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1.
Int J Med Sci ; 16(12): 1557-1563, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31839743

RESUMO

E2F3, a member of the E2F family, plays a critical role in cell cycle and proliferation by targeting downstream, retinoblastoma (RB) a tumor suppressor family protein. The purpose of this study, was to investigate the role and function of E2F3 in vivo. We examined phenotypic abnormalities, by deletion of the E2f3 gene in mice. Complete ablation of the E2F3 was fully penetrant, in the pure C57BL/6N background. The E2f3+/ - mouse embryo developed normally without fatal disorder. However, they exhibited reduced body weight, growth retardation, skeletal imperfection, and poor grip strength ability. Findings suggest that E2F3 has a pivotal role in muscle and bone development, and affect normal mouse growth.


Assuntos
Desenvolvimento Ósseo/genética , Fator de Transcrição E2F3/genética , Desenvolvimento Embrionário/genética , Músculo Esquelético/crescimento & desenvolvimento , Animais , Apoptose/genética , Peso Corporal/genética , Ciclo Celular/genética , Proliferação de Células/genética , Embrião de Mamíferos , Humanos , Camundongos , Camundongos Knockout , Músculo Esquelético/metabolismo , Músculo Esquelético/fisiopatologia , Fenótipo
2.
J Biol Chem ; 294(28): 11023-11034, 2019 07 12.
Artigo em Inglês | MEDLINE | ID: mdl-31160336

RESUMO

The mycobacterial SenX3-RegX3 two-component system consists of the SenX3 sensor histidine kinase and its cognate RegX3 response regulator. This system is a phosphorelay-based regulatory system involved in sensing environmental Pi levels and induction of genes required for Pi acquisition under Pi-limiting conditions. Here we demonstrate that overexpression of the kinase domain of Mycobacterium tuberculosis PknB (PknB-KDMtb) inhibits the transcriptional activity of RegX3 of both M. tuberculosis and Mycobacterium smegmatis (RegX3Mtb and RegX3Ms, respectively). Mass spectrometry results, along with those of in vitro phosphorylation and complementation analyses, revealed that PknB kinase activity inhibits the transcriptional activity of RegX3Mtb through phosphorylation events at Thr-100, Thr-191, and Thr-217. Electrophoretic mobility shift assays disclosed that phosphorylation of Thr-191 and Thr-217 abolishes the DNA-binding ability of RegX3Mtb and that Thr-100 phosphorylation likely prevents RegX3Mtb from being activated through conformational changes induced by SenX3-mediated phosphorylation. We propose that the convergence of the PknB and SenX3-RegX3 signaling pathways might enable mycobacteria to integrate environmental Pi signals with the cellular replication state to adjust gene expression in response to Pi availability.


Assuntos
Proteínas de Bactérias/metabolismo , Fosfotransferases/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/fisiologia , Regulação Bacteriana da Expressão Gênica/genética , Mycobacterium smegmatis/genética , Mycobacterium tuberculosis/genética , Fosforilação , Fosfotransferases/genética , Regiões Promotoras Genéticas/genética , Proteínas Serina-Treonina Quinases/fisiologia , Rifabutina/metabolismo , Transdução de Sinais/genética
3.
ACS Nano ; 12(8): 8187-8196, 2018 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-30059622

RESUMO

Precise control of the oxidation state of transition-metal oxides, such as copper, is important for high selectivity of CO2 reduction in an aqueous condition to compete with the reduction of water. The phase of copper oxide nanofibers was controlled by predictive synthesis, which controls the nanoscale gas-solid reaction by considering thermodynamics and kinetics. The driving force of the phase transformation between the different oxidation states of copper oxide is calculated by comparing the Gibbs free energy of each of the oxidation states. From the calculation, the kinetically processable window for the fabrication of Cu2O in which monophase Cu2O can be fabricated in a reasonable reaction time scale is discovered. Herein, we report the monophase Cu2O nanofiber photocathode, which photoelectrochemically converted CO2 into methanol with over 90% selectivity in an aqueous electrolyte, and a hierarchical structure is developed to optimize the photoactivity and stability of the electrode. Our work suggests a rational design of the calcination strategy for precisely controlling the oxidation states of transition metals that can be applied to various applications in which the phase of the materials plays an important role.

