Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 104.391
Filtrar
1.
Arch Virol ; 164(10): 2585-2592, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31377889

RESUMO

Marbled eel reovirus (MERV) is an aquareovirus (AQRV) isolated from diseased marbled eels (Anguilla marmorata) with petechial skin hemorrhage. In this study, we propagated MERV in a cell line derived from the brain of Aequidens rivulatus and purified viral particles by using a discontinuous cesium chloride gradient. Genomic RNA sequences were obtained through next-generation sequencing. MERV, similar to most other AQRVs, showed the presence of 11 double-stranded RNA segments encoding 12 proteins; however, the genome sequence displayed very little similarity to known AQRV sequences. Furthermore, the structural proteins of MERV were most closely related to American grass carp reovirus with sequence identity values of no more than 64.89%. Phylogenetic analysis based on the sequences of structural proteins indicated that MERV shows an evolutionary history between AQRV-B and -G, which belong to the saline and freshwater environment subgroups, respectively. We also observed that MERV showed a closer relationship to orthoreoviruses based on the protein sequences of NS38 and NS73. In summary, MERV is a novel AQRV that could be classified as a member of the new proposed AQRV species "Aquareovirus H". The taxonomic assignments and evolution of AQRVs thus warrant further investigation.


Assuntos
Anguilla/virologia , Doenças dos Peixes/virologia , Infecções por Reoviridae/veterinária , Reoviridae/isolamento & purificação , Animais , Encéfalo/virologia , Linhagem Celular , Genoma Viral , Sequenciamento de Nucleotídeos em Larga Escala , Microscopia Eletrônica de Transmissão , Filogenia , RNA de Cadeia Dupla/genética , RNA Viral/genética , Reoviridae/classificação , Reoviridae/genética , Infecções por Reoviridae/virologia , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos , Coloração e Rotulagem , Proteínas Virais/genética , Vírion/ultraestrutura , Cultura de Vírus
2.
World J Microbiol Biotechnol ; 35(9): 133, 2019 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-31432254

RESUMO

There is a significant increase in the discovery of new antimicrobial compounds in recent past to combat drug resistant pathogens. Members of the genus Bacillus and related genera have been screened extensively due to their ability to produce wide range of antimicrobial compounds. In this study, we have isolated and characterized a new antimicrobial peptide from a marine bacterium identified as Virgibacillus species. The low molecular mass and stability of the antimicrobial substance pointed towards the bacteriocinogenic nature of the compound. The RAST analysis of genome sequence showed presence of a putative bacteriocin biosynthetic cluster containing genes necessary for synthesis of a lanthipeptide. Translated amino acid sequence of mature C-terminal propeptide showed identity with salivaricin A (52.2%) and lacticin A (33.3%). Accordingly, the mass (2417 Da) obtained by MALDI analysis was in agreement with posttranslational modifications of the leader peptide to yield three methyl lanthionine rings and a disulfide bond between two free cysteine residues. The lanthipeptide was named as virgicin, which selectively inhibited the growth of Gram-positive bacteria and biofilm formation by Enterococcus faecalis. Inhibition of biofilm formation by E. faecalis was also observed in in vitro model experiments using hydroxyapatite discs. Thus, virgicin appears to be a promising new bacteriocin to control oral biofilm formation by selective pathogens.


Assuntos
Bacteriocinas/isolamento & purificação , Bacteriocinas/farmacologia , Enterococcus faecalis/efeitos dos fármacos , Enterococcus faecalis/crescimento & desenvolvimento , Peptídeos/isolamento & purificação , Peptídeos/farmacologia , Virgibacillus/metabolismo , Bacteriocinas/química , Bacteriocinas/genética , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Vias Biossintéticas/genética , Genoma Bacteriano , Peso Molecular , Família Multigênica , Peptídeos/química , Peptídeos/genética , Água do Mar/microbiologia , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Virgibacillus/classificação , Virgibacillus/isolamento & purificação
3.
Arch Virol ; 164(10): 2609-2611, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31312966

RESUMO

A new virus belonging to the genus Vitivirus in the family Betaflexiviridae was identified by next-generation sequencing of a blueberry plant showing green mosaic symptoms. The genome organization of the virus, which is tentatively named "blueberry green mosaic-associated virus" (BGMaV), is typical of vitiviruses, with five open reading frames (ORFs) and a polyadenylated 3' terminus. The ORFs code for the viral replicase, a 16K protein of unknown function, a movement protein, a coat protein (CP), and a nucleic acid binding protein. Phylogenetic analyses based on the deduced amino acid sequence of the CP and conserved motifs of the RNA-dependent RNA polymerase confirmed the taxonomic placement of BGMaV in the genus Vitivirus.


