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1.
Microb Cell Fact ; 18(1): 160, 2019 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-31547812

RESUMO

BACKGROUND: Alpha-Terpineol (α-Terpineol), a C10 monoterpenoid alcohol, is widely used in the cosmetic and pharmaceutical industries. Construction Saccharomyces cerevisiae cell factories for producing monoterpenes offers a promising means to substitute chemical synthesis or phytoextraction. RESULTS: α-Terpineol was produced by expressing the truncated α-Terpineol synthase (tVvTS) from Vitis vinifera in S. cerevisiae. The α-Terpineol titer was increased to 0.83 mg/L with overexpression of the rate-limiting genes tHMG1, IDI1 and ERG20F96W-N127W. A GSGSGSGSGS linker was applied to fuse ERG20F96W-N127W with tVvTS, and expressing the fusion protein increased the α-Terpineol production by 2.87-fold to 2.39 mg/L when compared with the parental strain. In addition, we found that farnesyl diphosphate (FPP) accumulation by down-regulation of ERG9 expression and deletion of LPP1 and DPP1 did not improve α-Terpineol production. Therefore, ERG9 was overexpressed and the α-Terpineol titer was further increased to 3.32 mg/L. The best α-Terpineol producing strain LCB08 was then used for batch and fed-batch fermentation in a 5 L bioreactor, and the production of α-Terpineol was ultimately improved to 21.88 mg/L. CONCLUSIONS: An efficient α-Terpineol production cell factory was constructed by engineering the S. cerevisiae mevalonate pathway, and the metabolic engineering strategies could also be applied to produce other valuable monoterpene compounds in yeast.


Assuntos
Cicloexenos/metabolismo , Engenharia Metabólica , Monoterpenos/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Fosfatos de Poli-Isoprenil/metabolismo , Sesquiterpenos/metabolismo , Vitis/enzimologia , Vitis/genética
2.
J Agric Food Chem ; 67(40): 11148-11157, 2019 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-31532654

RESUMO

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.


Assuntos
Licopeno/metabolismo , Engenharia Metabólica , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Vias Biossintéticas , Fermentação , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo
3.
BMC Bioinformatics ; 20(1): 435, 2019 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-31438841

RESUMO

BACKGROUND: Gene and protein interaction data are often represented as interaction networks, where nodes stand for genes or gene products and each edge stands for a relationship between a pair of gene nodes. Commonly, that relationship within a pair is specified by high similarity between profiles (vectors) of experimentally defined interactions of each of the two genes with all other genes in the genome; only gene pairs that interact with similar sets of genes are linked by an edge in the network. The tight groups of genes/gene products that work together in a cell can be discovered by the analysis of those complex networks. RESULTS: We show that the choice of the similarity measure between pairs of gene vectors impacts the properties of networks and of gene modules detected within them. We re-analyzed well-studied data on yeast genetic interactions, constructed four genetic networks using four different similarity measures, and detected gene modules in each network using the same algorithm. The four networks induced different numbers of putative functional gene modules, and each similarity measure induced some unique modules. In an example of a putative functional connection suggested by comparing genetic interaction vectors, we predict a link between SUN-domain proteins and protein glycosylation in the endoplasmic reticulum. CONCLUSIONS: The discovery of molecular modules in genetic networks is sensitive to the way of measuring similarity between profiles of gene interactions in a cell. In the absence of a formal way to choose the "best" measure, it is advisable to explore the measures with different mathematical properties, which may identify different sets of connections between genes.


