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Abstract
In an oxygenic environment, poorly soluble Fe3+ must be reduced to meet the cellular Fe2+ demand. This study demonstrates that elevated CO2/HCO3− levels accelerate chemical Fe3+ reduction through phenolic compounds, thus increasing intracellular Fe2+ availability. A number of biological environments are characterized by the presence of phenolic compounds and elevated HCO3− levels and include soil habitats and the human body. Fe2+ availability is of particular interest in the latter, as it controls the infectiousness of pathogens. Since the effect postulated here is abiotic, it generally affects the Fe2+ distribution in nature. Iron is a vital mineral for almost all living organisms and has a pivotal role in central metabolism. Despite its great abundance on earth, the accessibility for microorganisms is often limited, because poorly soluble ferric iron (Fe3+) is the predominant oxidation state in an aerobic environment. Hence, the reduction of Fe3+ is of essential importance to meet the cellular demand of ferrous iron (Fe2+) but might become detrimental as excessive amounts of intracellular Fe2+ tend to undergo the cytotoxic Fenton reaction in the presence of hydrogen peroxide. We demonstrate that the complex formation rate of Fe3+ and phenolic compounds like protocatechuic acid was increased by 46% in the presence of HCO3− and thus accelerated the subsequent redox reaction, yielding reduced Fe2+. Consequently, elevated CO2/HCO3− levels increased the intracellular Fe2+ availability, which resulted in at least 50% higher biomass-specific fluorescence of a DtxR-based Corynebacterium glutamicum reporter strain, and stimulated growth. Since the increased Fe2+ availability was attributed to the interaction of HCO3− and chemical iron reduction, the abiotic effect postulated in this study is of general relevance in geochemical and biological environments.
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202
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Battling S, Wohlers K, Igwe C, Kranz A, Pesch M, Wirtz A, Baumgart M, Büchs J, Bott M. Novel plasmid-free Gluconobacter oxydans strains for production of the natural sweetener 5-ketofructose. Microb Cell Fact 2020; 19:54. [PMID: 32131833 PMCID: PMC7055074 DOI: 10.1186/s12934-020-01310-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Accepted: 02/17/2020] [Indexed: 12/14/2022] Open
Abstract
Background 5-Ketofructose (5-KF) has recently been identified as a promising non-nutritive natural sweetener. Gluconobacter oxydans strains have been developed that allow efficient production of 5-KF from fructose by plasmid-based expression of the fructose dehydrogenase genes fdhSCL of Gluconobacter japonicus. As plasmid-free strains are preferred for industrial production of food additives, we aimed at the construction of efficient 5-KF production strains with the fdhSCL genes chromosomally integrated. Results For plasmid-free 5-KF production, we selected four sites in the genome of G. oxydans IK003.1 and inserted the fdhSCL genes under control of the strong P264 promoter into each of these sites. All four recombinant strains expressed fdhSCL and oxidized fructose to 5-KF, but site-specific differences were observed suggesting that the genomic vicinity influenced gene expression. For further improvement, a second copy of the fdhSCL genes under control of P264 was inserted into the second-best insertion site to obtain strain IK003.1::fdhSCL2. The 5-KF production rate and the 5-KF yield obtained with this double-integration strain were considerably higher than for the single integration strains and approached the values of IK003.1 with plasmid-based fdhSCL expression. Conclusion We identified four sites in the genome of G. oxydans suitable for expression of heterologous genes and constructed a strain with two genomic copies of the fdhSCL genes enabling efficient plasmid-free 5-KF production. This strain will serve as basis for further metabolic engineering strategies aiming at the use of alternative carbon sources for 5-KF production and for bioprocess optimization.
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Affiliation(s)
- Svenja Battling
- AVT-Biochemical Engineering, RWTH Aachen University, Forckenbeckstraße 51, 52074, Aachen, Germany
| | - Karen Wohlers
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, 52425, Jülich, Germany
| | - Chika Igwe
- AVT-Biochemical Engineering, RWTH Aachen University, Forckenbeckstraße 51, 52074, Aachen, Germany
| | - Angela Kranz
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, 52425, Jülich, Germany
| | - Matthias Pesch
- AVT-Biochemical Engineering, RWTH Aachen University, Forckenbeckstraße 51, 52074, Aachen, Germany
| | - Astrid Wirtz
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, 52425, Jülich, Germany
| | - Meike Baumgart
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, 52425, Jülich, Germany
| | - Jochen Büchs
- AVT-Biochemical Engineering, RWTH Aachen University, Forckenbeckstraße 51, 52074, Aachen, Germany.
| | - Michael Bott
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, 52425, Jülich, Germany.
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203
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Amon JD, Yadav AK, Ramirez-Guadiana FH, Meeske AJ, Cava F, Rudner DZ. SwsB and SafA Are Required for CwlJ-Dependent Spore Germination in Bacillus subtilis. J Bacteriol 2020; 202:e00668-19. [PMID: 31871031 PMCID: PMC7043669 DOI: 10.1128/jb.00668-19] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 12/13/2019] [Indexed: 02/07/2023] Open
Abstract
When Bacillus subtilis spores detect nutrients, they exit dormancy through the processes of germination and outgrowth. A key step in germination is the activation of two functionally redundant cell wall hydrolases (SleB and CwlJ) that degrade the specialized cortex peptidoglycan that surrounds the spore. How these enzymes are regulated remains poorly understood. To identify additional factors that affect their activity, we used transposon sequencing to screen for synthetic germination defects in spores lacking SleB or CwlJ. Other than the previously characterized protein YpeB, no additional factors were found to be specifically required for SleB activity. In contrast, our screen identified SafA and YlxY (renamed SwsB) in addition to the known factors GerQ and CotE as proteins required for CwlJ function. SafA is a member of the spore's proteinaceous coat and we show that, like GerQ and CotE, it is required for accumulation and retention of CwlJ in the dormant spore. SwsB is broadly conserved among spore formers, and we show that it is required for CwlJ to efficiently degrade the cortex during germination. Intriguingly, SwsB resembles polysaccharide deacetylases, and its putative catalytic residues are required for its role in germination. However, we find no chemical signature of its activity on the spore cortex or in vitro While the precise, mechanistic role of SwsB remains unknown, we explore and discuss potential activities.IMPORTANCE Spore formation in Bacillus subtilis has been studied for over half a century, and virtually every step in this developmental process has been characterized in molecular detail. In contrast, how spores exit dormancy remains less well understood. A key step in germination is the degradation of the specialized cell wall surrounding the spore called the cortex. Two enzymes (SleB and CwlJ) specifically target this protective layer, but how they are regulated and whether additional factors promote their activity are unknown. Here, we identified the coat protein SafA and a conserved but uncharacterized protein YlxY as additional factors required for CwlJ-dependent degradation of the cortex. Our analysis provides a more complete picture of this essential step in the exit from dormancy.
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Affiliation(s)
- Jeremy D Amon
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
| | - Akhilesh K Yadav
- Laboratory for Molecular Infection Medicine, Department of Molecular Biology, Umeå University, Umeå, Sweden
- Analytical Chemistry Division, CSIR-Indian Institute of Toxicology Research, Lucknow, India
| | | | - Alexander J Meeske
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
| | - Felipe Cava
- Laboratory for Molecular Infection Medicine, Department of Molecular Biology, Umeå University, Umeå, Sweden
| | - David Z Rudner
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
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204
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Peng Z, Peralta MDR, Cox DL, Toney MD. Bottom-up synthesis of protein-based nanomaterials from engineered β-solenoid proteins. PLoS One 2020; 15:e0229319. [PMID: 32084222 PMCID: PMC7034853 DOI: 10.1371/journal.pone.0229319] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Accepted: 01/02/2020] [Indexed: 02/04/2023] Open
Abstract
Biomolecular self-assembly is an emerging bottom-up approach for the synthesis of novel nanomaterials. DNA and viruses have both been used to create scaffolds but the former lacks chemical diversity and the latter lack spatial control. To date, the use of protein scaffolds to template materials on the nanoscale has focused on amyloidogenic proteins that are known to form fibrils or two-protein systems where a second protein acts as a cross-linker. We previously developed a unique approach for self-assembly of nanomaterials based on engineering β-solenoid proteins (BSPs) to polymerize into micrometer-length fibrils. BSPs have highly regular geometries, tunable lengths, and flat surfaces that are amenable to engineering and functionalization. Here, we present a newly engineered BSP based on the antifreeze protein of the beetle Rhagium inquisitor (RiAFP-m9), which polymerizes into stable fibrils under benign conditions. Gold nanoparticles were used to functionalize the RiAFP-m9 fibrils as well as those assembled from the previously described SBAFP-m1 protein. Cysteines incorporated into the sequences provide site-specific gold attachment. Additionally, silver was deposited on the gold-labelled fibrils by electroless plating to create nanowires. These results bolster prospects for programable self-assembly of BSPs to create scaffolds for functional nanomaterials.
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Affiliation(s)
- Zeyu Peng
- Department of Chemistry, University of California Davis, Davis, California, United States of America
- * E-mail:
| | - Maria D. R. Peralta
- Department of Chemistry, University of California Davis, Davis, California, United States of America
| | - Daniel L. Cox
- Department of Physics, University of California Davis, Davis, California, United States of America
| | - Michael D. Toney
- Department of Chemistry, University of California Davis, Davis, California, United States of America
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205
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Koendjbiharie JG, Hon S, Pabst M, Hooftman R, Stevenson DM, Cui J, Amador-Noguez D, Lynd LR, Olson DG, van Kranenburg R. The pentose phosphate pathway of cellulolytic clostridia relies on 6-phosphofructokinase instead of transaldolase. J Biol Chem 2020; 295:1867-1878. [PMID: 31871051 PMCID: PMC7029132 DOI: 10.1074/jbc.ra119.011239] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Revised: 12/16/2019] [Indexed: 01/24/2023] Open
Abstract
The genomes of most cellulolytic clostridia do not contain genes annotated as transaldolase. Therefore, for assimilating pentose sugars or for generating C5 precursors (such as ribose) during growth on other (non-C5) substrates, they must possess a pathway that connects pentose metabolism with the rest of metabolism. Here we provide evidence that for this connection cellulolytic clostridia rely on the sedoheptulose 1,7-bisphosphate (SBP) pathway, using pyrophosphate-dependent phosphofructokinase (PPi-PFK) instead of transaldolase. In this reversible pathway, PFK converts sedoheptulose 7-phosphate (S7P) to SBP, after which fructose-bisphosphate aldolase cleaves SBP into dihydroxyacetone phosphate and erythrose 4-phosphate. We show that PPi-PFKs of Clostridium thermosuccinogenes and Clostridium thermocellum indeed can convert S7P to SBP, and have similar affinities for S7P and the canonical substrate fructose 6-phosphate (F6P). By contrast, (ATP-dependent) PfkA of Escherichia coli, which does rely on transaldolase, had a very poor affinity for S7P. This indicates that the PPi-PFK of cellulolytic clostridia has evolved the use of S7P. We further show that C. thermosuccinogenes contains a significant SBP pool, an unusual metabolite that is elevated during growth on xylose, demonstrating its relevance for pentose assimilation. Last, we demonstrate that a second PFK of C. thermosuccinogenes that operates with ATP and GTP exhibits unusual kinetics toward F6P, as it appears to have an extremely high degree of cooperative binding, resulting in a virtual on/off switch for substrate concentrations near its K½ value. In summary, our results confirm the existence of an SBP pathway for pentose assimilation in cellulolytic clostridia.
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Affiliation(s)
| | - Shuen Hon
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire 03755; Center for Bioenergy Innovation, Oak Ridge National Laboratories, Oak Ridge, Tennessee 37830
| | - Martin Pabst
- Cell Systems Engineering, Delft University of Technology, 2629 HZ Delft, The Netherlands
| | - Robert Hooftman
- Laboratory of Microbiology, Wageningen University & Research, 6708 WE Wageningen, The Netherlands
| | - David M Stevenson
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin 53706
| | - Jingxuan Cui
- Center for Bioenergy Innovation, Oak Ridge National Laboratories, Oak Ridge, Tennessee 37830; Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire, 03755
| | - Daniel Amador-Noguez
- Center for Bioenergy Innovation, Oak Ridge National Laboratories, Oak Ridge, Tennessee 37830; Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin 53706
| | - Lee R Lynd
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire 03755; Center for Bioenergy Innovation, Oak Ridge National Laboratories, Oak Ridge, Tennessee 37830; Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire, 03755
| | - Daniel G Olson
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire 03755; Center for Bioenergy Innovation, Oak Ridge National Laboratories, Oak Ridge, Tennessee 37830
| | - Richard van Kranenburg
- Corbion, 4206 AC Gorinchem, The Netherlands; Laboratory of Microbiology, Wageningen University & Research, 6708 WE Wageningen, The Netherlands.
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206
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Zong S, Mi T, Flores LG, Alpert A, Olivares S, Patel K, Maiti S, Mcnamara G, Cooper LJN, Torikai H. Very rapid cloning, expression and identifying specificity of T-cell receptors for T-cell engineering. PLoS One 2020; 15:e0228112. [PMID: 32040512 PMCID: PMC7010234 DOI: 10.1371/journal.pone.0228112] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Accepted: 01/07/2020] [Indexed: 11/29/2022] Open
Abstract
Neoantigens can be predicted and in some cases identified using the data obtained from the whole exome sequencing and transcriptome sequencing of tumor cells. These sequencing data can be coupled with single-cell RNA sequencing for the direct interrogation of the transcriptome, surfaceome, and pairing of αβ T-cell receptors (TCRαβ) from hundreds of single T cells. Using these 2 large datasets, we established a platform for identifying antigens recognized by TCRαβs obtained from single T cells. Our approach is based on the rapid expression of cloned TCRαβ genes as Sleeping Beauty transposons and the determination of the introduced TCRαβs’ antigen specificity and avidity using a reporter cell line. The platform enables the very rapid identification of tumor-reactive TCRs for the bioengineering of T cells with redirected specificity.