Assuntos
Mirtilos Azuis (Planta)/virologia , Flexiviridae/classificação , Flexiviridae/isolamento & purificação , Filogenia , Doenças das Plantas/virologia , Ordem dos Genes , Genoma Viral , Sequenciamento de Nucleotídeos em Larga Escala , Anotação de Sequência Molecular , Fases de Leitura Aberta , RNA Mensageiro , RNA Viral/genética , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos , Proteínas Virais/genética
4.
BMC Med Genet ; 20(1): 101, 2019 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-31174490

RESUMO

BACKGROUND: N-terminal acetylation is a common protein modification in human cells and is catalysed by N-terminal acetyltransferases (NATs), mostly cotranslationally. The NAA10-NAA15 (NatA) protein complex is the major NAT, responsible for acetylating ~ 40% of human proteins. Recently, NAA10 germline variants were found in patients with the X-linked lethal Ogden syndrome, and in other familial or de novo cases with variable degrees of developmental delay, intellectual disability (ID) and cardiac anomalies. METHODS: Here we report a novel NAA10 (NM_003491.3) c.248G > A, p.(R83H) missense variant in NAA10 which was detected by whole exome sequencing in two unrelated boys with intellectual disability, developmental delay, ADHD like behaviour, very limited speech and cardiac abnormalities. We employ in vitro acetylation assays to functionally test the impact of this variant on NAA10 enzyme activity. RESULTS: Functional characterization of NAA10-R83H by in vitro acetylation assays revealed a reduced enzymatic activity of monomeric NAA10-R83H. This variant is modelled to have an altered charge density in the acetyl-coenzyme A (Ac-CoA) binding region of NAA10. CONCLUSIONS: We show that NAA10-R83H has a reduced monomeric catalytic activity, likely due to impaired enzyme-Ac-CoA binding. Our data support a model where reduced NAA10 and/or NatA activity cause the phenotypes observed in the two patients.


Assuntos
Acetiltransferases/genética , Deficiência Intelectual/genética , Microcefalia/genética , Mutação de Sentido Incorreto , Acetiltransferase N-Terminal A/genética , Acetiltransferase N-Terminal E/genética , Acetilação , Acetiltransferases/metabolismo , Sequência de Aminoácidos , Pré-Escolar , Humanos , Lactente , Masculino , Modelos Moleculares , Acetiltransferase N-Terminal A/química , Acetiltransferase N-Terminal A/metabolismo , Acetiltransferase N-Terminal E/química , Acetiltransferase N-Terminal E/metabolismo , Fenótipo , Domínios Proteicos , Homologia de Sequência de Aminoácidos , Sequenciamento Completo do Exoma
5.
Artigo em Inglês | MEDLINE | ID: mdl-31176867

RESUMO

In rice field eel (Monopterus albus), germ cell development in the developing gonad has been revealed in detail. However, it is unclear how primordial germ cells (PGCs) migrate to the somatic part of the gonad (genital ridge). This study visualized PGC migration by injecting a chimeric mRNA containing a fluorescent protein fused to the 3' untranslated region (3'UTR) of three different genes, nanos3 of zebrafish (Danio rerio) and dead end (dnd) and vasa of rice field eel. The mRNAs were injected either alone or in pairs into embryos at the one-cell stage. The results showed that mRNAs containing nanos3 and dnd 3'UTRs labeled PGCs over a wider time frame than those containing vasa 3'UTR, suggesting that nanos3 and dnd 3'UTRs are suitable for visualizing PGCs in rice field eel. Using this direct visualization method, the normal migration route of PGCs was observed from the 50%-epiboly stage to hatching stage for the first time, and the ectopic PGCs were also visualized during this period in rice field eel. These findings extend our knowledge of germ cell development, and lay a foundation for further research on the relationship between PGCs and sex differentiation, and on incubation conditions for embryos in rice field eel.