Assuntos
Biologia Computacional/métodos , Epistasia Genética , Algoritmos , Redes Reguladoras de Genes , Genes Fúngicos , Glicosilação , Anotação de Sequência Molecular , Domínios Proteicos , Saccharomyces cerevisiae/genética , Estatística como Assunto
4.
Gene ; 717: 144046, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31434006

RESUMO

Flavonoids are major polyphenol compounds in plant secondary metabolism. The hydroxylation pattern of the B-ring of flavonoids is determined by the flavonoid 3'-hydroxylase (F3'H) and flavonoid 3',5'-hydroxylase (F3'5'H). In this paper, one CsF3'H and two CsF3'5'Hs (CsF3'5'Ha and CsF3'5'Hb) were isolated. The phylogenetic tree results showed that F3'H and F3'5'Hs belong to the CYP75B and CYP75A, respectively. The Expression pattern analysis showed that the expression of CsF3'5'Ha and CsF3'5'Hb in the bud and 1st leaf were higher than other tissues. However, the CsF3'H had the highest expression in the 4th and mature leaf. The correlation analysis showed that the expression of CsF3'5'Hs is positively associated with the concentration of B-trihydroxylated catechins, and the expression of CsF3'H is positively associated with the Q contentration. Heterologous expression of these genes in yeast showed that CsF3'H and CsF3'5'Ha can catalyze flavanones, flavonols and flavanonols to the corresponding 3', 4' or 3', 4', 5'-hydroxylated compounds, for which the optimum substrate is naringenin. The enzyme of CsF3'5'Hb can only catalyze flavonols (including K and Q) and flavanonols (DHK and DHQ), of which the highest activities in catalyzing are DHK. Interestingly, The experiment of site-directed mutagenesis suggested that two novel sites near the C-terminal were discovered impacting on the activity of the CsF3'5'H. These results provide a significantly molecular basis on the accumulation B-ring hydroxylation of flavonoids in tea plant.


Assuntos
Camellia sinensis/genética , Sistema Enzimático do Citocromo P-450/genética , Flavonoides/metabolismo , Camellia sinensis/metabolismo , Clonagem Molecular , Sistema Enzimático do Citocromo P-450/metabolismo , Flavonoides/química , Regulação da Expressão Gênica de Plantas , Hidroxilação , Mutagênese Sítio-Dirigida , Filogenia , Folhas de Planta/genética , Folhas de Planta/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Saccharomyces cerevisiae/genética
5.
Genome Biol ; 20(1): 162, 2019 08 09.
Artigo em Inglês | MEDLINE | ID: mdl-31399036

RESUMO

BACKGROUND: General translational cis-elements are present in the mRNAs of all genes and affect the recruitment, assembly, and progress of preinitiation complexes and the ribosome under many physiological states. These elements include mRNA folding, upstream open reading frames, specific nucleotides flanking the initiating AUG codon, protein coding sequence length, and codon usage. The quantitative contributions of these sequence features and how and why they coordinate to control translation rates are not well understood. RESULTS: Here, we show that these sequence features specify 42-81% of the variance in translation rates in Saccharomyces cerevisiae, Schizosaccharomyces pombe, Arabidopsis thaliana, Mus musculus, and Homo sapiens. We establish that control by RNA secondary structure is chiefly mediated by highly folded 25-60 nucleotide segments within mRNA 5' regions, that changes in tri-nucleotide frequencies between highly and poorly translated 5' regions are correlated between all species, and that control by distinct biochemical processes is extensively correlated as is regulation by a single process acting in different parts of the same mRNA. CONCLUSIONS: Our work shows that general features control a much larger fraction of the variance in translation rates than previously realized. We provide a more detailed and accurate understanding of the aspects of RNA structure that directs translation in diverse eukaryotes. In addition, we note that the strongly correlated regulation between and within cis-control features will cause more even densities of translational complexes along each mRNA and therefore more efficient use of the translation machinery by the cell.