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Affiliation(s)
- Shan Zong
- Division of Pediatrics, The University of Texas MD Anderson Cancer Center, Houston, Texas, United States of America
| | - Tiejuan Mi
- Division of Pediatrics, The University of Texas MD Anderson Cancer Center, Houston, Texas, United States of America
| | - Leo G. Flores
- Division of Pediatrics, The University of Texas MD Anderson Cancer Center, Houston, Texas, United States of America
| | - Amir Alpert
- Division of Pediatrics, The University of Texas MD Anderson Cancer Center, Houston, Texas, United States of America
| | - Simon Olivares
- Division of Pediatrics, The University of Texas MD Anderson Cancer Center, Houston, Texas, United States of America
| | - Krina Patel
- Department of Lymphoma and Myeloma, Division of Cancer Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas, United States of America
| | - Sourindra Maiti
- Division of Pediatrics, The University of Texas MD Anderson Cancer Center, Houston, Texas, United States of America
| | - George Mcnamara
- Division of Pediatrics, The University of Texas MD Anderson Cancer Center, Houston, Texas, United States of America
| | - Laurence J. N. Cooper
- Division of Pediatrics, The University of Texas MD Anderson Cancer Center, Houston, Texas, United States of America
- Ziopharm Oncology, Inc., Boston, Massachusetts, United States of America
| | - Hiroki Torikai
- Division of Pediatrics, The University of Texas MD Anderson Cancer Center, Houston, Texas, United States of America
- * E-mail:
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207
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Sun X, Zhang X, Huang H, Wang Y, Tu T, Bai Y, Wang Y, Zhang J, Luo H, Yao B, Su X. Engineering the cbh1 Promoter of Trichoderma reesei for Enhanced Protein Production by Replacing the Binding Sites of a Transcription Repressor ACE1 to Those of the Activators. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2020; 68:1337-1346. [PMID: 31933359 DOI: 10.1021/acs.jafc.9b05452] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The strong and inducible cbh1 promoter is most widely used to express heterologous proteins, useful in food and feed industries, in Trichoderma reesei. Enhancing its ability to direct transcription provides a general strategy to improve protein production in T. reesei. The cbh1 promoter was engineered by replacing eight binding sites of the transcription repressor ACE1 to those of the activators ACE2, Hap2/3/5, and Xyr1. While changing ACE1 to Hap2/3/5-binding sites completely abolished the transcription ability, replacements with ACE2- and Xyr1-binding sites (designated cbh1pA and cbh1pX promoters, respectively) largely improved the promoter transcription efficiency, as reflected by expression of a reporter gene DsRed. The cbh1pA and cbh1pX promoters were applied to improve secretory expression of a codon-optimized mannanase from Aspergillus niger to 3.6- and 5.0-fold higher, respectively, which has high application potential in feed industry.
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Affiliation(s)
- Xianhua Sun
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute , Chinese Academy of Agricultural Sciences , Beijing 100081 , China
| | - Xuhuan Zhang
- Biotechnology Research Institute , Chinese Academy of Agricultural Sciences , Beijing 100081 , People's Republic of China
| | - Huoqing Huang
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute , Chinese Academy of Agricultural Sciences , Beijing 100081 , China
| | - Yuan Wang
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute , Chinese Academy of Agricultural Sciences , Beijing 100081 , China
| | - Tao Tu
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute , Chinese Academy of Agricultural Sciences , Beijing 100081 , China
| | - Yingguo Bai
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute , Chinese Academy of Agricultural Sciences , Beijing 100081 , China
| | - Yaru Wang
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute , Chinese Academy of Agricultural Sciences , Beijing 100081 , China
| | - Jie Zhang
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute , Chinese Academy of Agricultural Sciences , Beijing 100081 , China
| | - Huiying Luo
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute , Chinese Academy of Agricultural Sciences , Beijing 100081 , China
| | - Bin Yao
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute , Chinese Academy of Agricultural Sciences , Beijing 100081 , China
| | - Xiaoyun Su
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute , Chinese Academy of Agricultural Sciences , Beijing 100081 , China
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208
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Farzadfard F, Gharaei N, Higashikuni Y, Jung G, Cao J, Lu TK. Single-Nucleotide-Resolution Computing and Memory in Living Cells. Mol Cell 2020; 75:769-780.e4. [PMID: 31442423 DOI: 10.1016/j.molcel.2019.07.011] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2018] [Revised: 05/07/2019] [Accepted: 07/08/2019] [Indexed: 12/22/2022]
Abstract
The ability to process and store information in living cells is essential for developing next-generation therapeutics and studying biology in situ. However, existing strategies have limited recording capacity and are challenging to scale. To overcome these limitations, we developed DOMINO, a robust and scalable platform for encoding logic and memory in bacterial and eukaryotic cells. Using an efficient single-nucleotide-resolution Read-Write head for DNA manipulation, DOMINO converts the living cells' DNA into an addressable, readable, and writable medium for computation and storage. DOMINO operators enable analog and digital molecular recording for long-term monitoring of signaling dynamics and cellular events. Furthermore, multiple operators can be layered and interconnected to encode order-independent, sequential, and temporal logic, allowing recording and control over the combination, order, and timing of molecular events in cells. We envision that DOMINO will lay the foundation for building robust and sophisticated computation-and-memory gene circuits for numerous biotechnological and biomedical applications.
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Affiliation(s)
- Fahim Farzadfard
- Synthetic Biology Group, Research Laboratory of Electronics, Department of Electrical Engineering & Computer Science and Department of Biological Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA; MIT Synthetic Biology Center, 500 Technology Square, Cambridge MA 02139, USA; MIT Microbiology Graduate Program, 77 Massachusetts Avenue, Cambridge MA 02139, USA.
| | - Nava Gharaei
- MCO Graduate Program, Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA
| | - Yasutomi Higashikuni
- Synthetic Biology Group, Research Laboratory of Electronics, Department of Electrical Engineering & Computer Science and Department of Biological Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA; MIT Synthetic Biology Center, 500 Technology Square, Cambridge MA 02139, USA
| | - Giyoung Jung
- Synthetic Biology Group, Research Laboratory of Electronics, Department of Electrical Engineering & Computer Science and Department of Biological Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA; MIT Synthetic Biology Center, 500 Technology Square, Cambridge MA 02139, USA; Harvard-MIT Division of Health Sciences and Technology, 77 Massachusetts Ave, Cambridge, MA 02139, USA
| | - Jicong Cao
- Synthetic Biology Group, Research Laboratory of Electronics, Department of Electrical Engineering & Computer Science and Department of Biological Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA; MIT Synthetic Biology Center, 500 Technology Square, Cambridge MA 02139, USA
| | - Timothy K Lu
- Synthetic Biology Group, Research Laboratory of Electronics, Department of Electrical Engineering & Computer Science and Department of Biological Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA; MIT Synthetic Biology Center, 500 Technology Square, Cambridge MA 02139, USA; MIT Microbiology Graduate Program, 77 Massachusetts Avenue, Cambridge MA 02139, USA.
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209
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Abstract
Candida albicans is a commensal as well as a pathogen of humans. C. albicans is able to mount a cellular response to a diverse range of external stimuli in the host and switch reversibly between the yeast and hyphal growth forms. Hyphal development is a key virulence determinant. Here, we studied how C. albicans senses different environmental signals to control its growth forms. Our study results suggest that robust hyphal development requires downregulation of two transcriptional repressors, Nrg1 and Sfl1. Acidic pH or cationic stress inhibits hyphal formation via stress-responsive kinases and Sfl1. Candida albicans is an important human pathogen responsible for causing both superficial and systemic infections. Its ability to switch from the yeast form to the hyphal growth form is required for its pathogenicity. Acidic pH inhibits hyphal initiation, but the nature of the mechanism for this inhibition is not completely clear. We show that acidic pH represses hyphal initiation independently of the temperature- and farnesol-mediated Nrg1 downregulation. Using a collection of transcription factor deletion mutants, we observed that the sfl1 mutant induced hyphae in acidic pH but not in farnesol at 37°C. Furthermore, transcription of hyphal regulators BRG1 and UME6 was not induced in wild-type (WT) cells but was induced in the sfl1 mutant during hyphal induction in acidic pH. Using the same screening conditions with the collection of kinase mutants, we found that deletions of the core stress response mitogen-activated protein (MAP) kinase HOG1 and its kinase PBS2, the cell wall stress MAP kinase MKC1, and the calcium/calmodulin-dependent kinase CMK1 allowed hyphal initiation in acidic pH. Furthermore, Hog1 phosphorylation induced by high osmotic stress also retarded hyphal initiation, and the effect was abolished in the sfl1 and three kinase mutants but was enhanced in the phosphatase mutant ptp2 ptp3. We also found functional associations among Cmk1, Hog1, and Sfl1 for cation stress. Our study results suggest that robust hyphal initiation requires downregulation of both Nrg1 and Sfl1 transcriptional repressors as well as timely BRG1 expression. Acidic pH and cationic stress retard hyphal initiation via the stress-responsive kinases and Sfl1. IMPORTANCECandida albicans is a commensal as well as a pathogen of humans. C. albicans is able to mount a cellular response to a diverse range of external stimuli in the host and switch reversibly between the yeast and hyphal growth forms. Hyphal development is a key virulence determinant. Here, we studied how C. albicans senses different environmental signals to control its growth forms. Our study results suggest that robust hyphal development requires downregulation of two transcriptional repressors, Nrg1 and Sfl1. Acidic pH or cationic stress inhibits hyphal formation via stress-responsive kinases and Sfl1.
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210
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Began J, Cordier B, Březinová J, Delisle J, Hexnerová R, Srb P, Rampírová P, Kožíšek M, Baudet M, Couté Y, Galinier A, Veverka V, Doan T, Strisovsky K. Rhomboid intramembrane protease YqgP licenses bacterial membrane protein quality control as adaptor of FtsH AAA protease. EMBO J 2020; 39:e102935. [PMID: 31930742 PMCID: PMC7231995 DOI: 10.15252/embj.2019102935] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 11/18/2019] [Accepted: 12/12/2019] [Indexed: 12/31/2022] Open
Abstract
Magnesium homeostasis is essential for life and depends on magnesium transporters, whose activity and ion selectivity need to be tightly controlled. Rhomboid intramembrane proteases pervade the prokaryotic kingdom, but their functions are largely elusive. Using proteomics, we find that Bacillus subtilis rhomboid protease YqgP interacts with the membrane‐bound ATP‐dependent processive metalloprotease FtsH and cleaves MgtE, the major high‐affinity magnesium transporter in B. subtilis. MgtE cleavage by YqgP is potentiated in conditions of low magnesium and high manganese or zinc, thereby protecting B. subtilis from Mn2+/Zn2+ toxicity. The N‐terminal cytosolic domain of YqgP binds Mn2+ and Zn2+ ions and facilitates MgtE cleavage. Independently of its intrinsic protease activity, YqgP acts as a substrate adaptor for FtsH, a function that is necessary for degradation of MgtE. YqgP thus unites protease and pseudoprotease function, hinting at the evolutionary origin of rhomboid pseudoproteases such as Derlins that are intimately involved in eukaryotic ER‐associated degradation (ERAD). Conceptually, the YqgP‐FtsH system we describe here is analogous to a primordial form of “ERAD” in bacteria and exemplifies an ancestral function of rhomboid‐superfamily proteins.
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Affiliation(s)
- Jakub Began
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Science, Prague, Czech Republic.,Department of Genetics and Microbiology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Baptiste Cordier
- Laboratoire de Chimie Bactérienne (LCB), Institut de Microbiologie de la Méditerranée (IMM), CNRS, UMR 7283, Aix Marseille Univ, Marseille Cedex 20, France
| | - Jana Březinová
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Science, Prague, Czech Republic.,Department of Biochemistry, Faculty of Science, Charles University, Prague, Czech Republic
| | - Jordan Delisle
- Laboratoire de Chimie Bactérienne (LCB), Institut de Microbiologie de la Méditerranée (IMM), CNRS, UMR 7283, Aix Marseille Univ, Marseille Cedex 20, France
| | - Rozálie Hexnerová
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Science, Prague, Czech Republic
| | - Pavel Srb
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Science, Prague, Czech Republic
| | - Petra Rampírová
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Science, Prague, Czech Republic
| | - Milan Kožíšek
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Science, Prague, Czech Republic
| | - Mathieu Baudet
- CEA, Inserm, IRIG-BGE, Univ. Grenoble Alpes, Grenoble, France
| | - Yohann Couté
- CEA, Inserm, IRIG-BGE, Univ. Grenoble Alpes, Grenoble, France
| | - Anne Galinier
- Laboratoire de Chimie Bactérienne (LCB), Institut de Microbiologie de la Méditerranée (IMM), CNRS, UMR 7283, Aix Marseille Univ, Marseille Cedex 20, France
| | - Václav Veverka
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Science, Prague, Czech Republic.,Department of Cell Biology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Thierry Doan
- Laboratoire de Chimie Bactérienne (LCB), Institut de Microbiologie de la Méditerranée (IMM), CNRS, UMR 7283, Aix Marseille Univ, Marseille Cedex 20, France.,Laboratoire d'Ingénierie des Systèmes Macromoléculaires (LISM), Institut de Microbiologie de la Méditerranée (IMM), CNRS, UMR 7255, Aix Marseille Univ, Marseille Cedex 20, France
| | - Kvido Strisovsky
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Science, Prague, Czech Republic
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211
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Wang J, Zhu J, Wang C, Zhou G, Yu X, Fan H, An R, Komiyama M, Liang X. Thermus thermophilus DNA Ligase Connects Two Fragments Having Exceptionally Short Complementary Termini at High Temperatures. Biochemistry 2020; 59:400-406. [PMID: 31887028 DOI: 10.1021/acs.biochem.9b00866] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Thermus thermophilus DNA ligase (Tth DNA ligase) is widely employed for cloning, enzymatic synthesis, and molecular diagnostics at high temperatures (e.g., 65 °C). It has been long believed that the complementary ends must be very long (e.g., >30 bp) to place two DNA fragments nearby for the ligation. In the current study, the length of the complementary portion was systematically varied, and the ligation efficiency was evaluated using the high resolution melting (HRM) method. Unexpectedly, very short oligonucleotides (7-10 nt) were successfully ligated on the complementary overhang attached to a dsDNA at 70 °C. Furthermore, sticky ends with the overhang of only 4 nt long, available after scission with many restriction enzymes, were also efficiently ligated at 45-70 °C. The ligation yield for the 6-nt-long sticky ends was as high as 80%. It was concluded that Tth DNA ligase can be used as a unique tool for DNA manipulation that cannot be otherwise easily accomplished.