Assuntos
Células Germinativas/metabolismo , Smegmamorpha/embriologia , Regiões 3' não Traduzidas , Sequência de Aminoácidos , Animais , Movimento Celular/genética , Movimento Celular/fisiologia , RNA Helicases DEAD-box/genética , RNA Helicases DEAD-box/metabolismo , Feminino , Proteínas de Peixes/genética , Proteínas de Peixes/metabolismo , Células Germinativas/citologia , Proteínas Luminescentes/genética , Proteínas Luminescentes/metabolismo , Masculino , RNA/genética , RNA Mensageiro/genética , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Homologia de Sequência de Aminoácidos , Smegmamorpha/genética , Smegmamorpha/metabolismo , Proteínas de Peixe-Zebra/genética , Proteínas de Peixe-Zebra/metabolismo
6.
Nat Commun ; 10(1): 2649, 2019 06 14.
Artigo em Inglês | MEDLINE | ID: mdl-31201333

RESUMO

In human and other mammalian cells, transport of L-lactate across plasma membranes is mainly catalyzed by monocarboxylate transporters (MCTs) of the SLC16 solute carrier family. MCTs play an important role in cancer metabolism and are promising targets for tumor treatment. Here, we report the crystal structures of an SLC16 family homologue with two different bound ligands at 2.54 and 2.69 Å resolution. The structures show the transporter in the pharmacologically relevant outward-open conformation. Structural information together with a detailed structure-based analysis of the transport function provide important insights into the molecular working mechanisms of ligand binding and L-lactate transport.


Assuntos
Proteínas de Bactérias/química , Ácido Láctico/metabolismo , Transportadores de Ácidos Monocarboxílicos/química , Proteínas de Bactérias/isolamento & purificação , Proteínas de Bactérias/metabolismo , Membrana Celular/metabolismo , Cristalografia por Raios X , Transporte de Íons/fisiologia , Ligantes , Transportadores de Ácidos Monocarboxílicos/isolamento & purificação , Transportadores de Ácidos Monocarboxílicos/metabolismo , Proteínas Musculares/química , Ligação Proteica/fisiologia , Estrutura Terciária de Proteína , Proteínas Recombinantes/química , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Relação Estrutura-Atividade , Simportadores/química
7.
BMC Med Genet ; 20(1): 76, 2019 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-31064337

RESUMO

BACKGROUND: Brown-Vialetto-Van Laere Syndrome (BVVLS), a rare neurological disorder characterized by motor, sensory, and cranial neuronopathies, is mainly associated with defective riboflavin transporters encoded by SLC52A2 and SLC52A3 genes. Clinical outcomes have been shown to be improved significantly by high-dose riboflavin supplementation. The aim of this study was to identify genetic causes and further evaluate the clinical course and response to riboflavin in a Chinese pedigree with BVVLS. CASE PRESENTATION: We report the novel compound heterozygous variants c.1328G>A p.(Cys443Tyr) and c.1022_1023insC p. (Leu341Profs*103) of SLC52A2 gene in a female proband who presented in our out-patient clinic at the age of one-year-old with progressive mental and motor regression, breath holding, and brain stem dysfunction including facial weakness, hearing loss, dysphagia. Following high-dose riboflavin supplementation, the respiratory insufficiency and mental, motor, and bulbar function improved. However, sensorineural hearing loss was not improved. The missense variant site was highly conserved. Both variants were not found in the population database gnomAD. The two variants were inherited from her mother and father, respectively. Both variants were predicted to be deleterious by Polyphen2, Mutation taster, and SIFT and were classified as likely pathogenic according to the ACMG guideline. CONCLUSIONS: Two novel pathogenic variations of SLC52A2 gene were firstly found from a Chinese pedigree with BVVLS. Clinical outcomes could be improved by early diagnosis and riboflavin supplementation.


Assuntos
Paralisia Bulbar Progressiva/genética , Perda Auditiva Neurossensorial/genética , Mutação , Receptores Acoplados a Proteínas-G/genética , Sequência de Aminoácidos , China , Feminino , Humanos , Lactente , Masculino , Linhagem , Receptores Acoplados a Proteínas-G/química , Homologia de Sequência de Aminoácidos
8.
BMC Med Genet ; 20(1): 91, 2019 05 27.
Artigo em Inglês | MEDLINE | ID: mdl-31132985

