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1.
PLoS Comput Biol ; 18(3): e1009949, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35286300

RESUMO

Automatic characterization of fluorescent labeling in intact mammalian tissues remains a challenge due to the lack of quantifying techniques capable of segregating densely packed nuclei and intricate tissue patterns. Here, we describe a powerful deep learning-based approach that couples remarkably precise nuclear segmentation with quantitation of fluorescent labeling intensity within segmented nuclei, and then apply it to the analysis of cell cycle dependent protein concentration in mouse tissues using 2D fluorescent still images. First, several existing deep learning-based methods were evaluated to accurately segment nuclei using different imaging modalities with a small training dataset. Next, we developed a deep learning-based approach to identify and measure fluorescent labels within segmented nuclei, and created an ImageJ plugin to allow for efficient manual correction of nuclear segmentation and label identification. Lastly, using fluorescence intensity as a readout for protein concentration, a three-step global estimation method was applied to the characterization of the cell cycle dependent expression of E2F proteins in the developing mouse intestine.


Assuntos
Aprendizado Profundo , Animais , Ciclo Celular , Proteínas de Ciclo Celular , Núcleo Celular , Processamento de Imagem Assistida por Computador/métodos , Mamíferos , Camundongos
2.
Angew Chem Int Ed Engl ; 62(29): e202305994, 2023 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-37199102

RESUMO

We show that cation ordering on A site columns, oppositely displaced via coupling to B site octahedral tilts, results in a polar phase of the columnar perovskite (NaY)MnMnTi4 O12 . This scheme is similar to hybrid improper ferroelectricity found in layered perovskites, and can be considered a realisation of hybrid improper ferroelectricity in columnar perovskites. The cation ordering is controlled by annealing temperature and when present it also polarises the local dipoles associated with pseudo-Jahn-Teller active Mn2+ ions to establish an additional ferroelectric order out of an otherwise disordered dipolar glass. Below TN ≈12 K, Mn2+ spins order, making the columnar perovskites rare systems in which ordered electric and magnetic dipoles may reside on the same transition metal sublattice.

3.
Crit Rev Biochem Mol Biol ; 55(5): 409-424, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32878499

RESUMO

The fragile X-related (FXR) family proteins FMRP, FXR1, and FXR2 are RNA binding proteins that play a critical role in RNA metabolism, neuronal plasticity, and muscle development. These proteins share significant homology in their protein domains, which are functionally and structurally similar to each other. FXR family members are known to play an essential role in causing fragile X mental retardation syndrome (FXS), the most common genetic form of autism spectrum disorder. Recent advances in our understanding of this family of proteins have occurred in tandem with discoveries of great importance to neurological disorders and cancer biology via the identification of their novel RNA and protein targets. Herein, we review the FXR family of proteins as they pertain to FXS, other mental illnesses, and cancer. We emphasize recent findings and analyses that suggest contrasting functions of this protein family in FXS and tumorigenesis based on their expression patterns in human tissues. Finally, we discuss current gaps in our knowledge regarding the FXR protein family and their role in FXS and cancer and suggest future studies to facilitate bench to bedside translation of the findings.


Assuntos
Proteína do X Frágil da Deficiência Intelectual/metabolismo , Neoplasias/metabolismo , Transtornos do Neurodesenvolvimento/metabolismo , Proteínas de Ligação a RNA/metabolismo , Proteína do X Frágil da Deficiência Intelectual/genética , Síndrome do Cromossomo X Frágil/metabolismo , Humanos , Mutação , Proteínas de Ligação a RNA/genética
4.
J Am Chem Soc ; 143(12): 4633-4638, 2021 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-33724822