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Affiliation(s)
- Jing Wang
- College of Food Science and Engineering , Ocean University of China , Qingdao 266003 , China.,CAS Key laboratory of Marine Ecology and Environmental Sciences , Institute of Oceanology, Chinese Academy of Sciences , Qingdao 266071 , China
| | - Jianming Zhu
- College of Food Science and Engineering , Ocean University of China , Qingdao 266003 , China
| | - Chenru Wang
- College of Food Science and Engineering , Ocean University of China , Qingdao 266003 , China
| | - Guangqing Zhou
- College of Food Science and Engineering , Ocean University of China , Qingdao 266003 , China
| | - Xin Yu
- College of Food Science and Engineering , Ocean University of China , Qingdao 266003 , China
| | - Huijun Fan
- College of Food Science and Engineering , Ocean University of China , Qingdao 266003 , China
| | - Ran An
- College of Food Science and Engineering , Ocean University of China , Qingdao 266003 , China.,Laboratory for Marine Drugs and Bioproducts , Qingdao National Laboratory for Marine Science and Technology , Qingdao 266003 , China
| | - Makoto Komiyama
- College of Food Science and Engineering , Ocean University of China , Qingdao 266003 , China
| | - Xingguo Liang
- College of Food Science and Engineering , Ocean University of China , Qingdao 266003 , China.,Laboratory for Marine Drugs and Bioproducts , Qingdao National Laboratory for Marine Science and Technology , Qingdao 266003 , China
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212
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Abstract
There was an explosion in the amount of commercially available DNA in sequence repositories over the last decade. The number of such plasmids increased from 12,000 to over 300,000 among three of the largest repositories: iGEM, Addgene, and DNASU. A challenge in biodesign remains how to use these and other repository-based sequences effectively, correctly, and seamlessly. This work describes an approach to plasmid design where a plasmid is specified as simply a DNA sequence or list of features. The proposed software then finds the most cost-effective combination of synthetic and PCR-prepared repository fragments to build the plasmid via Gibson assembly®. It finds existing DNA sequences in both user-specified and public DNA databases: iGEM, Addgene, and DNASU. Such a software application is introduced and characterized against all post-2005 iGEM composite parts and all Addgene vectors submitted in 2018 and found to reduce costs by 34% versus a purely synthetic plasmid design approach. The described software will improve current plasmid assembly workflows by shortening design times, improving build quality, and reducing costs.
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Affiliation(s)
- Joshua J. Timmons
- Lattice Automation Inc., Boston, Massachusetts, United States of America
| | - Doug Densmore
- Lattice Automation Inc., Boston, Massachusetts, United States of America
- Department of Electrical and Computer Engineering, Boston University, Boston, Massachusetts, United States of America
- Biological Design Center, Boston University, Boston, Massachusetts, United States of America
- * E-mail:
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213
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Coakley S, Ritchie FK, Galbraith KM, Hilliard MA. Epidermal control of axonal attachment via β-spectrin and the GTPase-activating protein TBC-10 prevents axonal degeneration. Nat Commun 2020; 11:133. [PMID: 31919407 PMCID: PMC6952388 DOI: 10.1038/s41467-019-13795-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Accepted: 11/28/2019] [Indexed: 12/28/2022] Open
Abstract
Neurons are subjected to strain due to body movement and their location within organs and tissues. However, how they withstand these forces over the lifetime of an organism is still poorly understood. Here, focusing on touch receptor neuron-epidermis interactions using Caenorhabditis elegans as a model system, we show that UNC-70/β-spectrin and TBC-10, a conserved GTPase-activating protein, function non-cell-autonomously within the epidermis to dynamically maintain attachment of the axon. We reveal that, in response to strain, UNC-70/β-spectrin and TBC-10 stabilize trans-epidermal hemidesmosome attachment structures which otherwise become lost, causing axonal breakage and degeneration. Furthermore, we show that TBC-10 regulates axonal attachment and maintenance by inactivating RAB-35, and reveal functional conservation of these molecules with their vertebrate orthologs. Finally, we demonstrate that β-spectrin functions in this context non-cell-autonomously. We propose a model in which mechanically resistant epidermal attachment structures are maintained by UNC-70/β-spectrin and TBC-10 during movement, preventing axonal detachment and degeneration.
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Affiliation(s)
- Sean Coakley
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Fiona K Ritchie
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Kate M Galbraith
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Massimo A Hilliard
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, 4072, Australia.
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214
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Gallo E. High-Throughput Generation of In Silico Derived Synthetic Antibodies via One-step Enzymatic DNA Assembly of Fragments. Mol Biotechnol 2020; 62:142-150. [PMID: 31894513 DOI: 10.1007/s12033-019-00232-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Phage-display technology offers robust methods for isolating antibody (Ab) molecules with specificity for different target antigens. Recent advancements couple Ab selections with in silico strategies, such as predictive computational models or next-generation sequencing metadata analysis of Ab selections. These advancements result in enhanced Ab clonal diversities with potential for enlarged epitope coverage of the target antigen. A current limitation however, is that de novo Ab sequences must undergo DNA gene synthesis, and subsequent expression as Ab proteins for downstream validations. Due to the high costs and time for commercially generating large sets of DNA genes, we report a high-throughput platform for the synthesis of in silico derived Ab clones. As a proof of concept we demonstrate the simultaneous synthesis of 96 unique Abs with varied lengths and complementary determining region compositions. Each of the 96 Ab clones undergoes a one-step enzymatic assembly of distinct DNA fragments that combine into a circularized Fab expression plasmid. This strategy allows for the rapid and efficient synthesis of 96 DNA constructs in a 3 day window, and exhibits high percentage fidelity-greater than 93%. Accordingly, the synthesis of Ab DNA constructs as Fab expression plasmids allow for rapid execution of downstream Ab protein validations, with potential for implementation into high-throughput Ab protein characterization pipelines. Altogether, the platform presented here proves rapid and also cost-effective, which is important for labs with limited resources, since it utilizes standard laboratory equipment and molecular reagents.
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Affiliation(s)
- Eugenio Gallo
- Department of Molecular Genetics, Charles Best Institute, University of Toronto, 112 College Street, 112 College Street, Room 70, Toronto, ON, M5G 1L6, Canada.
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215
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Abstract
Phytobricks are standardized DNA parts for plants that can be assembled hierarchically into transcriptional units and, subsequently, into multigene constructs. Phytobricks each contain the sequences of one or more functional elements that comprise eukaryotic transcription units, with sequence features that enable them to be used interchangeably in one-step cloning reactions to facilitate combinatorial assembly. The simplicity and efficiency of this one-step reaction has enabled Phytobrick assembly to be miniaturized and automated on liquid handing platforms. In this method, we describe how to design and construct new Phytobricks as well as how to assemble them in both manual and nanoscale automated one-step reactions. Finally, we describe a high-throughput method for sequence verification of assembled plasmids.
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216
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Dobihal GS, Brunet YR, Flores-Kim J, Rudner DZ. Homeostatic control of cell wall hydrolysis by the WalRK two-component signaling pathway in Bacillus subtilis. eLife 2019; 8:52088. [PMID: 31808740 PMCID: PMC7299342 DOI: 10.7554/elife.52088] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2019] [Accepted: 12/05/2019] [Indexed: 12/31/2022] Open
Abstract
Bacterial cells are encased in a peptidoglycan (PG) exoskeleton that protects them from osmotic lysis and specifies their distinct shapes. Cell wall hydrolases are required to enlarge this covalently closed macromolecule during growth, but how these autolytic enzymes are regulated remains poorly understood. Bacillus subtilis encodes two functionally redundant D,L-endopeptidases (CwlO and LytE) that cleave peptide crosslinks to allow expansion of the PG meshwork during growth. Here, we provide evidence that the essential and broadly conserved WalR-WalK two component regulatory system continuously monitors changes in the activity of these hydrolases by sensing the cleavage products generated by these enzymes and modulating their levels and activity in response. The WalR-WalK pathway is conserved among many Gram-positive pathogens where it controls transcription of distinct sets of PG hydrolases. Cell wall remodeling in these bacteria may be subject to homeostatic control mechanisms similar to the one reported here.
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Affiliation(s)
| | - Yannick R Brunet
- Department of Microbiology, Harvard Medical School, Boston, United States
| | - Josué Flores-Kim
- Department of Microbiology, Harvard Medical School, Boston, United States
| | - David Z Rudner
- Department of Microbiology, Harvard Medical School, Boston, United States
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217
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Beurton F, Stempor P, Caron M, Appert A, Dong Y, Chen RAJ, Cluet D, Couté Y, Herbette M, Huang N, Polveche H, Spichty M, Bedet C, Ahringer J, Palladino F. Physical and functional interaction between SET1/COMPASS complex component CFP-1 and a Sin3S HDAC complex in C. elegans. Nucleic Acids Res 2019; 47:11164-11180. [PMID: 31602465 PMCID: PMC6868398 DOI: 10.1093/nar/gkz880] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Revised: 09/13/2019] [Accepted: 10/07/2019] [Indexed: 12/23/2022] Open
Abstract
The CFP1 CXXC zinc finger protein targets the SET1/COMPASS complex to non-methylated CpG rich promoters to implement tri-methylation of histone H3 Lys4 (H3K4me3). Although H3K4me3 is widely associated with gene expression, the effects of CFP1 loss vary, suggesting additional chromatin factors contribute to context dependent effects. Using a proteomics approach, we identified CFP1 associated proteins and an unexpected direct link between Caenorhabditis elegans CFP-1 and an Rpd3/Sin3 small (SIN3S) histone deacetylase complex. Supporting a functional connection, we find that mutants of COMPASS and SIN3 complex components genetically interact and have similar phenotypic defects including misregulation of common genes. CFP-1 directly binds SIN-3 through a region including the conserved PAH1 domain and recruits SIN-3 and the HDA-1/HDAC subunit to H3K4me3 enriched promoters. Our results reveal a novel role for CFP-1 in mediating interaction between SET1/COMPASS and a Sin3S HDAC complex at promoters.
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Affiliation(s)
- Flore Beurton
- Laboratory of Biology and Modeling of the Cell, UMR5239 CNRS/Ecole Normale Supérieure de Lyon, INSERM U1210, UMS 3444 Biosciences Lyon Gerland, Université de Lyon, Lyon, France
| | - Przemyslaw Stempor
- The Gurdon Institute and Department of Genetics, University of Cambridge, Cambridge, UK
| | - Matthieu Caron
- Laboratory of Biology and Modeling of the Cell, UMR5239 CNRS/Ecole Normale Supérieure de Lyon, INSERM U1210, UMS 3444 Biosciences Lyon Gerland, Université de Lyon, Lyon, France
| | - Alex Appert
- The Gurdon Institute and Department of Genetics, University of Cambridge, Cambridge, UK
| | - Yan Dong
- The Gurdon Institute and Department of Genetics, University of Cambridge, Cambridge, UK
| | - Ron A-j Chen
- The Gurdon Institute and Department of Genetics, University of Cambridge, Cambridge, UK
| | - David Cluet
- Laboratory of Biology and Modeling of the Cell, UMR5239 CNRS/Ecole Normale Supérieure de Lyon, INSERM U1210, UMS 3444 Biosciences Lyon Gerland, Université de Lyon, Lyon, France
| | - Yohann Couté
- Grenoble Alpes, CEA, Inserm, BIG-BGE, 38000 Grenoble, France
| | - Marion Herbette
- Laboratory of Biology and Modeling of the Cell, UMR5239 CNRS/Ecole Normale Supérieure de Lyon, INSERM U1210, UMS 3444 Biosciences Lyon Gerland, Université de Lyon, Lyon, France
| | - Ni Huang
- The Gurdon Institute and Department of Genetics, University of Cambridge, Cambridge, UK
| | - Hélène Polveche
- INSERM UMR 861, I-STEM, 28, Rue Henri Desbruères, 91100 Corbeil-Essonnes, France
| | - Martin Spichty
- Laboratory of Biology and Modeling of the Cell, UMR5239 CNRS/Ecole Normale Supérieure de Lyon, INSERM U1210, UMS 3444 Biosciences Lyon Gerland, Université de Lyon, Lyon, France
| | - Cécile Bedet
- Laboratory of Biology and Modeling of the Cell, UMR5239 CNRS/Ecole Normale Supérieure de Lyon, INSERM U1210, UMS 3444 Biosciences Lyon Gerland, Université de Lyon, Lyon, France
| | - Julie Ahringer
- The Gurdon Institute and Department of Genetics, University of Cambridge, Cambridge, UK
| | - Francesca Palladino
- Laboratory of Biology and Modeling of the Cell, UMR5239 CNRS/Ecole Normale Supérieure de Lyon, INSERM U1210, UMS 3444 Biosciences Lyon Gerland, Université de Lyon, Lyon, France
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218
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Keener R, Connelly CJ, Greider CW. Tel1 Activation by the MRX Complex Is Sufficient for Telomere Length Regulation but Not for the DNA Damage Response in Saccharomyces cerevisiae. Genetics 2019; 213:1271-1288. [PMID: 31645360 PMCID: PMC6893380 DOI: 10.1534/genetics.119.302713] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Accepted: 10/17/2019] [Indexed: 12/26/2022] Open
Abstract
Previous models suggested that regulation of telomere length in Saccharomyces cerevisiae by Tel1(ATM) and Mec1(ATR) would parallel the established pathways regulating the DNA damage response. Here, we provide evidence that telomere length regulation differs from the DNA damage response in both the Tel1 and Mec1 pathways. We found that Rad53 mediates a Mec1 telomere length regulation pathway but is dispensable for Tel1 telomere length regulation, whereas in the DNA damage response, Rad53 is regulated by both Mec1 and Tel1 Using epistasis analysis with a Tel1 hypermorphic allele, Tel1-hy909, we found that the MRX complex is not required downstream of Tel1 for telomere elongation but is required downstream of Tel1 for the DNA damage response. Our data suggest that nucleolytic telomere end processing is not a required step for telomerase to elongate telomeres.
