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1.
Cult. cuid ; 27(67): 389-410, Dic 11, 2023. tab
Artigo em Espanhol | IBECS | ID: ibc-228593

RESUMO

Trafficking of women is a serious violation of human rights. It is related to vulnerability, poverty, gender inequality, lack of education and migration processes. This global problem also highlights the noncompliance with the Sustainable Development Goals. This reality brings serious health problems to its victims, a point of interest for nursing action. Thus, this work carried out through the collaborative learning method Jigsaw in the context of an elective course of the fourth year of the Degree in Nursing, aims to critically analyze the consequences of trafficking for women's health, relating it to the violation of their human rights and the incompatibility of this international practice with the achievement of the Sustainable Development Goals, to conclude with recommendations that can guide Nursing to provide more appropriate care from its competence as an activist in health for this group. Multiple actions aimed at the prevention, protection and care of women victims of trafficking have been identified, the conflict is generated at the time of executing them, since the neglect of these women from multiple approaches has been noted.(AU)


La trata de mujeres supone una grave violación de los derechos humanos. Está relacionada con la vulnerabilidad, la pobreza, la desigualdad de género, la desescolarización y con los procesos migratorios. En este problema global destaca además el incumplimiento de los Objetivos de Desarrollo Sostenible. Esta realidad acarrea graves problemas de salud a sus víctimas, punto de interés para la actuación de enfermería. Así, este trabajo realizado mediante el método de aprendizaje colaborativo Jigsaw, en el contexto de una asignatura optativa de cuarto curso del Grado en Enfermería, tiene como objetivo el análisis desde el paradigma socio crítico de las consecuencias que la trata supone para la salud de las mujeres, relacionándolo con la vulneración de sus derechos humanos y la incompatibilidad de esta práctica internacional con la consecución de los Objetivos de Desarrollo Sostenible, para concluir con recomendaciones que puedan orientar a la enfermería a proporcionar cuidados más adecuados desde su competencia como activista en salud. Se han identificado múltiples acciones dirigidas a la prevención, protección y atención de las mujeres víctima de trata, el conflicto se genera a la hora de ejecutarlas, ya que se ha constatado la desatención de estas mujeres desde múltiples enfoques.(AU)


O tráfico de mulheres é uma grave violação dos direitos humanos. Está ligado à vulnerabilidade, pobreza, desigualdade de género, falta de escolaridade e processos de migração. Este problema global também realça o fracasso no cumprimento dos Objectivos de Desenvolvimento Sustentável. Esta realidade causa graves problemas de saúde para as suas vítimas, um ponto de interesse para a acção de enfermagem. Assim, este trabalho, realizado utilizando o método de aprendizagem colaborativa Jigsaw no contexto de uma disciplina opcional no quarto ano do Bacharelato em Enfermagem, visa analisar criticamente as consequências do tráfico para a saúde das mulheres, relacionando o com a violação dos seus direitos humanos e a incompatibilidade desta prática internacional com a realização dos Objectivos de Desenvolvimento Sustentável, para concluir com recomendações que possam orientar a enfermagem no sentido de proporcionar cuidados mais adequados a partir da sua competência como activista de saúde para este grupo. Foram identificadas múltiplas acções que visam a prevenção, protecção e cuidados às mulheres vítimas de tráfico, o conflito surge quando se trata de as implementar, uma vez que se verificou a negligência destas mulheres em relação às múltiplas intervenções.(AU)


Assuntos
Humanos , Feminino , Vulnerabilidade em Saúde , Vulnerabilidade Sexual , Mulheres Maltratadas , Violações dos Direitos Humanos , 57444 , Desenvolvimento Sustentável , Enfermagem , Cuidados de Enfermagem , Direitos Humanos
2.
J Biol Chem ; 298(2): 101542, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34968463