Assuntos
Regulação da Expressão Gênica , Biossíntese de Proteínas , RNA Mensageiro/química , Animais , Arabidopsis/genética , Humanos , Camundongos , Modelos Genéticos , Conformação de Ácido Nucleico , Motivos de Nucleotídeos , Saccharomyces cerevisiae/genética , Schizosaccharomyces/genética
6.
Microbiol Res ; 227: 126298, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31421716

RESUMO

An increasing number of infections originating from probiotic use are reported worldwide, with the majority of such cases caused by the yeast Saccharomyces 'boulardii', a subtype of S. cerevisiae. Reliably linking infectious cases to probiotic products requires unequivocal genotyping data, however, these techniques are often time-consuming and difficult to implement in routine diagnostics. This leads to a widespread lack of genetic data regarding the origin of Saccharomyces infections. We propose a quick and reliable PCR-based protocol for the identification of S. 'boulardii' based on a combined analysis of interdelta fingerprinting and microsatellite typing. By applying various typing methods and our proposed method to the clinical yeast collection of a Hungarian hospital we show that probiotic origin is common among clinical Saccharomyces, and that the new multiplex method enables rapid and unequivocal identification of probiotic yeast infections. This method can be applied for the identification of yeast infection sources, helping decisions on probiotic use.


Assuntos
Reação em Cadeia da Polimerase Multiplex/métodos , Técnicas de Tipagem Micológica/métodos , Probióticos , Saccharomyces/genética , Saccharomyces/isolamento & purificação , DNA Fúngico/isolamento & purificação , Fungemia/microbiologia , Técnicas de Genotipagem , Humanos , Repetições de Microssatélites , Micoses/microbiologia , Saccharomyces/classificação , Saccharomyces/patogenicidade , Saccharomyces cerevisiae/classificação , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/isolamento & purificação
7.
Genes Dev ; 33(17-18): 1191-1207, 2019 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-31371435

RESUMO

The vast majority of eukaryotes possess two DNA recombinases: Rad51, which is ubiquitously expressed, and Dmc1, which is meiosis-specific. The evolutionary origins of this two-recombinase system remain poorly understood. Interestingly, Dmc1 can stabilize mismatch-containing base triplets, whereas Rad51 cannot. Here, we demonstrate that this difference can be attributed to three amino acids conserved only within the Dmc1 lineage of the Rad51/RecA family. Chimeric Rad51 mutants harboring Dmc1-specific amino acids gain the ability to stabilize heteroduplex DNA joints with mismatch-containing base triplets, whereas Dmc1 mutants with Rad51-specific amino acids lose this ability. Remarkably, RAD-51 from Caenorhabditis elegans, an organism without Dmc1, has acquired "Dmc1-like" amino acids. Chimeric C. elegans RAD-51 harboring "canonical" Rad51 amino acids gives rise to toxic recombination intermediates, which must be actively dismantled to permit normal meiotic progression. We propose that Dmc1 lineage-specific amino acids involved in the stabilization of heteroduplex DNA joints with mismatch-containing base triplets may contribute to normal meiotic recombination.


Assuntos
Aminoácidos/metabolismo , Rad51 Recombinase/química , Rad51 Recombinase/metabolismo , Recombinases/química , Recombinases/metabolismo , Recombinação Genética/genética , Aminoácidos/genética , Animais , Pareamento Incorreto de Bases , Caenorhabditis elegans/enzimologia , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/química , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Sequência Conservada , Mutação , Rad51 Recombinase/genética , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Recombinases/genética , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo
8.
Int J Nanomedicine ; 14: 4801-4816, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31308659

RESUMO

Background: Silver nanoparticles (AgNPs) inhibit the proliferation of various fungi; however, their mechanisms of action remain poorly understood. To better understand the inhibitory mechanisms, we focused on the early events elicited by 5 nm AgNPs in pathogenic Candida albicans and non-pathogenic Saccharomyces cerevisiae. Methods: The effect of 5 nm and 100 nm AgNPs on fungus cell proliferation was analyzed by growth kinetics monitoring and spot assay. We examined cell cycle progression, reactive oxygen species (ROS) production, and cell death using flow cytometry. Glucose uptake was assessed using tritium-labeled 2-deoxyglucose. Results: The growth of both C. albicans and S. cerevisiae was suppressed by treatment with 5 nm AgNPs but not with 100 nm AgNPs. In addition, 5 nm AgNPs induced cell cycle arrest and a reduction in glucose uptake in both fungi after 30 minutes of culture in a dose-dependent manner (P<0.05). However, in C. albicans only, an increase in ROS production was detected after exposure to 5 nm AgNPs. Concordantly, an ROS scavenger blocked the effect of 5 nm AgNPs on the cell cycle and glucose uptake in C. albicans only. Furthermore, the growth-inhibition effect of 5 nm AgNPs was not greater in S. cerevisiae mutant strains deficient in oxidative stress response genes than it was in wild type. Finally, 5 nm AgNPs together with a glycolysis inhibitor, 3-bromopyruvate, synergistically enhanced cell death in C. albicans (P<0.05) but not in S. cerevisiae. Conclusion: AgNPs exhibit antifungal activity in a manner that may or may not be ROS dependent, according to the fungal species. The combination of AgNPs with 3-bromopyruvate may be more useful against infection with C. albicans.