RESUMO

The [Zn1-xNix(HF2)(pyz)2]SbF6 (x = 0.2; pyz = pyrazine) solid solution exhibits a zero-field splitting (D) that is 22% larger [D = 16.2(2) K (11.3(2) cm-1)] than that observed in the x = 1 material [D = 13.3(1) K (9.2(1) cm-1)]. The substantial change in D is accomplished by an anisotropic lattice expansion in the MN4 (M = Zn or Ni) plane, wherein the increased concentration of isotropic Zn(II) ions induces a nonlinear variation in M-F and M-N bond lengths. In this, we exploit the relative donor atom hardness, where M-F and M-N form strong ionic and weak coordinate covalent bonds, respectively, the latter being more sensitive to substitution of Ni by the slightly larger Zn(II) ion. In this way, we are able to tune the single-ion anisotropy of a magnetic lattice site by Zn-substitution on nearby sites. This effect has possible applications in the field of single-ion magnets and the design of other molecule-based magnetic systems.

5.
Virol J ; 17(1): 3, 2020 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-31910855

RESUMO

A previously isolated a bacteriophage, vB_EcoS_AKFV33 of T5virus, demonstrated great potential in biocontrol of Shiga toxigenic Escherichia coli (STEC) O157. This study further evaluated its potential as a biocontrol agent in broth culture against other important non-O157 serogroups of STEC and Salmonella. AKFV33 was capable of lysing isolates of STEC serogroups O26 (n = 1), O145 (n = 1) and Salmonella enterica serovars (n = 6). In a broth culture microplate system, efficacy of AKFV33 for killing STEC O26:H11, O145:NM and Salmonella was improved (P < 0.05) at a lower multiplicity of infection and sampling time (6-10 h), when STEC O157:H7 was also included in the culture. This phage was able to simultaneously reduce numbers of STEC and Salmonella in mixtures with enhanced activity (P < 0.05) against O157:H7 and O26:H11, offering great promise for control of multiple zoonotic pathogens at both pre and post-harvest.


Assuntos
Salmonella/crescimento & desenvolvimento , Salmonella/virologia , Escherichia coli Shiga Toxigênica/crescimento & desenvolvimento , Escherichia coli Shiga Toxigênica/virologia , Siphoviridae/fisiologia , Técnicas Bacteriológicas , Agentes de Controle Biológico , Salmonella/classificação , Sorogrupo
6.
Inorg Chem ; 59(13): 9065-9076, 2020 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-32515189

RESUMO

The formation of NaRMn2Ti4O12 compounds (R = rare earth) under high pressure (about 6 GPa) and high temperature (about 1750 K) conditions was studied. Such compounds with R = Sm, Eu, Gd, Dy, Ho, Y adopt an A-site columnar-ordered quadruple-perovskite structure with the generic chemical formula A2A'A″B4O12. Their crystal structures were studied by powder synchrotron X-ray and neutron diffraction between 1.5 and 300 K. They maintain a paraelectric structure with centrosymmetric space group P42/nmc (No. 137) at all temperatures, in comparison with the related CaMnTi2O6 perovskite, in which a ferroelectric transition occurs at 630 K. The centrosymmetric structure was also confirmed by second-harmonic generation. It has a cation distribution of [Na+R3+]A[Mn2+]A'[Mn2+]A″[Ti4+4]BO12 (to match with the generic chemical formula) with statistical distributions of Na+ and R3+ at the large A site and a strongly split position of Mn2+ at the square-planar A' site. We found a C-type long-range antiferromagnetic structure of Mn2+ ions at the A' and A″ sites below TN = 12 K for R = Dy and found that the presence of Dy3+ disturbs the long-range ordering of Mn2+ below a second transition at lower temperatures. The first magnetic transition occurs below 8-13 K in all compounds, but the second magnetic transition occurs only for R = Dy, Sm, Eu. All compounds show large dielectric constants of a possible extrinsic origin similar to that of CaCu3Ti4O12. NaRMn2Ti4O12 with R = Er-Lu crystallized in the GdFeO3-type Pnma perovskite structure, and NaRMn2Ti4O12 with R = La, Nd contained two perovskite phases: an AA'3B4O12-type Im3̅ phase and a GdFeO3-type Pnma phase.