RESUMO

The monomorphic antigen-presenting molecule major histocompatibility complex-I-related protein 1 (MR1) presents small-molecule metabolites to mucosal-associated invariant T (MAIT) cells. The MR1-MAIT cell axis has been implicated in a variety of infectious and noncommunicable diseases, and recent studies have begun to develop an understanding of the molecular mechanisms underlying this specialized antigen presentation pathway. However, proteins regulating MR1 folding, loading, stability, and surface expression remain to be identified. Here, we performed a gene trap screen to discover novel modulators of MR1 surface expression through insertional mutagenesis of an MR1-overexpressing clone derived from the near-haploid human cell line HAP1 (HAP1.MR1). The most significant positive regulators identified included ß2-microglobulin, a known regulator of MR1 surface expression, and ATP13A1, a P5-type ATPase in the endoplasmic reticulum (ER) not previously known to be associated with MR1-mediated antigen presentation. CRISPR/Cas9-mediated knockout of ATP13A1 in both HAP1.MR1 and THP-1 cell lines revealed a profound reduction in MR1 protein levels and a concomitant functional defect specific to MR1-mediated antigen presentation. Collectively, these data are consistent with the ER-resident ATP13A1 being a key posttranscriptional determinant of MR1 surface expression.


Assuntos
Apresentação de Antígeno , Antígenos de Histocompatibilidade Classe I , Complexo Principal de Histocompatibilidade , Antígenos de Histocompatibilidade Menor , ATPases do Tipo-P , Antígenos de Histocompatibilidade Classe I/metabolismo , Humanos , Complexo Principal de Histocompatibilidade/imunologia , Antígenos de Histocompatibilidade Menor/imunologia , ATPases do Tipo-P/imunologia
4.
Metas enferm ; 24(3): 16-23, Abr. 2021. tab
Artigo em Espanhol | IBECS | ID: ibc-223048

RESUMO

Objetivo: explorar el estado de conciliación personal, laboral y familiar de los y las profesionales de Enfermería en España.Método: estudio descriptivo transversal de ámbito nacional en profesionales de Enfermería que trabajan en un centro sanitario. La recogida de los datos se realizó mediante un cuestionario ad hoc en función del índice efr de la Fundación Masfamilia. Se midieron variables sociodemográficas, laborales y profesionales, personales, familiares, y relacionadas con la conciliación. Se efectuaron análisis bivariados (prueba Z y t de Student).Resultados: se obtuvo una muestra de 2.762. El 87% era mujer, un 33% tenía entre 30 a 39 años. Los hombres dedicaban más tiempo diario al deporte (4,27 vs. 2,68) y la cultura (4,36 vs. 2,76) y menos al cuidado del hogar y la familia (5,99 vs. 6,50). Las mujeres reducían más su jornada laboral (30,98% vs. 12,97%), con más días de excedencia por cuidado de hijos/as, (96,55 vs. 8,22). Las mujeres percibían su proyecto profesional más afectado por falta de medidas de conciliación (3,09 vs. 2,62).Conclusiones: los y las profesionales de Enfermería valoran negativamente las medidas de conciliación de su institución, afectando a su salud, calidad de vida y suponiendo un coste para las instituciones sanitarias, mayormente las mujeres. Los roles de género de la sociedad española repercuten negativamente en la percepción de la conciliación de las enfermeras, en sus condiciones laborales y de promoción profesional.(AU)


Objective: to explore the scenario of the personal, working and family reconciliation of Nursing professionals in Spain.Method: a descriptive cross-sectional study at national level on Nursing professionals working at a healthcare centre. Data was collected through an ad hoc questionnaire based on the efr index by the Fundación Masfamilia. Sociodemographic, occupational, and professional variables were measured, as well as those associated with family and reconciliation. Bivariate analysis was conducted (Z and Student’s t tests).Results: a sample of 2,762 was obtained; 87% were female, and 33% were 30-to-39-years old. Men devoted more time during the day to sports (4.27 vs. 2.68) and culture (4.36 vs. 2.76), and less time to care for their home and family (5.99 vs. 6.50). Women reduced their working hours to a higher extent (30.98% vs. 12.97%), with more leave of absence days for children care (96,55 vs. 8.22). Women perceived a higher impact on their professional project by lack of reconciliation measures for women (3.09 vs. 2.62).Conclusions: nursing professionals value negatively the reconciliation measures in their working centre, which have impact on their health and quality of life, and represent expenses for healthcare institutions, mainly for women. Gender roles in Spanish society have a negative impact upon the perception of reconciliation for nurses, their working conditions and professional promotion.(AU)


