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1.
J Proteome Res ; 18(12): 4206-4214, 2019 12 06.
Artigo em Inglês | MEDLINE | ID: mdl-31599598

RESUMO

This manuscript collects all the efforts of the Russian Consortium, bottlenecks revealed in the course of the C-HPP realization, and ways of their overcoming. One of the main bottlenecks in the C-HPP is the insufficient sensitivity of proteomic technologies, hampering the detection of low- and ultralow-copy number proteins forming the "dark part" of the human proteome. In the frame of MP-Challenge, to increase proteome coverage we suggest an experimental workflow based on a combination of shotgun technology and selected reaction monitoring with two-dimensional alkaline fractionation. Further, to detect proteins that cannot be identified by such technologies, nanotechnologies such as combined atomic force microscopy with molecular fishing and/or nanowire detection may be useful. These technologies provide a powerful tool for single molecule analysis, by analogy with nanopore sequencing during genome analysis. To systematically analyze the functional features of some proteins (CP50 Challenge), we created a mathematical model that predicts the number of proteins differing in amino acid sequence: proteoforms. According to our data, we should expect about 100 000 different proteoforms in the liver tissue and a little more in the HepG2 cell line. The variety of proteins forming the whole human proteome significantly exceeds these results due to post-translational modifications (PTMs). As PTMs determine the functional specificity of the protein, we propose using a combination of gene-centric transcriptome-proteomic analysis with preliminary fractionation by two-dimensional electrophoresis to identify chemically modified proteoforms. Despite the complexity of the proposed solutions, such integrative approaches could be fruitful for MP50 and CP50 Challenges in the framework of the C-HPP.


Assuntos
Proteínas/análise , Proteoma , Proteômica/métodos , Técnicas Biossensoriais , Eletroforese em Gel Bidimensional , Genoma Humano , Humanos , Microscopia de Força Atômica/métodos , Nanotecnologia/métodos , Processamento de Proteína Pós-Traducional , Proteínas/isolamento & purificação , Federação Russa , Sensibilidade e Especificidade , Espectrometria de Massas por Ionização por Electrospray , Espectrometria de Massas em Tandem , Fluxo de Trabalho
2.
BMC Genomics ; 20(1): 399, 2019 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-31117933

RESUMO

BACKGROUND: The three epidemiologically important Opisthorchiidae liver flukes Opisthorchis felineus, O. viverrini, and Clonorchis sinensis, are believed to harbour similar potencies to provoke hepatobiliary diseases in their definitive hosts, although their populations have substantially different ecogeographical aspects including habitat, preferred hosts, population structure. Lack of O. felineus genomic data is an obstacle to the development of comparative molecular biological approaches necessary to obtain new knowledge about the biology of Opisthorchiidae trematodes, to identify essential pathways linked to parasite-host interaction, to predict genes that contribute to liver fluke pathogenesis and for the effective prevention and control of the disease. RESULTS: Here we present the first draft genome assembly of O. felineus and its gene repertoire accompanied by a comparative analysis with that of O. viverrini and Clonorchis sinensis. We observed both noticeably high heterozygosity of the sequenced individual and substantial genetic diversity in a pooled sample. This indicates that potency of O. felineus population for rapid adaptive response to control and preventive measures of opisthorchiasis is higher than in O. viverrini and C. sinensis. We also have found that all three species are characterized by more intensive involvement of trans-splicing in RNA processing compared to other trematodes. CONCLUSION: All revealed peculiarities of structural organization of genomes are of extreme importance for a proper description of genes and their products in these parasitic species. This should be taken into account both in academic and applied research of epidemiologically important liver flukes. Further comparative genomics studies of liver flukes and non-carcinogenic flatworms allow for generation of well-grounded hypotheses on the mechanisms underlying development of cholangiocarcinoma associated with opisthorchiasis and clonorchiasis as well as species-specific mechanisms of these diseases.