7.
Chemphyschem ; 19(19): 2449-2452, 2018 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-29938885

RESUMO

There is an emerging topic in the science of perovskite materials: A-site columnar-ordered A2 A'A''B4 O12 quadruple perovskites, which have an intrinsic triple order at the A sites. However, in many examples reported so far, A' and A'' cations are the same, and the intrinsic triple order is hidden. Here, we investigate structural properties of Dy2 CuMnMn4 O12 (1) and Ho2 MnGaMn4 O12 (2) by neutron and X-ray powder diffraction and prove the triple order at the A sites. The cation distributions determined are [Ho2 ]A [Mn]A' [Ga0.66 Mn0.34 ]A'' [Mn3.66 Ga0.34 ]B O12 and [Dy2 ]A [Cu0.73 Mn0.27 ]A' [Mn0.80 Dy0.20 ]A'' [Mn1.89 Cu0.11 ]B1 [Mn2 ]B2 O12 . There are clear signatures of Jahn-Teller distortions in 1 and 2, and the orbital pattern is combined with an original type of charge ordering in 1. Columnar-ordered quadruple perovskites represent a new playground to study complex interactions between different electronic degrees of freedom. No long-range magnetic order was found in 2 by neutron diffraction, and its magnetic properties in low fields are dominated by an impurity with negative magnetization or magnetization reversal. On the other hand, 1 shows three magnetic transitions at 21, 125, and 160 K.

8.
Inorg Chem ; 57(10): 5987-5998, 2018 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-29722530

RESUMO

A-site-ordered quadruple perovskites RMn7O12 with R = Sm, Eu, Gd, and Tb were synthesized at high pressure and high temperature (6 GPa and ∼1570 K), and their structural, magnetic, and dielectric properties are reported. They crystallize in space group I2/ m at room temperature. All four compounds exhibit a high-temperature phase transition to the cubic Im3̅ structure at ∼664 K (Sm), 663 K (Eu), 657 K (Gd), and 630 K (Tb). They all show one magnetic transition at TN1 ≈ 82-87 K at zero magnetic field, but additional magnetic transitions below TN2 ≈ 12 K were observed in SmMn7O12 and EuMn7O12 at high magnetic fields. Very weak kinklike dielectric anomalies were observed at TN1 in all compounds. We also observed pyroelectric current peaks near 14 K and frequency-dependent sharp steps in dielectric constant (near 18-35 K)-these anomalies are probably caused by dielectric relaxation, and they are not related to any ferroelectric transitions. TbMn7O12 shows signs of nonstoichiometry expressed as (Tb1- xMn x)Mn7O12, and these samples exhibit negative magnetization or magnetization reversal effects of an extrinsic origin on zero-field-cooled curves in intermediate temperature ranges. The crystal structures of SmMn7O12 and EuMn7O12 were refined from neutron powder diffraction data at 100 K, and the crystal structures of GdMn7O12 and (Tb0.88Mn0.12)Mn7O12 were studied by synchrotron X-ray powder diffraction at 295 K.