Assuntos
Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Enfermeiras e Enfermeiros , Identidade de Gênero , 57433 , Equilíbrio Trabalho-Vida , Espanha , Enfermagem , Epidemiologia Descritiva , Estudos Transversais , Inquéritos e Questionários
5.
Br J Cancer ; 124(4): 817-830, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33214684

RESUMO

BACKGROUND: Interferon (IFN) signalling pathways, a key element of the innate immune response, contribute to resistance to conventional chemotherapy, radiotherapy, and immunotherapy, and are often deregulated in cancer. The deubiquitylating enzyme USP18 is a major negative regulator of the IFN signalling cascade and is the predominant human protease that cleaves ISG15, a ubiquitin-like protein tightly regulated in the context of innate immunity, from its modified substrate proteins in vivo. METHODS: In this study, using advanced proteomic techniques, we have significantly expanded the USP18-dependent ISGylome and proteome in a chronic myeloid leukaemia (CML)-derived cell line. USP18-dependent effects were explored further in CML and colorectal carcinoma cellular models. RESULTS: Novel ISGylation targets were characterised that modulate the sensing of innate ligands, antigen presentation and secretion of cytokines. Consequently, CML USP18-deficient cells are more antigenic, driving increased activation of cytotoxic T lymphocytes (CTLs) and are more susceptible to irradiation. CONCLUSIONS: Our results provide strong evidence for USP18 in regulating antigenicity and radiosensitivity, highlighting its potential as a cancer target.


Assuntos
Neoplasias Colorretais/enzimologia , Neoplasias Colorretais/imunologia , Citocinas/metabolismo , Leucemia Mielogênica Crônica BCR-ABL Positiva/enzimologia , Leucemia Mielogênica Crônica BCR-ABL Positiva/imunologia , Ubiquitina Tiolesterase/metabolismo , Ubiquitinas/metabolismo , Variação Antigênica , Linhagem Celular Tumoral , Neoplasias Colorretais/radioterapia , Técnicas de Inativação de Genes , Células HCT116 , Humanos , Leucemia Mielogênica Crônica BCR-ABL Positiva/radioterapia , Tolerância a Radiação/genética , Tolerância a Radiação/imunologia , Ubiquitina Tiolesterase/deficiência , Ubiquitina Tiolesterase/genética
6.
Proc Natl Acad Sci U S A ; 117(19): 10465-10475, 2020 05 12.
Artigo em Inglês | MEDLINE | ID: mdl-32341160

RESUMO

The antigen-presenting molecule MR1 presents riboflavin-based metabolites to Mucosal-Associated Invariant T (MAIT) cells. While MR1 egress to the cell surface is ligand-dependent, the ability of small-molecule ligands to impact on MR1 cellular trafficking remains unknown. Arising from an in silico screen of the MR1 ligand-binding pocket, we identify one ligand, 3-([2,6-dioxo-1,2,3,6-tetrahydropyrimidin-4-yl]formamido)propanoic acid, DB28, as well as an analog, methyl 3-([2,6-dioxo-1,2,3,6-tetrahydropyrimidin-4-yl]formamido)propanoate, NV18.1, that down-regulate MR1 from the cell surface and retain MR1 molecules in the endoplasmic reticulum (ER) in an immature form. DB28 and NV18.1 compete with the known MR1 ligands, 5-OP-RU and acetyl-6-FP, for MR1 binding and inhibit MR1-dependent MAIT cell activation. Crystal structures of the MAIT T cell receptor (TCR) complexed with MR1-DB28 and MR1-NV18.1, show that these two ligands reside within the A'-pocket of MR1. Neither ligand forms a Schiff base with MR1 molecules; both are nevertheless sequestered by a network of hydrophobic and polar contacts. Accordingly, we define a class of compounds that inhibits MR1 cellular trafficking.