RESUMO

BACKGROUND: Hereditary sensory and autonomic neuropathy (HSAN) type II is a group of extremely rare autosomal recessive neurological disorders with heterogeneous clinical and genetic characteristics. METHODS: We performed high-depth next-generation targeted sequencing using a custom-ordered "HSAN" panel, covering WNK1, NTRK1, NGF, SPTLC1 and IKBKAP genes, to identify pathogenic variants of the proband as well as the family members. We also performed whole exome sequencing to further investigate the potential occurrence of additional pathogenic variants in genes that were not covered by the "HSAN" panel. Quantitative real-time PCR was used to identify pathogenic copy number variations (CNVs) and to analyze the mRNA level of WNK1 gene of the family. Western blot analysis was performed to evaluate the WNK1 protein expression level. RESULTS: After sequencing, a novel nonsense variant (c.2747 T > G, p.Leu916Ter) in exon 9 of WNK1 gene was identified in two patients (hemizygous) and their mother (heterozygous). This variant is absent in all public databases as well as in 600 Han Chinese healthy controls. The region of this variant is evolutionary highly conserved. Furthermore, by quantitative real-time PCR using DNA of the pedigree, we revealed a large deletion containing the whole WNK1 gene in two patients. The WNK1 expression levels of the patients were significantly reduced. CONCLUSIONS: Our study firstly revealed that the coexistence of a novel WNK1 nonsense variant and a CNV resulted in HSAN type IIA in a Han Chinese family.


Assuntos
Códon sem Sentido , Variações do Número de Cópias de DNA , Neuropatias Hereditárias Sensoriais e Autônomas/genética , Proteína Quinase 1 Deficiente de Lisina WNK/genética , Sequência de Aminoácidos , Sequência de Bases , Análise Mutacional de DNA , Saúde da Família , Feminino , Neuropatias Hereditárias Sensoriais e Autônomas/metabolismo , Neuropatias Hereditárias Sensoriais e Autônomas/patologia , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Humanos , Masculino , Linhagem , Homologia de Sequência de Aminoácidos , Proteína Quinase 1 Deficiente de Lisina WNK/metabolismo
9.
Mar Drugs ; 17(5)2019 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-31035409

RESUMO

Short chain fatty acids (SCFAs) are valued as a functional material in cosmetics. Cyanobacteria can accumulate SCFAs under some conditions, the related mechanism is unclear. Two potential genes Synpcc7942_0537 (fabB/F) and Synpcc7942_1455 (fabH) in Synechococcus sp. PCC 7942 have homology with fabB/F and fabH encoding ß-ketoacyl ACP synthases (I/II/III) in plants. Therefore, effects of culture time and cerulenin on SCFAs accumulation, expression levels and functions of these two potential genes were studied. The results showed Synechococcus sp. PCC 7942 accumulated high SCFAs (C12 + C14) in early growth stage (day 4) and at 7.5g/L cerulenin concentration, reaching to 2.44% and 2.84% of the total fatty acids respectively, where fabB/F expression was down-regulated. Fatty acid composition analysis showed C14 increased by 65.19% and 130% respectively, when fabB/F and fabH were antisense expressed. C14 increased by 10.79% (fab(B/F)-) and 6.47% (fabH-) under mutation conditions, while C8 increased by six times in fab(B/F)- mutant strain. These results suggested fabB/F is involved in fatty acid elongation (C <18) and the elongation of cis-16:1 to cis-18:1 fatty acid in Synechococcus sp. PCC 7942, while fabH was involved in elongation of fatty acid synthesis, which were further confirmed in complementary experiments of E. coli. The research could provide the scientific basis for the breeding of SCFA-rich microalgae species.


Assuntos
Ácidos Graxos Voláteis/biossíntese , Microalgas/metabolismo , Synechococcus/metabolismo , 3-Oxoacil-(Proteína de Transporte de Acila) Sintase/genética , 3-Oxoacil-(Proteína de Transporte de Acila) Sintase/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Cosméticos/química , Redes e Vias Metabólicas/genética , Microalgas/genética , Homologia de Sequência de Aminoácidos , Synechococcus/genética
10.
Acta Crystallogr F Struct Biol Commun ; 75(Pt 5): 340-347, 2019 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-31045563

RESUMO

Ebola virus is an emerging virus that is capable of causing a deadly disease in humans. Replication, transcription and packaging of the viral genome are carried out by the viral nucleocapsid. The nucleocapsid is a complex of the viral nucleoprotein, RNA and several other viral proteins. The nucleoprotein forms large, RNA-bound, helical filaments and acts as a scaffold for additional viral proteins. The 3.1 Šresolution single-particle cryo-electron microscopy structure of the nucleoprotein-RNA helical filament presented here resembles previous structures determined at lower resolution, while providing improved molecular details of protein-protein and protein-RNA interactions. The higher resolution of the structure presented here will facilitate the design and characterization of novel and specific Ebola virus therapeutics targeting the nucleocapsid.