9.
Appl Environ Microbiol ; 82(17): 5340-53, 2016 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-27342557

RESUMO

UNLABELLED: Bacteriophages present huge potential both as a resource for developing novel tools for bacterial diagnostics and for use in phage therapy. This potential is also valid for bacteriophages specific for Yersinia enterocolitica To increase our knowledge of Y. enterocolitica-specific phages, we characterized two novel yersiniophages. The genomes of the bacteriophages vB_YenM_TG1 (TG1) and vB_YenM_ϕR1-RT (ϕR1-RT), isolated from pig manure in Canada and from sewage in Finland, consist of linear double-stranded DNA of 162,101 and 168,809 bp, respectively. Their genomes comprise 262 putative coding sequences and 4 tRNA genes and share 91% overall nucleotide identity. Based on phylogenetic analyses of their whole-genome sequences and large terminase subunit protein sequences, a genus named Tg1virus within the family Myoviridae is proposed, with TG1 and ϕR1-RT (R1RT in the ICTV database) as member species. These bacteriophages exhibit a host range restricted to Y. enterocolitica and display lytic activity against the epidemiologically significant serotypes O:3, O:5,27, and O:9 at and below 25°C. Adsorption analyses of lipopolysaccharide (LPS) and OmpF mutants demonstrate that these phages use both the LPS inner core heptosyl residues and the outer membrane protein OmpF as phage receptors. Based on RNA sequencing and quantitative proteomics, we also demonstrate that temperature-dependent infection is due to strong repression of OmpF at 37°C. In addition, ϕR1-RT was shown to be able to enter into a pseudolysogenic state. Together, this work provides further insight into phage-host cell interactions by highlighting the importance of understanding underlying factors which may affect the abundance of phage host receptors on the cell surface. IMPORTANCE: Only a small number of bacteriophages infecting Y. enterocolitica, the predominant causative agent of yersiniosis, have been previously described. Here, two newly isolated Y. enterocolitica phages were studied in detail, with the aim of elucidating the host cell receptors required for infection. Our research further expands the repertoire of phages available for consideration as potential antimicrobial agents or as diagnostic tools for this important bacterial pathogen.


Assuntos
Proteínas de Bactérias/metabolismo , Bacteriófagos/fisiologia , Especificidade de Hospedeiro , Porinas/metabolismo , Receptores Virais/metabolismo , Yersinia enterocolitica/virologia , Proteínas de Bactérias/genética , Bacteriófagos/classificação , Bacteriófagos/genética , Bacteriófagos/isolamento & purificação , Genoma Viral , Humanos , Filogenia , Porinas/genética , Receptores Virais/genética , Temperatura , Replicação Viral , Yersiniose/microbiologia , Yersinia enterocolitica/genética , Yersinia enterocolitica/metabolismo
10.
BMC Microbiol ; 16: 20, 2016 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-26879347

RESUMO

BACKGROUND: Salmonellae are major worldwide zoonotic pathogens infecting a wide range of vertebrate species including humans. Consumption of contaminated dairy products and contact with dairy cattle represent a common source of non-typhoidal Salmonella infection in humans. Despite a large number of small-scale dairy farms in Addis Ababa and its surrounding districts, little is known about the status of Salmonella in these farms. RESULTS: Salmonella was recovered from the feces of at least one animal in 7.6% (10/132) of the dairy farms. Out of 1203 fecal samples examined, 30 were positive for Salmonella resulting in a weighted animal level prevalence of 2.3%. Detection of diarrhea in an animal and in a farm was significantly associated with animal level (p = 0.012) and herd level (p < 0.001) prevalence of Salmonella. Animal level prevalence of Salmonella was significantly associated with age (p = 0.023) and study location; it was highest among those under 6 months of age and in farms from Adaa district and Addis Ababa (p < 0.001). Nine different serotypes were identified using standard serological agglutination tests. The most frequently recovered serotypes were Salmonella Typhimurium (23.3%), S. Saintpaul (20%), S. Kentucky (16.7%) and S. Virchow (16.7%). All isolates were resistant or intermediately resistant to at least one of the 18 drugs tested. Twenty-six (86.7%), 19 (63.3 %), 18 (60%), 16 (53.3%) of the isolates were resistant to streptomycin, nitrofurantoin, sulfisoxazole and tetracycline , respectively. Resistance to 2 drugs was detected in 27 (90%) of the isolates. Resistance to 3 or more drugs was detected in 21 (70%) of the isolates, while resistance to 7 or more drugs was detected in 11 (36.7%) of the isolates. The rate of occurrence of multi-drug resistance (MDR) in Salmonella strains isolated from dairy farms in Addis Ababa was significantly higher than those isolated from farms outside of Addis Ababa (p = 0.009). MDR was more common in S. Kentucky, S. Virchow and S. Saintpaul. CONCLUSION: Isolation of Salmonella serotypes commonly known for causing human salmonellosis that are associated with an MDR phenotype in dairy farms in close proximity with human population is a major public health concern. These findings imply the need for a strict pathogen reduction strategy.


