64 results on '"PHOSPHORYLATION"'
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2. Post-translational regulation of the HYL1 protein and its impact on the biogenesis of micro RNAs
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Achkar, Natalia Patricia, Manavella, Pablo Andrés, Schommer, Carla, Cerdán, Pablo Diego, Strobl-Mazzulla, Pablo Hernán, and Yang, Seong Wook
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Light response ,Micro RNA ,Micro ARNs ,Silenciamiento génico ,Arabidopsis ,Respuesta a la luz ,Gene silencing ,HYL1 ,Phosphorylation ,Fosforilación - Abstract
Fil: Achkar, Natalia Patricia. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas; Argentina. Las plantas, como organismos foto-autótrofos y sésiles, deben superar las fluctuaciones ambientales, entre ellos la cantidad y calidad de luz, que desafian su supervivencia. Para esto, las mimas reprograman su desarrollo en busqueda de una fuente de luz adecuada. Tal plasticidad está orquestada a nivel transcripcional por la expresión y represión de factores de transcripción específicos, que son frecuentemente blancos del silenciamiento mediado por micro-ARNs (miARNs). En este trabajo mostramos que las plantas inhiben la biogénesis de miARNs durante largos períodos de luz limitada, seguido de una recuperación rápida después de la restauración de luz, para orquestar el desarrollo de la planta en respuesta a la transición oscuridad/luz. La forma activa desfosforilada del factor de biogénesis de miARNs HYL1 es degradada durante la privación de luz, mientras que una reserva inactiva de proteína fosforilada permanece protegida dentro del núcleo. La degradación del componente activo de HYL1 conduce a la liberación de silenciamiento génico que desencadena el desarrollo característico de la respuesta de la planta a oscuridad. Tras la restauración de luz, una desfosforilación rápida de las reservas de HYL1 conduce a la reactivación de la biogénesis de miARNs, un cambio en el programa de desarrollo y la activación de la respuesta fotomorfogénica. Además, encontramos que la fosforilación de HYL1 en su dominio C-terminal y la variación en su longitud podrían tener funciones reguladoras en la proteína, probablemente modificando su afinidad para interactuar con componentes de la vía de biogénesis de miARNs o de las vías de señalización de luz azul. As photo-autotrophic and sessile organisms, plants depend on light, a resource that may become scare in nature. To overcome such environmental fluctuations, plants reprogram their development to adjust their growth in search for a proper light source. The developmental plasticity of plants is orchestrated at the transcriptional level by the expression and represion of specific transcription factors, which in turn are common targets of miRNA-mediated silencing. The regulation of the miRNA biogenesis is not an unusual phenomenon. In this thesis, we show that plants rely on a microRNA (miRNA) biogenesis shutdown during long periods of limited light, followed by a quick recovery after light restoration, to orchestrate the plant development in response to dark/light transition. Mechanistically, an active form of the miRNA biogenesis factor HYPONASTIC LEAVES 1 (HYL1) is degraded during light deprivation while an inactive pool of phosphorylated protein remains protected inside the nucleus. Degradation of the active HYL1 component leads to the release of gene silencing, triggering the developmental features characteristic of the plant response to dark. Upon light restoration, a quick dephosphorylation of the HYL1 reserve pool leads to the reactivation of miRNA biogenesis, a switch in the developmental program and the activation of the photomorphogenic response. Additionally, we found that the phosphorylation of the C-terminal region of HYL1 also appears to have regulatory roles on the protein activity. Such protein modification and the length of this domain impact the affinity of HYL1 with other interacting partners of either the miRNA or the blue light signaling pathways. Consejo Nacional de Investigaciones Científicas y Técnicas
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- 2021
3. Characterization of regulatory systems mediated by post-translational modifications of proteins involved in carbon partitioning in plant cells
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Rojas, Bruno Ezequiel, Iglesias, Alberto Álvaro, Lodeyro, Anabella Fernanda, Moreno, Silvia, and Zabaleta, Eduardo Julián
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Kinase ,Quinasa ,Phosphoenolpyruvate carboxykinase ,Arabidopsis thaliana ,Allosterism ,Phosphorylation ,Proteólisis ,Fosfoenolpiruvato carboxiquinasa ,Fosforilación ,Proteolisis ,Alosterismo - Abstract
Fil: Rojas, Bruno Ezequiel. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas; Argentina. La fosfoenolpiruvato (PEP) carboxiquinasa dependiente de ATP (PEPCKasa, EC 4.1.1.49) es una enzima citosólica que cataliza la descarboxilación reversible del oxaloacetato a PEP. En plantas, esta enzima posee múltiples funciones: i) es parte de los mecanismos de concentración del CO2 que operan en la fotosíntesis C4 y CAM, ii) participa en las respuestas al estrés biótico y abiótico, iii) está involucrada en el metabolismo del nitrógeno y de los aminoácidos y iv) juega un rol clave en la gluconeogénesis. En esta Tesis, estudiamos las PEPCKasas presentes en Arabidopsis thaliana: la AthPEPCKasa1 (At4g37870) y la AthPEPCKasa2 (At5g65690). Realizamos la caracterización cinética, estructural y regulatoria de las proteínas recombinantes expresadas en Escherichia coli. Describimos la regulación alostérica de estas enzimas por metabolitos y dipéptidos. También estudiamos la regulación postraduccional de la AthPEPCKasa1 por proteólisis, óxido reducción y fosforilación. En todos los casos, los resultados se discutieron en un escenario metabólico. Por otra parte, se desarrolló un método fluorométrico para medir actividad quinasa de proteínas. También clonamos y la caracterizamos las quinasas de proteína recombinantes SnRK1 de Arabidopsis thaliana y SOS2 de Malus domestica. Además, estas quinasas se utilizaron para estudiar la fosforilación de enzimas involucradas en el metabolismo del carbono en plantas. En conjunto, los resultados obtenidos en esta Tesis profundizaron el conocimiento sobre la regulación del metabolismo del carbono en plantas por mecanismos postraduccionales. Anticipamos que nuestros resultados abrirán nuevas perspectivas en la regulación del metabolismo vegetal, en especial en la gluconeogénesis y la síntesis de azúcares alcoholes. ATP-dependent phosphoenolpyruvate (PEP) carboxykinase (PEPCK, EC 4.1.1.49) is a cytosolic enzyme that catalyzes the reversible decarboxylation of oxaloacetate to PEP. In plants, this enzyme has multiple functions: i) is part of the mechanisms of CO2 concentration operating in C4 and CAM photosynthesis, ii) participates in biotic and abiotic stress responses, iii) is involved in nitrogen and amino acids metabolisms, and iv) plays a crucial role in gluconeogenesis. In this Thesis, we studied in detail the PEPCKs present in Arabidopsis thaliana: AthPEPCK1 (At4g37870) and AthPEPCK2 (At5g65690). We performed the kinetic, structural, and regulatory characterization of the recombinant proteins expressed in Escherichia coli. We described the allosteric regulation of these enzymes by metabolites and dipeptides. Also, we studied the post-translational regulation of AthPEPCK1 by proteolysis, oxidation-reduction, and phosphorylation. In all cases, the results obtained were discussed in a metabolic scenario. On the other hand, we developed a fluorometric assay to measure protein kinase activity. Also, we cloned and characterized the recombinant protein kinases SnRK1 from Arabidopsis thaliana and SOS2 from Malus domestica. These kinases were then employed to study the phosphorylation of enzymes involved in plant carbon metabolism. Altogether, the results obtained in this Thesis deepen the knowledge regarding the regulation of carbon metabolism in plants by post-translational modifications. We anticipate that our results will open new perspectives on plant metabolism regulation, especially for gluconeogenesis and the synthesis of sugar alcohols. Agencia Nacional de Promoción Científica y Tecnológica Consejo Nacional de Investigaciones Científicas y Técnicas Universidad Nacional del Litoral
- Published
- 2021
4. On the metabolism of carbon in autotrophic and heterotrophic cells of plants. Characterization of regulatory mechanisms of key enzymes for the partitioning of photoassimilated carbon
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Ferrero, Danisa María Luján, Iglesias, Alberto Álvaro, Estevez, José Manuel, Irazoqui, Fernando José, Gómez-Casati, Diego Fabián, and Piattoni, Claudia Vanesa
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Seed ,Regulación enzimática ,Mejoramiento de cultivos ,Enzymatic regulation ,Síntesis de amidón ,Regulación alostérica ,Semilla ,Starch synthesis ,Phosphorylation ,Allosteric regulation ,Fosforilación ,Improvement of yields - Abstract
Fil: Ferrero, Danisa María Luján. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas; Argentina. En las semillas, el metabolismo es principalmente heterotrófico y depende de la sacarosa que proviene de los tejidos fotosintéticos para suplir sus necesidades metabólicas. El desarrollo de las semillas se caracteriza por variaciones en el flujo del carbono, primeramente, destinado a solventar la formación del nuevo tejido, y posteriormente destinado a la acumulación de compuestos de reserva. Todo este desarrollo está genéticamente programado y numerosas señales inducen cambios en el metabolismo, donde las quinasas de proteínas juegan un rol fundamental, regulando postraduccionalmente por fosforilación a diferentes actores del metabolismo. Para contribuir al conocimiento de la regulación global del metabolismo y la partición del carbono en tejidos heterotróficos de plantas, nos focalizamos en evaluar la regulación alostérica y la ocurrencia de la fosforilación de enzimas claves. Además, estudiamos las quinasas de proteínas involucradas. Obtuvimos resultados novedosos para la ADP-glucosa pirofosforilasa de endosperma de trigo, enzima clave para la síntesis de almidón. La caracterización bioquímica de la enzima recombinante se condijo con los resultados para la misma enzima purificada de fuente. En un análisis comparativo a lo largo del desarrollo de semillas de trigo y de ricino, determinamos que esta enzima únicamente se fosforila en semillas de trigo, específicamente por quinasas dependientes de calcio. La información obtenida abre líneas de investigación para comprender la síntesis de almidón en semillas de cereales. Estos estudios serán importantes para el diseño de estrategias y herramientas biotecnológicas para mejorar los rendimientos de cultivos de interés agronómico y considerar la aplicación del almidón en biocombustibles y bioplásticos. Seed metabolism is mainly heterotrophic and depends on the sucrose synthesized from photosynthetic tissues to supply its metabolic needs. Seed development is characterized by variations in the carbon flux, destined, firstly, to solve the formation of the new tissue, and later, to accumulate reserve compounds. This development is genetically programmed and numerous signals induce changes in metabolism, where protein kinases play a fundamental role, post-translationally regulating different metabolism actors by phosphorylation. To contribute to the knowledge in global regulation of metabolism and carbon partitioning in heterotrophic tissues of plants, we focused on evaluating allosteric regulation and the occurrence of phosphorylation of key enzymes. Furthermore, we studied the protein kinases involved. We obtained novel results for wheat endosperm ADP-glucose pyrophosphorylase, a key enzyme in the biosynthesis of starch. The biochemical characterization of the recombinant enzyme was consistent with the results for purified enzyme from endosperm. In a comparative analysis throughout the development of wheat and castor beans seeds, we determined that this enzyme is only phosphorylated in wheat seeds, specifically by calcium-dependent kinases. The information obtained opens lines of research to understand the synthesis of starch in cereal seeds. These studies will be important for the design of biotechnological strategies and tools to improve the yields of crops and consider the application of starch in biofuels and bioplastics. Agencia Nacional de Promoción Científica y Tecnológica Consejo Nacional de Investigaciones Científicas y Técnicas Universidad Nacional del Litoral
- Published
- 2020
5. Mecanismos de homeostasis del pH intracelular en levadura: activación de la bomba de protones Pma1 y estabilidad de RNA mensajeros de ciclinas G1
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Canales Quilis, Celia
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Regulación ,crecimiento ,Ciclo celular ,BIOQUIMICA Y BIOLOGIA MOLECULAR ,Grado en Biotecnología-Grau en Biotecnologia ,Growth ,TOR ,Saccharomyces cerevisiae ,Phosphorylation ,Cell cycle ,Fosforilación ,Regulation - Abstract
[ES] El cáncer es una enfermedad poligénica, altamente heretogénea y de causas diversas. A partir del año 2000 se propusieron diferentes características distintivas (“cancer hallmarks”) que son comunes a los distintos tipos de cáncer. Entre ellas el valor de pH intra- y extracelular, más alcalino en el citosol y más ácido en el exterior que en células normales. El pH intracelular alto está relacionado con la regulación del crecimiento celular y la proliferación. Uno de los elementos involucrados en la regulación del pH intracelular es el sistema de expulsión de protones del citoplasma, que en caso de la levadura es la bomba de protones, o H + -ATPasa de la membrana plasmática Pma1, mientras que en células animales es NHE1, un antiportador de H + /Na+ menos potente que Pma1. Se ha demostrado que la expresión ectópica de Pma1 en fibroblastos de ratón aumenta el pH intracelular y causa transformación tumorogénica. TORC1, un complejo regulador del crecimiento en todos los eucariotas, está activado por pH intracelular alto, explicando el efecto de este parámetro sobre el crecimiento celular. En este trabajo se propone un modelo en Saccharomyces cerevisiae para estudiar el conjunto de funciones reguladoras de la homeostasis del pH, teniendo en cuenta los elementos descritos anteriormente. Para estudiar la relación entre el pH intracelular y el crecimiento se estudiaron los diferentes perfiles de crecimiento en la cepa silvestre y en mutantes con pérdida de función, en los cuales se compararon los valores obtenidos para la velocidad de crecimiento, el rendimiento y la duración de la fase Lag de las levaduras al suministrarles ácidos débiles. También se determinó el valor de pH intracelular de las cepas de interés y su variación al tratarlas con ácidos débiles como el acético. Por otro lado, para estudiar el papel de la fosfatasa Sit4 como posible regulador de la bomba de protones Pma1, se analizaron a través de la técnica Western Blot los niveles de fosforilación de los residuos Ser507 y Ser899 de Pma1 en la cepa silvestre y en la cepa mutante sit4Δ con presencia y ausencia de glucosa. Sit4 es regulada directamente por el complejo TOR y se estima que pueda tener un papel importante en la regulación de la homeostasis de pH intracelular. Por último se estudió el papel del gen SSD1 como estabilizador de los mensajeros de las ciclinas de la fase G1 del ciclo celular, como posible diana de la regulación de la proliferación., [EN] Cancer is a polygenic and highly heterogeneous disease with diverse causes. Since 2000, different cancer hallmarks that are common to different types of cancer have been proposed. Among them is the intracellular and extracellular pH value, more alkaline in the cytosol and more acid in the exterior than normal cells. High values of intracellular pH are related to the regulation of cell growth and proliferation. One of the main elements involved in the pHi regulation is the proton expulsion system, which in the case of yeast is the proton pump, or H + - ATPase of the plasma membrane Pma1, whereas in animal cells it is NHE1, a H + /Na+ antiportrier less potent than Pma1. Ectopic expressión of Pma1 in mouse fibroblasts has been shown to increase intracellular pH and cause tumorogenic transofrmation. TORC1, a growth regulator complex in all eukaryotes is activated by high intracellular pH, explaining the effect of this parameter in cell growth. In this study, we propose a model in Saccharomyces cerevisiae, to study the set of regulatory functions of pH homeostasis, taking into account the elements described above. In order to study the relationship between intracellular pH and growth, different growth profiles were studied in the wild strain and mutants with loss of function, in which the values obtained for growth rate, yield and lag phase were compared between yeasts by supplying them with weak acids. The intracellular pH value of the strains of interest and their variation were also determined by treating them with weak acids, such as acetic acid. On the other hand, to study the role of the phosphatase Sit4 as a possible regulator of the proton pump, the phosphorylation levels of residues Ser507 and Ser899 of Pma1 were analyzed through Western Blot technique in the wild strains and sit4Δ with presence and absence. Sit4 is directly regulated by the TOR complex and is estimated to have an important role in the regulation of pHi homeostasis. Finally, the role of the SSD1 gene as a stabilizer of cyclin messengers of the G1 phase of the cells cycle was studied as a possible target for the regulation of proliferation.