Assuntos
Cricetinae/parasitologia , Cyprinidae/parasitologia , Genoma Helmíntico , Genômica/métodos , Proteínas de Helminto/genética , Opistorquíase/epidemiologia , Opisthorchis/genética , Sequência de Aminoácidos , Animais , Clonorquíase/epidemiologia , Clonorquíase/genética , Clonorquíase/parasitologia , Clonorchis sinensis/genética , Opistorquíase/genética , Opistorquíase/parasitologia , Homologia de Sequência
3.
PLoS Med ; 16(1): e1002724, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30605491

RESUMO

BACKGROUND: Several obesity-related factors have been associated with renal cell carcinoma (RCC), but it is unclear which individual factors directly influence risk. We addressed this question using genetic markers as proxies for putative risk factors and evaluated their relation to RCC risk in a mendelian randomization (MR) framework. This methodology limits bias due to confounding and is not affected by reverse causation. METHODS AND FINDINGS: Genetic markers associated with obesity measures, blood pressure, lipids, type 2 diabetes, insulin, and glucose were initially identified as instrumental variables, and their association with RCC risk was subsequently evaluated in a genome-wide association study (GWAS) of 10,784 RCC patients and 20,406 control participants in a 2-sample MR framework. The effect on RCC risk was estimated by calculating odds ratios (ORSD) for a standard deviation (SD) increment in each risk factor. The MR analysis indicated that higher body mass index increases the risk of RCC (ORSD: 1.56, 95% confidence interval [CI] 1.44-1.70), with comparable results for waist-to-hip ratio (ORSD: 1.63, 95% CI 1.40-1.90) and body fat percentage (ORSD: 1.66, 95% CI 1.44-1.90). This analysis further indicated that higher fasting insulin (ORSD: 1.82, 95% CI 1.30-2.55) and diastolic blood pressure (DBP; ORSD: 1.28, 95% CI 1.11-1.47), but not systolic blood pressure (ORSD: 0.98, 95% CI 0.84-1.14), increase the risk for RCC. No association with RCC risk was seen for lipids, overall type 2 diabetes, or fasting glucose. CONCLUSIONS: This study provides novel evidence for an etiological role of insulin in RCC, as well as confirmatory evidence that obesity and DBP influence RCC risk.


Assuntos
Carcinoma de Células Renais/etiologia , Neoplasias Renais/etiologia , Obesidade/complicações , Glicemia/análise , Pressão Sanguínea , Índice de Massa Corporal , Carcinoma de Células Renais/genética , Diabetes Mellitus Tipo 2/complicações , Feminino , Marcadores Genéticos , Estudo de Associação Genômica Ampla , Humanos , Insulina/sangue , Neoplasias Renais/genética , Lipídeos/sangue , Masculino , Análise da Randomização Mendeliana , Obesidade/genética , Fatores de Risco
4.
Int J Syst Evol Microbiol ; 69(7): 1953-1959, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31038447

RESUMO

Strain LBB-42T was isolated from sediment sampled at Lake Beloe Bordukovskoe, located in the Moscow region (Russia). Phylogenetic analyses based on 16S rRNA gene sequencing results assigned the strain to the genus Magnetospirillum. Major fatty acids were C16 : 1ω7c, C16 : 0 and C18 : 1 ω9/C18 : 1 ω7. Genome sequencing revealed a genome size of 4.40 Mbp and a G+C content of 63.4 mol%. The average nucleotide identity and digital DNA-DNA hybridization values suggested that strain LBB-42T represents a new species, for which we propose the name Magnetospirillum kuznetsovii sp. nov., with the type strain LBB-42T (=VKM B-3270T=KCTC 15749T).


Assuntos
Lagos/microbiologia , Magnetospirillum/classificação , Filogenia , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Magnetospirillum/isolamento & purificação , Moscou , Hibridização de Ácido Nucleico , RNA Ribossômico 16S/genética , Federação Russa , Análise de Sequência de DNA
5.
Int J Mol Sci ; 20(17)2019 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-31443555

RESUMO

Carnivorous plants have the ability to capture and digest small animals as a source of additional nutrients, which allows them to grow in nutrient-poor habitats. Here we report the complete sequences of the plastid genomes of two carnivorous plants of the order Caryophyllales, Drosera rotundifolia and Nepenthes × ventrata. The plastome of D. rotundifolia is repeat-rich and highly rearranged. It lacks NAD(P)H dehydrogenase genes, as well as ycf1 and ycf2 genes, and three essential tRNA genes. Intron losses are observed in some protein-coding and tRNA genes along with a pronounced reduction of RNA editing sites. Only six editing sites were identified by RNA-seq in D. rotundifolia plastid genome and at most conserved editing sites the conserved amino acids are already encoded at the DNA level. In contrast, the N. × ventrata plastome has a typical structure and gene content, except for pseudogenization of the ccsA gene. N. × ventrata and D. rotundifolia could represent different stages of evolution of the plastid genomes of carnivorous plants, resembling events observed in parasitic plants in the course of the switch from autotrophy to a heterotrophic lifestyle.