Assuntos
Candida albicans/citologia , Ciclo Celular/efeitos dos fármacos , Nanopartículas Metálicas/toxicidade , Piruvatos/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Saccharomyces cerevisiae/citologia , Prata/farmacologia , Antifúngicos/farmacologia , Candida albicans/efeitos dos fármacos , Candida albicans/crescimento & desenvolvimento , Morte Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Parede Celular/efeitos dos fármacos , Parede Celular/genética , Depuradores de Radicais Livres/farmacologia , Fase G1/efeitos dos fármacos , Genes Fúngicos , Glucose/metabolismo , Glicólise/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/genética , Saccharomyces cerevisiae/efeitos dos fármacos , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/crescimento & desenvolvimento
9.
Nat Commun ; 10(1): 2960, 2019 07 04.
Artigo em Inglês | MEDLINE | ID: mdl-31273196

RESUMO

Clone collections of modified strains ("libraries") are a major resource for systematic studies with the yeast Saccharomyces cerevisiae. Construction of such libraries is time-consuming, costly and confined to the genetic background of a specific yeast strain. To overcome these limitations, we present CRISPR-Cas12a (Cpf1)-assisted tag library engineering (CASTLING) for multiplexed strain construction. CASTLING uses microarray-synthesized oligonucleotide pools and in vitro recombineering to program the genomic insertion of long DNA constructs via homologous recombination. One simple transformation yields pooled libraries with >90% of correctly tagged clones. Up to several hundred genes can be tagged in a single step and, on a genomic scale, approximately half of all genes are tagged with only ~10-fold oversampling. We report several parameters that affect tagging success and provide a quantitative targeted next-generation sequencing method to analyze such pooled collections. Thus, CASTLING unlocks avenues for increasing throughput in functional genomics and cell biology research.


Assuntos
Sistemas CRISPR-Cas/genética , Técnicas Genéticas , Saccharomyces cerevisiae/genética , Células Clonais , Biblioteca Gênica , Engenharia Genética , Genoma Fúngico , Proteínas de Fluorescência Verde/metabolismo , Proteínas Nucleares/metabolismo
10.
Vet Microbiol ; 235: 127-135, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31282370

RESUMO

Lawsonia intracellularis is an obligate intracellular Gram-negative bacterium that has been identified as the etiological agent of the contagious disease proliferative enteropathy (PE) in a wide range of animals, mainly pigs. The genome sequence of L. intracellularis indicates that this bacterium possess a type III secretion system (T3SS), which may assist the bacterium during cell invasion and host innate immune system evasion and could be a mechanism for inducing cellular proliferation. However, the effectors secreted by the T3SS (T3Es) of L. intracellularis have not been reported. T3Es often target conserved eukaryotic cellular processes, and yeast is an established and robust model system in which to reveal their function. By screening the growth inhibition of an ordered array of Saccharomyces cerevisiae strains expressing the hypothetical genes of L. intracellularis, LI1035 was identified as the first putative effector that inhibits yeast growth. The LI1035-induced growth inhibition was rescued in two of the 14 mitogen-activated protein kinase (MAPK) yeast haploid deletion strains, suggesting that LI1035 interacts with the components of the MAPK pathway in yeast. Phosphorylation assays confirmed that LI1035 inhibits MAPK signaling cascades in yeast and mammalian cells. Actin staining assays revealed that LI1035 regulates actin organization in yeast and mammalian cells. Taken together, these results indicate that LI1035 alters MAPK pathway activity and regulates actin organization in the host. These findings may contribute to the understanding the pathogenesis of L. intracellularis and support the use of yeast as a heterologous system for the functional analysis of pathogen-specific gene products in the laboratory.