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Affiliation(s)
- Rebecca Keener
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
- Biochemistry, Cellular and Molecular Biology Graduate Program, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - Carla J Connelly
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - Carol W Greider
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
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219
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Aljannat MAK, Oldfield NJ, Albasri HM, Dorrington LKG, Ohri RL, Wooldridge KG, Turner DPJ. The moonlighting peroxiredoxin-glutaredoxin in Neisseria meningitidis binds plasminogen via a C-terminal lysine residue and contributes to survival in a whole blood model. Microb Pathog 2019; 139:103890. [PMID: 31765768 DOI: 10.1016/j.micpath.2019.103890] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Revised: 11/20/2019] [Accepted: 11/22/2019] [Indexed: 01/24/2023]
Abstract
Neisseria meningitidis is a human-restricted bacterium that can invade the bloodstream and cross the blood-brain barrier resulting in life-threatening sepsis and meningitis. Meningococci express a cytoplasmic peroxiredoxin-glutaredoxin (Prx5-Grx) hybrid protein that has also been identified on the bacterial surface. Here, recombinant Prx5-Grx was confirmed as a plasminogen (Plg)-binding protein, in an interaction which could be inhibited by the lysine analogue ε-aminocapronic acid. rPrx5-Grx derivatives bearing a substituted C-terminal lysine residue (rPrx5-GrxK244A), but not the active site cysteine residue (rPrx5-GrxC185A) or the sub-terminal rPrx5-GrxK230A lysine residue, exhibited significantly reduced Plg-binding. The absence of Prx5-Grx did not significantly reduce the ability of whole meningococcal cells to bind Plg, but under hydrogen peroxide-mediated oxidative stress, the N. meningitidis Δpxn5-grx mutant survived significantly better than the wild-type or complemented strains. Significantly, using human whole blood as a model of meningococcal bacteremia, it was found that the N. meningitidis Δpxn5-grx mutant had a survival defect compared with the parental or complemented strain, confirming an important role for Prx5-Grx in meningococcal pathogenesis.
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Affiliation(s)
- Mahab A K Aljannat
- School of Life Sciences, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Neil J Oldfield
- School of Life Sciences, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Hibah M Albasri
- School of Life Sciences, University of Nottingham, Nottingham, NG7 2RD, UK
| | | | - Radhica L Ohri
- School of Life Sciences, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Karl G Wooldridge
- School of Life Sciences, University of Nottingham, Nottingham, NG7 2RD, UK
| | - David P J Turner
- School of Life Sciences, University of Nottingham, Nottingham, NG7 2RD, UK.
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220
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Highly efficient multiplex human T cell engineering without double-strand breaks using Cas9 base editors. Nat Commun 2019; 10:5222. [PMID: 31745080 PMCID: PMC6864045 DOI: 10.1038/s41467-019-13007-6] [Citation(s) in RCA: 133] [Impact Index Per Article: 26.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Accepted: 10/07/2019] [Indexed: 12/16/2022] Open
Abstract
The fusion of genome engineering and adoptive cellular therapy holds immense promise for the treatment of genetic disease and cancer. Multiplex genome engineering using targeted nucleases can be used to increase the efficacy and broaden the application of such therapies but carries safety risks associated with unintended genomic alterations and genotoxicity. Here, we apply base editor technology for multiplex gene modification in primary human T cells in support of an allogeneic CAR-T platform and demonstrate that base editor can mediate highly efficient multiplex gene disruption with minimal double-strand break induction. Importantly, multiplex base edited T cells exhibit improved expansion and lack double strand break-induced translocations observed in T cells edited with Cas9 nuclease. Our findings highlight base editor as a powerful platform for genetic modification of therapeutically relevant primary cell types.
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221
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Khatiwada B, Purslow JA, Underbakke ES, Venditti V. N-terminal fusion of the N-terminal domain of bacterial enzyme I facilitates recombinant expression and purification of the human RNA demethylases FTO and Alkbh5. Protein Expr Purif 2019; 167:105540. [PMID: 31740367 DOI: 10.1016/j.pep.2019.105540] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Revised: 11/14/2019] [Accepted: 11/14/2019] [Indexed: 01/20/2023]
Abstract
Various fusion tags are commonly employed to increase the heterologous expression and solubility of aggregation-prone proteins within Escherichia coli. Herein, we present a protocol for efficient recombinant expression and purification of the human RNA demethylases Alkbh5 and FTO. Our method incorporates a novel fusion tag (the N-terminal domain of bacterial enzyme I, EIN) that dramatically increases the solubility of its fusion partner and is promptly removed upon digestion with a protease. The presented protocol allows for the production of mg amounts of Alkbh5 and FTO in 1L of both rich and minimal media. We developed a liquid chromatography-mass spectrometry (LC-MS)-based assay to confirm that both proteins are enzymatically active. Furthermore, the LC-MS method developed here is applicable to other members of the AlkB family of Fe(II)/α-ketoglutarate-dependent dioxygenases. The superior protein yield, afforded by our expression and purification method, will facilitate biochemical investigations into the biological function of the human RNA demethylases and endorse employment of EIN as a broadly applicable fusion tag for recombinant expression projects.
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Affiliation(s)
| | - Jeffrey A Purslow
- Department of Chemistry, Iowa State University, Ames, IA, 50011, USA
| | - Eric S Underbakke
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA, 50011, USA
| | - Vincenzo Venditti
- Department of Chemistry, Iowa State University, Ames, IA, 50011, USA; Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA, 50011, USA.
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222
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Ballmann P, Lightfoot J, Müller M, Dröge S, Prade R. Redesigning the Aspergillus nidulans xylanase regulatory pathway to enhance cellulase production with xylose as the carbon and inducer source. Microb Cell Fact 2019; 18:193. [PMID: 31699093 PMCID: PMC6839167 DOI: 10.1186/s12934-019-1243-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Accepted: 10/24/2019] [Indexed: 11/10/2022] Open
Abstract
Background Biomass contains cellulose (C6-sugars), hemicellulose (C5-sugars) and lignin. Biomass ranks amongst the most abundant hydrocarbon resources on earth. However, biomass is recalcitrant to enzymatic digestion by cellulases. Physicochemical pretreatment methods make cellulose accessible but partially destroy hemicellulose, producing a C5-sugar-rich liquor. Typically, digestion of pretreated LCB is performed with commercial cellulase preparations, but C5-sugars could in principle be used for “on site” production of cellulases by genetically engineered microorganism, thereby reducing costs. Results Here we report a succession of genetic interventions in Aspergillus nidulans that redesign the natural regulatory circuitry of cellulase genes in such a way that recombinant strains use C5-sugar liquors (xylose) to grow a vegetative tissue and simultaneously accumulate large amounts of cellulases. Overexpression of XlnR showed that under xylose-induction conditions only xylanase C was produced. XlnR overexpression strains were constructed that use the xynCp promoter to drive the production of cellobiohydrolases, endoglucanases and β-glucosidase. All five cellulases accumulated at high levels when grown on xylose. Production of cellulases in the presence of pretreated-biomass C5-sugar liquors was investigated, and cellulases accumulated to much higher enzyme titers than those obtained for traditional fungal cell factories with cellulase-inducing substrates. Conclusions By replacing expensive substrates with a cheap by-product carbon source, the use of C5-sugar liquors directly derived from LCB pretreatment processes not only reduces enzyme production costs, but also lowers operational costs by eliminating the need for off-site enzyme production, purification, concentration, transport and dilution.
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Affiliation(s)
- Patrick Ballmann
- Prüf- und Forschungsinstitut Pirmasens e.V., Marie-Curie-Strasse 19, 66953, Pirmasens, Germany
| | - Jorge Lightfoot
- Department of Microbiology & Molecular Genetics, Oklahoma State University, Stillwater, OK, 74078, USA
| | - Michael Müller
- Prüf- und Forschungsinstitut Pirmasens e.V., Marie-Curie-Strasse 19, 66953, Pirmasens, Germany
| | - Stephan Dröge
- Prüf- und Forschungsinstitut Pirmasens e.V., Marie-Curie-Strasse 19, 66953, Pirmasens, Germany
| | - Rolf Prade
- Department of Microbiology & Molecular Genetics, Oklahoma State University, Stillwater, OK, 74078, USA.
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223
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Wehrmann M, Berthelot C, Billard P, Klebensberger J. Rare Earth Element (REE)-Dependent Growth of Pseudomonas putida KT2440 Relies on the ABC-Transporter PedA1A2BC and Is Influenced by Iron Availability. Front Microbiol 2019; 10:2494. [PMID: 31736923 PMCID: PMC6839425 DOI: 10.3389/fmicb.2019.02494] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Accepted: 10/16/2019] [Indexed: 01/09/2023] Open
Abstract
In the soil-dwelling organism Pseudomonas putida KT2440, the rare earth element (REE)-utilizing, and pyrroloquinoline quinone (PQQ)-dependent ethanol dehydrogenase PedH is part of a periplasmic oxidation system that is vital for growth on various alcoholic volatiles. Production of PedH and its Ca2+-dependent counterpart PedE is inversely regulated in response to lanthanide (Ln3+) bioavailability, a mechanism termed the REE-switch. In the present study, we demonstrate that copper, zinc, and in particular, iron availability influences this regulation in a pyoverdine-independent manner by increasing the minimal Ln3+ concentration required for the REE-switch to occur by several orders of magnitude. A combined genetic and physiological approach reveals that an ABC-type transporter system encoded by the gene cluster pedA1A2BC is essential for efficient growth on 2-phenylethanol with low (nanomolar) Ln3+ concentrations. In the absence of pedA1A2BC, a ∼100-fold higher La3+-concentration is needed for PedH-dependent growth but not for the ability to repress growth based on PedE activity. From these results, we conclude that cytoplasmic uptake of lanthanides through PedA1A2BC is essential to facilitate REE-dependent growth on 2-phenylethanol under environmental conditions with poor REE bioavailability. Our data further suggest that the La3+/Fe2+/3+ ratio impacts the REE-switch through the mismetallation of putative La3+-binding proteins, such as the sensor histidine kinase PedS2, in the presence of high iron concentrations. As such, this study provides an example for the complexity of bacteria-metal interactions and highlights the importance of medium compositions when studying physiological traits in vitro in particular in regard to REE-dependent phenomena.
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Affiliation(s)
- Matthias Wehrmann
- Department of Technical Biochemistry, Institute of Biochemistry and Technical Biochemistry, University of Stuttgart, Stuttgart, Germany
| | - Charlotte Berthelot
- LIEC UMR7360, Faculté des Sciences et Technologies, Université de Lorraine, Vandoeuvre-lès-Nancy, France
- CNRS, LIEC UMR7360, Faculté des Sciences et Technologies, Vandoeuvre-lès-Nancy, France
| | - Patrick Billard
- LIEC UMR7360, Faculté des Sciences et Technologies, Université de Lorraine, Vandoeuvre-lès-Nancy, France
- CNRS, LIEC UMR7360, Faculté des Sciences et Technologies, Vandoeuvre-lès-Nancy, France
| | - Janosch Klebensberger
- Department of Technical Biochemistry, Institute of Biochemistry and Technical Biochemistry, University of Stuttgart, Stuttgart, Germany
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Quorum Sensing Regulators AphA and OpaR Control Expression of the Operon Responsible for Biosynthesis of the Compatible Solute Ectoine. Appl Environ Microbiol 2019; 85:AEM.01543-19. [PMID: 31519665 DOI: 10.1128/aem.01543-19] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Accepted: 09/09/2019] [Indexed: 12/14/2022] Open
Abstract
To maintain the turgor pressure of the cell under high osmolarity, bacteria accumulate small organic compounds called compatible solutes, either through uptake or biosynthesis. Vibrio parahaemolyticus, a marine halophile and an important human and shellfish pathogen, has to adapt to abiotic stresses such as changing salinity. Vibrio parahaemolyticus contains multiple compatible solute biosynthesis and transporter systems, including the ectABC-asp_ect operon required for de novo ectoine biosynthesis. Ectoine biosynthesis genes are present in many halotolerant bacteria; however, little is known about the mechanism of regulation. We investigated the role of the quorum sensing master regulators OpaR and AphA in ect gene regulation. In an opaR deletion mutant, transcriptional reporter assays demonstrated that ect expression was induced. In an electrophoretic mobility shift assay, we showed that purified OpaR bound to the ect regulatory region indicating direct regulation by OpaR. In an aphA deletion mutant, expression of the ect genes was repressed, and purified AphA bound upstream of the ect genes. These data indicate that AphA is a direct positive regulator. CosR, a Mar-type regulator known to repress ect expression in V. cholerae, was found to repress ect expression in V. parahaemolyticus In addition, we identified a feed-forward loop in which OpaR is a direct activator of cosR, while AphA is an indirect activator of cosR Regulation of the ectoine biosynthesis pathway via this feed-forward loop allows for precise control of ectoine biosynthesis genes throughout the growth cycle to maximize fitness.IMPORTANCE Accumulation of compatible solutes within the cell allows bacteria to maintain intracellular turgor pressure and prevent water efflux. De novo ectoine production is widespread among bacteria, and the ect operon encoding the biosynthetic enzymes is induced by increased salinity. Here, we demonstrate that the quorum sensing regulators AphA and OpaR integrate with the osmotic stress response pathway to control transcription of ectoine biosynthesis genes in V. parahaemolyticus We uncovered a feed-forward loop wherein quorum sensing regulators also control transcription of cosR, which encodes a negative regulator of the ect operon. Moreover, our data suggest that this mechanism may be widespread in Vibrio species.
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225
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Taler K, Weiss O, Rotem-Bamberger S, Rubinstein AM, Seritrakul P, Gross JM, Inbal A. Lysyl hydroxylase 3 is required for normal lens capsule formation and maintenance of lens epithelium integrity and fate. Dev Biol 2019; 458:177-188. [PMID: 31669351 DOI: 10.1016/j.ydbio.2019.10.020] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 10/03/2019] [Accepted: 10/20/2019] [Indexed: 02/06/2023]
Abstract
Lens abnormalities are a major cause of reduced vision and blindness. One mechanism that can lead to reduced lens transparency, i.e. cataract, is abnormal behavior of lens epithelial cells (LECs), the precursors of the transparent lens fiber cells. Here we describe a zebrafish mutation causing the embryonic lens epithelium to generate cellular masses comprising partially differentiated lens fiber cells. We identify the mutant gene as plod3, which encodes for Lysyl hydroxylase 3 (Lh3), an enzyme essential for modification of collagens, including Collagen IV, a main component of the lens capsule. We show that plod3-deficient lenses have abnormal lens epithelium from an early developmental stage, as well as abnormal lens capsules. Subsequently, upregulation of TGFβ signaling takes place, which drives the formation of lens epithelial cellular masses. We identify a similar phenotype in Collagen IVα5-deficient embryos, suggesting a key role for the defective lens capsule in the pathogenesis. We propose that plod3 and col4a5 mutant zebrafish can serve as useful models for better understanding the biology of LECs during embryonic development and in formation of lens epithelium-derived cataract.