Assuntos
Ebolavirus/química , Nucleocapsídeo/química , Nucleoproteínas/química , RNA Viral/química , Proteínas Virais/química , Sequência de Aminoácidos , Sítios de Ligação , Clonagem Molecular , Microscopia Crioeletrônica , Expressão Gênica , Vetores Genéticos/química , Vetores Genéticos/metabolismo , Células HEK293 , Humanos , Modelos Moleculares , Conformação de Ácido Nucleico , Nucleocapsídeo/ultraestrutura , Nucleoproteínas/genética , Nucleoproteínas/metabolismo , Ligação Proteica , Conformação Proteica em alfa-Hélice , Domínios e Motivos de Interação entre Proteínas , RNA Viral/genética , RNA Viral/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Proteínas Virais/genética , Proteínas Virais/metabolismo
11.
BMC Genomics ; 20(1): 394, 2019 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-31113361

RESUMO

BACKGROUND: Mycobacterium tuberculosis (MTB) is a common bacterium causing tuberculosis and remains a major pathogen for mortality. Although the MTB genome has been extensively explored for two decades, the functions of 27% (1051/3906) of encoded proteins have yet to be determined and these proteins are annotated as hypothetical proteins. METHODS: We assigned functions to these hypothetical proteins using SSEalign, a newly designed algorithm utilizing structural information. A set of rigorous criteria was applied to these annotations in order to examine whether they were supported by each parameter. Virulence factors and potential drug targets were also screened among the annotated proteins. RESULTS: For 78% (823/1051) of the hypothetical proteins, we could identify homologs in Escherichia coli and Salmonella typhimurium by using SSEalign. Functional classification analysis indicated that 62.2% (512/823) of these annotated proteins were enzymes with catalytic activities and most of these annotations were supported by at least two other independent parameters. A relatively high proportion of transporter was identified in MTB genome, indicating the potential frequent transportation of frequent absorbing essential metabolites and excreting toxic materials in MTB. Twelve virulence factors and ten vaccine candidates were identified within these MTB hypothetical proteins, including two genes (rpoS and pspA) related to stress response to the host immune system. Furthermore, we have identified six novel drug target candidates among our annotated proteins, including Rv0817 and Rv2927c, which could be used for treating MTB infection. CONCLUSIONS: Our annotation of the MTB hypothetical proteins will probably serve as a useful dataset for future MTB studies.


Assuntos
Proteínas de Bactérias/fisiologia , Mycobacterium tuberculosis/genética , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Proteínas de Bactérias/imunologia , Genoma Bacteriano , Anotação de Sequência Molecular , Mycobacterium tuberculosis/imunologia , Homologia de Sequência de Aminoácidos , Fatores de Virulência
13.
Artigo em Inglês | MEDLINE | ID: mdl-31129291

RESUMO

Mollusk biomineralization is a process controlled by a complex interplay of proteins, ions and external regulators. In spite of several studies, there is a lack of knowledge of who (molecules involved), how (mechanism) and why (evolution and adaptation) mollusk are designed as we know them. In this study, a shell matrix protein, N66, has been purified and characterized biochemically from the shell of Pteria sterna. Two protein bands with carbohydrates associated were separated with a molecular weight of ~60 and 64 kDa. It has carbonic anhydrase activity and it is able to form crystal polymorphs of calcium carbonate in vitro. The mRNA N66 was obtained from the mantle tissue of Pteria sterna and the deduced amino acid sequence contained a carbonic anhydrase (CA) domain and a Asn/Gly-rich domain (aa243-439). The CA domain contained three His residues acting as zinc ligands and the gate-keeper residues present in all α-CAs (Glu166-Thr525), being thus similar to the human isoform hCAVII. Also, to test whether the posttranslational modifications present on the native N66 affects the CA activity and its crystallization capability in vitro, a recombinant N66 was overexpressed in Escherichia coli and functionally characterized. Our results show that recombinant N66 has higher CA activity and produce larger size crystals in vitro than the native N66 protein, suggesting that intrinsic properties of the native N66, such as glycosylations and/or phosphorylations, might regulate its activity.