- Published
- 2017
6. Modulación de la señalización celular por fosforilación de STIM1: Implicaciones fisiológicas
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Casas Rua, Vanessa, Martín Romero, Francisco Javier, Pozo Guisado, Eulalia, Álvarez Miguel, Ignacio Santiago, and Universidad de Extremadura. Departamento de Bioquímica, Biología Molecular y Genética
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Calcio ,STIM1 ,Calcium ,Phosphorylation ,Fosforilación - Abstract
En esta tesis doctoral se ha descrito que la proteína intracelular STIM1 se regula por fosforilación en los aminoácidos Ser575, Ser608 y Ser621. Esta fosforilación es llevada a cabo por las quinasas ERK1/2, y la fosforilación permite la activación de STIM1 para actuar como sensor de los niveles de Ca2+ intraluminales. La ausencia de esta fosforilación conlleva defectos en el nivel de multimerización de la proteína, y la ausencia de unión al canal de Ca2+ ORAI1, responsable de la entrada de Ca2+ extracelular hacia el citosol. Además, este trabajo pone de manifiesto que la fosforilación de STIM1 en los aminoácidos Ser575, Ser608 y Ser621 es necesaria para la disociación de la proteína de microtúbulos EB1, lo que le permite a STIM1 su reorganización hacia yuxtaposiciones del retículo endoplasmático y la membrana plasmática. Por otro lado el trabajo ha descrito que esta fosforilación de STIM1 es un mediador clave en la señalización celular iniciada por el factor de crecimiento epidérmico (EGF) en células de adenocarcinoma endometrial humano (células Ishikawa), de modo que la desfosforilación de STIM1 reduce significativamente la migración de estas células y la transición epiteliomesénquima estimulada por EGF. Finalmente el trabajo describe que la inhibición de la entrada de Ca2+ regulada por depósitos intracelulares (SOCE) mediada por la fitoalexina resveratrol es debida principalmente a la inhibición de la fosforilación de STIM1 y no a un efecto de bloqueo de los canales de Ca2+ regulados por STIM1., In this Doctoral Thesis we have described that STIM1, an endoplasmic reticulum Ca2+ sensor, is regulated by phosphorylation at residues Ser575, Ser608 and Ser621. The upstream kinase for this phosphorylation is ERK1/2. As a result of this phosphorylation STIM1 becomes fully activated to act as a Ca2+ sensor by letting phosphoSTIM1 to multimerize and to bind to the Ca2+ channel ORAI1, which is the channel that mediates the Ca2+ influx to the cytosol in response to Ca2+-store depletion. In this regard, a defective phosphorylation abrogates the multimerization and the binding to ORAI1. Moreover this work demonstrates that phosphorylation of STIM1 at Ser575, Ser608 and Ser621 is required for the dissociation from the microtubule growing end regulator EB1. This dissociation let STIM1 to relocalize in endoplasmic reticulum-plasma membrane juxtapositions. On the other hand, this Thesis describes that phospho-STIM1 is a key mediator in the signalling pathway triggered by the epidermal growth factor (EGF) in Ishikawa cells (endometrial adenocarcinoma cells), and dephospho- STIM1 inhibits cell migration and epithelial-mesenquimal transition in response to EGF. Finally, this work describes that the phytoalexin resveratrol inhibits of storeoperated calcium entry by inhibiting the phosphorylation of STIM1 and not by acting as a Ca2+ channel blocker.
- Published
- 2016
7. Estrés osmótico, inflamación y degeneración neuronal en la enfermedad de Alzheirmer: implicación de la proteína asociada a microtúbulos tau
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Caballero Bermejo, Montaña, Centeno Vázquez, Francisco, Lorenzo Benayas, María Jesús, and Universidad de Extremadura. Departamento de Bioquímica, Biología Molecular y Genética
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Inflammation ,Hyperosmotic stress ,Inflamación ,Estrés hiperosmótico ,Citoesqueleto ,Enfermedad de Alzheimer ,Proteolysis ,Cellular signaling ,Señalización intracelular ,Tau ,Proteólisis ,Phosphorylation ,Alzheimer’s disease ,Fosforilación ,Cytoskeleton - Abstract
La enfermedad de Alzheimer es un desorden neurodegenerativo que se caracteriza por la presencia de los denominados ovillos neurofibrilares que son depósitos intraneuronales compuestos principalmente por la proteína asociada a microtúbulos Tau hiperfosforilada y proteolizada. En el presente trabajo hemos estudiado los mecanismos que regulan las modificaciones postraduccionales de Tau inducidas por el estrés hiperosmótico e inflamatorio. Nuestros resultados muestran que sólo el estrés hiperosmótico induce la proteólisis de Tau y la apoptosis y que estos efectos están mediados por la activación de las caspasas 6 y 3, través de un mecanismo en el que están implicadas las quinasas JNKs. En este trabajo estudiamos el efecto del estrés hiperosmótico y la neuroinflamación sobre los niveles y la fosforilación de Tau y las vías de señalización intracelular implicadas en este proceso. Nuestros resultados muestran que sólo el tratamiento con TNF-α induce la expresión génica de Tau y que ambos tipos de estreses promueven su fosforilación en los residuos Thr-50, Thr-181 y Thr-205 mediada principalmente las quinasas p38 y las JNKs. Adicionalmente, analizamos distribución de la proteína Tau fosforilada y sin fosforilar y comprobamos que ambos tipos de estreses promovían la acumulación de Tau en el soma de la célula (citoplasma y núcleo) y que modificaban la localización de las formas fosforiladas de Tau de una manera específica del residuo fosforilado. También comprobamos que las modificaciones en la fosforilación y la localización de Tau en respuesta al estrés hiperosmótico se acompañaban de la desorganización del citoesqueleto y que las promovidas por la inflamación producían una disminución en el transporte axonal. Por último, el análisis funcional de Tau mutada en los residuos Thr-50 y Thr-69 realizado en las células HEK-293 y PC-12 diferenciadas nos indica que ambos residuos son esenciales para su funcionalidad., Alzheimer’s disease is a degenerative brain disorder characterized neuropathologically by the presence of neurofibrillary tangles, which are intracellular aggregates of hyperphosphorylated and proteolyzed Tau, a protein associated to microtubules. In this work we studied the mechanisms that regulate the posttranslational modifications of Tau induced by hyperosmotic stress and neuroinflammation. Our results show that only the hyperosmotic stress promotes Tau proteolysis and apoptosis in SH-SY5Y cells. These effects are mediated by the activation of caspases 6 and 3 through a mechanism that involved JNKs. We also studied the effect of hyperosmotic stress and neuroinflammation on Tau expression and phosphorylation and the signaling pathways involved. Our results show that only TNF-α treatment increases Tau expression and that both stimuli induce Tau phosphorylation at Thr-50, Thr-181 and Thr-205. This last process is regulated mainly by p38s and JNKs. Additionally, we analyzed Tau distribution (phosphorylated or not) and we observed that both stresses promote Tau accumulation in soma (in cytoplasma and nucleus), and also modify the location of phosphorylated Tau in a site-specific manner. We showed also that modifications of Tau phosphorylation and distribution in response to hyperosmotic stress were associated to cytoskeleton disorganization and that inflammation impairs axonal transport.
- Published
- 2016
8. Regulación de la H+-ATPasa de la membrana plasmática de levadura por la proteína kinasa TOR, la proteína fosfatasa Sit4 y la proteína de unión a RNA Ssd1
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Trujillo del Río, Cristina
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Mutante Termosensible ,Regulación ,Bomba de protones ,Grado en Biotecnología-Grau en Biotecnologia ,Growth ,Crecimiento ,ATPase activity ,Actividad ATPasa ,Proton Pump ,Thermosensitive mutant ,BIOQUIMICA Y BIOLOGIA MOLECULAR ,Phosphorylation ,Fosforilación ,Regulation - Abstract
[ES] La H+-ATPasa de la membrana plasmática de la levadura Saccharomyces cerevisiae (Pma1) regula el crecimiento celular por energizar la entrada de nutrientes y por modular el pH intracelular y extracelular. Los principales factores ambientales que regulan su actividad son la fuente de carbono (glucosa que es fermentable e induce crecimiento rápido activa más que etanol que es respirable e induce crecimiento lento) y el pH del medio (pH ácido externo activa). La activación va unida a doble fosforilación de Ser911 Thr912 en el dominio inhibidor carboxi-terminal de la enzima pero se desconocen las kinasas y fosfatasas involucradas. En este proyecto se utilizará un método de filtración rápida de los cultivos seguida de inmersión de las células en nitrógeno líquido para preservar el estado fisiológico de Pma1. Se investigará el efecto de rapamycin (inhibidor de TOR), de temperatura no permisiva en un mutante termosensible de TOR, de un mutante en Tco89 (una subunidad de TOR) y en mutantes en dos proteínas esenciales redundantes, la proteína fosfatasa Sit4 y la proteína de unión a RNA Ssd1. Está última ha sido relacionada recientemente con tolerancia a acidificación intracelular. Todas estas proteínas tienen en común el promover el crecimiento celular, probablemente a través de aumentar el pH intracelular y estos estudios sirven de modelo para el papel del pH intracelular en el crecimiento rápido de las celular tumorales., [EN] Yeast plasma membrane H+-ATPasa (Pma1) regulates cell growth by energizing nutrient uptake and modulating intracellular pH (together with potassium transport). Main factors regulating Pma1 are carbon source (glucose activates and induces fast growth and fermentative metabolism) and external acid pH. Activation of PMa1 correlates with double phosphorylation of Ser-9141 and Thr-912 within the inhibitory carboxy-terminal domain of the enzyme. The nature of the protein kinases and phosphorylation sites such as Ser507 are not known. This project has investigated the activity of Pma1 in strains with null mutations in the genes SSD1, SIT4 and TCO89. The RNA-binding protein Ssd1 has been identified as a positive factor for cell growth and for tolerance to intracellular acidification and it exhibits synthetic lethality with protein phosphate Sit4. Tco89 is a subunit of protein kinase TORC1, a master regulator of growth that is hyper-activated in cancer cells. The role of TORC1 in Pma1 activity has been investigated with the specific inhibitor rapamycin and with the effect of non-permisive temperature in a thermosensitive mutant of TOR. All these regulatory proteins have in common to promote cell growth and division, probably by increasing intracellular pH by activating PMa1 and potassium transport (Sit4 and TORC1). They could also reinforce cellular systems inhibited by intracellular acidification. Our results suggest that there is a regulation of the H+-ATPasa of the plasma membrane by TOR and protein phosphatase Sit 4. These studies with the yeast system serve as a model for the homeostasis of intracellular pH during the fast growth of tumor cells.
- Published
- 2016
9. La quinasa del factor de iniciación eIF-2: ¿una nueva diana de la acción del Li+? Estudios preliminares
- Author
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Maestro Inarejos, Inés
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HCI ,quinasa de eIF-2 ,hemina ,phosphorylation ,eIF-2 kinase ,Síntesis de Proteínas ,BIOQUIMICA Y BIOLOGIA MOLECULAR ,Grado en Biotecnología-Grau en Biotecnologia ,hemin ,Protein synthesis ,fosforilación - Abstract
[EN] One of the most studied regulatory systems of protein synthesis in eukaryotic cells is based on the inactivation of the eIF-2 translation initiation factor, by phosphorylation of its α subunit. Throughout the last decades, several protein kinases responsible for eIF-2α phosphorylation have been identified and characterized; they are activated under different experimental conditions, such as lack of nutrients (limiting levels of free amino acids) or the presence of double-stranded RNA. Preliminary data from the laboratory suggested that Li+ inhibits at least one of the kinases, HCI (hemin controlled inhibitor), that is activated in rabbit reticulocytes lysates in the absence of hemin or, independently, by oxidation of –SH groups in the protein. The project´s objective is to develop the methodology required to confirm this hypothesis, once partially purified fractions of the kinase and the initiation factor have been obtained. If this is achieved, we would be closer to know whether HCI would join the known targets of lithium: inositol monophosphatases and glycogen synthase kinase-3 (or its Drosophila counterparts, the shaggy kinase)- whose inhibition is assumed to be responsible for the varied physiological effects of this cation., [ES] Uno de los sistemas más estudiados de regulación de la síntesis de proteínas en células eucarióticas se basa en la inactivación del factor de iniciación de la traducción eIF-2, por fosforilación, de su subunidad α. A lo largo de las últimas décadas, se han identificado y caracterizado varias proteínas quinasas, responsables de la fosforilación de eIF-2α, que se activan en distintas condiciones experimentales, como por ejemplo el ayuno (niveles limitantes de aminoácidos libres) o la presencia de RNA de doble cadena. Datos preliminares del laboratorio sugieren que el Li+ inhibe al menos una de estas quinasas, el HCI (hemin controlled inhibitor), que se activa en lisados de reticulocitos de conejo en ausencia de hemina o, independientemente, por oxidación de grupos –SH de la proteína. El objetivo del proyecto es poner a punto la metodología necesaria para confirmar esta hipótesis, una vez se hayan obtenido las fracciones parcialmente purificadas del HCI y del factor de iniciación. De lograrse este objetivo, estaríamos más cerca de saber si HCI se uniría a las dianas conocidas del litio- las inositol monofosfatasas y la glucógeno sintasa quinasa-3 (o sus homólogos, de Drosophila, las quinasas shaggy) – cuya inhibición, se asume, es la responsable de los variados efectos fisiológicos de este catión tóxico.
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- 2014
10. [Frequent involvement of the amyloid pathway in prodromal dementia with Lewy bodies].
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Monge-Argiles JA, Monge-Garcia V, Gasparini-Berenguer R, Garcia-Perez C, Gabaldon-Torres L, Salas-Felipe J, and Leiva-Santana C
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- Aged, Alzheimer Disease cerebrospinal fluid, Biomarkers cerebrospinal fluid, Disease Progression, Female, Follow-Up Studies, Frontotemporal Dementia cerebrospinal fluid, Humans, Male, Middle Aged, Phosphorylation, Protein Processing, Post-Translational, Retrospective Studies, Spain, Amyloid beta-Peptides cerebrospinal fluid, Cognitive Dysfunction cerebrospinal fluid, Lewy Body Disease cerebrospinal fluid, Peptide Fragments cerebrospinal fluid, tau Proteins cerebrospinal fluid
- Abstract
Introduction: Lewy body dementia (LBD) is the most frequent of the degenerative dementias, after Alzheimer's disease., Aim: To analyse the core biomarkers of Alzheimer's disease in the cerebrospinal fluid of exclusively Hispanic patients with prodromal LBD, in order to determine whether there is involvement of the amyloid pathway or the tau pathway., Patients and Methods: Between 2008 and 2017 we included 430 patients with mild cognitive impairment according to Petersen criteria, from three hospitals in the province of Alicante. They underwent clinical check-ups every 6-12 months to evaluate their clinical stability or their progression to dementia using current clinical criteria. Among other complementary tests, biomarkers for Alzheimer's disease in the cerebrospinal fluid were analysed., Results: Of all the patients included, 26 developed LBD and 29 remained stable for at least five years, and were thus considered as a reference. In this group only five (17%) had Abeta(1-42) protein values below normal, whereas 16 (55%) of the patients with LBD had altered levels. No differences were found in the levels of tau protein. On comparing the LBD groups with and without amyloidosis, differences were only found in the levels of Abeta(1-42) protein., Conclusions: We highlight the frequent presence of amyloid pathology in prodromal LBD in our population, and the probable involvement of different metabolic pathways in the same clinically defined dementia.
