, United States of America
| | - Norma W. Andrews
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland, United States of America
| | - Otavio Henrique Thiemann
- Laboratory of Structural Biology, Sao Carlos Institute of Physics, University of São Paulo, São Carlos, SP, Brazil
- Department of Genetics and Evolution, Federal University of São Carlos, São Carlos, SP, Brazil
- * E-mail:
| |
Collapse
|
10
|
Scortecci JF, Serrão VHB, Fernandes AF, Basso LG, Gutierrez RF, Araujo APU, Neto MO, Thiemann OH. Initial steps in selenocysteine biosynthesis: The interaction between selenocysteine lyase and selenophosphate synthetase. Int J Biol Macromol 2020; 156:18-26. [DOI: 10.1016/j.ijbiomac.2020.03.241] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2020] [Revised: 02/29/2020] [Accepted: 03/28/2020] [Indexed: 10/24/2022]
|
11
|
Carlisle AE, Lee N, Matthew-Onabanjo AN, Spears ME, Park SJ, Youkana D, Doshi MB, Peppers A, Li R, Joseph AB, Smith M, Simin K, Zhu LJ, Greer PL, Shaw LM, Kim D. Selenium detoxification is required for cancer-cell survival. Nat Metab 2020; 2:603-611. [PMID: 32694795 PMCID: PMC7455022 DOI: 10.1038/s42255-020-0224-7] [Citation(s) in RCA: 93] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Accepted: 05/28/2020] [Indexed: 12/21/2022]
Abstract
The micronutrient selenium is incorporated via the selenocysteine biosynthesis pathway into the rare amino acid selenocysteine, which is required in selenoproteins such as glutathione peroxidases and thioredoxin reductases1,2. Here, we show that selenophosphate synthetase 2 (SEPHS2), an enzyme in the selenocysteine biosynthesis pathway, is essential for survival of cancer, but not normal, cells. SEPHS2 is required in cancer cells to detoxify selenide, an intermediate that is formed during selenocysteine biosynthesis. Breast and other cancer cells are selenophilic, owing to a secondary function of the cystine/glutamate antiporter SLC7A11 that promotes selenium uptake and selenocysteine biosynthesis, which, by allowing production of selenoproteins such as GPX4, protects cells against ferroptosis. However, this activity also becomes a liability for cancer cells because selenide is poisonous and must be processed by SEPHS2. Accordingly, we find that SEPHS2 protein levels are elevated in samples from people with breast cancer, and that loss of SEPHS2 impairs growth of orthotopic mammary-tumour xenografts in mice. Collectively, our results identify a vulnerability of cancer cells and define the role of selenium metabolism in cancer.
Collapse
Affiliation(s)
- Anne E Carlisle
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Namgyu Lee
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Asia N Matthew-Onabanjo
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Meghan E Spears
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Sung Jin Park
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA, USA
| | - Daniel Youkana
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Mihir B Doshi
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Austin Peppers
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Rui Li
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Alexander B Joseph
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Miles Smith
- Environmental Testing and Research Laboratories, Leominster, MA, USA
| | - Karl Simin
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Lihua Julie Zhu
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Paul L Greer
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA, USA
| | - Leslie M Shaw
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Dohoon Kim
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA, USA.
| |
Collapse
|
12
|
Varlamova EG, Maltseva VN. Micronutrient Selenium: Uniqueness and Vital Functions. Biophysics (Nagoya-shi) 2019. [DOI: 10.1134/s0006350919040213] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
|
13
|
Na J, Jung J, Bang J, Lu Q, Carlson BA, Guo X, Gladyshev VN, Kim J, Hatfield DL, Lee BJ. Selenophosphate synthetase 1 and its role in redox homeostasis, defense and proliferation. Free Radic Biol Med 2018; 127:190-197. [PMID: 29715549 DOI: 10.1016/j.freeradbiomed.2018.04.577] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Revised: 04/24/2018] [Accepted: 04/26/2018] [Indexed: 12/26/2022]
Abstract