Assuntos
Exoesqueleto/metabolismo , Anidrases Carbônicas/isolamento & purificação , Anidrases Carbônicas/metabolismo , Pinctada/metabolismo , Sequência de Aminoácidos , Animais , Sequência de Bases , Biomineralização , Anidrases Carbônicas/genética , Cristalização , DNA Complementar/genética , Microscopia Eletrônica de Varredura , Filogenia , Pinctada/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Homologia de Sequência de Aminoácidos
14.
Appl Microbiol Biotechnol ; 103(12): 4881-4887, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31053915

RESUMO

How cells of the fission yeast Schizosaccharomyces pombe respond to alkaline stress is not well understood. Here, to elucidate the molecular mechanism underlying the alkaline stress response in S. pombe, we performed DNA microarray analysis. We found that a homolog of human catechol O-methyltransferase 2 (COMT2) is highly upregulated in S. pombe cells exposed to alkaline conditions. We designated the S. pombe homolog as cmt2+ and also identified its paralog, cmt1+, in the S. pombe genome. Reverse transcription PCR confirmed that both cmt1+ and cmt2+ are upregulated within 1 h of exposure to alkaline stress and downregulated within 30 min of returning to an acidic environment. Moreover, we verified that recombinant Cmt proteins exhibit catechol O-methyltransferase activity. To further characterize the expression of cmt1+ and cmt2+, we carried out an EGFP reporter assay using their promoter sequences, which showed that both genes respond not only to alkaline but also to salt stress. Collectively, our findings indicate that the cmt promoter might be an advantageous expression system for use in S. pombe under alkaline culture conditions.


Assuntos
Antiácidos/farmacologia , Catecol O-Metiltransferase/genética , Estresse Salino , Schizosaccharomyces/efeitos dos fármacos , Schizosaccharomyces/enzimologia , Catecol O-Metiltransferase/metabolismo , Clonagem Molecular , Regulação Fúngica da Expressão Gênica , Humanos , Análise de Sequência com Séries de Oligonucleotídeos , Regiões Promotoras Genéticas , Proteínas de Schizosaccharomyces pombe/genética , Proteínas de Schizosaccharomyces pombe/metabolismo , Homologia de Sequência de Aminoácidos , Regulação para Cima
15.
Virol J ; 16(1): 70, 2019 05 27.
Artigo em Inglês | MEDLINE | ID: mdl-31133023

RESUMO

A novel nepovirus was identified and characterised from caraway, and tentatively named caraway yellows virus (CawYV). Tubular structures with isomeric virus particles typical for nepoviruses were observed in infected tissues by electron microscopy. The whole genome of CawYV was identified by high throughput sequencing (HTS). It consists of two segments with 8026 nt for RNA1 and 6405 nt for RNA2, excluding the poly(A) tails. CawYV-RNA1 shared closest nt identity to peach rosette mosaic virus (PRMV) with 63%, while RNA2 shared 41.5% with blueberry latent spherical virus (BLSV). The amino acid sequences of the CawYV protease-polymerase (Pro-Pol) and capsid protein (CP) regions share the highest identities with those of the subgroup C nepoviruses. The Pro-Pol region shared highest aa identity with PRMV (80.1%), while the CP region shared 39.6% to soybean latent spherical virus. Phylogenetic analysis of the CawYV-Pro-Pol and -CP aa sequences provided additional evidence of their association with nepoviruses subgroup C. Based on particle morphology, genomic organization and phylogenetic analyses, we propose CawYV as a novel species within the genus Nepovirus subgroup C.


Assuntos
Carum/virologia , Nepovirus/classificação , Doenças das Plantas/virologia , Folhas de Planta/virologia , Proteínas Virais/genética , Proteínas do Capsídeo/genética , Genoma Viral , Sequenciamento de Nucleotídeos em Larga Escala , Nepovirus/isolamento & purificação , Filogenia , RNA Viral/genética , Homologia de Sequência de Aminoácidos
16.
BMC Bioinformatics ; 20(1): 241, 2019 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-31092185