Assuntos
Farmacorresistência Bacteriana , Fezes/microbiologia , Salmonelose Animal/microbiologia , Salmonella/isolamento & purificação , Animais , Antibacterianos/farmacologia , Bovinos , Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/microbiologia , Estudos Transversais , Etiópia/epidemiologia , Feminino , Humanos , Masculino , Testes de Sensibilidade Microbiana , Prevalência , Salmonella/classificação , Salmonella/efeitos dos fármacos , Salmonella/genética , Infecções por Salmonella/microbiologia , Sorogrupo
11.
Foodborne Pathog Dis ; 13(6): 316-24, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-27023165

RESUMO

The objectives of this study were to characterize the phenotype and genotype of 36 non-O157 Shiga toxin-producing Escherichia coli (STEC) strains isolated from humans, ovines, or bovines, including the top 6 (O26, O45, O103, O111, O121, and O145) and three other serogroups implicated in serious illness (O91, O113, and O128). Biofilms were formed by all strains with intermediate to strong biofilm producers (n = 24) more common at 22°C than at 37°C (p < 0.001) and 48 and 72 h (p < 0.001) than 24 h of incubation time. Biofilm-forming potential differed by serogroup and origin with O113 and human strains exhibiting the highest potential (p < 0.001). Biofilm-associated genes, csgA/csgD/crl/fimH (100%), flu (94%), rpoS (92%), ehaA(α) (89%), and cah (72%), were most prevalent, while mlrA (22%) and ehaA(ß) (14%) were least prevalent, although there was no clear compliment of genes associated with strains exhibiting the greatest biofilm-forming capacity. Among 12 virulence genes screened, iha and ehxA were present in 92% of the strains. The occurrence of stx1 in the top 6 serogroups (8/12, 67%) did not differ (p = 0.8) from other serogroups (17/24, 71%), but stx2 was less likely (confidence interval [CI] = 0.14-1.12; p = 0.04) to be in the former (9/24, 38%) than the latter (9/12, 75%). Excluding serogroups, O91 and O121, at least one strain per serogroup was resistant to between three and six antimicrobials. Streptomycin (31%), sulfisoxazole (31%), and tetracycline (25%) resistance was most common and was 35-50% less likely (p < 0.05) in human than animal strains. All non-O157 STEC strains were able to form biofilms on an abiotic surface, with some exhibiting resistance to multiple antimicrobials. Potential as a reservoir of antimicrobial resistance genes may be another hazard of biofilms in food-processing plants. As a result, future strategies to control these pathogens may include measures to prevent biofilms.


Assuntos
Biofilmes , Escherichia coli Shiga Toxigênica/fisiologia , Animais , Antibacterianos/farmacologia , Biofilmes/crescimento & desenvolvimento , Canadá , Bovinos , Farmacorresistência Bacteriana , Microbiologia de Alimentos , Humanos , Fenótipo , Sorogrupo , Ovinos , Escherichia coli Shiga Toxigênica/classificação , Escherichia coli Shiga Toxigênica/efeitos dos fármacos , Escherichia coli Shiga Toxigênica/genética , Fatores de Virulência/genética
12.
Biochem Biophys Res Commun ; 465(3): 331-7, 2015 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-26255967

RESUMO

Although two-component signaling systems, comprising a sensory histidine kinase and a response regulator, are a primary means by which bacteria detect and respond to environmental stimuli, they are poorly characterized. Here we report optimized conditions for detecting histidine phosphorylation using a facile medium-throughput filter paper-binding assay. Employing this assay we report the kinetic parameters of previously uncharacterized histidine kinases from Vibrio haveyi, Vibrio parahaemolytius, Shewanella oneidensis, and Legionella pneumophila. In characterizing these kinases, we effectively double the number of kinetically characterized histidine kinases that have been reported in the literature.