Assuntos
Evolução Biológica , Drosera/genética , Genomas de Plastídeos , Genômica , Biologia Computacional/métodos , Drosera/parasitologia , Duplicação Gênica , Rearranjo Gênico , Genes de Plantas , Genômica/métodos , Edição de RNA
6.
Nature ; 475(7355): 189-95, 2011 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-21743474

RESUMO

Potato (Solanum tuberosum L.) is the world's most important non-grain food crop and is central to global food security. It is clonally propagated, highly heterozygous, autotetraploid, and suffers acute inbreeding depression. Here we use a homozygous doubled-monoploid potato clone to sequence and assemble 86% of the 844-megabase genome. We predict 39,031 protein-coding genes and present evidence for at least two genome duplication events indicative of a palaeopolyploid origin. As the first genome sequence of an asterid, the potato genome reveals 2,642 genes specific to this large angiosperm clade. We also sequenced a heterozygous diploid clone and show that gene presence/absence variants and other potentially deleterious mutations occur frequently and are a likely cause of inbreeding depression. Gene family expansion, tissue-specific expression and recruitment of genes to new pathways contributed to the evolution of tuber development. The potato genome sequence provides a platform for genetic improvement of this vital crop.


Assuntos
Genoma de Planta/genética , Genômica , Solanum tuberosum/genética , Evolução Molecular , Duplicação Gênica , Regulação da Expressão Gênica de Plantas , Genes de Plantas/genética , Variação Genética , Haplótipos/genética , Heterozigoto , Homozigoto , Imunidade Inata , Endogamia , Anotação de Sequência Molecular , Dados de Sequência Molecular , Doenças das Plantas/genética , Ploidias , Solanum tuberosum/fisiologia
7.
J Proteome Res ; 15(11): 4030-4038, 2016 11 04.
Artigo em Inglês | MEDLINE | ID: mdl-27527821

RESUMO

A gene-centric approach was applied for a large-scale study of expression products of a single chromosome. Transcriptome profiling of liver tissue and HepG2 cell line was independently performed using two RNA-Seq platforms (SOLiD and Illumina) and also by Droplet Digital PCR (ddPCR) and quantitative RT-PCR. Proteome profiling was performed using shotgun LC-MS/MS as well as selected reaction monitoring with stable isotope-labeled standards (SRM/SIS) for liver tissue and HepG2 cells. On the basis of SRM/SIS measurements, protein copy numbers were estimated for the Chromosome 18 (Chr 18) encoded proteins in the selected types of biological material. These values were compared with expression levels of corresponding mRNA. As a result, we obtained information about 158 and 142 transcripts for HepG2 cell line and liver tissue, respectively. SRM/SIS measurements and shotgun LC-MS/MS allowed us to detect 91 Chr 18-encoded proteins in total, while an intersection between the HepG2 cell line and liver tissue proteomes was ∼66%. In total, there were 16 proteins specifically observed in HepG2 cell line, while 15 proteins were found solely in the liver tissue. Comparison between proteome and transcriptome revealed a poor correlation (R2 ≈ 0.1) between corresponding mRNA and protein expression levels. The SRM and shotgun data sets (obtained during 2015-2016) are available in PASSEL (PASS00697) and ProteomeExchange/PRIDE (PXD004407). All measurements were also uploaded into the in-house Chr 18 Knowledgebase at http://kb18.ru/protein/matrix/416126 .