4.
J Bacteriol ; 200(14)2018 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-29712875

RESUMO

Here we demonstrated that the inhibition of electron flux through the respiratory electron transport chain (ETC) by either the disruption of the gene for the major terminal oxidase (aa3 cytochrome c oxidase) or treatment with KCN resulted in the induction of ald encoding alanine dehydrogenase in Mycobacterium smegmatis A decrease in functionality of the ETC shifts the redox state of the NADH/NAD+ pool toward a more reduced state, which in turn leads to an increase in cellular levels of alanine by Ald catalyzing the conversion of pyruvate to alanine with the concomitant oxidation of NADH to NAD+ The induction of ald expression under respiration-inhibitory conditions in M. smegmatis is mediated by the alanine-responsive AldR transcriptional regulator. The growth defect of M. smegmatis by respiration inhibition was exacerbated by inactivation of the ald gene, suggesting that Ald is beneficial to M. smegmatis in its adaptation and survival under respiration-inhibitory conditions by maintaining NADH/NAD+ homeostasis. The low susceptibility of M. smegmatis to bcc1 complex inhibitors appears to be, at least in part, attributable to the high expression level of the bd quinol oxidase in M. smegmatis when the bcc1-aa3 branch of the ETC is inactivated.IMPORTANCE We demonstrated that the functionality of the respiratory electron transport chain is inversely related to the expression level of the ald gene encoding alanine dehydrogenase in Mycobacterium smegmatis Furthermore, the importance of Ald in NADH/NAD+ homeostasis during the adaptation of M. smegmatis to severe respiration-inhibitory conditions was demonstrated in this study. On the basis of these results, we propose that combinatory regimens including both an Ald-specific inhibitor and respiration-inhibitory antitubercular drugs such as Q203 and bedaquiline are likely to enable a more efficient therapy for tuberculosis.


Assuntos
Alanina Desidrogenase/metabolismo , Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Mycobacterium smegmatis/enzimologia , Consumo de Oxigênio/fisiologia , Alanina Desidrogenase/genética , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Farmacorresistência Bacteriana , Imidazóis/farmacologia , Testes de Sensibilidade Microbiana , Mycobacterium smegmatis/genética , Mycobacterium smegmatis/metabolismo , NAD/metabolismo , Piperidinas/farmacologia , Piridinas/farmacologia
5.
Mol Cells ; 40(9): 632-642, 2017 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-28843272

RESUMO

The DevSR (DosSR) two-component system, which is a major regulatory system involved in oxygen sensing in mycobacteria, plays an important role in hypoxic induction of many genes in mycobacteria. We demonstrated that overexpression of the kinase domain of Mycobacterium tuberculosis (Mtb) PknB inhibited transcriptional activity of the DevR response regulator in Mycobacterium smegmatis and that this inhibitory effect was exerted through phosphorylation of DevR on Thr180 within its DNA-binding domain. Moreover, the purified kinase domain of Mtb PknB significantly phosphorylated RegX3, NarL, KdpE, TrcR, DosR, and MtrA response regulators of Mtb that contain the Thr residues corresponding to Thr180 of DevR in their DNA-binding domains, implying that transcriptional activities of these response regulators might also be inhibited when the kinase domain of PknB is overexpressed.


Assuntos
Hipóxia Celular/genética , Mycobacterium smegmatis/genética , Mycobacterium tuberculosis/genética , Proteínas Serina-Treonina Quinases/genética , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Regulação Bacteriana da Expressão Gênica/genética , Humanos , Mycobacterium smegmatis/metabolismo , Mycobacterium tuberculosis/metabolismo , Mycobacterium tuberculosis/patogenicidade , Oxigênio/química , Oxigênio/metabolismo , Fosforilação , Protamina Quinase/genética , Protamina Quinase/metabolismo , Proteínas Quinases/genética , Proteínas Quinases/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Tuberculose/genética , Tuberculose/microbiologia
6.
Adv Mater ; 29(12)2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28128879

RESUMO

Vertical stacking and lateral growth of molybdenum disulfide (MoS2 ) are controlled with remarkable precision, and MoS2 nanotubes are directly converted from nanofibers. Predictive synthesis is enabled by identifying the specific thermodynamic region where the Boudouard reaction becomes favored. It reveals how the chemical potential of each species in the MoSCO system can predict phase behaviors.