Assuntos
Actinas/metabolismo , Proteínas de Bactérias/metabolismo , Lawsonia (Bactéria)/metabolismo , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Saccharomyces cerevisiae/crescimento & desenvolvimento , Transdução de Sinais , Animais , Proteínas de Bactérias/genética , Proliferação de Células , Interações entre Hospedeiro e Microrganismos , Lawsonia (Bactéria)/genética , Fosforilação , Saccharomyces cerevisiae/genética , Sorbitol/farmacologia , Suínos , Temperatura Ambiente
11.
J Agric Food Chem ; 67(31): 8590-8598, 2019 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-31287301

RESUMO

Patchoulol, a natural sesquiterpene compound, is widely used in perfumes and cosmetics. Several strategies were adopted to enhance patchoulol production in Saccharomyces cerevisiae: (i) farnesyl pyrophosphate (FPP) synthase and patchoulol synthase were fused to increase the utilization of FPP precursor; (ii) expression of the limiting genes of the mevalonate pathway was enhanced; (iii) squalene synthase was weakened by a glucose-inducible promoter of HXT1 (promoter for hexose transporter) to reduce metabolic flux from FPP to ergosterol; and (iv) farnesol biosynthesis was inhibited to decrease the consumption of FPP. Glucose was used to balance the trade-off between the competitive squalene and patchoulol pathways. The patchoulol production was 59.2 ± 0.7 mg/L in a shaken flask with a final production of 466.8 ± 12.3 mg/L (20.5 ± 0.5 mg/g dry cell weight) combined with fermentation optimization, which was 7.8-fold higher than the reported maximum production. The work significantly promoted the industrialization process of patchoulol production using biobased microbial platforms.


Assuntos
Engenharia Metabólica , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Sesquiterpenos/metabolismo , Fermentação , Ácido Mevalônico/metabolismo , Fosfatos de Poli-Isoprenil/metabolismo , Regiões Promotoras Genéticas , Saccharomyces cerevisiae/enzimologia , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Esqualeno/metabolismo
12.
Food Chem ; 299: 125089, 2019 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-31319343

RESUMO

Synthesis of ß-ionone in recombinant Saccharomyces cerevisiae is limited by the efficiency of Carotenoid Cleavage Dioxygenases (CCD), membrane-tethered enzymes catalyzing the last step in the pathway. We performed in silico design and membrane affinity analysis, focused on single-point mutations of PhCCD1 to improve membrane anchoring. The resulting constructs were tested in a ß-carotene hyper-producing strain by comparing colony pigmentation against colonies transformed with native PhCCD1 and further analyzed by ß-ionone quantification via RP-HPLC. Two single-point mutants increased ß-ionone yields almost 3-fold when compared to native PhCCD1. We also aimed to improve substrate accessibility of PhCCD1 through the amino-terminal addition of membrane destination peptides directed towards the endoplasmic reticulum or plasma membrane. Yeast strains expressing peptide-PhCCD1 constructs showed ß-ionone yields up to 4-fold higher than the strain carrying the native enzyme. Our results demonstrate that protein engineering of CCDs significantly increases the yield of ß-ionone synthesized by metabolically engineered yeast.