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Affiliation(s)
- Kineret Taler
- Department of Medical Neurobiology, Institute for Medical Research - Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Omri Weiss
- Department of Medical Neurobiology, Institute for Medical Research - Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Shahar Rotem-Bamberger
- Department of Medical Neurobiology, Institute for Medical Research - Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Ariel M Rubinstein
- Department of Medical Neurobiology, Institute for Medical Research - Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Pawat Seritrakul
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Jeffrey M Gross
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Adi Inbal
- Department of Medical Neurobiology, Institute for Medical Research - Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel.
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226
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Preparation of virus-like particle mimetic nanovesicles displaying the S protein of Middle East respiratory syndrome coronavirus using insect cells. J Biotechnol 2019; 306:177-184. [PMID: 31614169 PMCID: PMC7114102 DOI: 10.1016/j.jbiotec.2019.10.007] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Revised: 09/26/2019] [Accepted: 10/07/2019] [Indexed: 11/25/2022]
Abstract
Virus-like particle mimetic nanovesicles were prepared using insect cells. Surfactant treatment or mechanical extrusion make it possible to display the S protein on VLPs. Mechanical extrusion is more effective way to display the S protein on VLPs. S protein on the surface of nanovesicles were confirmed by immuno-TEM. The purified S protein (SοTM) has the ability to bind a receptor of MERS-CoV.
Middle East respiratory syndrome coronavirus (MERS-CoV) first emerged in 2012, and over 2000 infections and 800 deaths have been confirmed in 27 countries. However, to date, no commercial vaccine is available. In this study, structural proteins of MERS-CoV were expressed in silkworm larvae and Bm5 cells for the development of vaccine candidates against MERS-CoV and diagnostic methods. The spike (S) protein of MERS-CoV lacking its transmembrane and cytoplasmic domains (SΔTM) was secreted into the hemolymph of silkworm larvae using a bombyxin signal peptide and purified using affinity chromatography. The purified SΔTM forms small nanoparticles as well as the full-length S protein and has the ability to bind human dipeptidyl peptidase 4 (DPP4), which is a receptor of MERS-CoV. These results indicate that bioactive SΔTM was expressed in silkworm larvae. To produce MERS-CoV-like particles (MERS-CoV-LPs), the coexpression of spike proteins was performed in Bm5 cells and envelope (E) and membrane (M) proteins secreted E and M proteins extracellularly, suggesting that MERS-CoV-LPs may be formed. However, this S protein was not displayed on virus-like particles (VLPs) even though E and M proteins were secreted into the culture supernatant. By surfactant treatment and mechanical extrusion using S protein- or three structural protein-expressing Bm5 cells, S protein-displaying nanovesicles with diameters of approximately 100-200 nm were prepared and confirmed by immuno-TEM. The mechanical extrusion method is favorable for obtaining uniform recombinant protein-displaying nanovesicles from cultured cells. The purified SΔTM from silkworm larvae and S protein-displaying nanovesicles from Bm5 cells may lead to the development of nanoparticle-based vaccines against MERS-CoV and the diagnostic detection of MERS-CoV.
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227
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A New Escherichia coli Entry Vector Series (pIIS18) for Seamless Gene Cloning Using Type IIS Restriction Enzymes. Microbiol Resour Announc 2019; 8:8/41/e00323-19. [PMID: 31601653 PMCID: PMC6787310 DOI: 10.1128/mra.00323-19] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A series of new Escherichia coli entry vectors (pIIS18-SapI, pIIS18-BsmBI, pIIS18-BsaI, pIIS18-BfuAI-1, and pIIS18-BfuAI-2) was constructed based on a modified pUC18 backbone, which carried newly designed multiple cloning sites, consisting of two facing type IIS enzyme cleavage sites and one blunt-end enzyme cleavage site. These vectors are useful for seamless gene cloning. A series of new Escherichia coli entry vectors (pIIS18-SapI, pIIS18-BsmBI, pIIS18-BsaI, pIIS18-BfuAI-1, and pIIS18-BfuAI-2) was constructed based on a modified pUC18 backbone, which carried newly designed multiple cloning sites, consisting of two facing type IIS enzyme cleavage sites and one blunt-end enzyme cleavage site. These vectors are useful for seamless gene cloning.
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228
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Shi B, Ma T, Ye Z, Li X, Huang Y, Zhou Z, Ding Y, Deng Z, Liu T. Systematic Metabolic Engineering of Saccharomyces cerevisiae for Lycopene Overproduction. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2019; 67:11148-11157. [PMID: 31532654 DOI: 10.1021/acs.jafc.9b04519] [Citation(s) in RCA: 73] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Lycopene is widely used in foods, cosmetics, nutritional supplements, and pharmaceuticals. Microbial production of lycopene has been intensively studied. However, there are few systematic engineering studies on Saccharomyces cerevisiae aimed at achieving high-yield lycopene production. In the current study, by employing a systematic optimization strategy, we screened the key lycopene biosynthetic genes, crtE, crtB, and crtI, from diverse organisms. By adjusting the copy number of these three key genes, knocking out endogenous bypass genes, increasing the supply of the precursor acetyl-CoA, balancing NADPH utilization, and regulating the GAL-inducible system, we constructed a high-yield lycopene-producing strain BS106, which can produce 310 mg/L lycopene in shake-flask fermentation, with gene expression controlled by glucose. In optimized two-stage fed-batch fermentation, BS106 produced 3.28 g/L lycopene in a 7 L fermenter, which is the highest concentration achieved in S. cerevisiae to date. It will decrease the consumption of tomatoes for lycopene extraction and increase the market supply of lycopene.
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Affiliation(s)
- Bin Shi
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education and School of Pharmaceutical Sciences , Wuhan University , Wuhan 430072 , China
| | - Tian Ma
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education and School of Pharmaceutical Sciences , Wuhan University , Wuhan 430072 , China
| | - Ziling Ye
- J1 Biotech Co., Ltd. , Wuhan 430075 , China
| | - Xiaowei Li
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education and School of Pharmaceutical Sciences , Wuhan University , Wuhan 430072 , China
| | - Yanglei Huang
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education and School of Pharmaceutical Sciences , Wuhan University , Wuhan 430072 , China
| | - Zhiyi Zhou
- J1 Biotech Co., Ltd. , Wuhan 430075 , China
| | - Yunkun Ding
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education and School of Pharmaceutical Sciences , Wuhan University , Wuhan 430072 , China
| | - Zixin Deng
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education and School of Pharmaceutical Sciences , Wuhan University , Wuhan 430072 , China
| | - Tiangang Liu
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education and School of Pharmaceutical Sciences , Wuhan University , Wuhan 430072 , China
- Hubei Engineering Laboratory for Synthetic Microbiology , Wuhan Institute of Biotechnology , Wuhan 430075 , China
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229
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Mu R, Shinde P, Zou Z, Kreth J, Merritt J. Examining the Protein Interactome and Subcellular Localization of RNase J2 Complexes in Streptococcus mutans. Front Microbiol 2019; 10:2150. [PMID: 31620106 PMCID: PMC6759994 DOI: 10.3389/fmicb.2019.02150] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 09/02/2019] [Indexed: 12/18/2022] Open
Abstract
Regulated RNA turnover is vital for the control of gene expression in all cellular life. In Escherichia coli, this process is largely controlled by a stable degradosome complex containing RNase E and a variety of additional enzymes. In the Firmicutes phylum, species lack RNase E and often encode the paralogous enzymes RNase J1 and RNase J2. Unlike RNase J1, surprisingly little is known about the regulatory function and protein interactions of RNase J2, despite being a central pleiotropic regulator for the streptococci and other closely related organisms. Using crosslink coimmunoprecipitation in Streptococcus mutans, we have identified the major proteins found within RNase J2 protein complexes located in the cytoplasm and at the cell membrane. In both subcellular fractions, RNase J2 exhibited the most robust interactions with RNase J1, while additional transient and/or weaker "degradosome-like" interactions were also detected. In addition, RNase J2 exhibits multiple novel interactions that have not been previously reported for any RNase J proteins, some of which were highly biased for either the cytoplasmic or membrane fractions. We also determined that the RNase J2 C-terminal domain (CTD) encodes a structure that is likely conserved among RNase J enzymes and may have an analogous function to the C-terminal portion of RNase E. While we did observe a number of parallels between the RNase J2 interactome and the E. coli degradosome paradigm, our results suggest that S. mutans degradosomes are either unlikely to exist or are quite distinct from those of E. coli.
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Affiliation(s)
- Rong Mu
- Department of Restorative Dentistry, School of Dentistry, Oregon Health and Science University, Portland, OR, United States
| | - Pushkar Shinde
- Emory College of Arts and Sciences, Atlanta, GA, United States
| | - Zhengzhong Zou
- Department of Restorative Dentistry, School of Dentistry, Oregon Health and Science University, Portland, OR, United States
| | - Jens Kreth
- Department of Restorative Dentistry, School of Dentistry, Oregon Health and Science University, Portland, OR, United States.,Department of Molecular Microbiology and Immunology, School of Medicine, Oregon Health and Science University, Portland, OR, United States
| | - Justin Merritt
- Department of Restorative Dentistry, School of Dentistry, Oregon Health and Science University, Portland, OR, United States.,Department of Molecular Microbiology and Immunology, School of Medicine, Oregon Health and Science University, Portland, OR, United States
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230
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Modular enzyme assembly for enhanced cascade biocatalysis and metabolic flux. Nat Commun 2019; 10:4248. [PMID: 31534134 PMCID: PMC6751169 DOI: 10.1038/s41467-019-12247-w] [Citation(s) in RCA: 124] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Accepted: 08/28/2019] [Indexed: 12/21/2022] Open
Abstract
Enzymatic reactions in living cells are highly dynamic but simultaneously tightly regulated. Enzyme engineers seek to construct multienzyme complexes to prevent intermediate diffusion, to improve product yield, and to control the flux of metabolites. Here we choose a pair of short peptide tags (RIAD and RIDD) to create scaffold-free enzyme assemblies to achieve these goals. In vitro, assembling enzymes in the menaquinone biosynthetic pathway through RIAD-RIDD interaction yields protein nanoparticles with varying stoichiometries, sizes, geometries, and catalytic efficiency. In Escherichia coli, assembling the last enzyme of the upstream mevalonate pathway with the first enzyme of the downstream carotenoid pathway leads to the formation of a pathway node, which increases carotenoid production by 5.7 folds. The same strategy results in a 58% increase in lycopene production in engineered Saccharomyces cerevisiae. This work presents a simple strategy to impose metabolic control in biosynthetic microbe factories.
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231
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Control of Type III Secretion System Effector/Chaperone Ratio Fosters Pathogen Adaptation to Host-Adherent Lifestyle. mBio 2019; 10:mBio.02074-19. [PMID: 31530678 PMCID: PMC6751064 DOI: 10.1128/mbio.02074-19] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Host colonization by extracellular pathogens often entails the transition from a planktonic lifestyle to a host-attached state. Enteropathogenic E. coli (EPEC), a Gram-negative pathogen, attaches to the intestinal epithelium of the host and employs a type III secretion system (T3SS) to inject effector proteins into the cytoplasm of infected cells. The most abundant effector protein injected is Tir, whose translocation is dependent on the Tir-bound chaperon CesT. Upon Tir injection, the liberated CesT binds to and inhibits the posttranscriptional regulator CsrA, resulting in reprogramming of gene expression in the host-attached bacteria. Thus, adaptation to the host-attached state involves dynamic remodeling of EPEC gene expression, which is mediated by the relative levels of Tir and CesT. Fluctuating from the optimal Tir/CesT ratio results in a decrease in EPEC virulence. Here we elucidate a posttranscriptional circuit that prevents sharp variations from this ratio, thus improving host colonization. The transition from a planktonic lifestyle to a host-attached state is often critical for bacterial virulence. Upon attachment to host cells, enteropathogenic Escherichia coli (EPEC) employs a type III secretion system (T3SS) to inject into the host cells ∼20 effector proteins, including Tir. CesT, which is encoded from the same operon downstream of tir, is a Tir-bound chaperone that facilitates Tir translocation. Upon Tir translocation, the liberated CesT remains in the bacterial cytoplasm and antagonizes the posttranscriptional regulator CsrA, thus eliciting global regulation in the infecting pathogen. Importantly, tight control of the Tir/CesT ratio is vital, since an uncontrolled surge in free CesT levels may repress CsrA in an untimely manner, thus abrogating colonization. We investigated how fluctuations in Tir translation affect the regulation of this ratio. By creating mutations that cause the premature termination of Tir translation, we revealed that the untranslated tir mRNA becomes highly unstable, resulting in a rapid drop in cesT mRNA levels and, thus, CesT levels. This mechanism couples Tir and CesT levels to ensure a stable Tir/CesT ratio. Our results expose an additional level of regulation that enhances the efficacy of the initial interaction of EPEC with the host cell, providing a better understanding of the bacterial switch from the planktonic to the cell-adherent lifestyle.
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232
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Programmed assembly of long DNA synthons: design, mechanism, and online monitoring. Appl Microbiol Biotechnol 2019; 103:9103-9117. [PMID: 31515595 DOI: 10.1007/s00253-019-10099-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Revised: 08/07/2019] [Accepted: 08/21/2019] [Indexed: 10/26/2022]
Abstract
Synthesis of custom de novo DNA sequences is highly demanded by fast-growing field of synthetic biology. Usually DNA sequences with length more than 1 kb are assembled from smaller synthetic DNA fragments (synthons) obtained by PCR assembly. The ability to synthesize longer synthons sufficiently reduces efforts and time for DNA synthesis. We developed a novel rational oligonucleotide design and programmed approach for the assembly of synthetic DNA synthons up to 1550 bp. The developed procedure was thoroughly investigated by synthesis of cholesterol oxidase gene from Streptomyces lavendulae (1544 bp). Our approach is based on combined design, oligonucleotide concentration gradient, and specialized assembly program that directs assembly reaction to full-length gene in a stepwise manner. The process includes conventional thermodynamically balanced assembly, thermodynamically balanced inside-out elongation, and further amplification. The ability of DNA polymerase to perform programmed assembly is highly influenced by the presence of 5' → 3'-exonuclease activity. Oligonucleotide probing of PCR assembly products allowed us to shed light on the nature of high molecular weight spurious by-products and to understand the mechanism of their formation. For the first time, we applied light scattering techniques for tracking of oligonucleotide annealing, analysis of gene assembly products, and even for real-time monitoring of gene assembly process.