7.
Adv Mater ; 28(8): 1636-43, 2016 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-26684678

RESUMO

UNLABELLED: Organogel-based stretchable electronic conductors exhibit electrical conduction even under a large stretching deformation of 300% without electrochemical reactions at DC voltages. The resistance change with stretching is almost strain-insensitive up to 50% strain and it remains at each deformation up to 1000 fatigue cycle. The polymeric conductive paths of PEDOT: PSS are well preserved during the mechanical deformation.

8.
Mol Cytogenet ; 6(1): 21, 2013 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-23725218

RESUMO

BACKGROUND: Array comparative genomic hybridization (CGH) is a powerful tool for detecting unbalanced chromosomal alterations. To validate the usefulness of array CGH in newborn screening, we examined 20,126 unselected infants. In addition, the number of newborns analyzed with array CGH is the largest one ever reported. FINDINGS: A total of 20,126 unselected newborns were investigated with array CGH and cytogenetic analyses. The analyses revealed 87 cases with chromosome abnormalities. Of these, 53 cases had significant chromosome aneuploidies, including trisomy 13, trisomy 21, 47,XXY or 45,X, and the other 34 cases presented partial chromosomal deletions or duplications. CONCLUSIONS: In this study, we show that array CGH is an appropriate tool for the screening of chromosomal abnormalities in newborns, especially for the infants without distinct clinical features.

9.
Mol Cytogenet ; 6(1): 22, 2013 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-23731833

RESUMO

BACKGROUND: Chromosomal abnormalities are common in embryos produced in vitro and cause implantation failure, miscarriage, and serious medical problems in infants. Because preimplantation genetic screening (PGS) is increasingly being used to detect aneuploidy in embryos with the purpose of improving implantation rates after IVF (in vitro fertilization), we aimed to validate the usefulness of array CGH for the preimplantation genetic screening (PGS) of embryos at the blastocyst stage of development. RESULTS: A total of 150 blastocysts were biopsied from couples undergoing IVF and analyzed using array CGH. We found that 54.5% (73/134) of the blastocysts were euploid embryos, whereas 45.5% of the embryos (61/134) had chromosomal abnormalities. Multiple chromosome abnormality was most frequently observed (34.4%), and dual aneuploidy was observed in 26.2% of the embryos. Monosomy (21.3%) appeared more frequently than trisomy (18%). CONCLUSION: Chromosomal microarray analysis provided clinically significant cytogenetic information regarding the frequency and variety of chromosomal abnormalities observed in embryos at the blastocyst stage, suggesting that this is a useful tool for comprehensive aneuploidy screening in IVF.

10.
Phys Chem Chem Phys ; 15(6): 2117-24, 2013 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-23288103

RESUMO

The enhancement of the electrical conductivity by doping is important in hematite (α-Fe(2)O(3)) photoanodes for efficient solar water oxidation. However, in spite of many successful demonstrations using extrinsic dopants, such as Sn, Ti, and Si, the achieved photocurrent is still lower than the practical requirement. There is still lack of our understanding of how intrinsic oxygen defects can change the photocurrent and interact with the extrinsic dopants. In this study, we systematically investigate the interplay of oxygen vacancies and extrinsic Sn dopants in the context of photoanodic properties. As a result, we demonstrate that the controlled generation of oxygen vacancies can activate the photoactivity of pure hematite remarkably and further enhance the Sn doping effects synergistically. Furthermore, the correlated behavior of oxygen vacancies and Sn dopants is closely linked to the variation of electrical conductance and results in the optimum concentration region to show the high photocurrent and low onset voltage.