Assuntos
Cromossomos Humanos Par 18 , Perfilação da Expressão Gênica , Proteoma/análise , Bases de Dados de Proteínas , Perfilação da Expressão Gênica/métodos , Células Hep G2 , Humanos , Fígado/química , Proteínas/análise , Proteoma/genética , Proteômica/métodos , RNA Mensageiro/análise
8.
Plant Mol Biol ; 91(4-5): 441-58, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27097902

RESUMO

Myco-heterotroph Monotropa hypopitys is a widely spread perennial herb used to study symbiotic interactions and physiological mechanisms underlying the development of non-photosynthetic plant. Here, we performed, for the first time, transcriptome-wide characterization of M. hypopitys miRNA profile using high throughput Illumina sequencing. As a result of small RNA library sequencing and bioinformatic analysis, we identified 55 members belonging to 40 families of known miRNAs and 17 putative novel miRNAs unique for M. hypopitys. Computational screening revealed 206 potential mRNA targets for known miRNAs and 31 potential mRNA targets for novel miRNAs. The predicted target genes were described in Gene Ontology terms and were found to be involved in a broad range of metabolic and regulatory pathways. The identification of novel M. hypopitys-specific miRNAs, some with few target genes and low abundances, suggests their recent evolutionary origin and participation in highly specialized regulatory mechanisms fundamental for non-photosynthetic biology of M. hypopitys. This global analysis of miRNAs and their potential targets in M. hypopitys provides a framework for further investigation of miRNA role in the evolution and establishment of non-photosynthetic myco-heterotrophs.


Assuntos
Ericaceae/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Sequenciamento de Nucleotídeos em Larga Escala/métodos , MicroRNAs/genética , Sequência de Bases , Sequência Conservada/genética , Ontologia Genética , MicroRNAs/metabolismo , Anotação de Sequência Molecular , Conformação de Ácido Nucleico , Filogenia , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo
9.
BMC Plant Biol ; 16(Suppl 3): 238, 2016 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-28105941

RESUMO

BACKGROUND: Chloroplasts of most plants are responsible for photosynthesis and contain a conserved set of about 110 genes that encode components of housekeeping gene expression machinery and photosynthesis-related functions. Heterotrophic plants obtaining nutrients from other organisms and their plastid genomes represent model systems in which to study the effects of relaxed selective pressure on photosynthetic function. The most evident is a reduction in the size and gene content of the plastome, which correlates with the loss of genes encoding photosynthetic machinery which become unnecessary. Transition to a non-photosynthetic lifestyle is expected also to relax the selective pressure on photosynthetic machinery in the nuclear genome, however, the corresponding changes are less known. RESULTS: Here we report the complete sequence of the plastid genome of Monotropa hypopitys, an achlorophyllous obligately mycoheterotrophic plant belonging to the family Ericaceae. The plastome of M. hypopitys is greatly reduced in size (35,336 bp) and lacks the typical quadripartite structure with two single-copy regions and an inverted repeat. Only 45 genes remained presumably intact- those encoding ribosomal proteins, ribosomal and transfer RNA and housekeeping genes infA, matK, accD and clpP. The clpP and accD genes probably remain functional, although their sequences are highly diverged. The sets of genes for ribosomal protein and transfer RNA are incomplete relative to chloroplasts of a photosynthetic plant. Comparison of the plastid genomes of two subspecies-level isolates of M. hypopitys revealed major structural rearrangements associated with repeat-driven recombination and the presence of isolate-specific tRNA genes. Analysis of the M. hypopitys transcriptome by RNA-Seq showed the absence of expression of nuclear-encoded components of photosystem I and II reaction center proteins, components of cytochrome b6f complex, ATP synthase, ribulose bisphosphate carboxylase components, as well as chlorophyll from protoporphyrin IX biosynthesis pathway. CONCLUSIONS: With the complete loss of genes related to photosynthesis, NADH dehydrogenase, plastid-encoded RNA polymerase and ATP synthase, the M. hypopitys plastid genome is among the most functionally reduced ones characteristic of obligate non-photosynthetic parasitic species. Analysis of the M. hypopitys transcriptome revealed coordinated evolution of the nuclear and plastome genomes and the loss of photosynthesis-related functions in both genomes.