Assuntos
Autorradiografia/métodos , Proteínas de Bactérias/metabolismo , Bioensaio/métodos , Mapeamento de Interação de Proteínas/métodos , Proteínas Quinases/metabolismo , Proteínas de Bactérias/química , Sítios de Ligação , Ativação Enzimática , Histidina Quinase , Fosforilação , Ligação Proteica , Proteínas Quinases/química
13.
Inorg Chem ; 54(16): 8012-21, 2015 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-26241691

RESUMO

Perovskite materials provide a large variety of interesting physical properties and applications. Here, we report on unique properties of a fully ordered magnetodielectric double-perovskite, Sc2NiMnO6 (space group P21/n, a = 4.99860 Å, b = 5.35281 Å, c = 7.34496 Å, and ß = 90.7915°), exhibiting sequential magnetic transitions at T1 = 35 K and T2 = 17 K. The transition at T1 corresponds to a single-k antiferromagnetic phase with propagation vector k1 = (1/2, 0, 1/2), while the second transition at T2 corresponds to a 2-k magnetic structure with propagation vectors k1 = (1/2, 0, 1/2) and k2 = (0, 1/2, 1/2). Symmetry analysis suggests that the two ordering wave vectors are independent, and calculations imply that k1 is associated with the Mn sublattice and k2 with the Ni sublattice, suggesting that Mn-Ni coupling is very small or absent. A magnetodielectric anomaly at T2 likely arises from an antiferroelectric ordering that results from the exchange-striction between the two magnetic sublattices belonging to k1 and k2. The behavior of Sc2NiMnO6 demonstrates 3d double-perovskites with small A-site cations as a promising avenue in which to search for magnetoelectric materials.

14.
Can J Microbiol ; 61(7): 467-75, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26011668

RESUMO

This study aimed to isolate and characterize bacteriophages that lyse non-O157 Shiga toxin-producing Escherichia coli (STEC) from cattle feces. Of 37 non-O157 STEC-infecting phages isolated, those targeting O26 (AXO26A, AYO26A, AYO26B), O103 (AXO103A, AYO103A), O111 (AXO111A, AYO111A), O121 (AXO121A, AXO121B), and O145 (AYO145A, AYO145B) were further characterized. Transmission electron microscopy showed that the 11 isolates belonged to 3 families and 6 genera: the families Myoviridae (types rV5, T4, ViI, O1), Siphoviridae (type T5), and Podoviridae (type T7). Genome size of the phages as determined by pulsed-field gel electrophoresis ranged from 38 to 177 kb. Excluding phages AXO26A, AYO103A, AYO145A, and AYO145B, all other phages were capable of lysing more than 1 clinically important strain from serogroups of O26, O91, O103, O111, O113, O121, and O128, but none exhibited infectivity across all serogroups. Moreover, phages AYO26A, AXO121A, and AXO121B were also able to lyse 4 common phage types of STEC O157:H7. Our findings show that a diversity of non-O157 STEC-infecting phages are harbored in bovine feces. Phages AYO26A, AYO26B, AXO103A, AXO111A, AYO111A, AXO121A, and AXO121B exhibited a broad host range against a number of serogroups of STEC and have potential for the biocontrol of STEC in the environment.


Assuntos
Bacteriófagos/isolamento & purificação , Bacteriófagos/fisiologia , Biodiversidade , Fezes/microbiologia , Fezes/virologia , Myoviridae/fisiologia , Escherichia coli Shiga Toxigênica/virologia , Siphoviridae/fisiologia , Animais , Bacteriófagos/classificação , Bacteriófagos/genética , Bovinos , Eletroforese em Gel de Campo Pulsado , Especificidade de Hospedeiro , Myoviridae/classificação , Myoviridae/genética , Myoviridae/isolamento & purificação , Escherichia coli Shiga Toxigênica/genética , Escherichia coli Shiga Toxigênica/isolamento & purificação , Siphoviridae/classificação , Siphoviridae/genética , Siphoviridae/isolamento & purificação
15.
Can J Microbiol ; 60(6): 417-8, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24849211

RESUMO

We report a concurrent case of infection with non-O157 Shiga-toxin-producing Escherichia coli (STEC) strain in an 8-month-old child. Laboratory and epidemiological investigations indicated child exposure to contaminated sheep meat following the Muslim feast of sacrifice (Eid al-Adha). Microbiological and molecular typing confirmed that the ovine strain O52:H45 (stx1+, eae-, hlyA-) was the causal agent. This is the first documented case of human infection to this STEC serotype.