Assuntos
Antígenos de Histocompatibilidade Classe I/metabolismo , Antígenos de Histocompatibilidade Menor/metabolismo , Células T Invariantes Associadas à Mucosa/metabolismo , Apresentação de Antígeno , Linhagem Celular , Membrana Celular/metabolismo , Regulação para Baixo , Regulação da Expressão Gênica/genética , Humanos , Ligantes , Ativação Linfocitária , Transporte Proteico , Receptores de Antígenos de Linfócitos T alfa-beta/metabolismo , Riboflavina/metabolismo , Células THP-1
7.
ACS Chem Biol ; 15(2): 437-445, 2020 02 21.
Artigo em Inglês | MEDLINE | ID: mdl-31909966

RESUMO

Mucosal-associated invariant T (MAIT) cells are antibacterial effector T cells that react to pyrimidines derived from bacterial riboflavin synthesis presented by the monomorphic molecule MR1. A major challenge in MAIT cell research is that the commonly used MAIT agonist precursor, 5-amino-6-d-ribitylaminouracil (5-A-RU), is labile to autoxidation, resulting in a loss of biological activity. Here, we characterize two independent autoxidation processes by LCMS. To overcome the marked instability, we report the synthesis of a 5-A-RU prodrug generated by modification of the 5-amino group with a cleavable valine-citrulline-p-aminobenzyl carbamate. The compound is stable in prodrug form, with the parent amine (i.e., 5-A-RU) released only after enzymatic cleavage. Analysis of the prodrug in vitro and in vivo showed an enhanced MAIT cell activation profile compared to 5-A-RU, which was associated with preferential loading within recycling endosomes, a route used by some natural agonists. This prodrug design therefore overcomes the difficulties associated with 5-A-RU in biological studies and provides an opportunity to explore different presentation pathways.


Assuntos
Endossomos/metabolismo , Antígenos de Histocompatibilidade Classe I/metabolismo , Fatores Imunológicos/farmacologia , Ativação Linfocitária/efeitos dos fármacos , Antígenos de Histocompatibilidade Menor/metabolismo , Células T Invariantes Associadas à Mucosa/efeitos dos fármacos , Pró-Fármacos/farmacologia , Animais , Humanos , Fatores Imunológicos/síntese química , Fatores Imunológicos/metabolismo , Camundongos , Pró-Fármacos/síntese química , Pró-Fármacos/metabolismo , Ribitol/análogos & derivados , Ribitol/síntese química , Ribitol/metabolismo , Ribitol/farmacologia , Uracila/análogos & derivados , Uracila/síntese química , Uracila/metabolismo , Uracila/farmacologia
8.
J Immunol ; 199(8): 2631-2638, 2017 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-28877992

RESUMO

Mucosal-associated invariant T (MAIT) cells are innate T cells that recognize intermediates of the vitamin B2 biosynthetic pathway presented by the monomorphic MR1 molecule. It remains unclear whether, in addition to their cytolytic activity that is important in antimicrobial defense, MAIT cells have immune-modulatory functions that could enhance dendritic cell (DC) maturation. In this study, we investigated the molecular mechanisms dictating the interactions between human MAIT cells and DCs and demonstrate that human MAIT cells mature monocyte-derived and primary DCs in an MR1- and CD40L-dependent manner. Furthermore, we show that MAIT cell-derived signals synergize with microbial stimuli to induce secretion of bioactive IL-12 by DCs. Activation of human MAIT cells in whole blood leads to MR1- and cytokine-dependent NK cell transactivation. Our results underscore an important property of MAIT cells, which can be of translational relevance to rapidly orchestrate adaptive immunity through DC maturation.


Assuntos
Células Dendríticas/imunologia , Ativação Linfocitária , Células T Matadoras Naturais/imunologia , Ligante de CD40/metabolismo , Comunicação Celular , Diferenciação Celular , Células Cultivadas , Antígenos de Histocompatibilidade Classe I/metabolismo , Humanos , Imunidade nas Mucosas , Interleucina-12/metabolismo , Antígenos de Histocompatibilidade Menor/metabolismo , Monócitos/imunologia , Receptor Cross-Talk , Riboflavina/imunologia , Riboflavina/metabolismo , Transdução de Sinais
9.
Traffic ; 15(2): 157-78, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24152084