RESUMO

BACKGROUND: Repertoire sequencing is enabling deep explorations into the cellular immune response, including the characterization of commonalities and differences among T cell receptor (TCR) repertoires from different individuals, pathologies, and antigen specificities. In seeking to understand the generality of patterns observed in different groups of TCRs, it is necessary to balance how well each pattern represents the diversity among TCRs from one group (sensitivity) vs. how many TCRs from other groups it also represents (specificity). The variable complementarity determining regions (CDRs), particularly the third CDRs (CDR3s) interact with major histocompatibility complex (MHC)-presented epitopes from putative antigens, and thus encode the determinants of recognition. RESULTS: We here systematically characterize the predictive power that can be obtained from CDR3 sequences, using representative, readily interpretable methods for evaluating CDR sequence similarity and then clustering and classifying sequences based on similarity. An initial analysis of CDR3s of known structure, clustered by structural similarity, helps calibrate the limits of sequence diversity among CDRs that might have a common mode of interaction with presented epitopes. Subsequent analyses demonstrate that this same range of sequence similarity strikes a favorable specificity/sensitivity balance in distinguishing twins from non-twins based on overall CDR3 repertoires, classifying CDR3 repertoires by antigen specificity, and distinguishing general pathologies. CONCLUSION: We conclude that within a fairly broad range of sequence similarity, matching CDR3 sequences are likely to share specificities.


Assuntos
Regiões Determinantes de Complementaridade/química , Receptores de Antígenos de Linfócitos T/química , Homologia de Sequência de Aminoácidos , Motivos de Aminoácidos , Sequência de Aminoácidos , Epitopos/química , Humanos , Complexo Principal de Histocompatibilidade , Peptídeos/química , Gêmeos
17.
Eur J Med Chem ; 175: 309-329, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31096153

RESUMO

Compounds simultaneously inhibiting two targets that are involved in the progression of the same complex disease may exhibit additive or even synergistic therapeutic effects. Here we unveil 2,4,5-trisubstituted imidazoles as dual inhibitors of p38α mitogen-activated protein kinase and glycogen synthase kinase 3ß (GSK3ß). Both enzymes are potential therapeutic targets for neurodegenerative disorders, like Alzheimer's disease. A set of 39 compounds was synthesized and evaluated in kinase activity assays for their ability to inhibit both target kinases. Among the synthesized compounds, potent dual-target-directed inhibitors showing IC50 values down to the low double-digit nanomolar range, were identified. One of the best balanced dual inhibitors presented in here is N-(4-(2-ethyl-4-(4-fluorophenyl)-1H-imidazol-5-yl)pyridin-2-yl)cyclopropanecarboxamide (20c) (p38α, IC50 = 16 nM; GSK3ß, IC50 = 35 nM) featuring an excellent metabolic stability and an appreciable isoform selectivity over the closely related GSK3α. Our findings were rationalized by computational docking studies based on previously published X-ray structures.


Assuntos
Glicogênio Sintase Quinase 3 beta/antagonistas & inibidores , Imidazóis/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Piridinas/farmacologia , Proteínas Quinases p38 Ativadas por Mitógeno/antagonistas & inibidores , Sequência de Aminoácidos , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Humanos , Imidazóis/química , Concentração Inibidora 50 , Simulação de Acoplamento Molecular , Espectroscopia de Prótons por Ressonância Magnética , Piridinas/química , Homologia de Sequência de Aminoácidos , Espectrometria de Massas por Ionização por Electrospray , Relação Estrutura-Atividade
18.
Nat Commun ; 10(1): 2344, 2019 05 28.
Artigo em Inglês | MEDLINE | ID: mdl-31138806

RESUMO

Infection by soil transmitted parasitic helminths, such as Trichuris spp, are ubiquitous in humans and animals but the mechanisms determining persistence of chronic infections are poorly understood. Here we show that p43, the single most abundant protein in T. muris excretions/secretions, is non-immunogenic during infection and has an unusual sequence and structure containing subdomain homology to thrombospondin type 1 and interleukin (IL)-13 receptor (R) α2. Binding of p43 to IL-13, the key effector cytokine responsible for T. muris expulsion, inhibits IL-13 function both in vitro and in vivo. Tethering of p43 to matrix proteoglycans presents a bound source of p43 to facilitate interaction with IL-13, which may underpin chronic intestinal infection. Our results suggest that exploiting the biology of p43 may open up new approaches to modulating IL-13 function and control of Trichuris infections.