Assuntos
Infecções por Escherichia coli/microbiologia , Carne/microbiologia , Escherichia coli Shiga Toxigênica/classificação , Animais , Fezes/microbiologia , Humanos , Lactente , Masculino , Reação em Cadeia da Polimerase em Tempo Real , Sorotipagem , Ovinos , Toxina Shiga I/genética , Escherichia coli Shiga Toxigênica/genética , Escherichia coli Shiga Toxigênica/isolamento & purificação
16.
J Virol ; 86(18): 10246, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22923804

RESUMO

The complete genome sequence of the Escherichia coli O157:H7 typing phage V7 was determined. Its double-stranded DNA genome is 166,452 bp long, encoding 273 proteins and including 11 tRNAs. This virus belongs to the genus T4-like viruses within the subfamily Tevenvirinae, family Myoviridae.


Assuntos
Colífagos/classificação , Colífagos/genética , Escherichia coli O157/virologia , Bacteriófago T4/classificação , Bacteriófago T4/genética , Tipagem de Bacteriófagos , DNA Viral/genética , Genoma Viral , Dados de Sequência Molecular , Myoviridae/classificação , Myoviridae/genética
17.
Virol J ; 10: 76, 2013 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-23497209

RESUMO

BACKGROUND: Bacteriophages (phages) have been used extensively as analytical tools to type bacterial cultures and recently for control of zoonotic foodborne pathogens in foods and in animal reservoirs. METHODS: We examined the host range, morphology, genome and proteome of the lytic E. coli O157 phage rV5, derived from phage V5, which is a member of an Escherichia coli O157:H7 phage typing set. RESULTS: Phage rV5 is a member of the Myoviridae family possessing an icosahedral head of 91 nm between opposite apices. The extended tail measures 121 x 17 nm and has a sheath of 44 x 20 nm and a 7 nm-wide core in the contracted state. It possesses a 137,947 bp genome (43.6 mol%GC) which encodes 233 ORFs and six tRNAs. Until recently this virus appeared to be phylogenetically isolated with almost 70% of its gene products ORFans. rV5 is closely related to coliphages Delta and vB-EcoM-FY3, and more distantly related to Salmonella phages PVP-SE1 and SSE-121, Cronobacter sakazakii phage vB_CsaM_GAP31, and coliphages phAPEC8 and phi92. A complete shotgun proteomic analysis was carried out on rV5, extending what had been gleaned from the genomic analyses. Host range studies revealed that rV5 is active against several other E. coli.


Assuntos
Bacteriófagos/genética , Escherichia coli O157/virologia , Genoma Viral , Especificidade de Hospedeiro , Myoviridae/fisiologia , Bacteriófagos/classificação , Bacteriófagos/isolamento & purificação , Bacteriófagos/fisiologia , Genômica , Dados de Sequência Molecular , Myoviridae/classificação , Myoviridae/genética , Myoviridae/isolamento & purificação , Fases de Leitura Aberta , Filogenia , Proteômica , Proteínas Virais/genética
18.
Mar Drugs ; 11(10): 3777-801, 2013 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-24152557