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233
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Sanchez JC, Ollodart A, Large CRL, Clough C, Alvino GM, Tsuchiya M, Crane M, Kwan EX, Kaeberlein M, Dunham MJ, Raghuraman MK, Brewer BJ. Phenotypic and Genotypic Consequences of CRISPR/Cas9 Editing of the Replication Origins in the rDNA of Saccharomyces cerevisiae. Genetics 2019; 213:229-249. [PMID: 31292210 PMCID: PMC6727806 DOI: 10.1534/genetics.119.302351] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 06/28/2019] [Indexed: 12/15/2022] Open
Abstract
The complex structure and repetitive nature of eukaryotic ribosomal DNA (rDNA) is a challenge for genome assembly, thus the consequences of sequence variation in rDNA remain unexplored. However, renewed interest in the role that rDNA variation may play in diverse cellular functions, aside from ribosome production, highlights the need for a method that would permit genetic manipulation of the rDNA. Here, we describe a clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9-based strategy to edit the rDNA locus in the budding yeast Saccharomyces cerevisiae, developed independently but similar to one developed by others. Using this approach, we modified the endogenous rDNA origin of replication in each repeat by deleting or replacing its consensus sequence. We characterized the transformants that have successfully modified their rDNA locus and propose a mechanism for how CRISPR/Cas9-mediated editing of the rDNA occurs. In addition, we carried out extended growth and life span experiments to investigate the long-term consequences that altering the rDNA origin of replication have on cellular health. We find that long-term growth of the edited clones results in faster-growing suppressors that have acquired segmental aneusomy of the rDNA-containing region of chromosome XII or aneuploidy of chromosomes XII, II, or IV. Furthermore, we find that all edited isolates suffer a reduced life span, irrespective of their levels of extrachromosomal rDNA circles. Our work demonstrates that it is possible to quickly, efficiently, and homogeneously edit the rDNA origin via CRISPR/Cas9.
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Affiliation(s)
- Joseph C Sanchez
- Department of Genome Sciences, University of Washington, Seattle, Washington 98195
- Molecular and Cellular Biology Program, University of Washington, Seattle, Washington 98195
- Bioscience Division, Los Alamos National Laboratory, Los Alamos New Mexico 87544
| | - Anja Ollodart
- Department of Genome Sciences, University of Washington, Seattle, Washington 98195
- Molecular and Cellular Biology Program, University of Washington, Seattle, Washington 98195
| | - Christopher R L Large
- Department of Genome Sciences, University of Washington, Seattle, Washington 98195
- Molecular and Cellular Biology Program, University of Washington, Seattle, Washington 98195
| | - Courtnee Clough
- Department of Genome Sciences, University of Washington, Seattle, Washington 98195
- Molecular and Cellular Biology Program, University of Washington, Seattle, Washington 98195
| | - Gina M Alvino
- Department of Genome Sciences, University of Washington, Seattle, Washington 98195
| | - Mitsuhiro Tsuchiya
- Department of Pathology, University of Washington, Seattle, Washington 98195
| | - Matthew Crane
- Department of Pathology, University of Washington, Seattle, Washington 98195
| | - Elizabeth X Kwan
- Department of Genome Sciences, University of Washington, Seattle, Washington 98195
| | - Matt Kaeberlein
- Department of Genome Sciences, University of Washington, Seattle, Washington 98195
- Molecular and Cellular Biology Program, University of Washington, Seattle, Washington 98195
- Department of Pathology, University of Washington, Seattle, Washington 98195
| | - Maitreya J Dunham
- Department of Genome Sciences, University of Washington, Seattle, Washington 98195
- Molecular and Cellular Biology Program, University of Washington, Seattle, Washington 98195
| | - M K Raghuraman
- Department of Genome Sciences, University of Washington, Seattle, Washington 98195
| | - Bonita J Brewer
- Department of Genome Sciences, University of Washington, Seattle, Washington 98195
- Molecular and Cellular Biology Program, University of Washington, Seattle, Washington 98195
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234
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Falo-Sanjuan J, Lammers NC, Garcia HG, Bray SJ. Enhancer Priming Enables Fast and Sustained Transcriptional Responses to Notch Signaling. Dev Cell 2019; 50:411-425.e8. [PMID: 31378591 PMCID: PMC6706658 DOI: 10.1016/j.devcel.2019.07.002] [Citation(s) in RCA: 64] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Revised: 05/23/2019] [Accepted: 07/01/2019] [Indexed: 11/23/2022]
Abstract
Information from developmental signaling pathways must be accurately decoded to generate transcriptional outcomes. In the case of Notch, the intracellular domain (NICD) transduces the signal directly to the nucleus. How enhancers decipher NICD in the real time of developmental decisions is not known. Using the MS2-MCP system to visualize nascent transcripts in single cells in Drosophila embryos, we reveal how two target enhancers read Notch activity to produce synchronized and sustained profiles of transcription. By manipulating the levels of NICD and altering specific motifs within the enhancers, we uncover two key principles. First, increased NICD levels alter transcription by increasing duration rather than frequency of transcriptional bursts. Second, priming of enhancers by tissue-specific transcription factors is required for NICD to confer synchronized and sustained activity; in their absence, transcription is stochastic and bursty. The dynamic response of an individual enhancer to NICD thus differs depending on the cellular context.
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Affiliation(s)
- Julia Falo-Sanjuan
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3DY, UK
| | | | - Hernan G Garcia
- Biophysics Graduate Group, UC Berkeley, Berkeley, CA 94720, USA; Department of Physics, UC Berkeley, Berkeley, CA 94720, USA; Department of Molecular and Cell Biology, UC Berkeley, Berkeley, CA 94720, USA; Institute for Quantitative Biosciences-QB3, UC Berkeley, Berkeley, CA 94720, USA
| | - Sarah J Bray
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3DY, UK.
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235
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Graf M, Haas T, Müller F, Buchmann A, Harm-Bekbenbetova J, Freund A, Nieß A, Persicke M, Kalinowski J, Blombach B, Takors R. Continuous Adaptive Evolution of a Fast-Growing Corynebacterium glutamicum Strain Independent of Protocatechuate. Front Microbiol 2019; 10:1648. [PMID: 31447790 PMCID: PMC6691914 DOI: 10.3389/fmicb.2019.01648] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2019] [Accepted: 07/03/2019] [Indexed: 12/30/2022] Open
Abstract
Corynebacterium glutamicum is a commonly applied host for the industrial production of amino acids. While valued for its robustness, it is somewhat inferior to competing strains such as Escherichia coli because of the relatively low growth rate of 0.40 h-1 in synthetic, industrial media. Accordingly, adaptive laboratory evolution (ALE) experiments were performed in continuous cultivation mode to select for a growth-improved host. To ensure industrial attractiveness, this ALE study aimed at a reduction of dependency on costly growth-boosting additives such as protocatechuate (PCA) or complex media supplements. Consequently, double selection pressures were installed consisting of a steady increase in growth rate demands and a parallel reduction of complex medium fractions. Selection yielded C. glutamicum EVO5 achieving 0.54 h-1 and 1.03 gGlc gCDW -1 h-1 in minimal medium without abovementioned supplements. Sequencing revealed 10 prominent mutations, three of them in key regulator genes.
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Affiliation(s)
- Michaela Graf
- Institute of Biochemical Engineering, University of Stuttgart, Stuttgart, Germany
| | - Thorsten Haas
- Institute of Biochemical Engineering, University of Stuttgart, Stuttgart, Germany
| | - Felix Müller
- Institute of Biochemical Engineering, University of Stuttgart, Stuttgart, Germany
| | - Anina Buchmann
- Institute of Biochemical Engineering, University of Stuttgart, Stuttgart, Germany
| | | | - Andreas Freund
- Institute of Biochemical Engineering, University of Stuttgart, Stuttgart, Germany
| | - Alexander Nieß
- Institute of Biochemical Engineering, University of Stuttgart, Stuttgart, Germany
| | - Marcus Persicke
- Center for Biotechnology (CeBiTec), Bielefeld University, Bielefeld, Germany
| | - Jörn Kalinowski
- Center for Biotechnology (CeBiTec), Bielefeld University, Bielefeld, Germany
| | - Bastian Blombach
- Institute of Biochemical Engineering, University of Stuttgart, Stuttgart, Germany
- Microbial Biotechnology, Campus Straubing for Biotechnology and Sustainability, Technical University of Munich, Straubing, Germany
| | - Ralf Takors
- Institute of Biochemical Engineering, University of Stuttgart, Stuttgart, Germany
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236
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Modular and Integrative Vectors for Synthetic Biology Applications in Streptomyces spp. Appl Environ Microbiol 2019; 85:AEM.00485-19. [PMID: 31175189 DOI: 10.1128/aem.00485-19] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Accepted: 05/22/2019] [Indexed: 01/28/2023] Open
Abstract
With the development of synthetic biology in the field of (actinobacterial) specialized metabolism, new tools are needed for the design or refactoring of biosynthetic gene clusters. If libraries of synthetic parts (such as promoters or ribosome binding sites) and DNA cloning methods have been developed, to our knowledge, not many vectors designed for the flexible cloning of biosynthetic gene clusters have been constructed. We report here the construction of a set of 12 standardized and modular vectors designed to afford the construction or the refactoring of biosynthetic gene clusters in Streptomyces species, using a large panel of cloning methods. Three different resistance cassettes and four orthogonal integration systems are proposed. In addition, FLP recombination target sites were incorporated to allow the recycling of antibiotic markers and to limit the risks of unwanted homologous recombination in Streptomyces strains when several vectors are used. The functionality and proper integration of the vectors in three commonly used Streptomyces strains, as well as the functionality of the Flp-catalyzed excision, were all confirmed. To illustrate some possible uses of our vectors, we refactored the albonoursin gene cluster from Streptomyces noursei using the BioBrick assembly method. We also used the seamless ligase chain reaction cloning method to assemble a transcription unit in one of the vectors and genetically complement a mutant strain.IMPORTANCE One of the strategies employed today to obtain new bioactive molecules with potential applications for human health (for example, antimicrobial or anticancer agents) is synthetic biology. Synthetic biology is used to biosynthesize new unnatural specialized metabolites or to force the expression of otherwise silent natural biosynthetic gene clusters. To assist the development of synthetic biology in the field of specialized metabolism, we constructed and are offering to the community a set of vectors that were intended to facilitate DNA assembly and integration in actinobacterial chromosomes. These vectors are compatible with various DNA cloning and assembling methods. They are standardized and modular, allowing the easy exchange of a module by another one of the same nature. Although designed for the assembly or the refactoring of specialized metabolite gene clusters, they have a broader potential utility, for example, for protein production or genetic complementation.
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237
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Brunet YR, Wang X, Rudner DZ. SweC and SweD are essential co-factors of the FtsEX-CwlO cell wall hydrolase complex in Bacillus subtilis. PLoS Genet 2019; 15:e1008296. [PMID: 31437162 PMCID: PMC6705773 DOI: 10.1371/journal.pgen.1008296] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Accepted: 07/08/2019] [Indexed: 01/10/2023] Open
Abstract
The peptidoglycan (PG) sacculus is composed of long glycan strands cross-linked together by short peptides forming a covalently closed meshwork that protects the bacterial cell from osmotic lysis and specifies its shape. PG hydrolases play essential roles in remodeling this three-dimensional network during growth and division but how these autolytic enzymes are regulated remains poorly understood. The FtsEX ABC transporter-like complex has emerged as a broadly conserved regulatory module in controlling cell wall hydrolases in diverse bacterial species. In most characterized examples, this complex regulates distinct PG hydrolases involved in cell division and is intimately associated with the cytokinetic machinery called the divisome. However, in the gram-positive bacterium Bacillus subtilis the FtsEX complex is required for cell wall elongation where it regulates the PG hydrolase CwlO that acts along the lateral cell wall. To investigate whether additional factors are required for FtsEX function outside the divisome, we performed a synthetic lethal screen taking advantage of the conditional essentiality of CwlO. This screen identified two uncharacterized factors (SweD and SweC) that are required for CwlO activity. We demonstrate that these proteins reside in a membrane complex with FtsX and that amino acid substitutions in residues adjacent to the ATPase domain of FtsE partially bypass the requirement for them. Collectively our data indicate that SweD and SweC function as essential co-factors of FtsEX in controlling CwlO during cell wall elongation. We propose that factors analogous to SweDC function to support FtsEX activity outside the divisome in other bacteria.
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Affiliation(s)
- Yannick R. Brunet
- Department of Microbiology, Harvard Medical School, Boston, MA, United States of America
| | - Xindan Wang
- Department of Microbiology, Harvard Medical School, Boston, MA, United States of America
| | - David Z. Rudner
- Department of Microbiology, Harvard Medical School, Boston, MA, United States of America
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238
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Grishin DV, Samoilenko VA, Gladilina YA, Zhdanov DD, Pokrovskaya MV, Aleksandrova SS, Pokrovsky VS, Sokolov NN. Effect of Heterologous Expression of Chemotaxis Proteins from Genus Thermotoga on the Growth Kinetics of Escherichia coli Cells. Bull Exp Biol Med 2019; 167:375-379. [PMID: 31346881 DOI: 10.1007/s10517-019-04530-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Indexed: 11/30/2022]
Abstract
In the process of optimization of heterologous expression of thermostable chemotaxis proteins CheW and CheY as industrially useful polypeptides, their direct influence on the cell growth kinetics and morphology of Escherichia coli was observed. CheW and CheY of bacteria of the genus Thermotoga, being expressed in recombinant form in E. coli cells, are involved in the corresponding signal pathways of the mesophilic microorganisms. The effects of such involvement in the metabolism of "host" cells are extremely diverse: from rapid aging of the culture to elongation of the stationary growth phase. We also discuss the mechanisms of the influence of the heterologous chemotaxis proteins on cells, their positive and negative effects, as well as potential applications in industry and biomedicine.