11.
PLoS One ; 6(10): e26896, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22046399

RESUMO

Leucine-responsive regulatory protein (Lrp) is known to be an indirect activator of type 1 fimbriae synthesis in Salmonella enterica serovar Typhimurium via direct regulation of FimZ, a direct positive regulator for type 1 fimbriae production. Using RT-PCR, we have shown previously that fimA transcription is dramatically impaired in both lrp-deletion (Δlrp) and constitutive-lrp expression (lrp(C)) mutant strains. In this work, we used chromosomal P(fimA)-lacZ fusions and yeast agglutination assays to confirm and extend our previous results. Direct binding of Lrp to P(fimA) was shown by an electrophoretic mobility shift assay (EMSA) and DNA footprinting assay. Site-directed mutagenesis revealed that the Lrp-binding motifs in P(fimA) play a role in both activation and repression of type 1 fimbriae production. Overproduction of Lrp also abrogates fimZ expression. EMSA data showed that Lrp and FimZ proteins independently bind to P(fimA) without competitive exclusion. In addition, both Lrp and FimZ binding to P(fimA) caused a hyper retardation (supershift) of the DNA-protein complex compared to the shift when each protein was present alone. Nutrition-dependent cellular Lrp levels closely correlated with the amount of type 1 fimbriae production. These observations suggest that Lrp plays important roles in type 1 fimbriation by acting as both a positive and negative regulator and its effect depends, at least in part, on the cellular concentration of Lrp in response to the nutritional environment.


Assuntos
Proteínas de Fímbrias/genética , Fímbrias Bacterianas , Regulação Bacteriana da Expressão Gênica/fisiologia , Proteína Reguladora de Resposta a Leucina/fisiologia , Salmonella typhimurium/metabolismo , Antígenos de Bactérias/metabolismo , Proteínas de Fímbrias/biossíntese , Proteínas de Fímbrias/metabolismo , Proteína Reguladora de Resposta a Leucina/metabolismo , Ligação Proteica
12.
Mol Cytogenet ; 4: 12, 2011 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-21549014

RESUMO

BACKGROUND: Array comparative genomic hybridization (CGH) is currently the most powerful method for detecting chromosomal alterations in pre and postnatal clinical cases. In this study, we developed a BAC based array CGH analysis platform for detecting whole genome DNA copy number changes including specific micro deletion and duplication chromosomal disorders. Additionally, we report our experience with the clinical implementation of our array CGH analysis platform. Array CGH was performed on 5080 pre and postnatal clinical samples from patients referred with a variety of clinical phenotypes. RESULTS: A total of 4073 prenatal cases (4033 amniotic fluid and 40 chorionic villi specimens) and 1007 postnatal cases (407 peripheral blood and 600 cord blood) were studied with complete concordance between array CGH, karyotype and fluorescence in situ hybridization results. Among 75 positive prenatal cases with DNA copy number variations, 60 had an aneuploidy, seven had a deletion, and eight had a duplication. Among 39 positive postnatal cases samples, five had an aneuploidy, 23 had a deletion, and 11 had a duplication. CONCLUSIONS: This study demonstrates the utility of using our newly developed whole-genome array CGH as first-tier test in 5080 pre and postnatal cases. Array CGH has increased the ability to detect segmental deletion and duplication in patients with variable clinical features and is becoming a more powerful tool in pre and postnatal diagnostics.

13.
PLoS One ; 5(7): e11855, 2010 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-20686617

RESUMO

SNP markers provide the primary data for population structure analysis. In this study, we employed whole-genome autosomal SNPs as a marker set (54,836 SNP markers) and tested their possible effects on genetic ancestry using 320 subjects covering 24 regional groups including Northern (=16) and Southern (=3) Asians, Amerindians (=1), and four HapMap populations (YRI, CEU, JPT, and CHB). Additionally, we evaluated the effectiveness and robustness of 50K autosomal SNPs with various clustering methods, along with their dependencies on recombination hotspots (RH), linkage disequilibrium (LD), missing calls and regional specific markers. The RH- and LD-free multi-dimensional scaling (MDS) method showed a broad picture of human migration from Africa to North-East Asia on our genome map, supporting results from previous haploid DNA studies. Of the Asian groups, the East Asian group showed greater differentiation than the Northern and Southern Asian groups with respect to Fst statistics. By extension, the analysis of monomorphic markers implied that nine out of ten historical regions in South Korea, and Tokyo in Japan, showed signs of genetic drift caused by the later settlement of East Asia (South Korea, Japan and China), while Gyeongju in South East Korea showed signs of the earliest settlement in East Asia. In the genome map, the gene flow to the Korean Peninsula from its neighboring countries indicated that some genetic signals from Northern populations such as the Siberians and Mongolians still remain in the South East and West regions, while few signals remain from the early Southern lineages.