RESUMO

Herpes simplex virus 1 (HSV1) is an enveloped virus that uses undefined transport carriers for trafficking of its glycoproteins to envelopment sites. Screening of an siRNA library against 60 Rab GTPases revealed Rab6 as the principal Rab involved in HSV1 infection, with its depletion preventing Golgi-to-plasma membrane transport of HSV1 glycoproteins in a pathway used by several integral membrane proteins but not the luminal secreted protein Gaussia luciferase. Knockdown of Rab6 reduced virus yield to 1% and inhibited capsid envelopment, revealing glycoprotein exocytosis as a prerequisite for morphogenesis. Rab6-dependent virus production did not require the effectors myosin-II, bicaudal-D, dynactin-1 or rabkinesin-6, but was facilitated by ERC1, a factor involved in linking microtubules to the cell cortex. Tubulation and exocytosis of Rab6-positive, glycoprotein-containing membranes from the Golgi was substantially augmented by infection, resulting in enhanced and targeted delivery to cell tips. This reveals HSV1 morphogenesis as one of the first biological processes shown to be dependent on the exocytic activity of Rab6.


Assuntos
Herpesvirus Humano 1/metabolismo , Proteínas do Envelope Viral/metabolismo , Proteínas rab de Ligação ao GTP/metabolismo , Rede trans-Golgi/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Exocitose , Células HeLa , Herpesvirus Humano 1/fisiologia , Humanos , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Transporte Proteico , Montagem de Vírus , Proteínas rab de Ligação ao GTP/genética
10.
EMBO J ; 31(21): 4204-20, 2012 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-22990238

RESUMO

Enveloped viruses employ diverse and complex strategies for wrapping at cellular membranes, many of which are poorly understood. Here, an ultrastructural study of herpes simplex virus 1 (HSV1)-infected cells revealed envelopment in tubular membranes. These tubules were labelled by the fluid phase marker horseradish peroxidase (HRP), and were observed to wrap capsids as early as 2 min after HRP addition, indicating that the envelope had recently cycled from the cell surface. Consistent with this, capsids did not colocalise with either the trans-Golgi network marker TGN46 or late endosomal markers, but showed coincidence with the transferrin receptor. Virus glycoproteins were retrieved from the plasma membrane (PM) to label wrapping capsids, a process that was dependent on both dynamin and Rab5. Combined depletion of Rab5 and Rab11 reduced virus yield to <1%, resulting in aberrant localisation of capsids. These results suggest that endocytosis from the PM into endocytic tubules provides the main source of membrane for HSV1, and reveal a new mechanism for virus exploitation of the endocytic pathway.


Assuntos
Capsídeo/metabolismo , Endocitose/fisiologia , Herpesvirus Humano 1/metabolismo , Membranas Intracelulares/metabolismo , Montagem de Vírus/fisiologia , Proteínas rab de Ligação ao GTP/metabolismo , Proteínas rab5 de Ligação ao GTP/metabolismo , Animais , Western Blotting , Membrana Celular/metabolismo , Células Cultivadas , Chlorocebus aethiops , Fibroblastos/citologia , Fibroblastos/metabolismo , Fibroblastos/virologia , Citometria de Fluxo , Imunofluorescência , Glicoproteínas/metabolismo , Células HeLa , Herpes Simples/metabolismo , Herpes Simples/virologia , Peroxidase do Rábano Silvestre/metabolismo , Humanos , Células Vero , Proteínas do Envelope Viral/metabolismo , Proteínas rab de Ligação ao GTP/genética , Proteínas rab5 de Ligação ao GTP/genética , Rede trans-Golgi/metabolismo , Rede trans-Golgi/virologia
11.
BMC Evol Biol ; 8: 207, 2008 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-18637173