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- 2019
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11. Phosphorylated ERM Mediates Lipopolysaccharide Induced Pulmonary Microvascular Endothelial Cells Permeability Through Negatively Regulating Rac1 Activity.
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Fei L, Sun G, Zhu Z, and You Q
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- Animals, Cell Membrane Permeability drug effects, Cells, Cultured, Cytoskeletal Proteins physiology, Male, Membrane Proteins physiology, Microcirculation, Microfilament Proteins antagonists & inhibitors, Microfilament Proteins chemistry, Microfilament Proteins genetics, Phosphorylation, Phosphothreonine metabolism, Protein Processing, Post-Translational, RNA Interference, RNA, Small Interfering genetics, Rats, Rats, Sprague-Dawley, Time Factors, rac1 GTP-Binding Protein antagonists & inhibitors, rac1 GTP-Binding Protein genetics, Endothelial Cells drug effects, Lipopolysaccharides pharmacology, Lung blood supply, Microfilament Proteins physiology, rac1 GTP-Binding Protein physiology
- Abstract
Introduction: The endotoxin lipopolysaccharide (LPS)-induced pulmonary endothelial barrier disruption is a key pathogenesis of acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). However, the molecular mechanisms underlying LPS-impaired permeability of pulmonary microvascular endothelial cells (PMVECs) are not fully understood., Methods: Rat PMVECs were isolated and monolayered cultured, then challenged with different doses of LPS (0.1mg/L, 1mg/L, and 10mg/L). Trans-endothelial electrical resistance (TER) was utilized to measure the integrity of the endothelial barrier. Ras-related C3 botulinum toxin substrate 1 (Rac1) activity and the phosphorylation of Ezrin/Radixin/Moesin proteins (ERM) were assessed by pulldown assay and Western Blotting. Small interfering RNA (siRNA) inhibition of Rac1 and Moesin were applied to evaluate the effect of PMVEs permeability and related pathway., Results: LPS induced dose and time-dependent decreases in TER and increase in ERM threonine phosphorylation, while inactivated Rac1 activity in PMVEC. siRNA study demonstrated that both Rac1 and Moesin were involved in the mediation of the LPS-induced hyperpermeability in PMVECs monolayers, and Rac1 and Moesin could regulate each other., Conclusion: Phosphorylated ERM mediates LPS induced PMVECs permeability through negatively regulating Rac1 activity., (Copyright © 2018 SEPAR. Publicado por Elsevier España, S.L.U. All rights reserved.)
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- 2019
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12. Identificación y análisis funcional de genes de Sacchoromyces cerevisiae implicados en la fosforilación de N-oligosacáridos
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Corbacho Cuello, Isaac, Olivero Jiménez, Isabel, Hernández Martín, Luis Miguel, and Universidad de Extremadura. Departamento de Ciencias Biomédicas
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N-glicosilación ,Saccharomyces cerevisia ,Phosphorylation ,Fosforilación - Abstract
Esta Tesis Doctoral recoge el trabajo realizado por el doctorando en el campo de la N-glicosilación de proteínas. La N-glicosilación es una modificación post-traduccional de las proteínas de sumo interés e importancia puesto que afecta a su estabilidad y función. También está relacionada con determinadas enfermedades humanas como los Desórdenes Congénitos de Glicosilación (CDG). Los Capítulos I y II se centraron en la búsqueda a escala genómica, identificación y análisis funcional de genes de Saccharomyces cerevisiae implicados en el proceso de fosforilación de N-oligosacáridos. Se encontraron 199 genes cuya función es requerida, directa o indirectamente para el proceso mencionado. El Capítulo III recoge los estudios realizados sobre la influencia de la actividad de la V-ATPasa en las distintas etapas de la síntesis de N-oligosacáridos que se llevan a cabo en el Aparato de Golgi. Se ha encontrado que la actividad de esta enzima influye, de una forma determinante, fundamentalmente sobre los procesos que tienen lugar en la región de trans-Golgi. En el Capítulo IV se ha identificado el gen responsable de la mutación mnn3 y se ha caracterizado desde un punto de vista funcional. En el Capítulo V se analizaron y discutieron los cambios en los patrones de expresión génica globales de los mutantes mnn2 y mnn3, en relación con el patrón de la cepa silvestre. Por último, el Capítulo VI recoge un estudio sobre las características de los sitios de N-glicosilación en proteínas, con especial atención a los factores que afectan a su utilización como receptores de N-oligosacáridos. El trabajo incluye la incorporación de nuevos sitios de glicosilación en proteínas modelo, y el análisis de su grado de ocupación por N-oligosacáridos en estas proteínas. Parte del trabajo presentado en esta Tesis ha sido publicado en cuatro artículos científicos en revistas internacionales de prestigio.
- Published
- 2013
13. Efecto de diferentes inhibidores y metales sobre las quinasas humanas VRK y la proteína viral B1R
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Barcia Sanjurjo, Iria, Barcia, R., Lazo, Pedro A., Xunta de Galicia, Universidad de Santiago de Compostela, CSIC-USAL - Instituto de Biología Molecular y Celular del Cancer de Salamanca (IBMCC), Ministerio de Educación y Ciencia (España), Junta de Castilla y León, and Obra Social Kutxa
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VRK1 ,Kinase ,Inhibición quinasas ,Inhibitors ,VRK2 ,Phosphorylation ,B1R ,Fosforilación - Abstract
Memoria presentada por Iria Barcia Sanjurjo, graduada en Ciencia y Tecnología de los Alimentos para optar al grado de Doctor en Bioquímica y Biología Molecular por la Universidad de Santiago de Compostela (Departamento de Bioquímica y Biología Molecular) y realizada en el Instituto de Biología Molecular y Celular del Cancer de Salamanca., Esta Tesis Doctoral ha sido realizada dentro del Proyecto de Investigación Zimofeed: 08MMA003CT financiado por la Secretaria Xeral de Investigación e Desenvolvemento da Xunta de Galicia. Doña Iria Barcia Sanjurjo ha disfrutado de un contrato predoctoral financiado por la Vicerrectoría de Investigación e Innovación junto con el Departamento de Bioquímica y Biología Molecular de la Universidad de Santiago de Compostela. La investigación en el laboratorio del Centro de Investigación del Cancer (CIC-C.S.I.C) ha sido financiada por los siguientes proyectos: Ministerio de Educación y Ciencia (SAF2004-02900; SAF2007-60242; CDS-2007-0017 y SAF2010-14935). Junta de Castilla y León, Consejería de Sanidad (SAN/673/SA05/08; BOCyL Nº 170). Junta de Castilla y León, Consejería de Educación (CSI14A08; CSI006A11-2 y grupo de excelencia GR-15). Kutxa-Fundación INBIOMED.
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- 2012
14. Role of phosphorylation in regulating the functional activity of the movement protein TGBp1 of potato virus X
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Binaghi, María and Zelada, Alicia M.
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VIRAL MOVEMENT ,FOSFORILACION ,SILENCIAMIENTO MEDIADO POR ARN ,MOVIMIENTO VIRAL ,REM ,RNA SILENCING ,TGBP1 ,POTATO VIRUS X ,PHOSPHORYLATION - Abstract
El Potato virus X (PVX) es un virus de plantas perteneciente al género Potexvirus. Sugenoma está compuesto por una única molécula de ARN que codifica una replicasaviral, tres proteínas de movimiento (MPs: TGBp1, TGBp2 y TGBp3) y la proteína de lacápside (CP). La proteína TGBp1 es una proteína multifuncional requerida para elmovimiento viral célula a célula en la planta hospedera. Se ha demostrado que esta MP es fosforilada en los residuos T193 y T214 por una quinasa tipo CK2. Diferenteslíneas de investigación sugieren que la fosforilación de las proteínas virales puederegular la replicación y el movimiento viral. El objetivo de este trabajo fue estudiar elrol de la fosforilación en la regulación funcional de la proteína de movimiento TGBp1de PVX y en su interacción con la proteína de plantas remorina (REM). Para ello seconstruyeron por mutagénesis dirigida versiones de TGBp1 no fosforilables (T193A y T214A) y otras que simulan la fosforilación (T193D y T214D). En ensayos detranscomplementación de la movilización célula a célula de un virus defectivo paradicha función, se demostró que las modificaciones en ambas treoninas resultanperjudiciales en la complementación del movimiento viral. Se determinó que lafosforilación de TGBp1 en la T193 regula la estabilidad de esta proteína viral por mediode un mecanismo que involucra la presencia de una secuencia de degradación tipo PEST en el extremo C-terminal de dicha proteína. A través de la combinación deestudios que involucran el análisis comparativo in silico de varias TGBp1s de virus delos géneros Alpha y Betaflexiviridae y de estudios por mutagénesis dirigida, sedeterminó que la T193 y la secuencia PEST C-terminal se encuentran conservadas entodas las TGBp1s analizadas, sugiriendo que la fosforilación en la T193 de estas MPssería un mecanismo regulatorio de la estabilidad de dichas proteínas. Por otra parte, elanálisis funcional de las fosfomutantes T193 y T214 de TGBp1 determinó que lafosforilación en dichos residuos afecta negativamente la actividad supresora del PTGSde TGBp1. Los ensayos de interacción entre TGBp1 de PVX y la proteína REMdeterminaron que tanto el dominio N- como el C-terminal de TGBp1 son necesariospara la interacción y que la misma no es regulada por fosforilación en los residuos T193 y T214 de TGBp1. Por otro lado, este trabajo presenta las primeras evidenciasque la interacción entre distintas proteínas TGBp1s y REM se encontraría conservadaentre los virus que utilizan estrategias de movilización del tipo Triple Bloque de Genes (TGB). Los análisis realizados para determinar el efecto biológico de REM sobre la TGBp1 de PVX demostraron que la proteína REM no interfiere en la actividad del PTGSde esta proteína viral. Finalmente estudios de localización subcelular determinaronque la localización subcelular de TGBp1 es influenciada por la presencia de las otrasproteínas virales y que a su vez varía según si la proteína se encuentra fusionada en suextremo N- o C- terminal a GFP. Potato virus X (PVX) is the type member of the Potexvirus genus. Its genome is basedon a single RNA molecule encoding one viral replicase protein, three movementproteins (MPs: TGBp1, TGBp2 and TGBp3) and the capsid protein (CP). In particular, TGBp1 is a multifunctional protein required for virus cell-to-cell movement inside thehost plant. Previously it has been demonstrated that TGBp1 is phosphorylated by a CK2-like kinase in T193A and T214 residues. Recent works on other plant viruses haveindicated that viral protein phosphorylation by host kinases can regulate processessuch us viral replication and mobilization. The aim of this work is to evaluate the roleof phosphorylation in regulating the functional activities of the movement protein TGBp1 of PVX and its interaction with the protein Remorin (REM). For this aimdifferent TGBp1 mutants have been developed by direct mutagenesis where theidentified threonines have been replaced by alanine (T193A and T214A) or aspartate (T193D and T214D) residues. The virus movement function of the phosphomutantswas assessed by complementation of PVX cell-to-cell movement in trans. It was shownthat all mutants were non-functional for virus movement, and that phosphorylation of T193 is essential for stability of the MP by a degradation mechanism that involves a PEST sequence at the C-terminus of TGBp1. Several experimental approaches involvingsequence comparison among TGBp1 homologues from viruses belonging to the Alphaand Betaflexiviridae genera and direct mutagenesis show that the T193 residue andthe PEST sequence are conserved among all TGBp1 analyzed, suggesting thatphosphorylation of T193 in these MPs could be a mechanism by which protein stabilityis regulated in several viruses. The results obtained in this work also have shown thatphosphorylation of T193 and T214 of TGBp1 negatively affects the PTGS suppressionactivity of this MP. Two-hybrid assays and pull down experiments demonstrated thatthe N- and C-term domain of TGBp1 are involved in the interaction between PVX TGBp1 and REM and that this interaction is not regulated by TGBp1 phosphorylation. In addition, this work presents the first evidence that the interaction between REMand other TGBp1s could be a conserved mechanism used by different TGB-containingviruses. The studies conducted to determine the biological effect of REM on TGBp1from PVX showed that REM protein does not interfere with PTGS- suppressing activityof TGBp1. Finally, sub-cellular localization studies demonstrated that TGBp1localization is influenced by the presence of other viral proteins and by the use of N- or C-terminal GFP fusion proteins. Fil: Binaghi, María. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.
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- 2012
15. Studies on the phosphorylation of the TGBp1 movement protein of Potato virus X
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Módena, Natalia A. and Mentaberry, Alejandro N.
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VIRAL MOVEMENT ,FOSFORILACION ,MOVIMIENTO VIRAL ,CK2 ,TGBP1 ,POTATO VIRUS X ,PHOSPHORYLATION - Abstract
El Potato virus X (PVX) es un virus de plantas, miembro tipo del género Potexvirus. Su genoma está compuesto por una única molécula de ARN que codificauna replicasa viral, tres proteínas de movimiento (MPs: TGBp1, TGBp2 y TGBp3) y laproteína de la cápside (CP). La proteína TGBp1 es una proteína multifuncionalrequerida para el movimiento viral de célula a célula en la planta hospedera. Diferenteslíneas de investigación sugieren que la fosforilación de las proteínas virales puederegular la replicación y el movimiento viral. En este estudio, se demostró que laproteína TGBp1 es fosforilada por al menos una proteína quinasa, presente enextractos de plantas de Nicotiana tabacum infectadas con PVX y no infectadas, queposee características distintivas de la caseína quinasa 2 (CK2). El análisis en gelesbidimensionales de extractos de plantas infectadas permitió determinar que la proteína TGBp1 producida durante la infección viral presenta múltiples isoformas de diferentespuntos isoeléctricos; el tratamiento con fosfatasas de los extractos de plantasinfectadas indicó la presencia de isoformas fosforiladas. A través de la combinación deestudios de determinación de aminoácidos fosforilados por espectrometría de masa,comparación de secuencias aminoacídicas de TGBp1 de distintos virus y evaluaciónde la fosforilación in vitro de mutantes puntuales y de deleción de la proteína TGBp1,se identificaron tres probables sitios de fosforilación por la quinasa CK2 de N.tabacum: S-165, T-193, T-214. Se observó que la simulación de la fosforilación en losresiduos T-193 y T-214 regula negativamente la dispersión viral y la capacidad de laproteína TGBp1 de hidrolizar ATP. Los resultados sugieren firmemente que unaproteína quinasa de la familia de CK2 estaría involucrada en la fosforilación de TGBp1durante el curso de la infección viral de N. tabacum. Además, se discute el modo enque la fosforilación podría regular las actividades de la proteína TGBp1 durante lainfección viral. Potato virus X (PVX) is the type member of the Potexvirus genus. Its genome isbased on a single RNA molecule encoding one viral replicase protein, three movementproteins (MPs: TGBp1, TGBp2 and TGBp3) and the capside protein (CP). In particular, TGBp1 is a multifunctional protein required for virus cell-to-cell movement inside thehost plant. Recent work on other plant viruses has indicated that viral proteinsphosphorylation by host kinases can regulate processes such us viral replication andmobilization. The results obtained during this Thesis work show that TGBp1 isphosphorylated by at least one kinase protein with properties characteristic of Caseinkinase 2 (CK2). This kinase activity is present in crude extracts prepared from bothnon-infected and PVX infected Nicotiana tabacum plants. Bi-dimensional gelexperiments with crude extracts from PVX infected plants showed that TGBp1expressed during infection presented several isoforms with different Isoelectricalpoints. Some of these isoforms were sensitive to phosphatase treatment, suggestingthat TGBp1 is phosphorylated in multiple residues. Several experimental approaches (mass spectrometer identification of phosphorylated aminoacids, sequence comparisonamong TGBp1 homologues from several viruses, and in vitro phosphorylationexperiments with mutated versions of TGBp1), allowed the identification of threepotential phosphorylation sites by recombinant alpha subunit N. tabacum CK2: S-165, T-193 and T-214. Mimicking phosphorylation on residues T-193 and T-214 had anegative impact on viral spreading and TGBp1 ATP hydrolysis activity. The results presented in this Thesis strongly suggest that a N. tabacum kinaseprotein belonging to CK2 family is involved in the phosphorylation of TGBp1 during PVX infection. How the phosphorylation regulates TGBp1 activities is discussed. Fil: Módena, Natalia A.. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.