Selenophosphate synthetase (SEPHS) synthesizes selenophosphate, the active selenium donor, using ATP and selenide as substrates. SEPHS was initially identified and isolated from bacteria and has been characterized in many eukaryotes and archaea. Two SEPHS paralogues, SEPHS1 and SEPHS2, occur in various eukaryotes, while prokaryotes and archaea have only one form of SEPHS. Between the two isoforms in eukaryotes, only SEPHS2 shows catalytic activity during selenophosphate synthesis. Although SEPHS1 does not contain any significant selenophosphate synthesis activity, it has been reported to play an essential role in regulating cellular physiology. Prokaryotic SEPHS contains a cysteine or selenocysteine (Sec) at the catalytic domain. However, in eukaryotes, SEPHS1 contains other amino acids such as Thr, Arg, Gly, or Leu at the catalytic domain, and SEPHS2 contains only a Sec. Sequence comparisons, crystal structure analyses, and ATP hydrolysis assays suggest that selenophosphate synthesis occurs in two steps. In the first step, ATP is hydrolyzed to produce ADP and gamma-phosphate. In the second step, ADP is further hydrolyzed and selenophosphate is produced using gamma-phosphate and selenide. Both SEPHS1 and SEPHS2 have ATP hydrolyzing activities, but Cys or Sec is required in the catalytic domain for the second step of reaction. The gene encoding SEPHS1 is divided by introns, and five different splice variants are produced by alternative splicing in humans. SEPHS1 mRNA is abundant in rapidly proliferating cells such as embryonic and cancer cells and its expression is induced by various stresses including oxidative stress and salinity stress. The disruption of the SEPHS1 gene in mice or Drosophila leads to the inhibition of cell proliferation, embryonic lethality, and morphological changes in the embryos. Targeted removal of SEPHS1 mRNA in insect, mouse, and human cells also leads to common phenotypic changes similar to those observed by in vivo gene knockout: the inhibition of cell growth/proliferation, the accumulation of hydrogen peroxide in mammals and an unidentified reactive oxygen species (ROS) in Drosophila, and the activation of a defense system. Hydrogen peroxide accumulation in SEPHS1-deficient cells is mainly caused by the down-regulation of genes involved in ROS scavenging, and leads to the inhibition of cell proliferation and survival. However, the mechanisms underlying SEPHS1 regulation of redox homeostasis are still not understood.
Collapse
Affiliation(s)
- Jiwoon Na
- School of Biological Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Jisu Jung
- School of Biological Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Jeyoung Bang
- School of Biological Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Qiao Lu
- School of Biological Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Bradley A Carlson
- National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Xiong Guo
- School of Public Health, Xi'an Jiaotong University, Xi'an 710061, PR China
| | - Vadim N Gladyshev
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Jinhong Kim
- School of Biological Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Dolph L Hatfield
- National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Byeong Jae Lee
- School of Biological Sciences, Seoul National University, Seoul 08826, Republic of Korea.
| |
Collapse
|
14
|
Rother M, Quitzke V. Selenoprotein synthesis and regulation in Archaea. Biochim Biophys Acta Gen Subj 2018; 1862:2451-2462. [DOI: 10.1016/j.bbagen.2018.04.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Revised: 04/09/2018] [Accepted: 04/10/2018] [Indexed: 01/23/2023]
|
15
|
Serrão VHB, Silva IR, da Silva MTA, Scortecci JF, de Freitas Fernandes A, Thiemann OH. The unique tRNASec and its role in selenocysteine biosynthesis. Amino Acids 2018; 50:1145-1167. [DOI: 10.1007/s00726-018-2595-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 05/26/2018] [Indexed: 12/26/2022]
|
16
|
Tobe R, Mihara H. Delivery of selenium to selenophosphate synthetase for selenoprotein biosynthesis. Biochim Biophys Acta Gen Subj 2018; 1862:2433-2440. [PMID: 29859962 DOI: 10.1016/j.bbagen.2018.05.023] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Revised: 05/28/2018] [Accepted: 05/29/2018] [Indexed: 11/16/2022]
Abstract
BACKGROUND Selenophosphate, the key selenium donor for the synthesis of selenoprotein and selenium-modified tRNA, is produced by selenophosphate synthetase (SPS) from ATP, selenide, and H2O. Although free selenide can be used as the in vitro selenium substrate for selenophosphate synthesis, the precise physiological system that donates in vivo selenium substrate to SPS has not yet been characterized completely. SCOPE OF REVIEW In this review, we discuss selenium metabolism with respect to the delivery of selenium to SPS in selenoprotein biosynthesis. MAJOR CONCLUSIONS Glutathione, selenocysteine lyase, cysteine desulfurase, and selenium-binding proteins are the candidates of selenium delivery system to SPS. The thioredoxin system is also implicated in the selenium delivery to SPS in Escherichia coli. GENERAL SIGNIFICANCE Selenium delivered via a protein-bound selenopersulfide intermediate emerges as a central element not only in achieving specific selenoprotein biosynthesis but also in preventing the occurrence of toxic free selenide in the cell. This article is part of a Special Issue entitled "Selenium research in biochemistry and biophysics - 200 year anniversary".