RESUMO

BACKGROUND: The molecular events and evolutionary forces underlying lethal mutagenesis of virus (or virus extinction through an excess of mutations) are not well understood. Here we apply for the first time phylogenetic methods and Partition Analysis of Quasispecies (PAQ) to monitor genetic distances and intra-population structures of mutant spectra of foot-and-mouth disease virus (FMDV) quasispecies subjected to mutagenesis by base and nucleoside analogues. RESULTS: Phylogenetic and PAQ analyses have revealed a highly dynamic variation of intrapopulation diversity of FMDV quasispecies. The population diversity first suffers striking expansions in the presence of mutagens and then compressions either when the presence of the mutagenic analogue was discontinued or when a mutation that decreased sensitivity to a mutagen was selected. The pattern of mutations found in the populations was in agreement with the behavior of the corresponding nucleotide analogues with FMDV in vitro. Mutations accumulated at preferred genomic sites, and dn/ds ratios indicate the operation of negative (or purifying) selection in populations subjected to mutagenesis. No evidence of unusually elevated genetic distances has been obtained for FMDV populations approaching extinction. CONCLUSION: Phylogenetic and PAQ analysis provide adequate procedures to describe the evolution of viral sequences subjected to lethal mutagenesis. These methods define the changes of intra-population structure more precisely than mutation frequencies and Shannon entropies. PAQ is very sensitive to variations of intrapopulation genetic distances. Strong negative (or purifying) selection operates in FMDV populations subjected to enhanced mutagenesis. The quantifications provide evidence that extinction does not imply unusual increases of intrapopulation complexity, in support of the lethal defection model of virus extinction.


Assuntos
Evolução Molecular , Vírus da Febre Aftosa/genética , Genoma Viral , Mutagênese , Seleção Genética , Análise de Variância , Animais , Linhagem Celular , Cricetinae , Vírus da Febre Aftosa/efeitos dos fármacos , Funções Verossimilhança , Modelos Biológicos , Mutagênicos , Mutação , Filogenia , RNA Viral/genética , Ribavirina/farmacologia
12.
J Virol ; 81(4): 2012-24, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17151116

RESUMO

The nucleoside analogue ribavirin (R) is mutagenic for foot-and-mouth disease virus (FMDV). Passage of FMDV in the presence of increasing concentrations of R resulted in the selection of FMDV with the amino acid substitution M296I in the viral polymerase (3D). Measurements of progeny production and viral fitness with chimeric viruses in the presence and absence of R documented that the 3D substitution M296I conferred on FMDV a selective replicative advantage in the presence of R but not in the absence of R. In polymerization assays, a purified mutant polymerase with I296 showed a decreased capacity to use ribavirin triphosphate as a substrate in the place of GTP and ATP, compared with the wild-type enzyme. The results suggest that M296I has been selected because it attenuates the mutagenic activity of R with FMDV. Replacement M296I is located within a highly conserved stretch in picornaviral polymerases which includes residues that interact with the template-primer complex and probably also with the incoming nucleotide, according to the three-dimensional structure of FMDV 3D. Given that a 3D substitution, distant from M296I, was associated with resistance to R in poliovirus, the results indicate that picornaviral polymerases include different domains that can alter the interaction of the enzyme with mutagenic nucleoside analogues. Implications for lethal mutagenesis are discussed.


Assuntos
Antivirais/farmacologia , Vírus da Febre Aftosa/efeitos dos fármacos , Vírus da Febre Aftosa/genética , Ribavirina/farmacologia , Seleção Genética , Substituição de Aminoácidos , Animais , Linhagem Celular , Cricetinae , RNA Polimerases Dirigidas por DNA/genética , Farmacorresistência Viral/genética , Modelos Moleculares , Mutagênese , Ribavirina/análogos & derivados , Inoculações Seriadas , Proteínas Virais/genética
13.
Curr Microbiol ; 53(1): 8-12, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16775780

RESUMO

Yarrowia lipolytica is a dimorphic fungus that secretes either an acidic or an alkaline protease depending on the environmental pH. Previous results have indicated that secretion of the alkaline protease is under control of the pH signaling Pal/Rim pathway originally described in Aspergillus nidulans. Several Y. lipolytica mutants defective in some Rim components of this pathway have been previously isolated and the RIM genes characterized. In the present study, Y. lipolytica RIM9 (palI) gene (YlRIM9) was sequenced from a plasmid (AL414126) of the Genolevures project (the DNA sequence data for YlRIM9 gene has been deposited at EMBL with accession number AJ566902). The derived translation product contains 724 amino acids with a predicted signal peptide and four transmembrane domains in its N-terminal region. We demonstrated that mutation in YlRIM9, as well as in other genes encoding members of the Pal/Rim pathway, did not affect the pH-dependent dimorphic transition of Y. lipolytica. A different pathway must exist in this fungus that controls the effect of pH on dimorphism.


Assuntos
Proteínas Fúngicas/metabolismo , Transdução de Sinais , Yarrowia/metabolismo , Proteínas Fúngicas/genética , Regulação da Expressão Gênica no Desenvolvimento , Regulação Fúngica da Expressão Gênica , Concentração de Íons de Hidrogênio , Dados de Sequência Molecular , Micélio/genética , Micélio/crescimento & desenvolvimento , Micélio/metabolismo , Análise de Sequência de DNA , Yarrowia/genética , Yarrowia/crescimento & desenvolvimento
14.
Infect Genet Evol ; 5(4): 366-74, 2005 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16002345

RESUMO

RNA viruses replicate as complex distributions of non-identical but closely related variant genomes termed viral quasispecies. When the error rate during genome replication exceeds a threshold value, the genetic information cannot be maintained and the system enters error catastrophe. This violation of the error threshold results in virus extinction and it is currently being investigated as a new antiviral strategy, based on antiviral activity of some mutagenic agents. Previous studies with the important animal pathogen foot-and-mouth disease virus (FMDV) have shown that FMDV entry into error catastrophe is associated with an increase of complexity (mutation frequency and Shannon entropy) of the mutant spectrum of the quasispecies and that mutated, pre-extinction RNA interferes with the infectivity of standard RNA. Here, we report that despite the increase of complexity, the genomic consensus nucleotide sequence of pre-extinction FMDV RNA remains invariant, and that the fitness of pre-extinction FMDV is at least six-fold lower than the fitness of the parental viral clone, prior to mutagenic treatments. Thus, a low fitness genome ensemble can suppress replication of high fitness virus. Furthermore, the results show that profound genetic modifications associated with fitness decrease of a virus population can take place without any manifestation in the consensus genomic sequence. Thus, increase in mutant spectrum complexity and invariance of the consensus sequence characterizes FMDV extinction through error catastrophe.


Assuntos
Sequência Consenso , Vírus da Febre Aftosa/genética , Genoma Viral , RNA Viral/genética , Animais , Antimetabólitos/metabolismo , Sequência de Bases , Cricetinae , Replicação do DNA , Fluoruracila/metabolismo , Guanidina/metabolismo , Mutação , RNA Viral/química , RNA Viral/metabolismo
15.
J Virol ; 78(7): 3319-24, 2004 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15016853

RESUMO

When the error rate during the copying of genetic material exceeds a threshold value, the genetic information cannot be maintained. This concept is the basis of a new antiviral strategy termed lethal mutagenesis or virus entry into error catastrophe. Critical for its success is preventing survival of residual infectious virus or virus mutants that escape the transition into error catastrophe. Here we document that mutated, preextinction foot-and-mouth disease virus (FMDV) RNA can interfere with and delay viral production up to 30 h when cotransfected in BHK-21 cells with standard RNA. Interference depended on the physical integrity of preextinction RNA and was not observed with unrelated RNAs or with nonmutated, defective FMDV RNA. These results suggest that this type of interference requires large size, preextinction FMDV RNA and is mediated neither by small interfering RNAs nor by RNAs that can compete with infectious RNA for host cell factors. A model based on the aberrant expression of mutated RNA as it is expected to occur in the initial stages of the transition into error catastrophe is proposed. Interference mediated by preextinction RNA indicates an advantage of mutagenesis versus inhibition in preventing the survival of virus escape mutants during antiviral treatments.


Assuntos
Vírus da Febre Aftosa/genética , Vírus da Febre Aftosa/fisiologia , Mutagênese/genética , RNA Viral/genética , RNA Viral/metabolismo , Replicação Viral , Animais , Linhagem Celular , Cricetinae , Vírus Defeituosos/genética , Vírus Defeituosos/fisiologia , Eletroporação , Cinética , Mutação/genética
16.
J Gen Virol ; 84(Pt 6): 1629-1639, 2003 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12771434