Assuntos
Fluxo Gênico/genética , Grupo com Ancestrais do Continente Asiático , China , Genótipo , Humanos , Japão , Polimorfismo de Nucleotídeo Único/genética , República da Coreia
14.
J Microbiol Biotechnol ; 18(6): 1064-9, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18600048

RESUMO

Levan fructotransferase (LFTase) preferentially catalyzes the transfructosylation reaction in addition to levan hydrolysis, whereas other levan-degrading enzymes hydrolyze levan into a levan-oligosaccharide and fructose. Based on sequence comparisons and enzymatic properties, the fructosyl transfer activity of LFTase is proposed to have evolved from levanase. In order to probe the residues that are critical to the intramolecular fructosyl transfer reaction of the Microbacterium sp. AL-210 LFTase, an error-prone PCR mutagenesis process was carried out, and the mutants that led to a shift in activity from transfructosylation towards hydrolysis of levan were screened by the DNS method. After two rounds of mutagenesis, TLC and HPLC analyses of the reaction products by the selected mutants revealed two major products; one is a di-D-fructose- 2,6':6,2'-dianhydride (DFAIV) and the other is a levanbiose. The newly detected levanbiose corresponds to the reaction product from LFTase lacking transferring activity. Two mutants (2-F8 and 2-G9) showed a high yield of levanbiose (38-40%) compared with the wild-type enzyme, and thus behaved as levanases. Sequence analysis of the individual mutants responsible for the enhanced hydrolytic activity indicated that Asn-85 was highly involved in the transfructosylation activity of LFTase.


Assuntos
Actinomycetales/enzimologia , Actinomycetales/genética , Hexosiltransferases/genética , Hexosiltransferases/metabolismo , Sítios de Ligação , Cromatografia Líquida de Alta Pressão , Cromatografia em Camada Delgada , Dissacarídeos/biossíntese , Escherichia coli/enzimologia , Escherichia coli/genética , Frutanos/biossíntese , Frutanos/metabolismo , Hidrólise , Mutagênese , Reação em Cadeia da Polimerase
15.
J Bacteriol ; 189(15): 5617-25, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17557830

RESUMO

In this study, the H303A mutant form of the cbb(3) oxidase (H303A oxidase), which has the H303A mutation in its catalytic subunit (CcoN), was purified from Rhodobacter sphaeroides. The H303A oxidase showed the same catalytic activity as did the wild-type form of the oxidase (WT oxidase). The heme contents of the mutant and WT forms of the cbb(3) oxidase were also comparable. However, the puf and puc operons, which are under the control of the PrrBA two-component system, were shown to be derepressed aerobically in the R. sphaeroides strain expressing the H303A oxidase. Since the strain harboring the H303A oxidase exhibited the same cytochrome c oxidase activity as the stain harboring the WT oxidase did, the aerobic derepression of photosynthesis gene expression observed in the H303A mutant appears to be the result of a defective signaling function of the H303A oxidase rather than reflecting any redox changes in the ubiquinone/ubiquinol pool. It was also demonstrated that ubiquinone inhibits not only the autokinase activity of full-length PrrB but also that of the truncated form of PrrB lacking its transmembrane domain, including the proposed quinone binding sequence. These results imply that the suggested ubiquinone binding site within the PrrB transmembrane domain is not necessary for the inhibition of PrrB kinase activity by ubiquinone. Instead, it is probable that signaling through H303 of the CcoN subunit of the cbb(3) oxidase is part of the pathway through which the cbb(3) oxidase affects the relative kinase/phosphatase activity of the membrane-bound PrrB.


Assuntos
Complexo IV da Cadeia de Transporte de Elétrons/fisiologia , Regulação Bacteriana da Expressão Gênica , Fotossíntese/fisiologia , Proteínas Quinases/metabolismo , Rhodobacter sphaeroides/fisiologia , Substituição de Aminoácidos/genética , Sítios de Ligação , Complexo IV da Cadeia de Transporte de Elétrons/genética , Complexo IV da Cadeia de Transporte de Elétrons/isolamento & purificação , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Histidina Quinase , Mutação de Sentido Incorreto , Fosforilação , Fotossíntese/genética , Rhodobacter sphaeroides/genética , Transdução de Sinais/genética , Ubiquinona/metabolismo
16.
Int J Food Microbiol ; 111(3): 270-5, 2006 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-16876280