Assuntos
Ericaceae/genética , Genoma de Planta/genética , Genomas de Plastídeos/genética , Fotossíntese/genética , Proteínas de Plantas/genética , Sequência de Aminoácidos , Evolução Biológica , Filogenia , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Alinhamento de Sequência
10.
Biochemistry ; 54(19): 3076-85, 2015 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-25900264

RESUMO

The physical chemical principles underlying enzymatic thermostability are keys to understand the way evolution has shaped proteins to adapt to a broad range of temperatures. Understanding the molecular determinants at the basis of protein thermostability is also an important factor for engineering more thermoresistant enzymes to be used in the industrial setting, such as, for instance, DNA ligases, which are important for DNA replication and repair and have been long used in molecular biology and biotechnology. Here, we first address the origin of thermostability in the thermophilic DNA ligase from archaeon Thermococcus sp. 1519 and identify thermosensitive regions using molecular modeling and simulations. In addition, we predict mutations that can enhance thermostability of the enzyme through bioinformatics analyses. We show that thermosensitive regions of this enzyme are stabilized at higher temperatures by optimization of charged groups on the surface, and we predict that thermostability can be further increased by further optimization of the network among these charged groups. Engineering this DNA ligase by introducing selected mutations (i.e., A287K, G304D, S364I, and A387K) eventually produced a significant and additive increase in the half-life of the enzyme when compared to that of the wild type.


Assuntos
DNA Ligases/química , DNA Ligases/metabolismo , Thermococcus/enzimologia , DNA Ligase Dependente de ATP , Estabilidade Enzimática , Estrutura Secundária de Proteína , Temperatura
11.
RNA ; 19(11): 1563-74, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24046481

RESUMO

Telomerase, a ribonucleoprotein, is responsible for the maintenance of eukaryotic genome integrity by replicating the ends of chromosomes. The core enzyme comprises the conserved protein TERT and an RNA subunit (TER) that, in contrast, displays large variations in size and structure. Here, we report the identification of the telomerase RNA from thermotolerant yeast Hansenula polymorpha (HpTER) and describe its structural features. We show further that the H. polymorpha telomerase reverse transcribes the template beyond the predicted boundary and adds a nontelomeric dT in vitro. Sequencing of the chromosomal ends revealed that this nucleotide is specifically present as a terminal nucleotide at the 3' end of telomeres. Mutational analysis of HpTER confirmed that the incorporation of dT functions to limit telomere length in this species.


Assuntos
Pichia/genética , RNA/genética , Telomerase/genética , Homeostase do Telômero , Sequência de Bases , Técnicas de Inativação de Genes , Dados de Sequência Molecular , Conformação de Ácido Nucleico , RNA/química , RNA/metabolismo , RNA Fúngico/química , RNA Fúngico/genética , RNA Fúngico/metabolismo , Análise de Sequência de RNA , Telomerase/química , Telomerase/metabolismo , Timina
12.
Appl Environ Microbiol ; 81(3): 1003-12, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25416759

RESUMO

Geoglobus acetivorans is a hyperthermophilic anaerobic euryarchaeon of the order Archaeoglobales isolated from deep-sea hydrothermal vents. A unique physiological feature of the members of the genus Geoglobus is their obligate dependence on Fe(III) reduction, which plays an important role in the geochemistry of hydrothermal systems. The features of this organism and its complete 1,860,815-bp genome sequence are described in this report. Genome analysis revealed pathways enabling oxidation of molecular hydrogen, proteinaceous substrates, fatty acids, aromatic compounds, n-alkanes, and organic acids, including acetate, through anaerobic respiration linked to Fe(III) reduction. Consistent with the inability of G. acetivorans to grow on carbohydrates, the modified Embden-Meyerhof pathway encoded by the genome is incomplete. Autotrophic CO2 fixation is enabled by the Wood-Ljungdahl pathway. Reduction of insoluble poorly crystalline Fe(III) oxide depends on the transfer of electrons from the quinone pool to multiheme c-type cytochromes exposed on the cell surface. Direct contact of the cells and Fe(III) oxide particles could be facilitated by pilus-like appendages. Genome analysis indicated the presence of metabolic pathways for anaerobic degradation of aromatic compounds and n-alkanes, although an ability of G. acetivorans to grow on these substrates was not observed in laboratory experiments. Overall, our results suggest that Geoglobus species could play an important role in microbial communities of deep-sea hydrothermal vents as lithoautotrophic producers. An additional role as decomposers would close the biogeochemical cycle of carbon through complete mineralization of various organic compounds via Fe(III) respiration.