Assuntos
Carotenoides/metabolismo , Dioxigenases/genética , Dioxigenases/metabolismo , Norisoprenoides/biossíntese , Engenharia de Proteínas , Saccharomyces cerevisiae/metabolismo , Engenharia Metabólica , Saccharomyces cerevisiae/citologia , Saccharomyces cerevisiae/genética
13.
J Agric Food Chem ; 67(32): 8986-8993, 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31347835

RESUMO

Trehalose plays a crucial role in response to freezing stress in baker's yeast. MAL62, a gene involved in the adenosine diphosphoglucose-dependent trehalose synthesis pathway, can increase trehalose content. However, the difference between MAL62-related trehalose synthesis and traditional uridine diphosphoglucose-dependent trehalose synthesis is not well-understood. MAL62 overexpression showed less effect in enhancing intracellular trehalose compared to TPS1 overexpression. However, MAL62 overexpression elicited trehalose synthesis before fermentation with enhanced maltose metabolism and had a similar effect on cell viability after freezing. Furthermore, MAL62 and TPS1 overexpression in the NTH1 deletion background further strengthened freezing tolerance and improved leavening ability. Our results suggest that the enhancement in freezing tolerance by MAL62 overexpression may involve multiple pathways rather than simply enhancing trehalose synthesis. The results reveal valuable insights into the relationship between maltose metabolism and freezing tolerance and may help to develop better yeast strains for enhancing fermentation characteristics of frozen dough.


Assuntos
Glucosiltransferases/metabolismo , Maltose/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/enzimologia , Saccharomyces cerevisiae/genética , alfa-Glucosidases/metabolismo , Farinha/análise , Farinha/microbiologia , Congelamento , Regulação Fúngica da Expressão Gênica , Glucosiltransferases/genética , Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/genética , Trealase/genética , Trealase/metabolismo , Trealose/metabolismo , alfa-Glucosidases/genética
14.
Bioengineered ; 10(1): 335-344, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31322471

RESUMO

Selenium-enriched yeast can transform toxic inorganic selenium into absorbable organic selenium, which is of great significance for human health and pharmaceutical industry. A yeast Rhodotorula glutinis X-20 we obtained before has good selenium-enriched ability, but its selenium content is still low for industrial application. In this study, strategies of process optimization and transport regulation of selenium were thus employed to further improve the cell growth and selenium enrichment. Through engineering phosphate transporters from Saccharomyces cerevisiae into R. glutinis X-20, the selenium content was increased by 21.1%. Through using mixed carbon culture (20 g L-1, glycerol: glucose 3:7), both biomass and selenium content were finally increased to 5.3 g L-1 and 5349.6 µg g-1 (cell dry weight, DWC), which were 1.14 folds and 6.77 folds compared to their original values, respectively. Our results indicate that high selenium-enrichment ability and biomass production can be achieved through combining process optimization and regulation of selenium transport.


Assuntos
Engenharia Metabólica/métodos , Fosfatos/metabolismo , Rhodotorula/genética , Saccharomyces cerevisiae/genética , Selênio/metabolismo , Transgenes , Transporte Biológico , Biomassa , Meios de Cultura/química , Meios de Cultura/farmacologia , Fermentação , Expressão Gênica , Glucose/química , Glucose/metabolismo , Glicerol/química , Glicerol/metabolismo , Proteínas de Transporte de Fosfato/genética , Proteínas de Transporte de Fosfato/metabolismo , Plasmídeos/química , Plasmídeos/metabolismo , Simportadores de Próton-Fosfato/genética , Simportadores de Próton-Fosfato/metabolismo , Rhodotorula/metabolismo , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Proteínas Cotransportadoras de Sódio-Fosfato Tipo III/genética , Proteínas Cotransportadoras de Sódio-Fosfato Tipo III/metabolismo
15.
Nat Commun ; 10(1): 2894, 2019 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-31263106

RESUMO

The Origin Recognition Complex (ORC) is essential for replication, heterochromatin formation, telomere maintenance and genome stability in eukaryotes. Here we present the structure of the yeast Orc1 BAH domain bound to the nucleosome core particle. Our data reveal that Orc1, unlike its close homolog Sir3 involved in gene silencing, does not appear to discriminate between acetylated and non-acetylated lysine 16, modification states of the histone H4 tail that specify open and closed chromatin respectively. We elucidate the mechanism for this unique feature of Orc1 and hypothesize that its ability to interact with nucleosomes regardless of K16 modification state enables it to perform critical functions in both hetero- and euchromatin. We also show that direct interactions with nucleosomes are essential for Orc1 to maintain the integrity of rDNA borders during meiosis, a process distinct and independent from its known roles in silencing and replication.