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- 2011
16. Hormonal regulation and functional role of map kinase phosphatase-1 (MKP-1) IN STEROIDOGENIC CELLS
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Brion, Laura and del Valle Paz, Cristina
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LH ,ESTEROIDOGENESIS ,MKP-1 ,FOSFORILACION ,STAR ,STEROIDOGENESIS ,PHOSPHORYLATION - Abstract
Las MAP quinasas fosfatasas (MKPs) son componentes regulatorios importantes en aquellos procesos fisiológicos en los cuales participan las MAPKs debido a su capacidad de inactivar específicamente a estas enzimas. En este trabajo se analizó el rol funcional y la regulación transcripcional y post-traduccional de MKP-1 en células esteroidogénicas. Demostramos que hCG y AMPc incrementan los niveles de MKP-1 por mecanismos transcripcionales y post-traduccionales. Los resultados obtenidos indican que hCG/AMPc promueven la fosforilación de MKP-1 por acción de PKA y ERK1/2 y que esta modificación promueve su estabilización. También demostramos que esta fosfatasa se localiza tanto en núcleo como en mitocondrias. En lo que respecta al papel funcional de MKP-1, se comprobó que la expresión de MKP-1 inhibe la producción de esteroides por su capacidad de interferir con la inducción de StAR, una proteína clave para la esteroidogénesis. En conclusión, en este trabajo demostramos que LH/ACTH, además de promover la activación de enzimas necesarias para la síntesis de esteroides como ERK1/2, también dispara la activación de mecanismos que contribuyen a la inactivacion de esta enzima. Se concluye que el aumento en la expresión de MKP-1 y la estabilización de la proteína por acción de hCG/AMPc es un mecanismo clave para el cierre de la acción hormonal sobre la esteoidogénesis. MAP kinase phosphatases (MKPs) are important regulatory components in the physiological processes in which the MAPKs are involved, due to its ability to inactivate specifically these enzymes. In this study we have analyzed the functional role and transcriptional and post-translational regulation of MKP-1 in steroidogenic cells. We show that hCG and cAMP increase MKP-1 levels by transcriptional and posttranslational mechanisms. The results indicate that hCG/cAMP promotes MKP-1 phosphorylation by PKA and ERK1/2 action and that this modification promotes its stabilization. We also show that this phosphatase is localized in nucleus and mitochondria. Regarding the functional role of MKP-1, it was found that the expression of MKP-1 inhibits the production of steroids by its ability to interfere with the induction of StAR, a key protein for steroidogenesis. In conclusion, in this work we demonstrate that LH/ACTH, in addition of promoting the activation of ERK1/2, which is necessary for steroid synthesis, also triggers the activation of mechanisms that contribute to the inactivation of this enzyme. We show the increased expression of MKP-1 and stabilization of the protein by hCG/cAMP action, as a key mechanism for the closure of hormone action on steroidogenesis. Fil: Brion, Laura. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.
- Published
- 2010
17. Influence of PKA-dependent phosphorylation on the conformation and function of the GTPase Rap 1b
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Edreira, Martín Miguel and Altschuler, Daniel L.
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FOSFORILACION ,EPAC ,RAP 1B ,AMPC ,PKA ,ALOSTERIC EFFECT ,CAP1 ,CAMP ,PHOSPHORYLATION - Abstract
La activación de Rap1b por la proteína de intercambio activada por AMPc (Epac) y sufosforilación mediada por la proteína quinasa dependiente de AMPc (PKA), son requeridas parala mitogénesis dependiente de AMPc. Sin embargo, el rol de la fosforilación permanece incierto. Evaluamos potenciales cambios conformacionales inducidos por la fosforilación de Rap1b, utilizando el intercambio hidrogeno/deuterio acoplado a espectroscopia de masa (DXMS)y cristalografía. Velocidades de intercambio hidrogeno/deuterio para Rap1b fosforilada (Rap1-P)y fosfomimética (Rap1-D) mostraron un perfil de intercambio idéntico, con velocidadesincrementadas en regiones discretas a lo largo de la proteína, incluyendo un dominio alrededordel sitio de fosforilación y la región efectora. La estructura cristalina de Rap1b-G12V-S179Dmostró que la presencia del S179D induce cambios en la interfase con los switch I y II. Nuestro segundo objetivo fue la búsqueda de efectores de Rap1b modulados porfosforilación. Entre los clones aislados por doble hibrido, se encontró la proteína asociada a la adenilil ciclasa 1 (CAP1). Rap y CAP presentaron una asociación independiente del nucleótido,pero dependiente de la isoprenilación de Rap1b. Aunque la fosforilación demostró modularnegativamente esta interacción, su efecto sobre la señal mitogénica mediada por Rap1 fuepositivo. CAP1, actuando como proteína andamio de Rap, resultó necesaria para la acción de Rap1, siendo requerida además para su activación y fosforilación, efecto que estaría mediado porla estimulación del aumento de los niveles de AMPc. Activation of Rap1b by the exchange protein activated by cAMP (Epac) and its cAMPdependentprotein kinase (PKA)-mediated phosphorylation are required for cAMP dependentmitogenesis. However, the role of phosphorylation remains unknown. We assessed potential conformational changes induced by phosphorylation of Rap1busing the amide hydrogen/deuterium exchange mass spectroscopy (DXMS) and Crystallography. Exchange rates PKA-phosphorylated (Rap1-P) and phosphomimetic (Rap1-D) Rap1b proteinsshowed the same pattern of exchange, revealing an increased exchange rate in discrete regionsalong the protein, including a domain around the phosphorylation site and the effector domain. Crystal structure for the full length Rap1b-G12V-S179D showed that the presence of the S179Dinduce changes at the interface with switch I and II. Our second objective was finding Rap1b effectors modulated in a phospho-dependentfashion.. Within the clones isolated by Two Hybrid, we found the adenylate cyclase-associatedprotein 1 (CAP1). Rap/CAP association showed to be nucleotide independent, but dependent on Raps’ isoprenylation. Although, phosphorylation showed to negatively modulate this interaction,it had positive effect on the mitogenic signal mediated by Rap1. CAP, acting as a scaffoldingprotein for Rap1b, was necessary for Rap1 mediated action, and required for Rap1b activationand phosphorylation, effect mediated by stimulating the increase of the levels of cAMP. Fil: Edreira, Martín Miguel. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.
- Published
- 2009
18. Study of calmodulin expression and detection of changes in signal transduction pathways during the differentiation processes of parasite Giardia intestinalis
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Alvarado Mora, Magda Elvira and Wasserman Lerner, Moisés (Thesis advisor)
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54 Química y ciencias afines / Chemistry ,Diferenciación ,Calmodulin ,Giardia ,Differentiation ,Calmodulina ,Protozoa ,Phosphorylation ,Fosforilación - Abstract
Giardia intestinalis es un parásito que infecta humanos. El proceso de exquistación es fundamental para que Giardia pueda infectar a un nuevo hospedero. Es un proceso biológico muy interesante, en donde la forma dormitante (quiste) detecta que las condiciones ambientales son las adecuadas para la reactivación celular. En este trabajo se estableció un método para la purificación de quistes del parásito, y se realizaron experimentos de exquistación. Se analizaron cambios en el patrón de fosforilación durante las tres fases del proceso de exquistación usando una tinción específica de fosfoproteínas. Se encontraron dos proteínas fosforiladas, y fueron identificadas usando MALDI-TOF. Además, por medio de experimentos de inhibición se estableció que la actividad serina-treonina kinasa es necesaria para que ocurra la citoquinesis en la fase final del proceso. Se analizó la vía de señalización dependiente de calcio y calmodulina en Giardia. Por un lado, se identificaron proteínas de unión a calcio de la familia EF-hand por medio de bioinformática; también se realizó un acercamiento experimental usando una tinción para proteínas de unión a calcio. Por otro lado, se clonó el gen de calmodulina del parásito y se obtuvo una proteína recombinante contra la que se desarrollo un anticuerpo altamente específico. Con el anticuerpo se realizaron experimentos de western-blot y de inmunofluoresencia, que permitieron determinar el nivel de expresión y la localización de calmodulina durante la exquistación y enqustación de Giardia. Además, usando experimentos de pull-down se aislaron e identificación por primera vez cuatro proteínas de unión a calmodulina en este organismo. / Abstract. The parasite Giardia intestinalis undergoes a differentiation process that allows it to infect its mammal host. That process is excystation. The excystation is a highly interesting biological process in which the dormant form (cyst) perceives that the environmental conditions are right for cell reactivation. We report a new method for quick and effective isolation of parasite cysts. We examined the importance of protein phosphorylation during the passage from cyst to trophozoite. Using a specific staining for phosphoproteins. We found two phosphorylated proteins and identified them with MALDI-TOF. In addition, the inhibition of serine-threonine kinases during excystation specifically affected the cytokinesis. In this study we analyzed the calcium/calmodulin signal pathway in Giardia. We used two approaches to identify calcium binding proteins. First, we analyzed its completed genome sequence for genes encoding EF-hand-containing proteins. Second, we carried out assays with a specific staining for calcium binding proteins. On the other hand, we produced a highly specific antibody against the calmodulin of the parasite which allowed us to detect the protein level on western-blot and its localization in immunofluorescence assays. This is the first report of the isolation and identification of calmodulin binding proteins in the parasite Giardia intestinalis. Doctorado
- Published
- 2009
19. El mecanismo molecular de la regulación de la contracción muscular
- Author
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Padrón, Raúl
- Subjects
three-dimensional reconstruction ,muscle ,phosphorylation ,filamento grueso ,regulation ,cryo-electron microscopy ,regulatory light chain ,músculo ,myosin ,miosina ,crio-microscopia electrónica ,cadena ligera reguladora ,regulación ,activación ,reconstrucción tridimensional ,thick filament ,activation ,fosforilación - Abstract
La estructura de los filamentos gruesos de músculo estriado en el estado relajado ha sido finalmente comprendida a nivel molecular. La estructura revela interacciones intra- e intermoleculares que mantienen las cabezas de miosina unidas formando hélices adosadas a la superficie del filamento grueso. La fosforilación de las cadenas ligeras reguladoras de la miosina induce el debilitamiento de estas interacciones permitiendo la activación de los filamentos gruesos, produciendo el desorden y la liberación de las cabezas de miosina, y permitiendo su interacción con los filamentos delgados. Estos resultados abren las puertas para la comprensión del mecanismo molecular de la regulación ligada a miosina de la contracción muscular, de relevancia ya que las mutaciones asociadas a la cardiomiopatía hipertrófica medioventricular están ubicadas cercanas al sitio de fosforilación en las cadenas ligeras reguladoras de miosina. The structure of the thick filaments of striated muscle has been finally understood at the molecular level. The structure reveals intra- and inter-molecular interactions that held the myosin heads forming helices on the thick filament surface. The phosphorylation of the myosin regulatory light chains induces the weakening of these interactions, allowing the activation of thick filaments, and enabling their interaction with the thin filaments. These results open the possibility to the understanding of the molecular mechanism of the myosinlinked regulation of muscle contraction. This is of relevance as the mutations associated with mid ventricular cardiomyopathy are located near the phosphorylation site in the regulatory light chain.
- Published
- 2008
20. Increased intracellular Ca2+ and SR Ca2+ load contribute to arrhythmias after acidosis in rat heart : Role of Ca2+/calmodulin-dependent protein kinase II
- Author
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Romina Valeria Becerra, Julieta Palomeque, John R. Dedman, María Matilde Said, Leticia Vittone, Marcia A. Kaetzel, Cecilia Mundiña-Weilenmann, Alicia Mattiazzi, Paula L. Diaz-Sylvester, J. A. Copello, and Gustavo Rinaldi
- Subjects
Male ,Benzylamines ,Time Factors ,Physiology ,Action Potentials ,Ventricular Function, Left ,Mice ,Calcium-binding protein ,Myocyte ,Myocytes, Cardiac ,calcium/calmodulin-dependent protein kinase ,Enzyme Inhibitors ,Phosphorylation ,Acidosis ,Sulfonamides ,Ryanodine ,Ryanodine receptor ,Articles ,Hydrogen-Ion Concentration ,cardiovascular system ,Thapsigargin ,medicine.symptom ,Cardiology and Cardiovascular Medicine ,Intracellular ,medicine.drug ,medicine.medical_specialty ,Ischemia ,Mice, Transgenic ,Biology ,Dantrolene ,Sarcoplasmic Reticulum Calcium-Transporting ATPases ,Physiology (medical) ,Internal medicine ,Ventricular Pressure ,medicine ,Animals ,Rats, Wistar ,Calcium metabolism ,Calcium-Binding Proteins ,Arrhythmias, Cardiac ,Ryanodine Receptor Calcium Release Channel ,medicine.disease ,Rats ,sarcoplasmic reticulum ,Disease Models, Animal ,Endocrinology ,Ciencias Médicas ,Calcium ,Calcium-Calmodulin-Dependent Protein Kinase Type 2 ,Peptides - Abstract
Returning to normal pH after acidosis, similar to reperfusion after ischemia, is prone to arrhythmias. The type and mechanisms of these arrhythmias have never been explored and were the aim of the present work. Langendorff-perfused rat/mice hearts and rat-isolated myocytes were subjected to respiratory acidosis and then returned to normal pH. Monophasic action potentials and left ventricular developed pressure were recorded. The removal of acidosis provoked ectopic beats that were blunted by 1 mM of the CaMKII inhibitor KN-93, 1 mM thapsigargin, to inhibit sarcoplasmic reticulum (SR) Ca21 uptake, and 30 nM ryanodine or 45 mM dantrolene, to inhibit SR Ca21 release and were not observed in a transgenic mouse model with inhibition of CaMKII targeted to the SR. Acidosis increased the phosphorylation of Thr17 site of phospholamban (PT-PLN) and SR Ca21 load. Both effects were precluded by KN-93. The return to normal pH was associated with an increase in SR Ca21 leak, when compared with that of control or with acidosis at the same SR Ca21 content. Ca21 leak occurred without changes in the phosphorylation of ryanodine receptors type 2 (RyR2) and was blunted by KN-93. Experiments in planar lipid bilayers confirmed the reversible inhibitory effect of acidosis on RyR2. Ectopic activity was triggered by membrane depolarizations (delayed afterdepolarizations), primarily occurring in epicardium and were prevented by KN-93. The results reveal that arrhythmias after acidosis are dependent on CaMKII activation and are associated with an increase in SR Ca21 load, which appears to be mainly due to the increase in PT-PLN., Centro de Investigaciones Cardiovasculares
- Published
- 2008
21. Isolation and characterization of the pistil-produced ligand that interacts with pollen receptor kinases LePRK1 and LePRK2 from Solanum lycopersicon (tomato)
- Author
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Wengier, Diego Leonardo and Muschietti, Jorge P.