Assuntos
Proteínas de Helminto/metabolismo , Interleucina-13/metabolismo , Enteropatias Parasitárias/metabolismo , Proteoglicanas/metabolismo , Trichuris/metabolismo , Animais , Matriz Extracelular/metabolismo , Proteínas de Helminto/imunologia , Interleucina-13/imunologia , Subunidade alfa2 de Receptor de Interleucina-13/metabolismo , Enteropatias Parasitárias/imunologia , Camundongos , Homologia de Sequência de Aminoácidos , Trombospondina 1/metabolismo , Tricuríase
19.
Arch Virol ; 164(7): 1943-1947, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31076912

RESUMO

A new virus was identified in a celery plant showing chlorotic rings, mosaic and strong yellowing symptoms, and its complete genome sequence was determined. The genomic organization of this novel virus is analogous to that of known members of the genus Torradovirus, consisting of two single-stranded RNAs of 6,823 (RNA1) and 4,263 nucleotides (RNA2), excluding the poly(A) tails. BLAST searches against the nucleotide and protein databases showed that this virus is closely related to but different from carrot torradovirus 1 (CaTV1). Comparisons between the two viruses demonstrated relatively low levels of nucleotide and amino acid similarity in different parts of their genomes, as well as considerable differences in the sizes of their two genomic RNAs. However, the protease-polymerase (Pro-Pol) and capsid protein (CP) regions of this virus share >80% amino acid identity with the corresponding regions of CaTV1. Therefore, based on the current ICTV species demarcation criteria for the family Secoviridae, the virus from celery is a divergent strain of CaTV1, named "CaTV1-celery". Nevertheless, differences between CaTV1 and CaTV1-celery in genome size, as well as in biological and epidemiological features, may warrant their separation into two distinct species in the future.


Assuntos
Apium/virologia , Genoma Viral/genética , Doenças das Plantas/virologia , Secoviridae/classificação , Secoviridae/genética , Sequência de Aminoácidos , Sequência de Bases , Proteínas do Capsídeo/genética , Fases de Leitura Aberta/genética , Filogenia , RNA Viral/genética , Secoviridae/isolamento & purificação , Homologia de Sequência de Aminoácidos , Sequenciamento Completo do Genoma
20.
Mar Drugs ; 17(4)2019 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-30987002

RESUMO

α-Conotoxins selectively bind to nicotinic acetylcholine receptors (nAChRs), which are therapeutic targets due to their important role in signaling transmission in excitable cells. A previous experimental study has demonstrated that carboxylation of the C-terminal of α-conotoxin LsIA reduces its potency to inhibit human α7 nAChR relative to naturally amidated LsIA. However, little is known about the contribution of conformational changes in the receptor and interactions, induced by C-terminal amidation/carboxylation of conotoxins, to selective binding to nAChRs, since most conotoxins and some disulfide-rich peptides from other conotoxin subfamilies possess a naturally amidated C-terminal. In this study, we employ homology modeling and molecular dynamics (MD) simulations to propose the determinants for differential interactions between amidated and carboxylated LsIAs with α7 nAChR. Our findings indicate an overall increased number of contacts favored by binding of amidated LsIA versus its carboxylated counterpart. Toxin-receptor pairwise interactions, which may play a role in enhancing the potency of the former, include ARG10-TRP77, LEU141 and CYS17-GLN79 via persistent hydrogen bonds and cation-π interactions, which are weakened in the carboxylated form due to a strong intramolecular salt-bridge formed by ARG10 and carboxylated C-terminus. The binding of amidated LsIA also induces enhanced movements in loop C and the juxtamembrane Cys-loop that are closely associated with receptor function. Additionally, the impacts of binding of LsIA on the overall structure and inter-subunit contacts were examined using inter-residue network analysis, suggesting a clockwise tilting of the α7 C and F loops upon binding to carboxylated LsIA, which is absent for amidated LsIA binding. The predicted molecular mechanism of LsIA binding to the α7 receptor may provide new insights into the important role of the C-terminal in the binding potency of conotoxins at neuronal nAChRs for pharmacological purposes.


Assuntos
Aplysia , Conotoxinas/farmacologia , Simulação de Dinâmica Molecular , Antagonistas Nicotínicos/farmacologia , Receptor Nicotínico de Acetilcolina alfa7/metabolismo , Amidas/química , Sequência de Aminoácidos , Animais , Ácidos Carboxílicos/química , Conotoxinas/química , Conotoxinas/genética , Antagonistas Nicotínicos/química , Domínios Proteicos/genética , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Receptor Nicotínico de Acetilcolina alfa7/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA