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1.
Nat Commun ; 13(1): 2072, 2022 04 19.
Artigo em Inglês | MEDLINE | ID: mdl-35440597

RESUMO

Peripheral membrane proteins (PMPs) associate with cellular membranes through post-translational modifications like S-palmitoylation. The Golgi apparatus is generally viewed as the transitory station where palmitoyl acyltransferases (PATs) modify PMPs, which are then transported to their ultimate destinations such as the plasma membrane (PM). However, little substrate specificity among the many PATs has been determined. Here we describe the inherent partitioning of Gαo - α-subunit of heterotrimeric Go proteins - to PM and Golgi, independent from Golgi-to-PM transport. A minimal code within Gαo N-terminus governs its compartmentalization and re-coding produces G protein versions with shifted localization. We establish the S-palmitoylation at the outer nuclear membrane assay ("SwissKASH") to probe substrate specificity of PATs in intact cells. With this assay, we show that PATs localizing to different membrane compartments display remarkable substrate selectivity, which is the basis for PMP compartmentalization. Our findings uncover a mechanism governing protein localization and establish the basis for innovative drug discovery.


Assuntos
Aciltransferases , Lipoilação , Aciltransferases/metabolismo , Membrana Celular/metabolismo , Complexo de Golgi/metabolismo , Transporte Proteico
2.
Cells ; 11(8)2022 04 13.
Artigo em Inglês | MEDLINE | ID: mdl-35455992

RESUMO

The transcription factor CREB3L1 is expressed in a wide variety of tissues including cartilage, pancreas, and bone. It is located in the endoplasmic reticulum and upon stimulation is transported to the Golgi where is proteolytically cleaved. Then, the N-terminal domain translocates to the nucleus to activate gene expression. In thyroid follicular cells, CREB3L1 is a downstream effector of thyrotropin (TSH), promoting the expression of proteins of the secretory pathway along with an expansion of the Golgi volume. Here, we analyzed the role of CREB3L1 as a TSH-dependent transcriptional regulator of the expression of the sodium/iodide symporter (NIS), a major thyroid protein that mediates iodide uptake. We show that overexpression and inhibition of CREB3L1 induce an increase and decrease in the NIS protein and mRNA levels, respectively. This, in turn, impacts on NIS-mediated iodide uptake. Furthermore, CREB3L1 knockdown hampers the increase the TSH-induced NIS expression levels. Finally, the ability of CREB3L1 to regulate the promoter activity of the NIS-coding gene (Slc5a5) was confirmed. Taken together, our findings highlight the role of CREB3L1 in maintaining the homeostasis of thyroid follicular cells, regulating the adaptation of the secretory pathway as well as the synthesis of thyroid-specific proteins in response to TSH stimulation.


Assuntos
Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico , Simportadores , Células Epiteliais da Tireoide , Animais , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Ratos , Simportadores/genética , Simportadores/metabolismo , Células Epiteliais da Tireoide/metabolismo , Tireotropina/metabolismo , Tireotropina/farmacologia
3.
Neumol. pediátr. (En línea) ; 17(4): 129-133, 2022. ilus, tab
Artigo em Espanhol | LILACS | ID: biblio-1427371

RESUMO

La displasia broncopulmonar (DBP) es la enfermedad crónica más frecuente del recién nacido prematuro. Los avances en su prevención y tratamiento han permitido una mayor sobrevida de prematuros más pequeños, pero su incidencia se ha mantenido estable en el tiempo, con una fisiopatología y presentación clínica que abarca un amplio espectro y que difiere de la DBP descrita originalmente hace más de 50 años. Aún existen controversias en su definición, la que se ha establecido en base al tratamiento, específicamente al requerimiento de soporte respiratorio. Las definiciones más utilizadas son el requerimiento de oxígeno por 28 días y a las 36 semanas de edad gestacional corregida (EGC). Recientemente se ha propuesto definirla en base al requerimiento de ventilación mecánica a las 36 semanas de EGC, lo que identificaría a los prematuros con DBP más grave y mayor probabilidad de complicaciones respiratorias y neurológicas en los 2 primeros años de vida. Nuestro objetivo en la comisión de Neo-SOCHINEP es el de recomendar la definición y clasificación que nos parece más adecuada para identificar a los prematuros portadores de DBP, considerando los aspectos fisiopatológicos, del compromiso de la función pulmonar y consecuencias prácticas de la definición en nuestro medio. También proponemos la definición del requerimiento de oxígeno en el prematuro cuando esta en neonatología, las condiciones e interpretación de la saturometría contínua cuando está pronto al alta y el seguimiento de la oxigenoterapia posterior al alta.


Bronchopulmonary dysplasia (BPD) is the most frequent chronic disease of the premature newborn. Advances in its prevention and treatment have allowed a greater survival of smaller preterm infants, but its incidence has remained stable over time, with a pathophysiology and clinical presentation that covers a wide spectrum and differs from the BPD originally described more than 50 years ago. There are still controversies in its definition, which has been established based on the treatment, specifically the requirement of respiratory support. The most used definitions are the oxygen requirement for 28 days and at 36 weeks of postmenstrual age (PMA). It has recently been proposed a definition based on the requirement of mechanical ventilation at 36 weeks of PMA, which would identify premature infants with more severe BPD and a greater probability of respiratory and neurological complications in the first 2 years of life. Our objective in the Neo-SOCHINEP commission is to recommend the definition and classification that we believe is most appropriate to identify premature infants with BPD, considering the pathophysiological aspects, the compromised lung function, and practical consequences of the definition in our medium. We also propose the definition of the oxygen requirement in premature infants when they are in neonatology, the conditions and interpretation of continuous saturation when they are soon discharged, and the follow-up of post-discharge oxygen therapy.


Assuntos
Humanos , Recém-Nascido , Displasia Broncopulmonar/diagnóstico , Displasia Broncopulmonar/fisiopatologia , Doenças do Prematuro , Recém-Nascido Prematuro
4.
Front Mol Neurosci ; 14: 650338, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34421533

RESUMO

Nerve growth factor (NGF) stimulates numerous cellular physiological processes, including growth, differentiation, and survival, and maintains the phenotype of several neuronal types. Most of these NGF-induced processes require adaptation of the secretory pathway since they involve extensive remodeling of membranes and protein redistribution along newly formed neuritic processes. CREB3 transcription factors have emerged as signaling hubs for the regulation of numerous genes involved in the secretory pathway and Golgi homeostasis, integrating stimuli from multiple sources to control secretion, posttranslational modifications and trafficking of proteins. Although recent studies have focused on their role in the central nervous system, little is known about their participation in cell differentiation. Therefore, we aimed to analyze the expression and signaling mechanism of CREB3 transcription factor family members, using the NGF-induced PC12 cell differentiation model. Results show that NGF treatment causes Golgi enlargement and a parallel increased expression of proteins and mRNAs encoding for proteins required for membrane transport (transport factors). Additionally, a significant increase in CREB3L2 protein and mRNA levels is detected in response to NGF. Both MAPK and cAMP signaling pathways are required for this response. Interestingly, CREB3L2 overexpression hampers the NGF-induced neurite outgrowth while its inhibition enhances the morphological changes driven by NGF. In agreement, CREB3L2 overexpressing cells display higher immunofluorescence intensity of Rab5 GTPase (a negative regulator of PC12 differentiation) than control cells. Also, Rab5 immunofluorescence levels decrease in CREB3L2-depleted cells. Taken together, our findings imply that CREB3L2 is an important downstream effector of NGF-activated pathways, leading to neuronal differentiation.

5.
Rev. argent. reumatolg. (En línea) ; 31(3): 32-35, set. 2020. ilus
Artigo em Espanhol | LILACS, BINACIS | ID: biblio-1149673

RESUMO

La artritis séptica poliarticular se define como la infección de dos o más articulaciones, casi siempre de etiología bacteriana y diseminación hematógena. Es considerada una emergencia médica, lo que conlleva reconocerla precozmente, evitar la diseminación de la infección asociada con alta mortalidad y el riesgo de daño estructural articular. Presentamos tres casos de artritis séptica poliarticular, destacándose la importancia de la sospecha clínica y el estudio temprano del líquido sinovial para el diagnóstico y el tratamiento con antimicrobianos, evacuación y lavado articular.


Polyarticular septic arthritis is defined as the infection of two or more joints, almost always of bacterial etiology and hematogenous spread. It is considered a medical emergency, which should be recognized early, avoiding the spread of infection, associated with high mortality and the risk of joint structural damage. We present three cases of polyarticular septic arthritis, highlighting the importance of clinical suspicion and early synovial fluid study for diagnosis and treatment with antimicrobials, joint evacuation and joint lavage.


Assuntos
Humanos , Masculino , Artrite Reumatoide , Artrite , Líquido Sinovial , Terapêutica , Artrite Infecciosa
6.
Am J Med Genet A ; 182(7): 1767-1775, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32297715

RESUMO

Autosomal recessive SOPH syndrome was first described in the Yakuts population of Asia by Maksimova et al. in 2010. It arises from biallelic pathogenic variants in the NBAS gene and is characterized by severe postnatal growth retardation, senile facial appearance, small hands and feet, optic atrophy with loss of visual acuity and color vision, and normal intelligence (OMIM #614800). The presence of Pelger-Hüet anomaly in this disorder led to its name as an acronym for Short stature, Optic nerve atrophy, and Pelger-Hüet anomaly. Recent publications have further contributed to the characterization of this syndrome through additional phenotype-genotype correlations. We review the clinical features described in these publications and report on a 27-year-old woman with dwarfism with osteolysis and multiple skeletal problems, minor anomalies, immunodeficiency, diabetes mellitus, and multiple secondary medical problems. Her condition was considered an unknown autosomal recessive disorder for many years until exome sequencing provided the diagnosis by revealing a founder disease-causing variant that was compound heterozygous with a novel pathogenic variant in NBAS. Based on the major clinical features of this individual and others reported earlier, a revision of the acronym is warranted to facilitate clinical recognition.


Assuntos
Nanismo/genética , Síndromes de Imunodeficiência/genética , Proteínas de Neoplasias/genética , Anomalia de Pelger-Huët/genética , Adulto , Nanismo/complicações , Nanismo/patologia , Feminino , Predisposição Genética para Doença , Humanos , Síndromes de Imunodeficiência/complicações , Síndromes de Imunodeficiência/patologia , Mutação/genética , Atrofia Óptica/genética , Atrofia Óptica/patologia , Anomalia de Pelger-Huët/complicações , Anomalia de Pelger-Huët/patologia , Sequenciamento do Exoma
7.
Rev. cuba. pediatr ; 92(supl.1): e1128, 2020. tab
Artigo em Espanhol | LILACS, CUMED | ID: biblio-1156609

RESUMO

En diciembre de 2019 se reporta un brote de infección respiratoria aguda de etiología desconocida, en la ciudad de Wuhan, China, cuya causa se atribuyó poco después a un nuevo virus denominado SARS-CoV-2. En marzo de 2020 la enfermedad causada por este virus: COVID-19, fue declarada pandemia por la OMS. Como consecuencia, se recomendó restringir las intervenciones quirúrgicas, limitándolas a aquellas urgentes y las que no debían diferirse por comprometer la salud del paciente. Organismos internacionales y sociedades científicas han emitido recomendaciones para la asistencia sanitaria y la actividad quirúrgica. Se requeriría adecuarlas al contexto social y geográfico donde se desarrollará la actividad de salud en Cuba. Atendiendo a estas circunstancias se elaboraron recomendaciones adaptadas a las condiciones propias de las instituciones hospitalarias de perfil pediátrico más comunes de nuestro país, con el objetivo de contribuir a organizar la asistencia médico quirúrgica de urgencia a pacientes pediátricos positivos o sospechosos de tener COVID-19, cumpliendo las condiciones de seguridad para el paciente y el personal sanitario a su cargo(AU)


In December 2019, it was reported the outbreak of an acute respiratory infection of unknown etiology, in the city of Wuhan, China, whose cause was shortly after attributed to a new virus called SARS-CoV-2. In March 2020 the disease caused by this virus, COVID-19, was declared a pandemic by the WHO. As a consequence, it was recommended to restrict surgical interventions, limiting them to those that are priorities and the ones that should not be deferred since can be compromised the health of the patient. International agencies and scientific societies have issued recommendations for the health care and surgical activities. It is needed to suit them to the social and geographical context where the health activity is developed in Cuba. This is the reason to conform recommendations adapted to the conditions of pediatric medical institutions in our country, with the aim of contributing to organize the emergency surgical care to pediatric patients positive or suspected of having COVID-19, while accomplishing the safety requirements for the patient and the health personnel in charge(AU)


Assuntos
Humanos , Procedimentos Cirúrgicos Operatórios , Organização Mundial da Saúde , Agências Internacionais , Infecções por Coronavirus , Emergências , Betacoronavirus
8.
Neumol. pediátr. (En línea) ; 14(4): 216-221, dic. 2019. ilus, tab
Artigo em Espanhol | LILACS | ID: biblio-1087955

RESUMO

The bronchial challenge test with exercise aims to demonstrate the presence of exercise-induced bronchial hyperreactivity, characteristic of bronchial asthma. Its realization is well standardized, requiring special environmental conditions, preparation and submaximum effort of the patient. The response is measured by spirometry, and it is considered a positive exercise test a drop in the expired volume at the first second (FEV1) of 10%. This article describes the elements necessary to facilitate this exam, according to national and international standards and guidelines.


La prueba de provocación bronquial con ejercicio tiene como objetivo demostrar la presencia de hiperreactividad bronquial inducida por ejercicio, característica del asma bronquial. Su realización está bien estandarizada, requiriendo de condiciones ambientales especiales, preparación y esfuerzo submáximo del paciente. La respuesta se mide mediante espirometría, y se considera una prueba de provocación con ejercicio positivo, a una caída del volumen espirado al primer segundo (VEF1) del 10%. En este artículo se describen los elementos necesarios para facilitar la realización de este examen, acorde a normas y guías nacionales e internacionales.


Assuntos
Humanos , Criança , Testes de Provocação Brônquica/métodos , Exercício Físico/fisiologia , Hiper-Reatividade Brônquica/diagnóstico , Índice de Gravidade de Doença , Volume Expiratório Forçado/fisiologia , Hiper-Reatividade Brônquica/fisiopatologia
9.
Neumol. pediátr. (En línea) ; 14(3): 175-179, sept. 2019. tab
Artigo em Espanhol | LILACS | ID: biblio-1087789

RESUMO

This document updates the recommendations of the bronchial challenge test with methacholine in children. It is based primarily on the recommendations contained in the guide on the technical standard of the bronchial challenge test for methacholine from the European Society of Respiratory Diseases. The main change is the recommendation to use PD20 (methacholine dose that causes a 20% drop in FEV1) instead of PC20 (methacholine concentration that causes a 20% drop in FEV1), which allows for comparable results when different devices and different protocols are used.


Este documento actualiza las recomendaciones de la prueba de provocación bronquial con metacolina en niños. Se basa fundamentalmente en las recomendaciones contenidas en la guía sobre el estándar técnico de la prueba de provocación bronquial de metacolina de la Sociedad Europea de Enfermedades Respiratorias. El principal cambio es la recomendación de utilizar la PD20 (dosis de metacolina que provoca una caída de 20% del VEF1) en vez de PC20 (concentración de metacolina que provoca una caída del 20% en el VEF1), lo cual permite tener resultados comparables cuando se usan diferentes dispositivos y diferentes protocolos.


Assuntos
Humanos , Criança , Testes de Provocação Brônquica/métodos , Cloreto de Metacolina/administração & dosagem , Hiper-Reatividade Brônquica/diagnóstico , Hiper-Reatividade Brônquica/fisiopatologia
10.
Front Cell Dev Biol ; 7: 123, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31334233

RESUMO

CREB3 family of transcription factors are ER localized proteins that belong to the bZIP family. They are transported from the ER to the Golgi, cleaved by S1P and S2P proteases and the released N-terminal domains act as transcription factors. CREB3 family members regulate the expression of a large variety of genes and according to their tissue-specific expression profiles they play, among others, roles in acute phase response, lipid metabolism, development, survival, differentiation, organelle autoregulation, and protein secretion. They have been implicated in the ER and Golgi stress responses as regulators of the cell secretory capacity and cell specific cargos. In this review we provide an overview of the diverse functions of each member of the family (CREB3, CREB3L1, CREB3L2, CREB3L3, CREB3L4) with special focus on their role in the central nervous system.

11.
Neumol. pediátr. (En línea) ; 14(2): 105-110, jul. 2019. graf, ilust, tab
Artigo em Espanhol | LILACS | ID: biblio-1015136

RESUMO

Spirometry is better pulmonary function test for evaluating preschoolers with chronic lung disease and recurrent wheeze. It is useful, accessible and very good performance. For a correct interpretation it must be under the conditions specially controlled for this age group. In this review, product of the work done during the year 2018, by the Committee on pulmonary function in pediatric pulmonology Chilean society, will be showcased aspects for the realization and interpretation of spirometry in preschool children, with emphasis on the differences in the criteria typically described for older children and adults.


La espirometría es la prueba de función pulmonar más adecuada para evaluar a preescolares con enfermedades pulmonares crónicas y sibilancias recurrentes. Es útil, accesible y de buen rendimiento. Para una correcta interpretación debe realizarse bajo las condiciones especialmente normadas para este grupo etario. En esta revisión, producto del trabajo realizado durante el año 2018, por la comisión de función pulmonar de la sociedad Chilena de Neumología Pediátrica, se expondrán los aspectos actualizados para la realización e interpretación de la espirometría en preescolares, con énfasis en las diferencias de los criterios clásicamente descritos para niños mayores y adultos.


Assuntos
Humanos , Pré-Escolar , Espirometria/métodos , Testes de Função Respiratória , Asma/diagnóstico , Asma/fisiopatologia , Índice de Gravidade de Doença , Capacidade Vital , Volume Expiratório Forçado , Fibrose Cística/diagnóstico , Fibrose Cística/fisiopatologia , Pneumopatias/diagnóstico , Pneumopatias/fisiopatologia
12.
Neumol. pediátr. (En línea) ; 14(1): 41-51, abr. 2019. ilus, graf, tab
Artigo em Espanhol | LILACS | ID: biblio-995742

RESUMO

Spirometry is the most commonly used test to evaluate lung function in children and adults. To obtain good quality results, several requirements must be fulfilled: professional capacity of the technician, the quality of the equipment, the patient's collaboration, the use of appropriate reference standards. The purpose of spirometry is to define types of ventilatory alterations of the central and peripheral airways, to evaluate the response to bronchodilators and to guide the presence of restrictive diseases. The new consensus of national and international experts are described, which have been perfecting several aspects of this test.


La espirometría es el examen más comúnmente utilizado para evaluar la función pulmonar en niños y adultos. Para obtener resultados de buena calidad deben cumplirse varios requisitos, desde la capacidad profesional del técnico, calidad de los equipos, colaboración del paciente y utilización de patrones de referencia adecuados. La espirometría tiene como utilidad definir alteraciones ventilatorias obstructivas de vía aérea central y periférica, evaluar respuesta a broncodilatador y orientar al diagnóstico de enfermedades restrictivas. Se describen los nuevos consensos de expertos nacionales e internacionales, los cuales han ido perfeccionando varios aspectos de este examen.