Assuntos
Nucleossomos/metabolismo , Complexo de Reconhecimento de Origem/química , Complexo de Reconhecimento de Origem/metabolismo , Proteínas de Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Ciclo Celular , Montagem e Desmontagem da Cromatina , Eucromatina/genética , Eucromatina/metabolismo , Heterocromatina/genética , Heterocromatina/metabolismo , Histonas/genética , Histonas/metabolismo , Nucleossomos/genética , Complexo de Reconhecimento de Origem/genética , Ligação Proteica , Domínios Proteicos , Saccharomyces cerevisiae/química , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/genética , Proteínas Reguladoras de Informação Silenciosa de Saccharomyces cerevisiae/genética , Proteínas Reguladoras de Informação Silenciosa de Saccharomyces cerevisiae/metabolismo
16.
World J Microbiol Biotechnol ; 35(7): 111, 2019 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-31280424

RESUMO

Clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated (Cas) immune systems in bacteria have been used as tools for genome engineering. Thus far, the CRISPR-Cas system has been used in various yeast, bacterial, and mammalian cells. Saccharomyces cerevisiae is a nonpathogenic yeast, classified under "generally recognized as safe", and has long been used to produce consumables such as alcohol or bread. Additionally, recombinant cells of S. cerevisiae have been constructed and used to produce various bio-based chemicals. Some types of CRISPR-Cas system for genetic manipulation have been constructed during the early developmental stages of the CRISPR-Cas system and have been mainly used for gene knock-in and knock-out manipulations. Thereafter, these systems have been used for various novel purposes such as metabolic engineering and tolerance engineering. In this review, we have summarized different aspects of the CRISPR-Cas in the yeast S. cerevisiae, from its basic principles to various applications. This review describes the CRISPR system in S. cerevisiae based on the differences in its origin and efficiency followed by its basic applications; for example, its involvement in gene knock-in and knock-out has been outlined. Finally, advanced applications of the CRISPR system in the bioproduction of useful chemicals have been summarized.


Assuntos
Sistemas CRISPR-Cas , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas , Engenharia Metabólica/métodos , Saccharomyces cerevisiae/metabolismo , Edição de Genes/métodos , Regulação Fúngica da Expressão Gênica , Técnicas de Introdução de Genes/métodos , Técnicas de Inativação de Genes/métodos , Saccharomyces cerevisiae/genética
17.
World J Microbiol Biotechnol ; 35(7): 112, 2019 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-31286266

RESUMO

Microorganisms have evolved permeases to incorporate various essential nutrients and exclude harmful products, which assists in adaptation to different environmental conditions for survival. As permeases are directly involved in the utilization of and regulatory response to nutrient sources, metabolic engineering of microbial permeases can predictably influence nutrient metabolism and regulation. In this mini-review, we have summarized the mechanisms underlying the general regulation of permeases, and the current advancements and future prospects of metabolic engineering strategies targeting the permeases in Saccharomyces cerevisiae. The different types of permeases and their regulatory mechanisms have been discussed. Furthermore, methods for metabolic engineering of permeases have been highlighted. Understanding the mechanisms via which permeases are meticulously regulated and engineered will not only facilitate research on regulation of global nutrition and yeast metabolic engineering, but can also provide important insights for future studies on the synthesis of valuable products and elimination of harmful substances in S. cerevisiae.