RESUMO

The therapeutic potentials of twenty-two medicinal herb species traditionally used in Korea to treat gastrointestinal infections were evaluated for the treatment of salmonellosis. Candidates were primarily screened using the disk-agar method for antibacterial activity against three different Salmonella serotypes. Of the herbs tested, the aqueous and methanolic extracts of Schizandrae Fructus exhibited antibacterial activity against all three Salmonella. The extracts of this herb were further tested against 13 additional Salmonella strains of 6 different serotypes. All of these strains were also affected by these extracts, though the methanolic extract had slightly higher activity. The MIC values of this extract against the 16 Salmonella strains varied from 15.6 to 125 microg/ml. Nine of the 16 strains tested had MIC values of <31.3 microg/ml for the methanolic extract of Schizandrae Fructus. The in vivo antibacterial activity of Schizandrae Fructus extract was examined in a S. Typhimurium infection mouse model. Mice were initially infected with S. Typhimurium, and then administered with Schizandrae Fructus extract. The extract was found to have major effects on mortality and on the numbers of viable S. Typhimurium recovered from feces. Clinical signs and histological damages were rarely observed in the treated mice, whereas the untreated controls showed clinical signs, e.g., lethargy, and histological damage in the kidney, liver, intestine, and spleen. We conclude that Schizandrae Fructus has the potential to provide an effective treatment for salmonellosis.


Assuntos
Antibacterianos/farmacologia , Extratos Vegetais/farmacologia , Plantas Medicinais/química , Intoxicação Alimentar por Salmonella/tratamento farmacológico , Salmonella/efeitos dos fármacos , Animais , Bioensaio , Contagem de Colônia Microbiana , Relação Dose-Resposta a Droga , Farmacorresistência Bacteriana , Humanos , Camundongos , Testes de Sensibilidade Microbiana , Salmonella/crescimento & desenvolvimento
17.
FEBS Lett ; 580(11): 2736-40, 2006 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-16647704

RESUMO

MELDB is a comprehensive protein database of microbial esterases and lipases which are hydrolytic enzymes important in the modern industry. Proteins in MELDB are clustered into groups according to their sequence similarities based on a local pairwise alignment algorithm and a graph clustering algorithm (TribeMCL). This differs from traditional approaches that use global pairwise alignment and joining methods. Our procedure was able to reduce the noise caused by dubious alignment in the distantly related or unrelated regions in the sequences. In the database, 883 esterase and lipase sequences derived from microbial sources are deposited and conserved parts of each protein are identified. HMM profiles of each cluster were generated to classify unknown sequences. Contents of the database can be keyword-searched and query sequences can be aligned to sequence profiles and sequences themselves.


Assuntos
Bactérias/enzimologia , Bases de Dados de Proteínas , Esterases/classificação , Lipase/classificação , Sequência de Aminoácidos , Sítios de Ligação , Sequência Conservada , Esterases/química , Esterases/genética , Lipase/química , Lipase/genética , Dados de Sequência Molecular , Filogenia
18.
Int J Food Microbiol ; 110(2): 123-6, 2006 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-16682093

RESUMO

Enterohemorrhagic Escherichia coli (EHEC) is an important cause of diarrhea, hemorrhagic colitis and hemolytic uremic syndrome worldwide. E. coli O26 and O111 are the serotypes most frequently isolated from human EHEC infections in Korea. Cattle are considered to be the major sources of E. coli O26 and O111. This study investigated the prevalence of E. coli O26 and O111 in fecal samples from cattle in Korea from April 2002 to March 2004. Out of 809 samples, 54 (6.67%), 37 (4.57%), and 16 (1.98%) tested positive for O26, O111, and both O26 and O111, respectively. Most of the E. coli O26 and O111 strains were isolated from May to October of each year. PCR analysis of the EHEC virulence markers revealed that most of the E. coli O26 and O111 isolates were positive for ehxA, eaeA and stx1 and/or stx2. These results suggest that the majority of Korean E. coli O26 and O111 isolates from cattle can cause serious diseases in humans.