Collapse
Affiliation(s)
- Ryuta Tobe
- Department of Biotechnology, College of Life Sciences, Ritsumeikan University, Kusatsu, Shiga 525-8577, Japan
| | - Hisaaki Mihara
- Department of Biotechnology, College of Life Sciences, Ritsumeikan University, Kusatsu, Shiga 525-8577, Japan.
| |
Collapse
|
17
|
Silva IR, Serrão VHB, Manzine LR, Faim LM, da Silva MTA, Makki R, Saidemberg DM, Cornélio ML, Palma MS, Thiemann OH. Formation of a Ternary Complex for Selenocysteine Biosynthesis in Bacteria. J Biol Chem 2015; 290:29178-88. [PMID: 26378233 DOI: 10.1074/jbc.m114.613406] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Indexed: 11/06/2022] Open
Abstract
The synthesis of selenocysteine-containing proteins (selenoproteins) involves the interaction of selenocysteine synthase (SelA), tRNA (tRNA(Sec)), selenophosphate synthetase (SelD, SPS), a specific elongation factor (SelB), and a specific mRNA sequence known as selenocysteine insertion sequence (SECIS). Because selenium compounds are highly toxic in the cellular environment, the association of selenium with proteins throughout its metabolism is essential for cell survival. In this study, we demonstrate the interaction of SPS with the SelA-tRNA(Sec) complex, resulting in a 1.3-MDa ternary complex of 27.0 ± 0.5 nm in diameter and 4.02 ± 0.05 nm in height. To assemble the ternary complex, SPS undergoes a conformational change. We demonstrated that the glycine-rich N-terminal region of SPS is crucial for the SelA-tRNA(Sec)-SPS interaction and selenoprotein biosynthesis, as revealed by functional complementation experiments. Taken together, our results provide new insights into selenoprotein biosynthesis, demonstrating for the first time the formation of the functional ternary SelA-tRNA(Sec)-SPS complex. We propose that this complex is necessary for proper selenocysteine synthesis and may be involved in avoiding the cellular toxicity of selenium compounds.
Collapse
Affiliation(s)
- Ivan R Silva
- From the Physics and Informatics Department, Physics Institute of Sao Carlos, University of Sao Paulo - USP, CEP 13563-120 Sao Carlos, SP
| | - Vitor H B Serrão
- From the Physics and Informatics Department, Physics Institute of Sao Carlos, University of Sao Paulo - USP, CEP 13563-120 Sao Carlos, SP, the Physics Department, Federal University of Sao Carlos - UFSCar, 13565-905 Sao Carlos, SP, Brazil
| | - Livia R Manzine
- From the Physics and Informatics Department, Physics Institute of Sao Carlos, University of Sao Paulo - USP, CEP 13563-120 Sao Carlos, SP
| | - Lívia M Faim
- From the Physics and Informatics Department, Physics Institute of Sao Carlos, University of Sao Paulo - USP, CEP 13563-120 Sao Carlos, SP
| | - Marco T A da Silva
- From the Physics and Informatics Department, Physics Institute of Sao Carlos, University of Sao Paulo - USP, CEP 13563-120 Sao Carlos, SP
| | - Raphaela Makki
- From the Physics and Informatics Department, Physics Institute of Sao Carlos, University of Sao Paulo - USP, CEP 13563-120 Sao Carlos, SP
| | - Daniel M Saidemberg
- the Department of Biology/CEIS, Biosciences Institute of Rio Claro, Sao Paulo State University - UNESP, 13506-900 Rio Claro, SP, and
| | - Marinônio L Cornélio
- the Physics Department, Institute of Biosciences, Letters and Exact Sciences (IBILCE), Sao Paulo State University - UNESP, 15054-000 Sao Jose do Rio Preto, SP, Brazil
| | - Mário S Palma
- the Department of Biology/CEIS, Biosciences Institute of Rio Claro, Sao Paulo State University - UNESP, 13506-900 Rio Claro, SP, and
| | - Otavio H Thiemann
- From the Physics and Informatics Department, Physics Institute of Sao Carlos, University of Sao Paulo - USP, CEP 13563-120 Sao Carlos, SP,
| |
Collapse
|
18
|
Li GP, Jiang L, Ni JZ, Liu Q, Zhang Y. Computational identification of a new SelD-like family that may participate in sulfur metabolism in hyperthermophilic sulfur-reducing archaea. BMC Genomics 2014; 15:908. [PMID: 25326317 PMCID: PMC4210487 DOI: 10.1186/1471-2164-15-908] [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: 09/05/2013] [Accepted: 10/07/2014] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND Selenium (Se) and sulfur (S) are closely related elements that exhibit similar chemical properties. Some genes related to S metabolism are also involved in Se utilization in many organisms. However, the evolutionary relationship between the two utilization traits is unclear. RESULTS In this study, we conducted a comparative analysis of the selenophosphate synthetase (SelD) family, a key protein for all known Se utilization traits, in all sequenced archaea. Our search showed a very limited distribution of SelD and Se utilization in this kingdom. Interestingly, a SelD-like protein was detected in two orders of Crenarchaeota: Sulfolobales and Thermoproteales. Sequence and phylogenetic analyses revealed that SelD-like protein contains the same domain and conserved functional residues as those of SelD, and might be involved in S metabolism in these S-reducing organisms. Further genome-wide analysis of patterns of gene occurrence in different thermoproteales suggested that several genes, including SirA-like, Prx-like and adenylylsulfate reductase, were strongly related to SelD-like gene. Based on these findings, we proposed a simple model wherein SelD-like may play an important role in the biosynthesis of certain thiophosphate compound. CONCLUSIONS Our data suggest novel genes involved in S metabolism in hyperthermophilic S-reducing archaea, and may provide a new window for understanding the complex relationship between Se and S metabolism in archaea.