Assuntos
Humanos , Criança , Adolescente , Fenômenos Fisiológicos Respiratórios , Espirometria/normas , Medidas de Volume Pulmonar/instrumentação , Controle de Qualidade , Valores de Referência , Espirometria/instrumentação , Calibragem , Capacidade Vital/fisiologia , Volume Expiratório Forçado/fisiologia , Curvas de Fluxo-Volume Expiratório Máximo , Pulmão/fisiologia
13.
J Cell Sci ; 130(24): 4155-4167, 2017 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-29093023

RESUMO

Many secretory cells increase the synthesis and secretion of cargo proteins in response to specific stimuli. How cells couple increased cargo load with a coordinate rise in secretory capacity to ensure efficient transport is not well understood. We used thyroid cells stimulated with thyrotropin (TSH) to demonstrate a coordinate increase in the production of thyroid-specific cargo proteins and ER-Golgi transport factors, and a parallel expansion of the Golgi complex. TSH also increased expression of the CREB3L1 transcription factor, which alone caused amplified transport factor levels and Golgi enlargement. Furthermore, CREB3L1 potentiated the TSH-induced increase in Golgi volume. A dominant-negative CREB3L1 construct hampered the ability of TSH to induce Golgi expansion, implying that this transcription factor contributes to Golgi expansion. Our findings support a model in which CREB3L1 acts as a downstream effector of TSH to regulate the expression of cargo proteins, and simultaneously increases the synthesis of transport factors and the expansion of the Golgi to synchronize the rise in cargo load with the amplified capacity of the secretory pathway.


Assuntos
Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/genética , Complexo de Golgi/genética , Proteínas do Tecido Nervoso/genética , Glândula Tireoide/metabolismo , Tireotropina/genética , Linhagem Celular , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Retículo Endoplasmático/genética , Retículo Endoplasmático/metabolismo , Regulação da Expressão Gênica/genética , Complexo de Golgi/metabolismo , Humanos , Proteínas do Tecido Nervoso/metabolismo , Via Secretória/genética , Tireotropina/metabolismo
14.
PLoS One ; 11(8): e0160838, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27500526

RESUMO

The GTPase Rab1b is involved in ER to Golgi transport, with multiple Rab1b effectors (located at ERES, VTCs and the Golgi complex) being required for its function. In this study, we performed live-cell dual-expression studies to analyze the dynamics of Rab1b and some effectors located at the ERES-Golgi interface. Rab1b occupied widely distributed mobile punctate and tubular structures, displaying a transient overlaps with its effectors and showing that these overlaps occurred at the same time in spatially distinct steps of ER to Golgi transport. In addition, we assessed Rab1b dynamics during cargo sorting by analyzing the concentration at ERES of a Golgi protein (SialT2-CFP) during Brefeldin A washout (BFA WO). Rab1b was associated to most of the ERES structures, but at different times during BFA WO, and recurrently SialT2-CFP was sorted in the ERES-Rab1b positive structures. Furthermore, we reveal for first time that Rab1b localization time at ERES depended on GBF1, a Rab1b effector that acts as the guanine nucleotide exchange factor of Arf1, and that Rab1b membrane association/dissociation dynamics at ERES was dependent on the GBF1 membrane association and activity, which strongly suggests that GBF1 activity modulates Rab1b membrane cycling dynamic.


Assuntos
Retículo Endoplasmático/metabolismo , Complexo de Golgi/metabolismo , Proteínas de Transporte Vesicular/metabolismo , Proteínas rab1 de Ligação ao GTP/metabolismo , Brefeldina A/farmacologia , Retículo Endoplasmático/efeitos dos fármacos , Complexo de Golgi/efeitos dos fármacos , Células HeLa , Humanos , Inibidores da Síntese de Proteínas/farmacologia , Transporte Proteico
15.
Neumol. pediátr. (En línea) ; 11(3): 114-131, jul. 2016. ilus, tab
Artigo em Espanhol | LILACS | ID: biblio-835070

RESUMO

Pulmonary rehabilitation (PR) is an essential tool in the management of chronic respiratory diseases in childhood. PR improve symptoms, physical performance, quality of life and social integration in children who have limitations in their daily activities. Health professionals have a key role in identifying those children who are candidates for pulmonary rehabilitation programs, in the initial evaluation and in the implementation of therapeutic strategies for training and education. This document is intended as a reference guide for all those professionals who are dedicated to the care of children with chronic respiratory diseases.


La rehabilitación respiratoria (RR) es un componente esencial en el manejo de las enfermedades respiratorias crónicas en la infancia. La RR ha demostrado mejorar los síntomas, el rendimiento físico, la calidad de vida y su participación social en aquellos niños que tienen limitaciones en el desarrollo de sus actividades de la vida diaria. Los profesionales de la salud tienen un rol fundamental en identificar aquellos niños que son candidatos para los programas de rehabilitación respiratoria, en la evaluación inicial y en la implementación de estrategias terapéuticas de entrenamiento y de educación. Este documento pretende ser una guía de consulta para todos aquellos profesionales que se dedican a la atención de niños con enfermedades respiratorias crónicas.


Assuntos
Humanos , Criança , Exercício Físico , Doenças Respiratórias/reabilitação , Qualidade de Vida , Doença Crônica
16.
Traffic ; 16(9): 962-77, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26031340

RESUMO

Dengue viruses cause the most important human viral disease transmitted by mosquitoes. In recent years, a great deal has been learned about molecular details of dengue virus genome replication; however, little is known about genome encapsidation and the functions of the viral capsid protein. During infection, dengue virus capsid progressively accumulates around lipid droplets (LDs) by an unknown mechanism. Here, we examined the process by which the viral capsid is transported from the endoplasmic reticulum (ER) membrane, where the protein is synthesized, to LDs. Using different methods of intervention, we found that the GBF1-Arf1/Arf4-COPI pathway is necessary for capsid transport to LDs, while the process is independent of both COPII components and Golgi integrity. The transport was sensitive to Brefeldin A, while a drug resistant form of GBF1 was sufficient to restore capsid subcellular distribution in infected cells. The mechanism by which LDs gain or lose proteins is still an open question. Our results support a model in which the virus uses a non-canonical function of the COPI system for capsid accumulation on LDs, providing new ideas for antiviral strategies.


Assuntos
Fator 1 de Ribosilação do ADP/metabolismo , Proteínas do Capsídeo/metabolismo , Complexo I de Proteína do Envoltório/metabolismo , Vírus da Dengue/metabolismo , Fatores de Troca do Nucleotídeo Guanina/metabolismo , Gotículas Lipídicas/metabolismo , Linhagem Celular Tumoral , Vírus da Dengue/patogenicidade , Retículo Endoplasmático/metabolismo , Retículo Endoplasmático/virologia , Humanos , Gotículas Lipídicas/virologia , Transporte Proteico
18.
Mol Biol Cell ; 24(5): 617-32, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23325787

RESUMO

Rab1b belongs to the Rab-GTPase family that regulates membrane trafficking and signal transduction systems able to control diverse cellular activities, including gene expression. Rab1b is essential for endoplasmic reticulum-Golgi transport. Although it is ubiquitously expressed, its mRNA levels vary among different tissues. This work aims to characterize the role of the high Rab1b levels detected in some secretory tissues. We report that, in HeLa cells, an increase in Rab1b levels induces changes in Golgi size and gene expression. Significantly, analyses applied to selected genes, KDELR3, GM130 (involved in membrane transport), and the proto-oncogene JUN, indicate that the Rab1b increase acts as a molecular switch to control the expression of these genes at the transcriptional level, resulting in changes at the protein level. These Rab1b-dependent changes require the activity of p38 mitogen-activated protein kinase and the cAMP-responsive element-binding protein consensus binding site in those target promoter regions. Moreover, our results reveal that, in a secretory thyroid cell line (FRTL5), Rab1b expression increases in response to thyroid-stimulating hormone (TSH). Additionally, changes in Rab1b expression in FRTL5 cells modify the specific TSH response. Our results show, for the first time, that changes in Rab1b levels modulate gene transcription and strongly suggest that a Rab1b increase is required to elicit a secretory response.


Assuntos
Complexo de Golgi/metabolismo , Glândula Tireoide/metabolismo , Transcrição Gênica , Proteínas rab1 de Ligação ao GTP/genética , Transporte Biológico , Retículo Endoplasmático/metabolismo , Retículo Endoplasmático/ultraestrutura , Regulação da Expressão Gênica/efeitos dos fármacos , Complexo de Golgi/ultraestrutura , Células HeLa , Humanos , Proto-Oncogene Mas , Transdução de Sinais , Glândula Tireoide/citologia , Glândula Tireoide/efeitos dos fármacos , Tireotropina/metabolismo , Tireotropina/farmacologia , Proteínas rab1 de Ligação ao GTP/metabolismo
19.
Bioinformatics ; 28(18): 2394-6, 2012 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-22815362

RESUMO

SUMMARY: The application of docking to large-scale experiments or the explicit treatment of protein flexibility are part of the new challenges in structural bioinformatics that will require large computer resources and more efficient algorithms. Highly optimized fast Fourier transform (FFT) approaches are broadly used in docking programs but their optimal code implementation leaves hardware acceleration as the only option to significantly reduce the computational cost of these tools. In this work we present Cell-Dock, an FFT-based docking algorithm adapted to the Cell BE processor. We show that Cell-Dock runs faster than FTDock with maximum speedups of above 200×, while achieving results of similar quality. AVAILABILITY AND IMPLEMENTATION: The source code is released under GNU General Public License version 2 and can be downloaded from http://mmb.pcb.ub.es/~cpons/Cell-Dock. CONTACT: djimenez@ac.upc.edu or juanf@bsc.es SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.


Assuntos
Algoritmos , Simulação de Acoplamento Molecular/métodos , Complexos Multiproteicos/química , Análise de Fourier , Software
20.
J Cell Sci ; 125(Pt 8): 1896-909, 2012 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-22328511

RESUMO

The tethering factor p115 (known as Uso1p in yeast) has been shown to facilitate Golgi biogenesis and membrane traffic in cells in culture. However, the role of p115 within an intact animal is largely unknown. Here, we document that depletion of p115 by using RNA interference (RNAi) in C. elegans causes accumulation of the 170 kD soluble yolk protein (YP170) in the body cavity and retention of the yolk receptor RME-2 in the ER and the Golgi within oocytes. Structure-function analyses of p115 have identified two homology regions (H1 and H2) within the N-terminal globular head and the coiled-coil 1 (CC1) domain as essential for p115 function. We identify a new C-terminal domain of p115 as necessary for Golgi ribbon formation and cargo trafficking. We show that p115 mutants that lack the fourth CC domain (CC4) act in a dominant-negative manner to disrupt Golgi and prevent cargo trafficking in cells containing endogenous p115. Furthermore, using RNAi of p115 and the subsequent transfection with p115 deletion mutants, we show that CC4 is necessary for Golgi ribbon formation and membrane trafficking in cells depleted of endogenous p115. p115 has been shown to bind a subset of ER-Golgi SNAREs through CC1 and CC4 domains (Shorter et al., 2002). Our findings show that CC4 is required for p115 function, and suggest that both the CC1 and the CC4 SNARE-binding motifs participate in p115-mediated membrane tethering.


Assuntos
Caenorhabditis elegans/metabolismo , Membrana Celular/metabolismo , Complexo de Golgi/metabolismo , Proteínas de Transporte Vesicular/química , Proteínas de Transporte Vesicular/metabolismo , Animais , Caenorhabditis elegans/química , Caenorhabditis elegans/genética , Membrana Celular/genética , Complexo de Golgi/química , Complexo de Golgi/genética , Proteínas da Matriz do Complexo de Golgi , Estrutura Terciária de Proteína , Transporte Proteico , Proteínas de Transporte Vesicular/genética
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