Assuntos
Acetatos/metabolismo , Archaeoglobales/genética , Processos Autotróficos , Compostos Ferrosos/metabolismo , Genoma Arqueal , Redes e Vias Metabólicas , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Biotransformação , DNA Arqueal/química , DNA Arqueal/genética , Dados de Sequência Molecular , Oxirredução , Análise de Sequência de DNA
13.
Indian J Microbiol ; 55(4): 440-6, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26543270

RESUMO

Pravastatin is one of the most popular cholesterol-lowering drugs. Its industrial production represents a two-stage process including the microbial production of compactin and its further biocatalytic conversion to pravastatin. To increase a conversion rate, a higher compactin content in fermentation medium should be used; however, high compactin concentrations inhibit microbial growth. Therefore, the improvement of the compactin resistance of a producer still remains a relevant problem. A multi-step random UV mutagenesis of a Streptomyces xanthochromogenes strain RIA 1098 and the further selection of high-yield compactin-resistant mutants have resulted in a highly productive compactin-resistant strain S 33-1. After the fermentation medium improvement, the maximum bioconversion rate of this strain has reached 91 % at the daily compactin dose equal to 1 g/L and still remained high (83 %) even at the doubled dose (2 g/L). A 1-year study of the mutant strain stability has proved a stable inheritance of its characteristics that provides this strain to be very promising for the pravastatin-producing industry.

14.
J Proteome Res ; 13(1): 183-90, 2014 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-24328317

RESUMO

We report the results obtained in 2012-2013 by the Russian Consortium for the Chromosome-centric Human Proteome Project (C-HPP). The main scope of this work was the transcriptome profiling of genes on human chromosome 18 (Chr 18), as well as their encoded proteome, from three types of biomaterials: liver tissue, the hepatocellular carcinoma-derived cell line HepG2, and blood plasma. The transcriptome profiling for liver tissue was independently performed using two RNaseq platforms (SOLiD and Illumina) and also by droplet digital PCR (ddPCR) and quantitative RT-PCR. The proteome profiling of Chr 18 was accomplished by quantitatively measuring protein copy numbers in the three types of biomaterial (the lowest protein concentration measured was 10(-13) M) using selected reaction monitoring (SRM). In total, protein copy numbers were estimated for 228 master proteins, including quantitative data on 164 proteins in plasma, 171 in the HepG2 cell line, and 186 in liver tissue. Most proteins were present in plasma at 10(8) copies/µL, while the median abundance was 10(4) and 10(5) protein copies per cell in HepG2 cells and liver tissue, respectively. In summary, for liver tissue and HepG2 cells a "transcriptoproteome" was produced that reflects the relationship between transcript and protein copy numbers of the genes on Chr 18. The quantitative data acquired by RNaseq, PCR, and SRM were uploaded into the "Update_2013" data set of our knowledgebase (www.kb18.ru) and investigated for linear correlations.


Assuntos
Cromossomos Humanos Par 18 , Fígado/metabolismo , Plasma , Proteoma , Transcriptoma , Células Hep G2 , Humanos , Reação em Cadeia da Polimerase/métodos
15.
BMC Biotechnol ; 14: 56, 2014 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-24929670