- Subjects
RECEPTOR-LIGANDO ,LIGAND-RECEPTOR ,INTERACCION POLEN-PISTILO ,FOSFORILACION ,PURIFICACION DE LIGANDO ,LIGAND PURIFICATION ,POLLEN-PISTIL INTERACTIONS ,SIGNAL TRANSDUCTION ,TRANSDUCCION DE SEÑALES ,PHOSPHORYLATION - Abstract
Los LePRKs son receptores quinasa que se localizan en la membrana plasmática de polen, posiblemente mediando interacciones polen-pistilo. Previamente, hemos demostrado que LePRK2 se encuentra fosforilada en polen maduro y germinado, y se desfosforila cuando microsomas de polen son incubados con extractos de estigma-estilo. Esto sugiere que por lo menos LePRK2 podría estar transduciendo una señal del pistilo a través de la actividad de LePRK2. En esta tesis, mostramos que la desfosforilación de LePRK2 está mediada por una molécula proveniente del pistilo resistente al tratamiento térmico, alcalino y proteasas. Basándonos en la desfosforilación de LePRK2, desarrollamos un protocolo de purificación con el cual obtuvimos un pico aislado de ~3550 Da (determinado por UV-MALDI-TOF MS) correspondiente a esta molécula peptídica que nombramos MrX. Con el fin de evaluar los efectos de MrX en tubos polínicos en crecimiento, realizamos ensayos de germinación in vitro en presencia de MrX parcialmente purificado y determinamos la longitud del tubo polínico como marcador del estado fisiológico. La adición de MrX al medio de germinación resultó en un aumento del largo del largo del tubo polínico en una forma dependiente de la dosis, mientras que las fracciones control no tuvieron efecto alguno. Nuestra hipótesis plantea que las interacciones polen-pistilo a través del complejo de LePRKs involucran la percepción de MrX por LePRK2, seguido de una desfosforilación de ésta y un incremento de la tasa de crecimiento del tubo polínico. LePRK1 and LePRK2 are pollen specific receptor kinases that belong to a plasma membrane high molecular weight complex possibly involved in pollen-pistil interactions. Previously, we have shown that LePRK2 is phosphorylated in mature and germinated pollen grains, but is dephosphorylated when pollen microsomes are incubated with stigma-style extracts. This suggests that LePRK complex might be transducing a signal from pistils through LePRK2 activity. In this thesis, we show that LePRK2 dephosphorylation is mediated by a heat-, base- and protease-resistant molecule from pistils. Based on LePRK2 phosphorylation, we developed a purification protocol and obtained an isolated peak of ~3550 Da peptidic compound (as determined by UV-MALDI-TOF MS) that we named MrX. In order to assess the effects of MrX on growing pollen tubes, we did in vitro germination assays in the presence of partially purified fraction of MrX and determined pollen tube length as a marker of the physiological state. MrX addition to germination medium resulted in pollen tube length increase in a dose-dependent manner, but not when pollen grains were incubated with control fractions. We hypothesize that pollen-pistil interactions through LePRK complex involve MrX perception by LePRK2, followed by LePRK2 dephosphorylation and an increase in pollen tube growth rate. Fil: Wengier, Diego Leonardo. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.
- Published
- 2008
22. CDPKs en dos procesos de desarrollo : la tuberización en Solanum tuberosum y la nodulación en Medicago spp
- Author
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Gargantini, Pablo Rubén and Ulloa, Rita M.
- Subjects
GIBBERELLINS ,NODULATION ,TRANSGENIC PLANTS ,SOLANUM TUBEROSUM ,CITOQUININAS ,NODULACION ,CYTOKININS ,TUBERIZACION ,QUINASA DE PROTEINAS DEPENDIENTES DE CALCIO (CDPK) ,FOSFORILACION ,CALCIUM DEPENDENT PROTEIN KINASE ,GIBERELINAS ,MEDICAGO TRUNCATULA ,TUBERIZATION ,PHOSPHORYLATION ,PLANTAS TRANSGENICAS - Abstract
En este trabajo se estudió la participación de las CDPKs en dos procesos de desarrollo: la tuberización y la nodulación. Por un lado se obtuvo la secuencia genómica de StCDPK1, se determinó su estructura y organización génica y se la comparó con otras quinasas pertenecientes al grupo II-A de las CDPKs. La localización cromosómica más probable de este gen resultó ser el extremo distal “inferior” del cromosoma 12. Además se obtuvo un anticuerpo policlonal anti-StCDPK1 con el cual se confirmó la presencia de esta isoforma en las fracciones solubles y particuladas de estolones inducidos, siendo mayor en la fracción asociada a membranas. Se observó que la proteína StCDPK1 aumenta en respuesta a concentraciones crecientes de sacarosa en forma gradual, alcanzando el máximo a 8% sacarosa (condiciones inductoras de tuberización). Se obtuvieron plantas transgénicas con expresión disminuida de StCDPK1 (β7) que mostraron cierta insensibilidad a las giberelinas (GAs). Además, presentaron una respuesta más temprana a las condiciones inductoras de la tuberización y una sensibilidad aumentada a las altas concentraciones de sacarosa. En presencia de hormonas inductoras de la tuberización (ácido abscícico -ABA y bencilaminopurina- BAP) la expresión de StCDPK1 no se vio afectada en la línea transgénica β7, pero sí en las plantas salvajes, lo mismo ocurrió al estudiar el efecto de las GAs a tiempos cortos. Nuestros datos sugieren que StCDPK1 podría estar involucrada en la tuberización, y que la sacarosa y las fitohormonas ABA y BAP estimulan su transcripción, actuando como un regulador negativo de este proceso de desarrollo. Por otra parte en Medicago truncatula se identificó una CDPK (MtCPK3) que se expresa principalmente en raíces en desarrollo. Estudios de expresión de MtCPK3 y otra isoforma de alfalfa estrechamente relacionada (MsCPK3), junto con datos de actividad quinasa dependiente de calcio, indicaron que estas isoformas pueden participar en los eventos de fosforilación que ocurren durante la formación del nódulo. Ensayos de expresión transitoria mostraron que la miristoilación y palmitoilación son necesarias para la localización en membrana plasmática de estas isoformas. Se detectó una inducción temprana (10 minutos) de MtCPK3 en raíces inoculadas con Rhizobium sp. que resultó estar asociada a una respuesta al estrés inducido por la infección. Asimismo las citoquininas indujeron la expresión de MtCPK3, sugiriendo que esta isoforma podría ser un componente común en las señales de transducción disparada por Rhizobium sp., citoquininas y estrés abiótico. Raíces transgénicas con expresión disminuida de MtCPK3 produjeron un número significativamente mayor de nódulos que las plantas control, sugiriendo que esta quinasa podría regular negativamente la acción de señales vegetales que controlan la relación entre los tejidos proveedores de energía y aquellos de reserva. In this work the participation of CDPKs in two developmental processes: the tuberization and the nodulation was studied. On one side the genomic sequence of StCDPK1 was obtained, its structure and genetic organization was determined and compared with others kinases of the CDPKs group II-A. The most probable chromosomic location of this gene turned out to be the distal end of chromosome 12. In addition, a polyclonal antibody against StCDPK1 was obtained and the presence of this isoform in the soluble and particulate fractions of induced stolons was confirmed, being greater in the membrane-associated fraction. It was observed that the StCDPK1 protein increased in the presence of different sucrose concentrations, being highest at 8% sucrose (tuber inducing conditions). Transgenic plants with diminished expression of StCDPK1 (β7) showed certain insensibility to gibberellins (GAs). In addition, they displayed an earlier response to tuber inducing conditions and an increased sensitivity to high sucrose concentrations. In the presence of tuber inducing hormones (abscicic acid - ABA and bencilaminopurine - BAP) StCDPK1 expression was not affected in the transgenic line β7, but it increased in wild type plants; the same happened when studying the early response to GAs. Our data suggest that StCDPK1 could be a negative regulator of tuberization eventhough sucrose and the phytohormones ABA and BAP stimulate its transcription. On the other hand, we identified a Medicago truncatula CDPK (MtCPK3) that is mainly expressed in developing roots. Expression studies of MtCPK3 and MsCPK3 (a closely related isoform in alfalfa), along with calcium dependent protein kinase activity assays indicated that these isoforms could participate in the phosphorylation events triggered during nodule formation. Transient expression studies showed that myristoylation and palmitoylation are necessary for the plasma membrane localization of these isoforms. An early MtCPK3 induction (10 minutes) was detected in Rhizobium sp. inoculated roots, but turned out to be associated to a stress response induced by the infection. Cytokinins also induced MtCPK3 expression,suggesting that this isoform could be a common component in the transduction pathways triggered by Rhizobium sp., cytokinins and abiotic stress. Transgenics roots with diminished MtCPK3 expression produced more nodules (x 3) than control plants, suggesting that this kinase could negatively regulate the action of plant signals that control sink-source interactions. Fil: Gargantini, Pablo Rubén. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.
- Published
- 2006
23. Cardiac 18 F-FDG PET/CT procedure for the diagnosis of prosthetic endocarditis and intracardiac devices.
- Author
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Aguadé Bruix S, Roque Pérez A, Cuéllar Calabria H, and Pizzi MN
- Subjects
- Computed Tomography Angiography methods, Diet, Carbohydrate-Restricted, Dietary Fats, Endocarditis etiology, Fasting, Fluorine Radioisotopes pharmacokinetics, Fluorodeoxyglucose F18 pharmacokinetics, Glycolysis, Heparin administration & dosage, Heparin pharmacology, Humans, Leukocytes metabolism, Macrophages metabolism, Myocardium metabolism, Myocytes, Cardiac metabolism, Phosphorylation, Radiopharmaceuticals pharmacokinetics, Endocarditis diagnostic imaging, Heart Valve Prosthesis adverse effects, Positron Emission Tomography Computed Tomography methods, Prostheses and Implants adverse effects, Prosthesis-Related Infections diagnostic imaging
- Abstract
Infective endocarditis (IE) is a serious condition with a poor prognosis, its mortality unchanged significantly despite diagnostic and therapeutic advances in the last 30years. The diagnostic ability of the modified Duke criteria in prosthetic endocarditis and/or devices does not exceed 50%, so new tools are necessary for the diagnosis of this entity in this context. The
18 F-FDG PET/CTA combines a highly sensitive technique to detect inflammatory-infectious activity with a technique with high anatomical resolution to assess the structural lesions associated with endocarditis. With a diagnostic sensitivity between 91-97%, this hybrid technique has become a useful diagnostic tool for patients with prosthetic valves or devices and suspicion of IE, becoming a major criterion in the diagnostic algorithm of current guidelines. This excellent diagnostic ability depends directly on the quality of the obtained exploration and the knowledge at the time of interpreting the images. The aim of this review is to describe and standardize the methodology of cardiac18 F-FDG PET/CTA in the diagnosis of endocarditis in prosthetic valves and intracardiac devices, with special emphasis on the particularities of the patient's preparation, the PET and CT acquisition procedures, and the subsequent imaging postprocessing and interpretation., (Copyright © 2018 Elsevier España, S.L.U. y SEMNIM. All rights reserved.)- Published
- 2018
- Full Text
- View/download PDF
24. Actividad de ATP asa en corazón de cobayos de altura
- Author
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H Luz Oyola, A Elizabeth Carranza, W Delia Whu, L Elizabeth Gonzáles, R Edgar Florentini, and C Haydée Zúñiga
- Subjects
Differential centrifugation ,phosphorylation ,mitocondria ,Oxidative phosphorylation ,Biology ,Mitochondrion ,Effects of high altitude on humans ,Oxygen uptake ,Molecular biology ,ATP ,mitochondria ,fosforilación ,polarografía ,Biochemistry ,ATP hydrolysis ,Phosphorylation ,Respiratory control ,General Environmental Science ,polarographically - Abstract
Heart rnitochondrion ATPase activity, ADP:O ratio (P:O) and Respiratory Control (RCR) are compared between guinea pigs from high altitude (Morococha, 4540 m) (HA) and those from sea level (SL). The study comprised 60 male guinea pigs, 30 from each altitude level, with mean weight 400-450 grams. Heart mitochondria were obtained by differential centrifugation at 4°C. P:O ratio and RCR were measured polarographically by Tyler method, and ATP hydrolysis was done by Holton et al. Method. Mean values obtained for heart mitochondria at SL and HA, expressed in mmoles oxygen uptake/mg protein/hour, were, with Glutamate + Malate as subtrates, respectiveIy: P:O 2.90, RCR 6.02 and P:O 2.93, RCR 6.0; and, with Pyruvate + Malate as subtrates, respectively P:O 2.60, RCR 5.0 and P:O 2.70, RCR 4.80. ATPase activity was at SL and HA, respectively: 57.50 and 64.50 mmoles P /mg protein/hour. The results suggest that high altitude guinea pigs may have developed the ability to perform oxydative phosphorylation more efficiently, and that the slight increment observed in ATPase activity indicates that some adjustments are made to maintain the equilibrium within the mitochondrial environment., Se compara la actividad de ATPasa, la relación ADP:O (P:O) y el Control Respiratorio (RCR) en mitocondria de corazón entre cobayos de altura (Morococha, 4540 m.s.n.m.) (Alt) y cobayos del nivel del mar (Lima, 150 m,s.n.m.) (NM). El estudio se realizó en 60 cobayos machos, 30 en cada nivel de altitud, con un peso promedio de 400 a 450 gramos. Las mitocondrias de corazón fueron obtenidas por centrifugación diferencial a 4° C. La relación P:O y el RCR fueron medidos polarográficamente por el método de Tyler, y la hidrólisis del ATP se realizó por el método de Holton et al. Los valores medios obtenidos en mitocondrias de corazón al NM y en Alt, expresados en micromoles de oxígeno consumido / mg de proteína/hora, fueron: con Glutamato + Malato como sustratos, respectivamente: P:O 2.90, RCR 6.02 y P:O 2.93, RCR 6.0; y con Piruvato + Malato como sustratos, respectivamente: P:O 2.60, RCR 5.0 y P:O 2.70, RCR 4.80. La actividad ATPasa fue al NM y en Alt, respectivamente: 57.50 y 64.50 mmoles de P /mg proteína/hora. Los resultados sugieren que los cobayos de altura han desarrollado la habilidad de realizar la fosforilación oxidativa en forma más eficiente, y el ligero incremento observado en la actividad de ATPasa indica que tal vez se realizan pequeños ajustes para mantener el equilibrio dentro del medio ambiente mitocondrial.