Assuntos
Doenças dos Bovinos/epidemiologia , Infecções por Escherichia coli/veterinária , Escherichia coli/isolamento & purificação , Animais , Bovinos , Doenças dos Bovinos/microbiologia , Doenças dos Bovinos/transmissão , Qualidade de Produtos para o Consumidor , Reservatórios de Doenças/microbiologia , Reservatórios de Doenças/veterinária , Escherichia coli/classificação , Infecções por Escherichia coli/epidemiologia , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/transmissão , Fezes/microbiologia , Coreia (Geográfico)/epidemiologia , Reação em Cadeia da Polimerase/métodos , Reação em Cadeia da Polimerase/veterinária , Prevalência , Medição de Risco , Estações do Ano , Sorotipagem
19.
Haematologica ; 91(5): 659-62, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16627254

RESUMO

To identify a fast and sensitive method for screening for mutations in patients with imatinib- resistant chronic myeloid leukemia (CML), we compared allele specific oligonucleotide- polymerase chain reaction (ASO-PCR) assay with conventional direct sequencing. Among the 68 imatinib resistant CML patients studied, 18 amino acid substitutions were detected in 44 patients by two assays. The sensitivity of ASO-PCR was superior to that of direct sequencing as it could detect one mutant allele in 100 approximately 100,000 wild type sequences. The fastness, simplicity, and sensitivity of ASO-PCR assays will be useful for routine monitoring of mutations, especially for frequently identified mutations.


Assuntos
Antineoplásicos/farmacologia , Resistencia a Medicamentos Antineoplásicos/genética , Proteínas de Fusão bcr-abl/genética , Genes abl , Testes Genéticos/métodos , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Piperazinas/farmacologia , Reação em Cadeia da Polimerase/métodos , Inibidores de Proteínas Quinases/farmacologia , Pirimidinas/farmacologia , Análise de Sequência de DNA , Alelos , Substituição de Aminoácidos , Antineoplásicos/uso terapêutico , Benzamidas , Proteínas de Fusão bcr-abl/antagonistas & inibidores , Humanos , Mesilato de Imatinib , Células K562/efeitos dos fármacos , Células K562/enzimologia , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Leucemia Mielogênica Crônica BCR-ABL Positiva/enzimologia , Mutação de Sentido Incorreto , Piperazinas/uso terapêutico , Mutação Puntual , Inibidores de Proteínas Quinases/uso terapêutico , Pirimidinas/uso terapêutico , Sensibilidade e Especificidade , Fatores de Tempo
20.
Nucleic Acids Res ; 33(22): 7066-73, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16352867

RESUMO

Harmful algal blooms, caused by rapid growth and accumulation of certain microalgae in the ocean, pose considerable impacts on marine environments, aquatic industries and even public health. Here, we present the 7.2-megabase genome of the marine bacterium Hahella chejuensis including genes responsible for the biosynthesis of a pigment which has the lytic activity against a red-tide dinoflagellate. H.chejuensis is the first sequenced species in the Oceanospiralles clade, and sequence analysis revealed its distant relationship to the Pseudomonas group. The genome was well equipped with genes for basic metabolic capabilities and contained a large number of genes involved in regulation or transport as well as with characteristics as a marine heterotroph. Sequence analysis also revealed a multitude of genes of functional equivalence or of possible foreign origin. Functions encoded in the genomic islands include biosynthesis of exopolysacchrides, toxins, polyketides or non-ribosomal peptides, iron utilization, motility, type III protein secretion and pigmentation. Molecular structure of the algicidal pigment, which was determined through LC-ESI-MS/MS and NMR analyses, indicated that it is prodigiosin. In conclusion, our work provides new insights into mitigating algal blooms in addition to genetic make-up, physiology, biotic interactions and biological roles in the community of a marine bacterium.


Assuntos
Antiprotozoários/farmacologia , Dinoflagelados/efeitos dos fármacos , Gammaproteobacteria/genética , Genoma Bacteriano , Fitoplâncton/efeitos dos fármacos , Prodigiosina/farmacologia , Adaptação Fisiológica , Animais , Antiprotozoários/química , Antiprotozoários/metabolismo , Sequência de Bases , Gammaproteobacteria/classificação , Gammaproteobacteria/metabolismo , Genômica , Dados de Sequência Molecular , Oceanos e Mares , Filogenia , Prodigiosina/biossíntese , Prodigiosina/química , Virulência/genética
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