RESUMO

BACKGROUND: Establishing highly productive clonal cell lines with constant productivity over 2-3 months of continuous culture remains a tedious task requiring the screening of tens of thousands of clonal colonies. In addition, long-term cultivation of many candidate lines derived in the absence of drug selection pressure is necessary. Expression vectors based on the elongation factor-1 alpha (EEF1A) gene and the dihydrofolate reductase (DHFR) selection marker (with separate promoters) can be used to obtain highly productive populations of stably transfected cells in the selection medium, but they have not been tested for their ability to support target gene amplification under gradually increasing methotrexate pressure. RESULTS: We have modified EEF1A-based vectors by linking the DHFR selection marker to the target gene in the bicistronic RNA, shortening the overall plasmid size, and adding an Epstein-Barr virus terminal repeat fragment (EBVTR) element. Presence of the EBVTR element increased the rate of stable transfection by the plasmid by 24 times that of the EBVTR-minus control and improved the rate of methotrexate-driven gene amplification. The mean expression level of the enhanced green fluorescent protein (eGFP) used herein as a model protein, increased up to eight-fold using a single round of amplification in the case of adherent colonies formation and up to 4.5-fold in the case of suspension polyclonal cultures. Several eGFP-expressing cell populations produced using vectors with antibiotic resistance markers instead of the DHFR marker were compared with each other. Stable transfection of Chinese hamster ovary (CHO) DG44 cells by the p1.2-Hygro-eGFP plasmid (containing a hygromycin resistance marker) generated highest eGFP expression levels of up to 8.9% of the total cytoplasmic protein, with less than 5% of the cell population being eGFP-negative. CONCLUSIONS: The p1.1 vector was very effective for stable transfection of CHO cells and capable of rapid MTX-driven target gene amplification, while p1.2-Hygro achieved similar eGFP expression levels as p1.1. The set of vectors we have developed should speed-up the process of generating highly productive clonal cell lines while substantially decreasing the associated experimental effort.


Assuntos
Fator 1 de Elongação de Peptídeos/metabolismo , Animais , Células CHO , Cricetinae , Cricetulus , Amplificação de Genes , Vetores Genéticos/metabolismo , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Herpesvirus Humano 4/genética , Metotrexato/química , Metotrexato/metabolismo , Fator 1 de Elongação de Peptídeos/genética , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/genética , Sequências Repetidas Terminais/genética , Tetra-Hidrofolato Desidrogenase/genética , Tetra-Hidrofolato Desidrogenase/metabolismo , Transfecção
16.
Extremophiles ; 18(2): 295-309, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24366681

RESUMO

The complete genome of the obligately anaerobic crenarchaeote Fervidicoccus fontis Kam940(T), a terrestrial hot spring inhabitant with a growth optimum of 65-70 °C, has been sequenced and analyzed. The small 1.3-Mb genome encodes several extracellular proteases and no other extracellular hydrolases. No complete pathways of carbohydrate catabolism were found. Genes coding for enzymes necessary for amino acid transamination and further oxidative decarboxylation are present. The genome encodes no mechanisms of acyl-CoA and acetyl-CoA oxidation. Two [NiFe]-hydrogenases are encoded: a membrane-bound energy-converting hydrogenase and a cytoplasmic one. The ATP-synthase is H(+)-dependent as inferred from the amino acid sequence of the membrane rotor subunit. On the whole, genome analysis shows F. fontis to be a peptidolytic heterotroph with a restricted biosynthetic potential, which is in accordance with its phenotypic properties. The analysis of phylogenetic markers and of the distribution of best blastp hits of F. fontis proteins in the available genomes of Crenarchaeota supports distinct phylogenetic position of the order Fervidicoccales as a separate lineage adjoining the heterogeneous order Desulfurococcales. In addition, certain F. fontis genomic features correlate with its adaptation to temperatures of 60-80 °C, which are lower than temperatures preferred by Desulfurococcales.


Assuntos
Crenarchaeota/genética , Genoma Arqueal , Filogenia , Proteínas Arqueais/genética , Proteínas Arqueais/metabolismo , Sequência de Bases , Crenarchaeota/classificação , Crenarchaeota/metabolismo , Meio Ambiente , Redes e Vias Metabólicas , Dados de Sequência Molecular
17.
BMC Genomics ; 14: 837, 2013 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-24279325

RESUMO

BACKGROUND: Hansenula polymorpha DL1 is a methylotrophic yeast, widely used in fundamental studies of methanol metabolism, peroxisome biogenesis and function, and also as a microbial cell factory for production of recombinant proteins and metabolic engineering towards the goal of high temperature ethanol production. RESULTS: We have sequenced the 9 Mbp H. polymorpha DL1 genome and performed whole-genome analysis for the H. polymorpha transcriptome obtained from both methanol- and glucose-grown cells. RNA-seq analysis revealed the complex and dynamic character of the H. polymorpha transcriptome under the two studied conditions, identified abundant and highly unregulated expression of 40% of the genome in methanol grown cells, and revealed alternative splicing events. We have identified subtelomerically biased protein families in H. polymorpha, clusters of LTR elements at G + C-poor chromosomal loci in the middle of each of the seven H. polymorpha chromosomes, and established the evolutionary position of H. polymorpha DL1 within a separate yeast clade together with the methylotrophic yeast Pichia pastoris and the non-methylotrophic yeast Dekkera bruxellensis. Intergenome comparisons uncovered extensive gene order reshuffling between the three yeast genomes. Phylogenetic analyses enabled us to reveal patterns of evolution of methylotrophy in yeasts and filamentous fungi. CONCLUSIONS: Our results open new opportunities for in-depth understanding of many aspects of H. polymorpha life cycle, physiology and metabolism as well as genome evolution in methylotrophic yeasts and may lead to novel improvements toward the application of H. polymorpha DL-1 as a microbial cell factory.


Assuntos
Genoma Fúngico , Saccharomycetales/genética , Processamento Alternativo , Antioxidantes/metabolismo , Cromossomos Fúngicos , Análise por Conglomerados , Códon , Elementos de DNA Transponíveis , Evolução Molecular , Ácidos Graxos/metabolismo , Duplicação Gênica , Perfilação da Expressão Gênica , Genes Fúngicos , Glucose/metabolismo , Redes e Vias Metabólicas , Metanol/metabolismo , Anotação de Sequência Molecular , Família Multigênica , Oxirredução , Via de Pentose Fosfato , Peroxissomos/metabolismo , Filogenia , Sítios de Splice de RNA , Saccharomycetales/classificação , Saccharomycetales/metabolismo , Análise de Sequência de DNA , Telômero/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Transcriptoma
18.
J Bacteriol ; 194(3): 727-8, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22247528

RESUMO

Strain 1860, a novel member of the genus Pyrobaculum, is a hyperthermophilic organotrophic crenarchaeon growing anaerobically with various electron acceptors. The complete genome sequence reveals genes for several membrane-bound oxidoreductases, the Embden-Meyerhof and Entner-Doudoroff pathways for glucose metabolism, the tricarboxylic acid cycle, the glyoxylate cycle, and the dicarboxylate/4-hydroxybutyrate cycle.


Assuntos
Genoma Arqueal , Lagos/microbiologia , Pyrobaculum/genética , Pyrobaculum/metabolismo , Anaerobiose , Sequência de Bases , Elétrons , Glucose/metabolismo , Dados de Sequência Molecular , Pyrobaculum/crescimento & desenvolvimento , Pyrobaculum/isolamento & purificação
19.
J Bacteriol ; 194(16): 4446-7, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22843584

RESUMO

Strain 1633, a novel member of the genus Thermogladius, isolated from a freshwater hot spring, is an anaerobic hyperthermophilic crenarchaeon capable of fermenting proteinaceous and cellulose substrates. The complete genome sequence reveals genes for protein and carbohydrate-active enzymes, the Embden-Meyerhof pathway for glucose metabolism, cytoplasmic NADP-dependent hydrogenase, and several energy-coupling membrane-bound oxidoreductases.


Assuntos
DNA Arqueal/química , DNA Arqueal/genética , Desulfurococcaceae/genética , Genoma Arqueal , Análise de Sequência de DNA , Anaerobiose , Celulose/metabolismo , Desulfurococcaceae/isolamento & purificação , Desulfurococcaceae/metabolismo , Desulfurococcaceae/fisiologia , Fontes Termais/microbiologia , Temperatura Alta , Redes e Vias Metabólicas/genética , Dados de Sequência Molecular , Proteínas/metabolismo
20.
J Bacteriol ; 193(9): 2355-6, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21398550

RESUMO

Strain 768-28 was isolated from a hot spring in Kamchatka, Russia, and represents a novel member of the Vulcanisaeta genus. The complete genome sequence of this thermoacidophilic anaerobic crenarchaeon reveals genes for protein and carbohydrate-active enzymes, the Embden-Meyerhof and Entner-Doudoroff pathways for glucose metabolism, the tricarboxylic acid cycle, beta-oxidation of fatty acids, and sulfate reduction.


Assuntos
Genoma Arqueal , Thermoproteales/genética , Sequência de Bases , DNA Arqueal/genética , Regulação da Expressão Gênica em Archaea/fisiologia , Dados de Sequência Molecular
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