- Published
- 2004
25. Identification and characterization of protein kinase and phosphatases that are induced during tuberization in Solanum tuberosum
- Author
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Raíces, Marcela and Téllez-Iñón, María Teresa
- Subjects
PALMITOILACION ,SOLANUM TUBEROSUM ,CALCIUM-DEPENDENT PROTEIN KINASE(CDPK) ,MYRISTOYLATION ,TUBERIZACION ,FOSFORILACION ,PP2A PHOSPHATASE ,QUINASA DE PROTEINAS DEPENDIENTE DE CALCIO (CDPK) ,SACAROSA ,TUBERIZATION ,PALMITOYLATION ,PHOSPHORYLATION ,FOSFATASA PP2A ,SUCROSE ,MIRISTOILACION - Abstract
En este trabajo se estudiaron genes posiblemente involucrados en los procesos deseñalización relacionados con la tuberización. Se identificaron los genes StCDPK1, StCDPK2 y StCDPK3, que son los primeros miembros de la familia CDPK de Solanumtuberosum. En particular se caracterizó el gen StCDPK1 que codifica para una quinasaactiva con todas las propiedades de las CDPKs. Se demostró que StCDPK1 semiristoíla in vitro y que su localización subcelular depende de miristoilación ypalmitoilación. Por otra parte se determinó que existe una fuerte correlación entre la expresión de StCDPK1 y el engrosamiento del estolón. Mediante ensayos de hibridación in situ seobservó que StCDPK1 se expresa en el ápice de estolones inducidos a tuberizar. También se determinó que StCDPK3 se expresa diferencialmente en estolonestempranos. En ensayos de Western blot se identificaron dos CDPKs, de 55 y 60 kDa, cuyaexpresión correlaciona con la expresión de los genes StCDPK3 y StCDPK1respectivamente. Se determinó que la actividad CDPK asociada a estolonestempranos y la actividad CDPK asociada a estolones inducidos poseen diferenteespecificidad de sustrato y distinta localización subcelular. Por otra parte se estudió el efecto de la sacarosa sobre la tuberización y sobre laexpresión de StCDPK1. Se determinó la importancia de las actividades quinasadurante la inducción de la tuberización inducida por sacarosa y se demostró que esteazúcar induce la expresión de StCDPK1 mediante un mecanismo que involucra laactividad de fosfatasas de la familia PP1/PP2A. Además, se identificó el gen StPP2A1c que codifica para la primer fosfatasa de lafamilia PP2A de Solanum tuberosum. Se determinó que el gen StPP2A1c se expresadiferencialmente durante la tuberización y, mediante ensayos de complementación enlevaduras, se demostró que este gen codifica para una fosfatasa funcional. In this work we studied genes which are possiby involved in the signalling eventsleading to tuber development. The first members of Solanum tuberosum CDPK family, StCDPK1, StCDPK2 y StCDPK3, were identified. The gene StCDPK1, which encodesan active kinase with all the features of CDPKs, was characterized. It wasdemonstrated that StCDPK1 suffers myristoylation in vitro and that its subcellularlocalization depends on myristoylation and palmitoylation. On the other hand, a strong correlation between StCDPK1 expression and stolonswelling was established. Using in situ hybridization we observed that StCDPK1 isexpressed in the apical dome of tuberizing stolons. Moreover, StCDPK3 is differentiallyexpressed in early stolons. By Western blot assays, two CDPKs of 55 y 60 kDa which correlated with theexpression of StCDPK3 y StCDPK1 respectively, were detected. The CDPK activityassociated to early and induced stolons showed different substrate specificity andsubcellular localization. The effect of sucrose on tuberization and StCDPK1 expression was also analyzed. Theimportance of protein kinase activities during sucrose-induced tuber development wasestablished and the induction of StCDPK1 by sucrose, through a mechanism thatinvolves PP1/PP2A phosphatase activities,was demonstrated. Besides, we identified StPP2A1c, a gene that encodes the first phosphatase of the PP2A family in Solanum tuberosum. StPP2A1c was differentially expressed duringtuberization and encoded a functional phosphatase, as was observed in yeastcomplementation assays. Fil: Raíces, Marcela. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.
- Published
- 2003
26. Fosforilación en células eucarióticas: Papel de fosfatasas y quinasas en la biología, patogenia y control de protozoosis tisulares y sanguíneas
- Author
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Jorge González C
- Subjects
Leishmania ,Phosphorylase kinase ,Trypanosoma ,biology ,Kinase ,Phosphatase ,General Medicine ,Phosphorylase phosphatase ,biology.organism_classification ,Cell biology ,Biochemistry ,Protozoan infections ,parasitic diseases ,Phosphorylation ,Protein phosphorylation ,Signal transduction ,Protein kinase A - Abstract
Cells respond to environmental or cellular changes, rapidly switching protein activities from one state to another. In eukaryotes, a way to achieve these changes is through protein phosphorylation cycles, involving independent protein kinase and protein phosphatase activities. Current evidences show that phosphatases and kinases are also involved in the molecular basis of immune response and in diseases such as diabetes obesity and Alzheimer. In protozoan parasites like Trypanosoma and Leishmania, several kinases and phosphatases have been identified, many of them have been cloned but in several cases their biological role remains undetermined. In this review, the state-of-the art is summarized and the role of phosphatases and kinases in biological phenomena such as remodeling, invasion and pathogenic capacity of protozoan parasites is described. The real chance to use these components of signal transduction pathways as target for chemotherapeutic intervention is also discussed (Rev Méd Chile 2000; 128: 1150-60).
- Published
- 2000
27. Fosforilación en células eucarióticas: Papel de fosfatasas y quinasas en la biología, patogenia y control de protozoosis tisulares y sanguíneas
- Author
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González C, Jorge
- Subjects
Leishmania ,Phosphorylase kinase ,Trypanosoma ,Protozoan infections ,parasitic diseases ,Phosphorylation ,Phosphorylase phosphatase - Abstract
Cells respond to environmental or cellular changes, rapidly switching protein activities from one state to another. In eukaryotes, a way to achieve these changes is through protein phosphorylation cycles, involving independent protein kinase and protein phosphatase activities. Current evidences show that phosphatases and kinases are also involved in the molecular basis of immune response and in diseases such as diabetes obesity and Alzheimer. In protozoan parasites like Trypanosoma and Leishmania, several kinases and phosphatases have been identified, many of them have been cloned but in several cases their biological role remains undetermined. In this review, the state-of-the art is summarized and the role of phosphatases and kinases in biological phenomena such as remodeling, invasion and pathogenic capacity of protozoan parasites is described. The real chance to use these components of signal transduction pathways as target for chemotherapeutic intervention is also discussed (Rev Méd Chile 2000; 128: 1150-60).
- Published
- 2000
28. Caracterización molecular de una fosfoproteína novel intermediaria en el mecanismo de acción de hormonas proteicas
- Author
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Finkielstein, Carla V. and Podestá, Ernesto Jorge
- Subjects
endocrine system ,ACIDO ARQUIDONICO ,FOSFORILACION Y ESTEROIDEOGENESIS ,ARACHIDONIC ACID ,STEROIDEOGENESIS ,ACYL-COA THIOESTERASE ,ACIL-COA TIOESTERASA ,PHOSPHORYLATION - Abstract
Trabajos previos de nuestro laboratorio han permitido caracterizar unafosfoproteína novel (p43), intermediaria en la síntesis de esteroides en lazona fasciculata de la corteza adrenal de rata (Paz C. et al. (1994) Eur. J. Biochem. 224:709-716). En la presente Tesis, se describe la caracterizaciónmolecular de p43 asi como también la regulación hormonal del transcripto. Los resultados obtenidos mostraron que p43 es homóloga a una acil-CoAtioesterasa mitocondrial. La secuencia aminoacídica deducida de la proteína presentó sitios consensode fosforilación para diferentes proteínas quinasas y un motíf para serina Lipasa. Anticuerpos dirigidos contra un péptido sintético que incluye dichomotif y otro contra la región N-terminal de p43, bloquearon la actividadbiológica de la proteína. El transcripto de p43 fue detectado en ovario deratas pseudopreñadas, en zona fasciculata y glomerulosa de adrenal derata, en una línea tumoral de células de Leydig, en cerebro de ratón y enplacenta humana. El tratamiento de ratas con dexametasona (Dx) provocauna disminución en los niveles del ARNm de p43 de manera dosisdependienteen adrenales de rata. El tratamiento posterior con ACTH nosólo revierte el efecto de la Dx, sino que produce un aumento rápido (5 min)en los niveles del mensajero alcanzando un máximo a los 15 min (62%) yretornando a los valores basales a los 30 min posteriores al estímulo. Eltratamiento con actinomicina D o cicloheximida antes del estímulo con ACTHprovoca una disminución o un aumento en los niveles del ARNm de p43respectivamente. Estos resultados relacionan por primera vez que unaactividad de acil-CoA tioesterasa está involucrada en los procesosesteroidogénicos. We have previously reported the purification of a phosphoprotein (p43)intermediary in steroid synthesis from adrenal zona fasciculata (Paz C. et al. (1994) Eur. J. Biochem. 224:709-716). Here we describe the cloning andsequencing of a cDNA encoding p43 as well as the hormonal regulation ofp43 transcript. The protein resulted homologous to a very recently describedmitochondrial peroxisome proliferator-induced very-long-chain acyl-CoAthioesterase. The deduced amino acid sequence of the protein showsconsensus sites for phosphorylation by different protein kinases, and a Lipaseserine motif. Antibodies raised against a synthetic peptide that includes the Lipase serine motif and against the N-terminal region of p43 block the actionof the protein. The transcript of p43 was detected in ovary of pseudopregnantrats, rat adrenal zona fasciculata and glomerulosa, mouse Leydig tumor cellline, rat brain and human placenta. Inhibition of adrenocorticotropin hormone (ACTH)release and steroid synthesis by dexamethasone produced a dosedependentdecrease in the abundance of the adrenal transcript. Thetranscript was induced by in vivo stimulation of the adrenals with ACTH. Theeffect had a rapid onset (5 min), reached maximal stimulation (62%) at 15min and returned to basal levels at 30 min. ACTH effect on p43 transcriptwas inhibited by actinomycin D and enhanced by cycloheximide. Our resultsprovide the first evidence linking acyl-CoA thioesterases, with very-long-chainspecificities, and a protein intermediary in steroid synthesis, therebysupporting a regulatory role for acyI-CoA thioesterases in steroidogenictissues. Fil: Finkielstein, Carla V.. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.
- Published
- 1998
29. [Injury markers in two models of cerebral ischemia].
- Author
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Céspedes AE, Arango CA, and Cardona GP
- Subjects
- Animals, Biomarkers, Disease Models, Animal, Disease Progression, Female, Fluoresceins, Glial Fibrillary Acidic Protein, Phosphorylation, Rats, Rats, Wistar, Time Factors, tau Proteins metabolism, Brain Ischemia diagnosis, Brain Ischemia immunology
- Abstract
Introduction: Spatio-temporal indicators of injury are essential for the study of neuropathological processes and for developing therapeutic approaches for stroke., Objective: This study sought to optimize the techniques of two cerebral ischemia models (focal and global) and to comparatively evaluate the progression of brain damage by analyzing markers of neurodegeneration., Materials and Methods: Wistar rats were subjected to temporary occlusion of the middle cerebral artery (t-MCAO) or four-vessel occlusion (4-VO), and surgical time, survival rate and neurological recovery were comparatively evaluated. Triphenyl tetrazolium was used to determine the distribution of the infarction, and Fluoro-Jade B was used as a marker of neurodegeneration. Astroglial immunoreactivity was assessed with an anti-glial fibrillary acidic protein (GFAP) antibody, and an anti-AT-8 antibody was used to detect hyperphosphorylated tau protein at 24, 48 and 72 hours post-ischemia., Results: The cerebral ischemia models employed (t-MCAO and 4-VO) required less surgical time and presented less of a death risk compared to those in previous studies. In the focal model, Fluoro-Jadepositive cells and reactive astrocytes were observed in the cerebral cortex and the hippocampus at 24 hours post-ischemia. In the global model, we observed Fluoro-Jade-positive cells at 24 hours, and a significant increase in the reactivity of GFAP was observed at 72 hours in the cortex and at 48 hours in the hippocampus. The immunoreactivity of hyperphosphorylated tau protein increased progressively, reaching a maximum at 72 hours post-ischemia in both models., Conclusions: These results suggest that in the t-MCAO and 4-VO ischemia models, the expression of Fluoro-Jade and GFAP indicates early neurodegeneration at 24 hours post-insult. In contrast, the immunoreactivity of the hyperphosphorylated tau protein marker (AT-8) progressively increases until 72 hours post-insult, which suggests that the progression of excitotoxicity and alteration of enzymes involves the phosphorylation of cytoskeletal proteins.
- Published
- 2013
30. [Ca2+ and sphingolipids as modulators for apoptosis and cancer].
- Author
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Pimentel AA and Benaim G
- Subjects
- Apoptosis drug effects, Apoptosis Regulatory Proteins physiology, Calcium Channels physiology, Ceramides physiology, Endoplasmic Reticulum Stress, Humans, Ion Transport, Mitochondria physiology, Neoplasm Proteins physiology, Phosphorylation, Signal Transduction physiology, Sphingosine physiology, Apoptosis physiology, Calcium Signaling physiology, Neoplasms physiopathology, Sphingolipids physiology
- Abstract
Ca2+ is a second messenger which regulates many functions directly related with cancer such as proliferation, differentiation and apoptosis. The intracellular Ca2+ concentration ([Ca2+],) is finely regulated by several mechanisms, among them ionic channels, the endoplasmic reticulum Ca2+-ATPase (SERCA), the plasma membrane calcium pump (PMCA) and the mitochondrial Ca2+ transport. In cancer, the tumour cell proliferates without control since the capacity to recognize apoptotic signals has been lost. The apoptosis is regulated by changes in several proteins, as caspases and the Bcl-2 family members, among others. Additionally, the "reticulum stress", promoted by the accumulation and aggregation of unfolded proteins in the interior of the endoplasmic reticulum (ER), ussually leads to apoptosis. The "reticulum stress" can be induced by several agents, remarkably with thapsigargin, a selective inhibitor of the SERCA, which in turn induces a large increment in [Ca2+],, leading to apoptosis. As a consequence, currently, derivatives of thapsigargin are successfully been assayed as anti-neoplastic agents. Ca2+ is then transferred to the mitochondria, where it is known to constitute a main apoptotic signal. On the other hand, several sphingolipids, such as ceramide and sphingosine, and their phosphorylated derivatives ceramide-1-phosphate and sphingosine-1-phosphate, directly involved in the [Ca2+]1 regulation, are also recognized as signal messengers related with cancer processes. In this review we discuss new evidences on the effect of several sphingolipids in the intracellular Ca2+ homeostasis and its relationship with apoptosis and cancer.
- Published
- 2012
31. [Role of mitogen-activated protein kinase (MAPK) in the sporadic renal cell carcinoma].