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Affiliation(s)
- D V Grishin
- V. N. Orekhovich Research Institute of Biomedical Chemistry, Moscow, Russia.
| | - V A Samoilenko
- G. K. Skryabin Institute of Biochemistry and Physiology of Microorganisms, Russian Academy of Sciences, Pushchino, Moscow Region, Russia
| | - Yu A Gladilina
- V. N. Orekhovich Research Institute of Biomedical Chemistry, Moscow, Russia
| | - D D Zhdanov
- V. N. Orekhovich Research Institute of Biomedical Chemistry, Moscow, Russia
| | - M V Pokrovskaya
- V. N. Orekhovich Research Institute of Biomedical Chemistry, Moscow, Russia
| | - S S Aleksandrova
- V. N. Orekhovich Research Institute of Biomedical Chemistry, Moscow, Russia
| | - V S Pokrovsky
- V. N. Orekhovich Research Institute of Biomedical Chemistry, Moscow, Russia
| | - N N Sokolov
- V. N. Orekhovich Research Institute of Biomedical Chemistry, Moscow, Russia
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239
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Tian L, Conway PM, Cervenka ND, Cui J, Maloney M, Olson DG, Lynd LR. Metabolic engineering of Clostridium thermocellum for n-butanol production from cellulose. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:186. [PMID: 31367231 PMCID: PMC6652007 DOI: 10.1186/s13068-019-1524-6] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Accepted: 07/05/2019] [Indexed: 05/15/2023]
Abstract
BACKGROUND Biofuel production from plant cell walls offers the potential for sustainable and economically attractive alternatives to petroleum-based products. In particular, Clostridium thermocellum is a promising host for consolidated bioprocessing (CBP) because of its strong native ability to ferment cellulose. RESULTS We tested 12 different enzyme combinations to identify an n-butanol pathway with high titer and thermostability in C. thermocellum. The best producing strain contained the thiolase-hydroxybutyryl-CoA dehydrogenase-crotonase (Thl-Hbd-Crt) module from Thermoanaerobacter thermosaccharolyticum, the trans-enoyl-CoA reductase (Ter) enzyme from Spirochaeta thermophila and the butyraldehyde dehydrogenase and alcohol dehydrogenase (Bad-Bdh) module from Thermoanaerobacter sp. X514 and was able to produce 88 mg/L n-butanol. The key enzymes from this combination were further optimized by protein engineering. The Thl enzyme was engineered by introducing homologous mutations previously identified in Clostridium acetobutylicum. The Hbd and Ter enzymes were engineered for changes in cofactor specificity using the CSR-SALAD algorithm to guide the selection of mutations. The cofactor engineering of Hbd had the unexpected side effect of also increasing activity by 50-fold. CONCLUSIONS Here we report engineering C. thermocellum to produce n-butanol. Our initial pathway designs resulted in low levels (88 mg/L) of n-butanol production. By engineering the protein sequence of key enzymes in the pathway, we increased the n-butanol titer by 2.2-fold. We further increased n-butanol production by adding ethanol to the growth media. By combining all these improvements, the engineered strain was able to produce 357 mg/L of n-butanol from cellulose within 120 h.
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Affiliation(s)
- Liang Tian
- Thayer School of Engineering, Dartmouth College, Hanover, NH 03755 USA
- Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN 37830 USA
| | | | | | - Jingxuan Cui
- Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN 37830 USA
- Department of Biological Sciences, Dartmouth College, Hanover, NH 03755 USA
| | - Marybeth Maloney
- Thayer School of Engineering, Dartmouth College, Hanover, NH 03755 USA
- Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN 37830 USA
| | - Daniel G. Olson
- Thayer School of Engineering, Dartmouth College, Hanover, NH 03755 USA
- Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN 37830 USA
| | - Lee R. Lynd
- Thayer School of Engineering, Dartmouth College, Hanover, NH 03755 USA
- Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN 37830 USA
- Department of Biological Sciences, Dartmouth College, Hanover, NH 03755 USA
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240
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Gumkowski JD, Martinie RJ, Corrigan PS, Pan J, Bauerle MR, Almarei M, Booker SJ, Silakov A, Krebs C, Boal AK. Analysis of RNA Methylation by Phylogenetically Diverse Cfr Radical S-Adenosylmethionine Enzymes Reveals an Iron-Binding Accessory Domain in a Clostridial Enzyme. Biochemistry 2019; 58:3169-3184. [PMID: 31246421 DOI: 10.1021/acs.biochem.9b00197] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Cfr is a radical S-adenosylmethionine (SAM) RNA methylase linked to multidrug antibiotic resistance in bacterial pathogens. It catalyzes a chemically challenging C-C bond-forming reaction to methylate C8 of A2503 (Escherichia coli numbering) of 23S rRNA during ribosome assembly. The cfr gene has been identified as a mobile genetic element in diverse bacteria and in the genome of select Bacillales and Clostridiales species. Despite the importance of Cfr, few representatives have been purified and characterized in vitro. Here we show that Cfr homologues from Bacillus amyloliquefaciens, Enterococcus faecalis, Paenibacillus lautus, and Clostridioides difficile act as C8 adenine RNA methylases in biochemical assays. C. difficile Cfr contains an additional Cys-rich C-terminal domain that binds a mononuclear Fe2+ ion in a rubredoxin-type Cys4 motif. The C-terminal domain can be truncated with minimal impact on C. difficile Cfr activity, but the rate of turnover is decreased upon disruption of the Fe2+-binding site by Zn2+ substitution or ligand mutation. These findings indicate an important purpose for the observed C-terminal iron in the native fusion protein. Bioinformatic analysis of the C. difficile Cfr Cys-rich domain shows that it is widespread (∼1400 homologues) as a stand-alone gene in pathogenic or commensal Bacilli and Clostridia, with >10% encoded adjacent to a predicted radical SAM RNA methylase. Although the domain is not essential for in vitro C. difficile Cfr activity, the genomic co-occurrence and high abundance in the human microbiome suggest a possible functional role for a specialized rubredoxin in certain radical SAM RNA methylases that are relevant to human health.
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Affiliation(s)
- James D Gumkowski
- Department of Chemistry , The Pennsylvania State University , University Park , Pennsylvania 16802 , United States
| | - Ryan J Martinie
- Department of Chemistry , The Pennsylvania State University , University Park , Pennsylvania 16802 , United States
| | - Patrick S Corrigan
- Department of Chemistry , The Pennsylvania State University , University Park , Pennsylvania 16802 , United States
| | - Juan Pan
- Department of Chemistry , The Pennsylvania State University , University Park , Pennsylvania 16802 , United States
| | - Matthew R Bauerle
- Department of Chemistry , The Pennsylvania State University , University Park , Pennsylvania 16802 , United States
| | - Mohamed Almarei
- Department of Biochemistry and Molecular Biology , The Pennsylvania State University , University Park , Pennsylvania 16802 , United States
| | - Squire J Booker
- Department of Chemistry , The Pennsylvania State University , University Park , Pennsylvania 16802 , United States.,Department of Biochemistry and Molecular Biology , The Pennsylvania State University , University Park , Pennsylvania 16802 , United States.,Howard Hughes Medical Institute , The Pennsylvania State University , University Park , Pennsylvania 16802 , United States
| | - Alexey Silakov
- Department of Chemistry , The Pennsylvania State University , University Park , Pennsylvania 16802 , United States
| | - Carsten Krebs
- Department of Chemistry , The Pennsylvania State University , University Park , Pennsylvania 16802 , United States.,Department of Biochemistry and Molecular Biology , The Pennsylvania State University , University Park , Pennsylvania 16802 , United States
| | - Amie K Boal
- Department of Chemistry , The Pennsylvania State University , University Park , Pennsylvania 16802 , United States.,Department of Biochemistry and Molecular Biology , The Pennsylvania State University , University Park , Pennsylvania 16802 , United States
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241
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Marine Biosurfactants: Biosynthesis, Structural Diversity and Biotechnological Applications. Mar Drugs 2019; 17:md17070408. [PMID: 31323998 PMCID: PMC6669457 DOI: 10.3390/md17070408] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Revised: 07/04/2019] [Accepted: 07/07/2019] [Indexed: 11/16/2022] Open
Abstract
Biosurfactants are amphiphilic secondary metabolites produced by microorganisms. Marine bacteria have recently emerged as a rich source for these natural products which exhibit surface-active properties, making them useful for diverse applications such as detergents, wetting and foaming agents, solubilisers, emulsifiers and dispersants. Although precise structural data are often lacking, the already available information deduced from biochemical analyses and genome sequences of marine microbes indicates a high structural diversity including a broad spectrum of fatty acid derivatives, lipoamino acids, lipopeptides and glycolipids. This review aims to summarise biosyntheses and structures with an emphasis on low molecular weight biosurfactants produced by marine microorganisms and describes various biotechnological applications with special emphasis on their role in the bioremediation of oil-contaminated environments. Furthermore, novel exploitation strategies are suggested in an attempt to extend the existing biosurfactant portfolio.
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242
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Svoboda M, Konvalinka J, Trempe JF, Grantz Saskova K. The yeast proteases Ddi1 and Wss1 are both involved in the DNA replication stress response. DNA Repair (Amst) 2019; 80:45-51. [PMID: 31276951 DOI: 10.1016/j.dnarep.2019.06.008] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 05/23/2019] [Accepted: 06/26/2019] [Indexed: 01/05/2023]
Abstract
Genome integrity and cell survival are dependent on proper replication stress response. Multiple repair pathways addressing obstacles generated by replication stress arose during evolution, and a detailed understanding of these processes is crucial for treatment of numerous human diseases. Here, we investigated the strong negative genetic interaction between two proteases involved in the DNA replication stress response, yeast Wss1 and Ddi1. While Wss1 proteolytically acts on DNA-protein crosslinks, mammalian DDI1 and DDI2 proteins remove RTF2 from stalled forks via a proposed proteasome shuttle hypothesis. We show that the double-deleted Δddi1, Δwss1 yeast strain is hypersensitive to the replication drug hydroxyurea and that this phenotype can be complemented only by catalytically competent Ddi1 protease. Furthermore, our data show the key involvement of the helical domain preceding the Ddi1 protease domain in response to replication stress caused by hydroxyurea, offering the first suggestion of this domain's biological function. Overall, our study provides a basis for a novel dual protease-based mechanism enabling yeast cells to counteract DNA replication stress.
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Affiliation(s)
- Michal Svoboda
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo n. 2, 16610, Prague, Czech Republic; Department of Physical and Macromolecular Chemistry, Charles University, Hlavova 8, 12843, Prague, Czech Republic; Department of Genetics and Microbiology, Charles University, Viničná 5, 12843, Prague, Czech Republic
| | - Jan Konvalinka
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo n. 2, 16610, Prague, Czech Republic; Department of Biochemistry, Charles University, Hlavova 8, 12843, Prague, Czech Republic
| | - Jean-François Trempe
- Centre for Structural Biology and Department of Pharmacology & Therapeutics, McGill University, Montreal, Quebec, Canada
| | - Klara Grantz Saskova
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo n. 2, 16610, Prague, Czech Republic; Department of Genetics and Microbiology, Charles University, Viničná 5, 12843, Prague, Czech Republic.
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243
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Kassa EG, Zlotkin-Rivkin E, Friedman G, Ramachandran RP, Melamed-Book N, Weiss AM, Belenky M, Reichmann D, Breuer W, Pal RR, Rosenshine I, Lapierre LA, Goldenring JR, Aroeti B. Enteropathogenic Escherichia coli remodels host endosomes to promote endocytic turnover and breakdown of surface polarity. PLoS Pathog 2019; 15:e1007851. [PMID: 31242273 PMCID: PMC6615643 DOI: 10.1371/journal.ppat.1007851] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2019] [Revised: 07/09/2019] [Accepted: 05/20/2019] [Indexed: 12/11/2022] Open
Abstract
Enteropathogenic E. coli (EPEC) is an extracellular diarrheagenic human pathogen which infects the apical plasma membrane of the small intestinal enterocytes. EPEC utilizes a type III secretion system to translocate bacterial effector proteins into its epithelial hosts. This activity, which subverts numerous signaling and membrane trafficking pathways in the infected cells, is thought to contribute to pathogen virulence. The molecular and cellular mechanisms underlying these events are not well understood. We investigated the mode by which EPEC effectors hijack endosomes to modulate endocytosis, recycling and transcytosis in epithelial host cells. To this end, we developed a flow cytometry-based assay and imaging techniques to track endosomal dynamics and membrane cargo trafficking in the infected cells. We show that type-III secreted components prompt the recruitment of clathrin (clathrin and AP2), early (Rab5a and EEA1) and recycling (Rab4a, Rab11a, Rab11b, FIP2, Myo5b) endocytic machineries to peripheral plasma membrane infection sites. Protein cargoes, e.g. transferrin receptors, β1 integrins and aquaporins, which exploit the endocytic pathways mediated by these machineries, were also found to be recruited to these sites. Moreover, the endosomes and cargo recruitment to infection sites correlated with an increase in cargo endocytic turnover (i.e. endocytosis and recycling) and transcytosis to the infected plasma membrane. The hijacking of endosomes and associated endocytic activities depended on the translocated EspF and Map effectors in non-polarized epithelial cells, and mostly on EspF in polarized epithelial cells. These data suggest a model whereby EPEC effectors hijack endosomal recycling mechanisms to mislocalize and concentrate host plasma membrane proteins in endosomes and in the apically infected plasma membrane. We hypothesize that these activities contribute to bacterial colonization and virulence. Enteropathogenic Escherichia coli (EPEC) are pathogenic bacteria that cause infantile diarrhea. Upon ingestion, EPEC reaches the small intestine, where an injection device termed the type III secretion system is utilized to inject a set of effector proteins from the bacteria into the host cell. These proteins manipulate the localization and functions of host proteins, lipids and organelles and contribute to the emergence of the EPEC disease. The molecular mechanisms underlying the functions of the EPEC effector proteins are not completely understood. Here we show that early upon infection, two such effector proteins, EspF and Map, hijack host endosomes at bacterial adherence sites to facilitate endocytosis and recycling of plasma membrane proteins at these sites. The consequence of this event is the enrichment and mislocalization of host plasma membrane proteins at infection sites. One such protein is the transferrin receptor, which is a carrier for transferrin, whose function is to mediate cellular uptake of iron. Iron is a critical nutrient for bacterial growth and survival. We postulate that the unique manipulation of transferrin receptor endocytic membrane trafficking by EPEC plays an important role in its survival on the luminal surface of the intestinal epithelium.