Collapse
Affiliation(s)
| | | | | | | | - Yan Zhang
- Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai 200031, P, R, China.
| |
Collapse
|
19
|
Faim LM, e Silva IR, Dias MVB, Pereira HD, Brandao-Neto J, da Silva MTA, Thiemann OH. Crystallization and preliminary X-ray diffraction analysis of selenophosphate synthetases from Trypanosoma brucei and Leishmania major. Acta Crystallogr Sect F Struct Biol Cryst Commun 2013; 69:864-7. [PMID: 23908029 PMCID: PMC3729160 DOI: 10.1107/s1744309113014632] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2013] [Accepted: 05/27/2013] [Indexed: 11/10/2022]
Abstract
Selenophosphate synthetase (SPS) plays an indispensable role in selenium metabolism, being responsible for catalyzing the activation of selenide with adenosine 5'-triphosphate (ATP) to generate selenophosphate, the essential selenium donor for selenocysteine synthesis. Recombinant full-length Leishmania major SPS (LmSPS2) was recalcitrant to crystallization. Therefore, a limited proteolysis technique was used and a stable N-terminal truncated construct (ΔN-LmSPS2) yielded suitable crystals. The Trypanosoma brucei SPS orthologue (TbSPS2) was crystallized by the microbatch method using paraffin oil. X-ray diffraction data were collected to resolutions of 1.9 Å for ΔN-LmSPS2 and 3.4 Å for TbSPS2.
Collapse
Affiliation(s)
- Lívia Maria Faim
- Institute of Physics, University of São Paulo, Avenida Trabalhador São-carlense 400, 13566-590 São Carlos-SP, Brazil
| | - Ivan Rosa e Silva
- Institute of Physics, University of São Paulo, Avenida Trabalhador São-carlense 400, 13566-590 São Carlos-SP, Brazil
| | - Marcio Vinicius Bertacine Dias
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 1GA, England
- Brazilian Biosciences National Laboratory (LNBio), Brazilian Center of Research in Energy and Materials (CNPEM), Caixa Postal 6192, 13083-970 Campinas-SP, Brazil
| | - Humberto D’Muniz Pereira
- Institute of Physics, University of São Paulo, Avenida Trabalhador São-carlense 400, 13566-590 São Carlos-SP, Brazil
| | - José Brandao-Neto
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0DE, England
| | - Marco Túlio Alves da Silva
- Institute of Physics, University of São Paulo, Avenida Trabalhador São-carlense 400, 13566-590 São Carlos-SP, Brazil
| | - Otavio Henrique Thiemann
- Institute of Physics, University of São Paulo, Avenida Trabalhador São-carlense 400, 13566-590 São Carlos-SP, Brazil
| |
Collapse
|
20
|
Rapid depletion of target proteins allows identification of coincident physiological responses. J Bacteriol 2012; 194:5932-40. [PMID: 22942249 DOI: 10.1128/jb.00913-12] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Targeted protein degradation is a powerful tool that can be used to create unique physiologies depleted of important factors. Current strategies involve modifying a gene of interest such that a degradation peptide is added to an expressed target protein and then conditionally activating proteolysis, either by expressing adapters, unmasking cryptic recognition determinants, or regulating protease affinities using small molecules. For each target, substantial optimization may be required to achieve a practical depletion, in that the target remains present at a normal level prior to induction and is then rapidly depleted to levels low enough to manifest a physiological response. Here, we describe a simplified targeted degradation system that rapidly depletes targets and that can be applied to a wide variety of proteins without optimizing target protease affinities. The depletion of the target is rapid enough that a primary physiological response manifests that is related to the function of the target. Using ribosomal protein S1 as an example, we show that the rapid depletion of this essential translation factor invokes concomitant changes to the levels of several mRNAs, even before appreciable cell division has occurred.
Collapse
|