- Author
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Salinas-Sánchez AS, Giménez-Bachs JM, Serrano-Oviedo L, Nam Cha S, and Sánchez-Prieto R
- Subjects
- Antigens, Neoplasm physiology, Antineoplastic Agents therapeutic use, Benzenesulfonates therapeutic use, Carbonic Anhydrase IX, Carbonic Anhydrases physiology, Carcinoma, Renal Cell drug therapy, Cell Transformation, Neoplastic, Drug Resistance, Neoplasm, Enzyme Activation, Humans, Hypoxia-Inducible Factor 1, alpha Subunit physiology, Kidney Neoplasms drug therapy, Niacinamide analogs & derivatives, Phenylurea Compounds, Phosphorylation, Protein Kinase Inhibitors therapeutic use, Protein Processing, Post-Translational, Pyridines therapeutic use, Radiation Tolerance, Sorafenib, Von Hippel-Lindau Tumor Suppressor Protein physiology, Carcinoma, Renal Cell enzymology, Kidney Neoplasms enzymology, MAP Kinase Signaling System physiology, Neoplasm Proteins physiology
- Abstract
Context: Only on the basis of the involvement of the vhl suppressor gene in the cases of renal cell carcinomas (RCC), the involvement of the signaling pathway between the pVHL and the Hypoxia inducible factor 1, alpha (HIF-1α) has been evaluated because of the need to find new diagnostic and prognostic and response to drugs markers., Evidence Synthesis: The overexpression of HIF-1α confers better prognosis in clear cell type RCC (ccRCC). Furthermore, HIF-1α regulates other genes, specifically that of the carbon anhydrase IX (CA-IX), whose overexpression is practically only of the ccRCC and its determination is useful for this subtype. However, the involvement of the CA-IX has not been demonstrated in the prognosis or in the response to immunomodulators or antiangiogenics. Therefore, it is necessary to make a global evaluation of all this pathway: pVHL → HIF-1α → CA-IX, and even the analysis of other proteins and signaling pathways that also control the HIF-1α activity. In the latter case, the MAPK are critical in the HIF-1α activation, there being evidence on the experimental level of the control on its activity. although its clinical role as a biomarkers has not been established. Although the role of the MAPK in the phenomena of resistance to conventional chemotherapy and radiotherapy has been demonstrated, it has not been demonstrated in response to sorafenib, an important piece of information if we consider that it is an inhibitor of several protein kinases. Recently, it has been observed that the MAPK may be involved in the responses to different therapies, included those based on tyrosine kinase inhibitors., Conclusions: The confirmation of these data would suppose an explanation of the variation observed between patients who, with the same functional alteration of the vhl gene, have a different biological, clinical behavior and better selection of non-surgical therapies., (Copyright © 2011 AEU. Published by Elsevier Espana. All rights reserved.)
- Published
- 2012
- Full Text
- View/download PDF
32. [Insulin-like growth factor receptor I signaling in a breast cancer cell line].
- Author
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Mejía W, Castro C, Umaña A, de Castro C, Riveros T, and Sánchez-Gómez M
- Subjects
- Aged, Extracellular Signal-Regulated MAP Kinases metabolism, Female, Humans, Phosphatidylinositol 3-Kinases metabolism, Phosphorylation, Proto-Oncogene Proteins c-akt metabolism, Receptor, IGF Type 1 genetics, Breast Neoplasms physiopathology, Cell Line, Tumor, Receptor, IGF Type 1 metabolism, Signal Transduction physiology
- Abstract
Introduction: In vitro studies strongly suggest that proliferation, migration and cell survival of breast cancer cell lines are significantly affected by activation of the IGF type 1 receptor (IGF-IR)., Objective: The phosphorylation by IGF-I of IGF-IR and the intracellular signaling molecules Akt (PI-3K pathway) and Erk1/2 (MAPK pathway) was characterized in a human breast cancer cell lines., Materials and Methods: The study compared a standard breast adenocarcinoma line (MCF-7) cell line with a line (CSC 1595) derived from an infiltrating ductal breast cancer in a Colombian patient. The CSC 1595 and MCF-7 cell lines were cultured in DMEM supplemented with 10% fetal bovine serum, 2 mM glutamine, 100 U/ml penicillin, and 100 µg/ml streptomycin and grown at 37 °C in 5% CO₂ atmosphere and 95% humidity. Cell extracts were prepared, followed by immunoprecipitation and immunoblotting with specific anti-pIGF-IR, anti-pERK1/2 and anti-pAkt antibodies., Results: After 5 minute stimulation with IGF-I, 70% of the IGF-IR was phosphorylated in the cell line CSC 1595 and 25% in MCF-7. In addition, Akt (oncogene protein v-akt) and ERK1/2 (extracellular signal-regulated MAP kinases) were phosphorylated. Basal and stimulated levels of phosphorylated ERK1/2 were substantially higher compared to those in the MCF-7 cell line., Conclusions: The IGF-IR and MAPK kinase pathway involving proteins ERK1/2 showed more significant phosphorylation in the 1,595 cells compared to the observed in the MCF-7 cell line. Since the IGF-IR is the major activator of this pathway it may play an important role in ductal infiltrating breast cancer tumor growth and metastases.
- Published
- 2010
33. [The role of lithium in neurodegenerative diseases: new registries for old actors].
- Author
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Pérez-Martínez DA
- Subjects
- Animals, Glycogen Synthase Kinase 3 antagonists & inhibitors, Humans, Neurodegenerative Diseases metabolism, Phosphorylation, tau Proteins metabolism, Lithium Compounds therapeutic use, Neurodegenerative Diseases drug therapy
- Abstract
Introduction: Lithium has been used for more than one century in medicine. Currently, it is used effectively in acute phase treatment and in the prevention of manic-depressive symptoms of patients with bipolar disorder. Lithium acts by inhibiting a protein- kinase called glycogen synthase kinase 3 (GSK3) that has important actions on the intracellular signal transmission by protein phosphorylation., Method: A review has been made of the studies conducted in vivo and in vitro on the utility of lithium in animal models of neurodegenerative disease and its efficacy in studies performed in humans., Development: Research on lithium on GSK-3 inhibition in animal models of disease with aggregates of hyperphosphorylated protein tau and Alzheimer's disease has provided promising results. Inhibition of this enzyme also seems to have a neuroprotector effect in other neurodegenerative disease models such as amyotrophic lateral sclerosis, spinocerebellar ataxia type 1 and Huntington's disease. There is indirect evidence in humans on a possible neuroprotector effect in chronic patients with bipolar disorder and on slow down of the progression of the disease in patients with amyotrophic lateral sclerosis., Conclusions: Lithium, and in a more extensive way, GSK-3 inhibitors, are proposed as a new drug generation with potential action on the progression of different neurodegenerative diseases, especially those related with abnormal aggregation of the protein tau.
- Published
- 2009
34. [Telbivudine in the treatment of the chronic B hepatitis].
- Author
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Butí MA
- Subjects
- Adolescent, Adult, Aged, Antiviral Agents adverse effects, Antiviral Agents pharmacology, Biomarkers, Pharmacological blood, Biotransformation, Clinical Trials, Phase III as Topic statistics & numerical data, Drug Resistance, Viral, Female, Hepatitis B Surface Antigens blood, Hepatitis B e Antigens blood, Hepatitis B virus drug effects, Hepatitis B virus genetics, Hepatitis B virus physiology, Humans, Lamivudine adverse effects, Lamivudine therapeutic use, Male, Middle Aged, Muscular Diseases chemically induced, Nucleosides adverse effects, Nucleosides pharmacology, Phosphorylation, Prodrugs adverse effects, Prodrugs pharmacology, Pyrimidinones adverse effects, Pyrimidinones pharmacology, Randomized Controlled Trials as Topic statistics & numerical data, Telbivudine, Thymidine analogs & derivatives, Virus Replication drug effects, Antiviral Agents therapeutic use, Hepatitis B, Chronic drug therapy, Nucleosides therapeutic use, Prodrugs therapeutic use, Pyrimidinones therapeutic use
- Published
- 2008
- Full Text
- View/download PDF
35. [AMPK as a cellular energy sensor and its function in the organism].
- Author
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Miranda N, Tovar AR, Palacios B, and Torres N
- Subjects
- Adenosine Monophosphate metabolism, Adenosine Triphosphate metabolism, Adenylate Kinase antagonists & inhibitors, Adenylate Kinase chemistry, Adipokines physiology, Adipose Tissue metabolism, Animals, Diabetes Mellitus, Type 2 drug therapy, Diabetes Mellitus, Type 2 enzymology, Diabetes Mellitus, Type 2 physiopathology, Enzyme Activation drug effects, Fatty Liver drug therapy, Fatty Liver enzymology, Fatty Liver physiopathology, Glucose metabolism, Humans, Hypoglycemic Agents pharmacology, Hypothalamus metabolism, Lipogenesis physiology, Liver metabolism, Myocardium metabolism, Obesity drug therapy, Obesity enzymology, Obesity physiopathology, Organ Specificity, Phosphorylation, Physical Exertion physiology, Protein Processing, Post-Translational, Adenylate Kinase physiology, Energy Metabolism physiology
- Abstract
The adenine monophosphate (AMP) activated protein kinase (AMPK), is a heterotrimeric complex that is activated by an increase in the AMP/ATP ratio, and is considered to be a cellular energy sensor that contributes to regulate energy balance and caloric intake. AMPK is activated by LKB1 hinase and it can phophorylate several enzymes involved in anabolism to prevent further ATP consumption, and induces some catabolic enzymes to increase ATP generation. Furthermore, AMPK regulates the expression of genes involved in lipogenesis and mitochondrial biogenesis, among others. AMPK is distributed in most organs including, liver, skeletal muscle, heart and hypothalamus; and even in adipose cells. In addition, AMPK is activated in the hypothalamus stimulating appetite due to energy depletion. AMPK also participates in glycolysis regulation, glucose uptake, lipid oxidation, fatty acid synthesis, cholesterol synthesis and gluconeogenesis, and it has been considered as a possible target enzyme in the treatment of some diseases such as obesity, type 2 diabetes and hepatic steatosis. This review provides a general overview of AMPK structure, its activators and its function in the organism.
- Published
- 2007
36. [Platelet filamin: a cytoskeletal protein involved in cell signal integration and function].
- Author
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García E and Jay D
- Subjects
- Actins physiology, Animals, Contractile Proteins chemistry, Contractile Proteins metabolism, Cytoskeletal Proteins chemistry, Cytoskeletal Proteins metabolism, Drosophila, Filamins, Humans, Integrins physiology, Microfilament Proteins chemistry, Microfilament Proteins metabolism, Phosphorylation, Platelet Membrane Glycoproteins genetics, Receptors, Cell Surface genetics, Blood Platelets physiology, Contractile Proteins physiology, Cytoskeletal Proteins physiology, Microfilament Proteins physiology, Platelet Activation physiology, Platelet Membrane Glycoproteins physiology, Receptors, Cell Surface physiology, Signal Transduction physiology
- Abstract
Activation of cellular receptors by diverse stimuli induces dramatic changes in shape and function to respond to the new circumstances of the cell. This modified behavior depends on the reorganization of the peripheral actin meshwork. An outstanding example of these processes can be found in platelets, from which much of the information available on cytoskeletal function has been obtained. Among the many actin-crosslinking proteins like spectrin, fimbrin or alpha actinin, filamin a (FLNa) emerges as the one with the highest potential in initiating the polimerization of actin filaments (F-actin) during the formation of tridimensional actin gels. FLNa also links actin filaments to the cytosolic domain of many membrane glycoproteins in platelets through its C-terminal region. In addition to participating in cell shape changes, FLNa is a scaffoldding protein that recruits numerous proteins involved in a completely different set of functions, including signal transduction, gene transcription regulation, and receptor translocation; however, the physiological role of FLNa in these processes has remained elusive. The purpose of the present communication is to briefly describe the characteristics of the macromolecules able to interact with FLNa and to discuss a possible role of FLNa during the transduction of signals from those molecular elements in platelets.
- Published
- 2006
37. [Clinical effects of the alterations that emerge in the signaling mechanisms of the insulin receptor].
- Author
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Hernández-Valencia M
- Subjects
- Humans, Phosphorylation, Diabetes Mellitus, Type 2 physiopathology, Receptor, Insulin physiology, Signal Transduction physiology
- Abstract
Phosphorilation of subunit beta from insulin receptor induced mainly by insulin, it begins a series of intracellular complex signaling in cascade. Through this way establish multiple effects, which permits to the cell initiate its biological activity. This activity include the glucose metabolism, the regulation of ions and amino acids transport, lipids metabolism, glycogen synthesis, genetic transcription, mRNA expression, synthesis and degradation of proteins, as well as synthesis of DNA. Therefore, a modification in anyone of the proteins involved in the insulin signaling, can take place a dysfunction in the glucose metabolism. The impaired glucose can be due because there are many proteins, ions and enzymes that participate in the downstream pathways of the insulin signaling, it has become difficult to find a single phatophysiologic level as cause of diabetes. In spite of the advances in the study of this disease, it has been reached the conclusion that the glucose control is not enough to impede the complications that characterize to type 2 diabetes, since the organic worsening does not stop, which indicates that insulin signaling dysfunction is directly involved in all cellular process, and a better understanding in the communication ways of this hormone will take to new forms of treatment to impaired insulin response.
- Published
- 2006
38. [Hepatitis C and diabetes].
- Author
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Salmerón J
- Subjects
- Animals, Antiretroviral Therapy, Highly Active, Antiviral Agents therapeutic use, Comorbidity, Diabetes Mellitus, Type 2 epidemiology, Drug Interactions, Fatty Liver etiology, Female, HIV Infections drug therapy, HIV Infections epidemiology, Hepacivirus genetics, Hepacivirus pathogenicity, Hepatitis C, Chronic drug therapy, Hepatitis C, Chronic epidemiology, Humans, Hypoglycemic Agents therapeutic use, Immunosuppressive Agents adverse effects, Insulin Receptor Substrate Proteins, Insulin Resistance, Liver Cirrhosis etiology, Liver Transplantation, Male, Mice, Mice, Transgenic, Phosphoproteins metabolism, Phosphorylation, Postoperative Complications epidemiology, Risk Factors, Signal Transduction, Viral Proteins physiology, Diabetes Mellitus, Type 2 etiology, Hepatitis C, Chronic complications
- Published
- 2005
- Full Text
- View/download PDF
39. [Genomic retinoblastoma perspectives: implications of tumor supressor gene RB1].
- Author
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Rodríguez-Cruz M, del Prado M, and Salcedo M
- Subjects
- Cell Cycle physiology, Cell Division genetics, Cell Division physiology, Chromosomes, Human, Pair 13 genetics, DNA Methylation, Exons genetics, Eye Neoplasms diagnosis, Eye Neoplasms epidemiology, Gene Expression Regulation, Genetic Techniques, Humans, Incidence, Infant, Newborn, Neoplasms, Multiple Primary genetics, Phosphorylation, Point Mutation, Protein Processing, Post-Translational, Retinoblastoma diagnosis, Retinoblastoma epidemiology, Eye Neoplasms genetics, Genes, Retinoblastoma, Retinoblastoma genetics, Retinoblastoma Protein physiology
- Abstract
In order to define the molecular and cellular bases of the development of retinoblastomas it is necessary to know its etiology, and to apply the advances in genome technology to this kind of neoplasia. Retinoblastomas are childhood tumors of the eye with an average incidence of one case in every 15,000-20,000 live births, which occur in sporadic and hereditary forms. The sporadic form appears regularly as a unilateral tumor, while in the familial form of the disease, tumors may be unilateral and bilateral. This neoplasia is characterized by leukocoria, strabism, and heterochromia. The retinoblastoma gene (RB1) is a molecular marker of retinoblastoma tumors. This gene is located in chromosome 13q14.2 and encodes a nuclear phosphoprotein (pRB) of 110 KDa, which plays a major role in cell proliferation control through cell cycle-regulated phosphorylation/dephosphorylation cycles of this protein. The RB1 gene is mainly affected by point mutations, which occur most frequently in exons 3, 8, 18 and 20. At the end of the last century, DNA technology has improved notably, allowing for its application to the study of a vast array of diseases. The aim of this work is to show the molecular aspects involved in retinoblastoma which are currently deciphering; this is possible thanks to new technology platforms that have been developed. This will allow us in a near future, to offer tests for the early diagnoses, prognoses, and the determination of individual predisposition towards this neoplasia.