RESUMO

The results of a previous study demonstrated that avian reovirus is highly resistant to the antiviral effects of interferon and suggested that the double-stranded RNA (dsRNA)-binding sigmaA protein might play an important role in that resistance. To gather more evidence on the interferon-inhibitory activity of sigmaA protein, its gene was cloned into the prokaryotic maltose-binding protein (MBP) gene fusion vector pMalC and into the recombinant vaccinia virus WRS2. The two recombinant sigmaA proteins displayed a dsRNA-binding affinity similar to that of sigmaA protein synthesized in avian reovirus-infected cells. Interestingly, MBP-sigmaA, but not MBP, was able to relieve the translation-inhibitory activity of dsRNA in reticulocyte lysates by blocking the activation of endogenous dsRNA-dependent enzymes. In addition, transient expression of sigmaA protein in HeLa cells rescued gene expression of a vaccinia virus mutant lacking the E3L gene, and insertion of the sigmaA-encoding gene into vaccinia virus conferred protection for the virus against interferon in chicken cells. Further studies demonstrated that expression of recombinant sigmaA in mammalian cells interfered with dsRNA-dependent protein kinase (PKR) function. From these results we conclude that sigmaA is capable of reversing the interferon-induced antiviral state by down-regulating PKR activity in a manner similar to other virus-encoded dsRNA-binding proteins.


Assuntos
Orthoreovirus Aviário/fisiologia , Proteínas de Ligação a RNA/fisiologia , Proteínas do Core Viral/fisiologia , eIF-2 Quinase/antagonistas & inibidores , Animais , Anticorpos Antivirais , Embrião de Galinha , Expressão Gênica , Células HeLa , Humanos , Técnicas In Vitro , Interferons/metabolismo , Interferons/farmacologia , Orthoreovirus Aviário/genética , Orthoreovirus Aviário/imunologia , Orthoreovirus Aviário/patogenicidade , Biossíntese de Proteínas , RNA de Cadeia Dupla/genética , RNA de Cadeia Dupla/metabolismo , Proteínas de Ligação a RNA/genética , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Reticulócitos/metabolismo , Vírus Vaccinia/efeitos dos fármacos , Vírus Vaccinia/genética , Vírus Vaccinia/imunologia , Proteínas do Core Viral/genética , Replicação Viral/efeitos dos fármacos , eIF-2 Quinase/metabolismo
17.
Genetics ; 160(2): 417-27, 2002 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11861549

RESUMO

Depending on the pH of the growth medium, the yeast Yarrowia lipolytica secretes an acidic protease or an alkaline protease, the synthesis of which is also controlled by carbon, nitrogen, and sulfur availability, as well as by the presence of extracellular proteins. Previous results have indicated that the alkaline protease response to pH was dependent on YlRim101p, YlRim8p/YlPalF, and YlRim21p/YlPalH, three components of a conserved pH signaling pathway initially described in Aspergillus nidulans. To identify other partners of this response pathway, as well as pH-independent regulators of proteases, we searched for mutants that affect the expression of either or both acidic and alkaline proteases, using a YlmTn1-transposed genomic library. Four mutations affected only alkaline protease expression and identified the homolog of Saccharomyces cerevisiae SIN3. Eighty-nine mutations affected the expression of both proteases and identified 10 genes. Five of them define a conserved Rim pathway, which acts, as in other ascomycetes, by activating alkaline genes and repressing acidic genes at alkaline pH. Our results further suggest that in Y. lipolytica this pathway is active at acidic pH and is required for the expression of the acidic AXP1 gene. The five other genes are homologous to S. cerevisiae OPT1, SSY5, VPS28, NUP85, and MED4. YlOPT1 and YlSSY5 are not involved in pH sensing but define at least a second protease regulatory pathway.


Assuntos
Ácido Aspártico Endopeptidases/biossíntese , Ácido Aspártico Endopeptidases/genética , Proteínas Fúngicas , Regulação Enzimológica da Expressão Gênica , Regulação Fúngica da Expressão Gênica , Yarrowia/enzimologia , Yarrowia/genética , Sequência de Aminoácidos , Ácido Aspártico Endopeptidases/metabolismo , Concentração de Íons de Hidrogênio , Dados de Sequência Molecular , Mutação , Alinhamento de Sequência , Transdução de Sinais/fisiologia
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