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Affiliation(s)
- Ephrem G. Kassa
- Department of Cell and Developmental Biology, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Efrat Zlotkin-Rivkin
- Department of Cell and Developmental Biology, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Gil Friedman
- Department of Cell and Developmental Biology, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Rachana P. Ramachandran
- Department of Cell and Developmental Biology, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Naomi Melamed-Book
- Bio-imaging Unit, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Aryeh M. Weiss
- Bio-imaging Unit, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
- Faculty of Engineering, Bar Ilan University, Ramat Gan, Israel
| | - Michael Belenky
- Department of Cell and Developmental Biology, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Dana Reichmann
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
- Proteomics and Mass Spectrometry Unit, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - William Breuer
- Proteomics and Mass Spectrometry Unit, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Ritesh Ranjan Pal
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Ilan Rosenshine
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Lynne A. Lapierre
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - James R. Goldenring
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Benjamin Aroeti
- Department of Cell and Developmental Biology, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
- * E-mail:
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244
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Makukhin N, Havelka V, Poláchová E, Rampírová P, Tarallo V, Strisovsky K, Míšek J. Resolving oxidative damage to methionine by an unexpected membrane-associated stereoselective reductase discovered using chiral fluorescent probes. FEBS J 2019; 286:4024-4035. [PMID: 31166082 DOI: 10.1111/febs.14951] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2019] [Revised: 04/24/2019] [Accepted: 06/04/2019] [Indexed: 10/26/2022]
Abstract
Nonenzymatic oxidative processes in living organisms are among the inevitable consequences of respiration and environmental conditions. These oxidative processes can lead to the formation of two stereoisomers (R and S) of methionine sulfoxide, and the redox balance between methionine and methionine sulfoxide in proteins has profound implications on their function. Methionine oxidation can be reverted enzymatically by methionine sulfoxide reductases (Msrs). The two enzyme classes known to fulfill this role are MsrA, reducing the (S)-isomer, and MsrB, reducing the (R)-isomer of methionine sulfoxide. They are strictly stereoselective and conserved throughout the tree of life. Under stress conditions such as stationary phase and nutrient starvation, Escherichia coli upregulates the expression of MsrA but a similar effect has not been described for MsrB, raising the conundrum of which pathway enables reduction of the (R)-isomer of methionine sulfoxide in these conditions. Using the recently developed chiral fluorescent probes Sulfox-1, we show that in stationary phase-stressed E. coli, MsrA does have a stereocomplementary activity reducing the (R)-isomer of methionine sulfoxide. However, this activity is not provided by MsrB as expected, but instead by the DMSO reductase complex DmsABC, widely conserved in bacteria. This finding reveals an unexpected diversity in the metabolic enzymes of redox regulation concerning methionine, which should be taken into account in any antibacterial strategies exploiting oxidative stress. DATABASE: The mass spectrometry proteomics data have been deposited to the ProteomeXchange Consortium via the PRIDE partner repository with the dataset identifier PXD013610.
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Affiliation(s)
- Nikolai Makukhin
- Department of Organic Chemistry, Faculty of Science, Charles University, Prague, Czech Republic
| | - Václav Havelka
- Department of Organic Chemistry, Faculty of Science, Charles University, Prague, Czech Republic.,Department of Biochemistry, Faculty of Science, Charles University, Prague, Czech Republic
| | - Edita Poláchová
- First Faculty of Medicine, Charles University, Prague, Czech Republic.,Institute of Organic Chemistry and Biochemistry, Czech Academy of Science, Prague, Czech Republic
| | - Petra Rampírová
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Science, Prague, Czech Republic
| | - Vincenzo Tarallo
- Department of Organic Chemistry, Faculty of Science, Charles University, Prague, Czech Republic
| | - Kvido Strisovsky
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Science, Prague, Czech Republic
| | - Jiří Míšek
- Department of Organic Chemistry, Faculty of Science, Charles University, Prague, Czech Republic
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245
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An asymmetric allelic interaction drives allele transmission bias in interspecific rice hybrids. Nat Commun 2019; 10:2501. [PMID: 31175302 PMCID: PMC6555797 DOI: 10.1038/s41467-019-10488-3] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Accepted: 05/15/2019] [Indexed: 12/30/2022] Open
Abstract
Hybrid sterility (HS) between Oryza sativa (Asian rice) and O. glaberrima (African rice) is mainly controlled by the S1 locus. However, our limited understanding of the HS mechanism hampers utilization of the strong interspecific heterosis. Here, we show that three closely linked genes (S1A4, S1TPR, and S1A6) in the African S1 allele (S1-g) constitute a killer-protector system that eliminates gametes carrying the Asian allele (S1-s). In Asian–African rice hybrids (S1-gS1-s), the S1TPR-S1A4-S1A6 interaction in sporophytic tissues generates an abortion signal to male and female gametes. However, S1TPR can rescue S1-g gametes, while the S1-s gametes selectively abort for lacking S1TPR. Knockout of any of the S1-g genes eliminates the HS. Evolutionary analysis suggests that S1 may have arisen from newly evolved genes, multi-step recombination, and nucleotide variations. Our findings will help to overcome the interspecific reproductive barrier and use Asian–African hybrids for increasing rice production. Our limited understanding of the hybrid sterility (HS) mechanism in Asian–African rice hybrids hampers utilization of the interspecific heterosis for rice production. Here, the authors identify S1-mediated HS-related tripartite gamete killer-protector system, and explore their evolutionary relationship.
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246
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Weihmann R, Domröse A, Drepper T, Jaeger KE, Loeschcke A. Protocols for yTREX/Tn5-based gene cluster expression in Pseudomonas putida. Microb Biotechnol 2019; 13:250-262. [PMID: 31162833 PMCID: PMC6922528 DOI: 10.1111/1751-7915.13402] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 02/25/2019] [Accepted: 03/08/2019] [Indexed: 11/30/2022] Open
Abstract
Bacterial gene clusters, which represent a genetic treasure trove for secondary metabolite pathways, often need to be activated in a heterologous host to access the valuable biosynthetic products. We provide here a detailed protocol for the application of the yTREX ‘gene cluster transplantation tool’: Via yeast recombinational cloning, a gene cluster of interest can be cloned in the yTREX vector, which enables the robust conjugational transfer of the gene cluster to bacteria like Pseudomonas putida, and their subsequent transposon Tn5‐based insertion into the host chromosome. Depending on the gene cluster architecture and chromosomal insertion site, the respective pathway genes can be transcribed effectively from a chromosomal promoter, thereby enabling the biosynthesis of a natural product. We describe workflows for the design of a gene cluster expression cassette, cloning of the cassette in the yTREX vector by yeast recombineering, and subsequent transfer and expression in P. putida. As an example for yTREX‐based transplantation of a natural product biosynthesis, we provide details on the cloning and activation of the phenazine‐1‐carboxylic acid biosynthetic genes from Pseudomonas aeruginosa in P. putidaKT2440 as well as the use of β‐galactosidase‐encoding lacZ as a reporter of production levels.
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Affiliation(s)
- Robin Weihmann
- Institute of Molecular Enzyme Technology, Heinrich-Heine-University Düsseldorf, Forschungszentrum Jülich, Jülich, Germany
| | - Andreas Domröse
- Institute of Medical Microbiology and Hospital Hygiene, Heinrich-Heine-University, Düsseldorf, Germany
| | - Thomas Drepper
- Institute of Molecular Enzyme Technology, Heinrich-Heine-University Düsseldorf, Forschungszentrum Jülich, Jülich, Germany
| | - Karl-Erich Jaeger
- Institute of Molecular Enzyme Technology, Heinrich-Heine-University Düsseldorf, Forschungszentrum Jülich, Jülich, Germany
| | - Anita Loeschcke
- Institute of Molecular Enzyme Technology, Heinrich-Heine-University Düsseldorf, Forschungszentrum Jülich, Jülich, Germany
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247
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Vera Rodriguez A, Frey S, Görlich D. Engineered SUMO/protease system identifies Pdr6 as a bidirectional nuclear transport receptor. J Cell Biol 2019; 218:2006-2020. [PMID: 31023724 PMCID: PMC6548132 DOI: 10.1083/jcb.201812091] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Revised: 03/26/2019] [Accepted: 03/28/2019] [Indexed: 01/07/2023] Open
Abstract
Cleavage of affinity tags by specific proteases can be exploited for highly selective affinity chromatography. The SUMO/SENP1 system is the most efficient for such application but fails in eukaryotic expression because it cross-reacts with endogenous proteases. Using a novel selection system, we have evolved the SUMOEu/SENP1Eu pair to orthogonality with the yeast and animal enzymes. SUMOEu fusions therefore remain stable in eukaryotic cells. Likewise, overexpressing a SENP1Eu protease is nontoxic in yeast. We have used the SUMOEu system in an affinity-capture-proteolytic-release approach to identify interactors of the yeast importin Pdr6/Kap122. This revealed not only further nuclear import substrates such as Ubc9, but also Pil1, Lsp1, eIF5A, and eEF2 as RanGTP-dependent binders and thus as export cargoes. We confirmed that Pdr6 functions as an exportin in vivo and depletes eIF5A and eEF2 from cell nuclei. Thus, Pdr6 is a bidirectional nuclear transport receptor (i.e., a biportin) that shuttles distinct sets of cargoes in opposite directions.
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Affiliation(s)
- Arturo Vera Rodriguez
- Department of Cellular Logistics, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Steffen Frey
- Department of Cellular Logistics, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Dirk Görlich
- Department of Cellular Logistics, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
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248
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Liu H, Lu Z, Zhang X, Guo X, Mei L, Zou X, Zhong Y, Wang M, Hung T. Single Plasmid-Based, Upgradable, and Backward-Compatible Adenoviral Vector Systems. Hum Gene Ther 2019; 30:777-791. [DOI: 10.1089/hum.2018.258] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Affiliation(s)
- Hongyan Liu
- State Key Laboratory of Toxicology and Medical Counter Measures, Beijing Institute of Pharmacology and Toxicology, Beijing, P.R. China
| | - Zhuozhuang Lu
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, P.R. China
| | - Xin Zhang
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, P.R. China
- School of Public Health and Management, Weifang Medical University, Weifang, P.R. China
| | - Xiaojuan Guo
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, P.R. China
| | - Lingling Mei
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, P.R. China
- School of Public Health and Management, Weifang Medical University, Weifang, P.R. China
| | - Xiaohui Zou
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, P.R. China
| | - Yuxu Zhong
- State Key Laboratory of Toxicology and Medical Counter Measures, Beijing Institute of Pharmacology and Toxicology, Beijing, P.R. China
| | - Min Wang
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, P.R. China
| | - Tao Hung
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, P.R. China
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249
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The Second Messenger c-di-AMP Regulates Diverse Cellular Pathways Involved in Stress Response, Biofilm Formation, Cell Wall Homeostasis, SpeB Expression, and Virulence in Streptococcus pyogenes. Infect Immun 2019; 87:IAI.00147-19. [PMID: 30936159 DOI: 10.1128/iai.00147-19] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Accepted: 03/25/2019] [Indexed: 02/07/2023] Open
Abstract
Cyclic di-AMP (c-di-AMP) is a recently discovered second messenger in bacteria. The cellular level of c-di-AMP in Streptococcus pyogenes is predicted to be controlled by the synthase DacA and two putative phosphodiesterases, GdpP and Pde2. To investigate the role of c-di-AMP in S. pyogenes, we generated null mutants in each of these proteins by gene deletion. Unlike those in other Gram-positive pathogens such as Staphylococcus aureus and Listeria monocytogenes, DacA in S. pyogenes was not essential for growth in rich media. The DacA null mutant presented a growth defect that manifested through an increased lag time, produced no detectable biofilm, and displayed increased susceptibility toward environmental stressors such as high salt, low pH, reactive oxygen radicals, and cell wall-targeting antibiotics, suggesting that c-di-AMP plays significant roles in crucial cellular processes involved in stress management. The Pde2 null mutant exhibited a lower growth rate and increased biofilm formation, and interestingly, these phenotypes were distinct from those of the null mutant of GdpP, suggesting that Pde2 and GdpP play distinctive roles in c-di-AMP signaling. DacA and Pde2 were critical to the production of the virulence factor SpeB and to the overall virulence of S. pyogenes, as both DacA and Pde2 null mutants were highly attenuated in a mouse model of subcutaneous infection. Collectively, these results show that c-di-AMP is an important global regulator and is required for a proper response to stress and for virulence in S. pyogenes, suggesting that its signaling pathway could be an attractive antivirulence drug target against S. pyogenes infections.
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250
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Jan Vonk P, Escobar N, Wösten HAB, Lugones LG, Ohm RA. High-throughput targeted gene deletion in the model mushroom Schizophyllum commune using pre-assembled Cas9 ribonucleoproteins. Sci Rep 2019; 9:7632. [PMID: 31113995 PMCID: PMC6529522 DOI: 10.1038/s41598-019-44133-2] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Accepted: 05/09/2019] [Indexed: 12/11/2022] Open
Abstract
Efficient gene deletion methods are essential for the high-throughput study of gene function. Compared to most ascomycete model systems, gene deletion is more laborious in mushroom-forming basidiomycetes due to the relatively low incidence of homologous recombination (HR) and relatively high incidence of non-homologous end-joining (NHEJ). Here, we describe the use of pre-assembled Cas9-sgRNA ribonucleoproteins (RNPs) to efficiently delete the homeodomain transcription factor gene hom2 in the mushroom-forming basidiomycete Schizophyllum commune by replacing it with a selectable marker. All components (Cas9 protein, sgRNA, and repair template with selectable marker) were supplied to wild type protoplasts by PEG-mediated transformation, abolishing the need to optimize the expression of cas9 and sgRNAs. A Δku80 background further increased the efficiency of gene deletion. A repair template with homology arms of 250 bp was sufficient to efficiently induce homologous recombination. This is the first report of the use of pre-assembled Cas9 RNPs in a mushroom-forming basidiomycete and this approach may also improve the genetic accessibility of non-model species.
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Affiliation(s)
- Peter Jan Vonk
- Microbiology, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| | - Natalia Escobar
- Microbiology, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| | - Han A B Wösten
- Microbiology, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| | - Luis G Lugones
- Microbiology, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| | - Robin A Ohm
- Microbiology, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands.
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