Assuntos
Proteínas de Membrana Transportadoras/metabolismo , Engenharia Metabólica/métodos , Saccharomyces cerevisiae/metabolismo , Transporte Biológico , Carbono/metabolismo , Glucose/metabolismo , Proteínas de Membrana Transportadoras/genética , Nitrogênio/metabolismo , Saccharomyces cerevisiae/genética
18.
Genes Dev ; 33(15-16): 1031-1047, 2019 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-31196865

RESUMO

Aneuploidy, a condition characterized by chromosome gains and losses, causes reduced fitness and numerous cellular stresses, including increased protein aggregation. Here, we identify protein complex stoichiometry imbalances as a major cause of protein aggregation in aneuploid cells. Subunits of protein complexes encoded on excess chromosomes aggregate in aneuploid cells, which is suppressed when expression of other subunits is coordinately altered. We further show that excess subunits are either degraded or aggregate and that protein aggregation is nearly as effective as protein degradation at lowering levels of excess proteins. Our study explains why proteotoxic stress is a universal feature of the aneuploid state and reveals protein aggregation as a form of dosage compensation to cope with disproportionate expression of protein complex subunits.


Assuntos
Aneuploidia , Citosol/metabolismo , Compensação de Dosagem (Genética)/fisiologia , Agregados Proteicos/genética , Humanos , Complexos Multiproteicos/química , Complexos Multiproteicos/metabolismo , Agregação Patológica de Proteínas , Subunidades Proteicas/metabolismo , Proteólise , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo
19.
BMC Bioinformatics ; 20(1): 350, 2019 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-31221092

RESUMO

BACKGROUND: Computational strain optimisation methods (CSOMs) have been successfully used to exploit genome-scale metabolic models, yielding strategies useful for allowing compound overproduction in metabolic cell factories. Minimal cut sets are particularly interesting since their definition allows searching for intervention strategies that impose strong growth-coupling phenotypes, and are not subject to optimality bias when compared with simulation-based CSOMs. However, since both types of methods have different underlying principles, they also imply different ways to formulate metabolic engineering problems, posing an obstacle when comparing their outputs. RESULTS: In this work, we perform an in-depth analysis of potential strategies that can be obtained with both methods, providing a critical comparison of performance, robustness, predicted phenotypes as well as strategy structure and size. To this end, we devised a pipeline including enumeration of strategies from evolutionary algorithms (EA) and minimal cut sets (MCS), filtering and flux analysis of predicted mutants to optimize the production of succinic acid in Saccharomyces cerevisiae. We additionally attempt to generalize problem formulations for MCS enumeration within the context of growth-coupled product synthesis. Strategies from evolutionary algorithms show the best compromise between acceptable growth rates and compound overproduction. However, constrained MCSs lead to a larger variety of phenotypes with several degrees of growth-coupling with production flux. The latter have proven useful in revealing the importance, in silico, of the gamma-aminobutyric acid shunt and manipulation of cofactor pools in growth-coupled designs for succinate production, mechanisms which have also been touted as potentially useful for metabolic engineering. CONCLUSIONS: The two main groups of CSOMs are valuable for finding growth-coupled mutants. Despite the limitations in maximum growth rates and large strategy sizes, MCSs help uncover novel mechanisms for compound overproduction and thus, analyzing outputs from both methods provides a richer overview on strategies that can be potentially carried over in vivo.


Assuntos
Algoritmos , Células/metabolismo , Biologia Computacional/métodos , Modelos Biológicos , Saccharomyces cerevisiae/genética , Succinatos/metabolismo
20.
Chem Commun (Camb) ; 55(60): 8868-8871, 2019 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-31240288

RESUMO

New evidence on the role of H2S as a gasotransmitter suggests that the true signalling effectors are polysulfides. Both oxidized polysulfides and hydropolysulfides were synthesized and their presence in S. cerevisiae was observed for the first time. A single gene-deletant approach allowed observation of the modulation of polysulfide species and levels.


Assuntos
Gasotransmissores/análise , Saccharomyces cerevisiae/química , Sulfetos/análise , Proteínas de Transporte/genética , Cistationina beta-Sintase/genética , Cistationina gama-Liase/genética , Gasotransmissores/síntese química , Gasotransmissores/metabolismo , Deleção de Genes , Metabolômica/métodos , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Sulfetos/síntese química , Sulfetos/metabolismo
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