RESUMO

Although emerging evidence indicates that deep-sea water contains an untapped reservoir of high metabolic and genetic diversity, this realm has not been studied well compared with surface sea water. The study provided the first integrated meta-genomic and -transcriptomic analysis of the microbial communities in deep-sea water of North Pacific Ocean. DNA/RNA amplifications and simultaneous metagenomic and metatranscriptomic analyses were employed to discover information concerning deep-sea microbial communities from four different deep-sea sites ranging from the mesopelagic to pelagic ocean. Within the prokaryotic community, bacteria is absolutely dominant (~90%) over archaea in both metagenomic and metatranscriptomic data pools. The emergence of archaeal phyla Crenarchaeota, Euryarchaeota, Thaumarchaeota, bacterial phyla Actinobacteria, Firmicutes, sub-phyla Betaproteobacteria, Deltaproteobacteria, and Gammaproteobacteria, and the decrease of bacterial phyla Bacteroidetes and Alphaproteobacteria are the main composition changes of prokaryotic communities in the deep-sea water, when compared with the reference Global Ocean Sampling Expedition (GOS) surface water. Photosynthetic Cyanobacteria exist in all four metagenomic libraries and two metatranscriptomic libraries. In Eukaryota community, decreased abundance of fungi and algae in deep sea was observed. RNA/DNA ratio was employed as an index to show metabolic activity strength of microbes in deep sea. Functional analysis indicated that deep-sea microbes are leading a defensive lifestyle.


Assuntos
Archaea/genética , Bactérias/genética , Eucariotos/genética , Variação Genética/genética , Água do Mar/microbiologia , Transcriptoma/genética , Perfilação da Expressão Gênica/métodos , Metagenômica/métodos , Oceano Pacífico
19.
Nat Genet ; 35(4): 318-21, 2003 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-14595441

RESUMO

Congenital fibrosis of the extraocular muscles type 1 (CFEOM1; OMIM #135700) is an autosomal dominant strabismus disorder associated with defects of the oculomotor nerve. We show that individuals with CFEOM1 harbor heterozygous missense mutations in a kinesin motor protein encoded by KIF21A. We identified six different mutations in 44 of 45 probands. The primary mutational hotspots are in the stalk domain, highlighting an important new role for KIF21A and its stalk in the formation of the oculomotor axis.


Assuntos
Variação Genética , Cinesinas/genética , Mutação/genética , Proteínas do Tecido Nervoso/genética , Músculos Oculomotores/patologia , Oftalmoplegia/congênito , Sequência de Aminoácidos , Criança , Feminino , Fibrose , Ligação Genética , Heterozigoto , Humanos , Masculino , Dados de Sequência Molecular , Oftalmoplegia/patologia , Linhagem , Fenótipo , Homologia de Sequência de Aminoácidos
20.
Cell Rep ; 42(4): 112314, 2023 04 25.
Artigo em Inglês | MEDLINE | ID: mdl-37000627

RESUMO

Elucidating the mechanisms of resistance to immunotherapy and developing strategies to improve its efficacy are challenging goals. Bioinformatics analysis demonstrates that high CDK6 expression in melanoma is associated with poor progression-free survival of patients receiving single-agent immunotherapy. Depletion of CDK6 or cyclin D3 (but not of CDK4, cyclin D1, or D2) in cells of the tumor microenvironment inhibits tumor growth. CDK6 depletion reshapes the tumor immune microenvironment, and the host anti-tumor effect depends on cyclin D3/CDK6-expressing CD8+ and CD4+ T cells. This occurs by CDK6 phosphorylating and increasing the activities of PTP1B and T cell protein tyrosine phosphatase (TCPTP), which, in turn, decreases tyrosine phosphorylation of CD3ζ, reducing the signal transduction for T cell activation. Administration of a PTP1B and TCPTP inhibitor prove more efficacious than using a CDK6 degrader in enhancing T cell-mediated immunotherapy. Targeting protein tyrosine phosphatases (PTPs) might be an effective strategy for cancer patients who resist immunotherapy treatment.


Assuntos
Quinase 6 Dependente de Ciclina , Neoplasias , Humanos , Ciclina D3/metabolismo , Quinase 6 Dependente de Ciclina/metabolismo , Transdução de Sinais , Fosforilação , Imunoterapia , Quinase 4 Dependente de Ciclina/metabolismo , Microambiente Tumoral
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