- Published
- 2005
40. [Transforming growth factor-beta as a therapeutic target].
- Author
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Gálvez-Gastélum FJ, Sandoval-Rodríguez AS, and Armendáriz-Borunda J
- Subjects
- Animals, Clinical Trials as Topic, Humans, Phosphorylation, Transforming Growth Factor beta therapeutic use
- Abstract
Transforming growth factor-beta (TGF-beta) family members include TGF-beta, activins, and bone morphogenetic proteins (BMP). These proteins are structurally related cytokines secreted in diverse Metazoans. TGF-beta family members regulate cellular functions such as proliferation, apoptosis, differentiation, and migration, and play an important role in organism development. Deregulated TGF-beta family signaling participates in various human pathologies including autoimmune diseases, vascular disorders, fibrotic disease, and cancer. Ligand-induced activation of TGF-beta family receptors with intrinsic serine/threonine kinase activity, triggers phosphorylation of the intracellular effectors of TGF-beta signaling, the Smads proteins. Once these proteins are activated they translocate into the nucleus, where they induce transcription of target genes and regulate cellular processes and functions. Novel therapeutic strategies are currently being developed to correct alterations in pathologies that involve TGF-beta as the main mediator. The English version of this paper is available at: http://www.insp.mx/salud/index.html.
- Published
- 2004
- Full Text
- View/download PDF
41. [Phosphorylation of tau and Alzheimer's disease].
- Author
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García T and Jay D
- Subjects
- Humans, Phosphorylation, Phosphotransferases metabolism, Alzheimer Disease metabolism, tau Proteins metabolism
- Abstract
Tau is an important component of neuronal cytosqueleton; the protein stabilizas microtubules, maintains cell shape and axonal transport mechanisms. However, for unknown reasons tau experiments important postranslation modifications including enhanced phosphorilation due to unbalanced activity between kinases and phosphatases, affecting its normal biological function. Under these circumstances tau begins to aggregate into neurofibrillary tangles (NFTS) complexes which are pathological hallmarks of Alzheimer's disease together with senile plaques. This review is mainly concerned with the role that different kinase play into the regulation of tau structure and function.
- Published
- 2004
42. [Calcium, the atom triggering life and cellular function].
- Author
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Mansilla-Olivares A
- Subjects
- Animals, Calcium Channels physiology, Calcium Signaling, Cell Nucleus metabolism, Enzyme Activation, Humans, Ion Transport, Membrane Potentials physiology, Phosphorylation, Protein Kinases physiology, Protein Processing, Post-Translational physiology, Synaptic Transmission physiology, Calcium physiology
- Abstract
Although during the last three decades phosphorylation and dephosphorylation systems have been pointed out as the mechanisms used by living cells to control biological processes, it seems that calcium dynamics is the phenomenon that precedes and controls protein activation by the introduction of phosphate groups into distinct protein structures. The process begins with activation of calcium channels that allows the influx of the ion, which once inside the cell leads to calcium-calmodulin complex, a molecule capable of triggering activation of distinct proteinkinases. Thus, the cell in addition to suffering a change in polarity enhances neuroconduction and release of different substances such as hormones and para-hormones, facilitates intra- and intercellular communication, and exerts determinant influence on phenotypic expression by means of promotion of immediate and mediate response genes. Ionic conformational calcium runs short- and long-term facilitation mechanisms, exerting its influence on control of memory through homosynaptic depression and hetersynaptic facilitation processes; triggers autophosphorylation of several enzymes leading and enhancing cellular activity and participates in signal transduction and decodification. Calcium influx rate activates certain groups of phosphatases capable of inhibiting autophosphorylation processes, only as a negative feedback mechanism. In addition, ionic calcium also participates in the "cross-activate" mechanism of proteinkinases A and G, influencing to production of systemic and central nervous system nitric oxide. On these bases, it is possible to guess that future pharmacologic interventions on calcium fluxes could be of invaluable importance in prevention and control of a number of distinct physiopathologic events.
- Published
- 2004
43. [Different enzymatic activities recruitment by specific domains of TIF2 are involved in NF-kappaB transactivation].
- Author
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Nojek IM, Werbajh SE, Colo GP, Rubio FM, Franco LD, Nahmod VE, and Costas MA
- Subjects
- Cell Nucleus metabolism, Cytoplasm metabolism, Enzyme Activation, Humans, Nuclear Receptor Coactivator 2, Phosphorylation, Transcriptional Activation, p38 Mitogen-Activated Protein Kinases antagonists & inhibitors, NF-kappa B metabolism, Transcription Factors physiology, p38 Mitogen-Activated Protein Kinases metabolism
- Abstract
We have previously shown that nuclear receptor coactivator overexpression significantly enhanced NF-kappaB activity in a dose response manner. We studied the mechanism by which TIF2 regulates NF-kappaB activity. We determined that: 1) the p38 specific inhibitor reduces 50% NF-kappaB transcriptional activity, even in cells that overexpress distinct TIF2 deletions; 2) there is a physical interaction between TIF2 and p38 and RelA determined through in vitro translated protein binding assays; 3) TIF2 is a p38 substrate; 4) there is a physical interaction between TIF2 and IKK in TNF-alpha 20 ng/ml stimulated or not HEK 293 cell protein extract, and IkappaB only in basal conditions, determined by binding pull down assays. This NF-kappaB complex regulates its activity and targets gene expression in a determined physiologic context depending on the coactivator complex content.
- Published
- 2004
44. [Regulation of NF-kappaB transcription factor. A molecular mediator in inflammatory process].
- Author
-
López-Bojorquez LN
- Subjects
- Humans, I-kappa B Proteins physiology, Infections etiology, Inflammation etiology, NF-kappa B genetics, NF-kappa B immunology, Phosphorylation, Signal Transduction, Ubiquitin physiology, Inflammation immunology, NF-kappa B physiology
- Published
- 2004
45. [Possible role of transcription factor AP1 in the tissue-specific regulation of human papillomavirus].
- Author
-
Velazquez Torres A and Gariglio Vidal P
- Subjects
- Epithelial Cells virology, Female, Gene Expression Regulation, Viral, Humans, Models, Biological, Mutagenesis, Oncogene Proteins, Viral biosynthesis, Organ Specificity, Papillomaviridae classification, Papillomaviridae physiology, Papillomavirus Infections virology, Phosphorylation, Promoter Regions, Genetic genetics, Protein Kinases metabolism, Protein Processing, Post-Translational, Transcription, Genetic, Tumor Virus Infections virology, Uterine Cervical Neoplasms virology, Uterine Neoplasms virology, Virus Replication, Genes, Immediate-Early, Genes, Viral, Immediate-Early Proteins biosynthesis, Oncogene Proteins, Viral genetics, Papillomaviridae genetics, Transcription Factor AP-1 physiology, Viral Structural Proteins genetics
- Abstract
Activator protein-1 (AP1) is a dimeric protein, consisting either of homodimers between c-Jun, JunB, and JunD of by heterodimers with members of the Fos-family by physically interacting via a "leucine zipper" region. AP1 is an important transcription factor initially identified as a DNA binding protein that bound to enhancer sequences of the human metallothionein IIA gene. The protein components of AP1 are encoded by a set of genes known as "immediate-early" genes that can be activated by a variety of growth factors and mitogens through several different signaling pathways. Until recently, AP1 was considered a transcription factor expressed in most tissues to regulate cellular and viral genes now, it is becoming evident that AP1 can be involved in tissue-specific regulation of target genes due to the differential combination of the components of this important transcription factor. AP1 plays a crucial role during human papillomavirus (HPV) early gene expression, in particular of the expression of E6 and E7 oncoproteins. The HPV are a group of DNA viruses consisting of more than 80 different genotypes. Some of these HPV, know as high risk HPV, are important etiologic agents of uterine-cervical cancer (CaCu). Of the different types of cancer, CaCu is one of the most frequent among women worldwide, constituting the second death cause due to neoplasia. During cellular transformation, HPV infect basal cells in stratified epithelium; their DNA integrate into the host genome usually through the E2 gene; as these cells differentiate and migrate into the upper layer of the epithelium, viral oncogene are expressed blocking their differentiation. Mutagenesis in AP1 sites belonging to the HPV promoter region (LCR) completely abolished the HPV promoter activity in different cell lines; these results and biochemistry assays on this AP1 transcription factor, that includes protein-protein interactions between AP1 and another factors as E7 from HPV, and YY-1; the post-translattional modification and, the retinoic acid interaction; suggest a role for this AP1 factor in tissue-specific transcription of the human papillomavirus.
- Published
- 2002
46. [TGF-beta: synthesis and mechanism of action].
- Author
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Prieto M, Rivas JV, López Novoa JM, and Pérez-Barriocanal F
- Subjects
- Animals, Antigens, CD, Chickens metabolism, DNA-Binding Proteins chemistry, DNA-Binding Proteins physiology, Endoglin, Gene Expression Regulation, Humans, Macromolecular Substances, Mammals metabolism, Phosphorylation, Promoter Regions, Genetic, Protein Isoforms physiology, Protein Precursors biosynthesis, Protein Processing, Post-Translational, Proteoglycans drug effects, Receptors, Cell Surface, Receptors, Transforming Growth Factor beta classification, Receptors, Transforming Growth Factor beta drug effects, Receptors, Transforming Growth Factor beta physiology, Species Specificity, Substrate Specificity, Transcription Factors chemistry, Transcription Factors physiology, Transforming Growth Factor beta biosynthesis, Transforming Growth Factor beta classification, Transforming Growth Factor beta pharmacology, Vascular Cell Adhesion Molecule-1 drug effects, Xenopus laevis metabolism, Signal Transduction physiology, Transforming Growth Factor beta physiology
- Published
- 2002
47. [The microtubule-associated protein tau in neurodegenerative diseases. Tauopathies].
- Author
-
Sánchez MP, Alvarez-Tallada V, and Avila J
- Subjects
- Alzheimer Disease metabolism, Amyloid beta-Protein Precursor metabolism, Animals, Axons metabolism, Biopolymers, Humans, Mice, Mice, Transgenic, Microtubules chemistry, Microtubules ultrastructure, Models, Animal, Nerve Tissue Proteins metabolism, Neurofibrillary Tangles chemistry, Neurofibrillary Tangles ultrastructure, Phosphoprotein Phosphatases metabolism, Phosphorylation, Protein Binding, Protein Conformation, Protein Isoforms chemistry, Protein Isoforms genetics, Protein Kinases metabolism, Protein Processing, Post-Translational, tau Proteins chemistry, tau Proteins genetics, Tauopathies genetics, Tauopathies metabolism, Tauopathies pathology, tau Proteins physiology
- Abstract
Introduction: Microtubules are the essential components of the cytoskeleton, they are responsible for the formation and maintenance of the neuronal morphology and their specific connections. The microtubule associated proteins (MAPs) contribute to regulate the dynamism and stability of the microtubules, and therefore they are essential to maintain the correct function of the microtubules. Among them, tau is a protein that seems to be crucial in stabilizing the neuronal polarity., Development: In this paper, factors affecting the affinity of tau to bind microtubules are reviewed, giving special attention to the processes that take place in the neurodegenerative diseases that present neurofibrillary tangles (NFTs), aggregates composed of modified tau in form of paired helical filaments (PHFs). One of the most important tau modification in this aberrant aggregates is the hyperphosphorylation. Thus, kinases and phosphatases responsible for tau modification could be altered in certain pathologies, leading to a decrease in the affinity of tau to bind microtubules and carrying out its self assembling and aberrant aggregation in the neurons of the affected nervous system regions. Those pathologies presenting a tau disfunction are known as tauopathies.
- Published
- 2001
48. [Phosphorylation in eukaryotic cells. Role of phosphatases and kinases in the biology, pathogenesis and control of intracellular and bloodstream protozoa].
- Author
-
González J
- Subjects
- Animals, Leishmania pathogenicity, Phosphorylation, Protozoan Infections enzymology, Protozoan Infections prevention & control, Signal Transduction, Trypanosoma pathogenicity, Eukaryotic Cells enzymology, Leishmania enzymology, Phosphoric Monoester Hydrolases metabolism, Protein Kinases metabolism, Trypanosoma enzymology
- Abstract
Cells respond to environmental or cellular changes, rapidly switching protein activities from one state to another. In eukaryotes, a way to achieve these changes is through protein phosphorylation cycles, involving independent protein kinase and protein phosphatase activities. Current evidences show that phosphatases and kinases are also involved in the molecular basis of immune response and in disease such as diabetes obesity and Alzheimer. In protozoan parasites like Trypanosoma and Leishmania, several kinases and phosphatases have been identified, many of them have been cloned but in several cases their biological role remains undetermined. In this review, the state-of-the art is summarized and the role of phosphatases and kinases in biological phenomena such as remodeling, invasion and pathogenic capacity of protozoan parasites is described. The real chance to use these components of signal transduction pathways as target for chemotherapeutic intervention is also discussed (Rev Méd Chile 2000; 128: 1150-60).
- Published
- 2000
49. [Escherichia coli L-asparaginase induces phosphorylation of endogenous polypeptides in human immune cells].
- Author
-
Mercado L and Arenas G
- Subjects
- Catalysis, Electrophoresis, Polyacrylamide Gel, Humans, Lymphocytes metabolism, Monocytes metabolism, Neutrophils metabolism, Phosphoproteins blood, Phosphorylation, Asparaginase metabolism, Blood Proteins metabolism, Escherichia coli enzymology, Immunity, Cellular
- Abstract
Purpose: To detect patterns of endogenous polypeptide phosphorylation in monocyte, lymphocyte, and polymorphonuclear leukocyte populations, induced by the products of the catalytic action of L-asparaginase (EcA)., Materials and Methods: Monocytes, polymorphonuclear cells and lymphocytes were isolated from heparinized blood from healthy, voluntary donors. The samples were incubated in 0.4 mCi/ml of [gamma-32P]H3PO4, with: 1 microgram/microliter of EcA, EcA and the substrate or with the products of EcA's catalytic activity: NH4+ and aspartate. The cells were lysated and electrophoresed using denaturing polyacrylamide gels that were then exposed on radiographic plates. The levels of polypeptide phosphorylation were quantified by computer densitometric analysis., Results: The autoradiographs and the densitometric quantification of the electrophoretic profiles of monocytes, polymorphonuclear leukocytes, and lymphocytes revealed an increase in polypeptide phosphorylation when the cells were incubated with the enzyme and its substrate, ammonium and aspartate, or ammonium, which demonstrates that the NH4+ triggers intracellular phosphotransferase activity. A 58 kDa phosphoprotein outstood, it being common to the three cell populations studied. There were also specific phosphorylable polypeptides in monocytes, polymorphonuclear leukocytes, and lymphocytes., Conclusions: Escherichia coli L-asparaginase, binds the plasma membrane in normal human immune cells, catalyzing the L-asparagine substrate. The products of its activity: aspartate and NH4+ modify the extracellular environment, particularly the latter since it could diffuse into the cytosol and modify the pH, which would activate signal transduction pathways associated with the phosphorylation of substrates.
- Published
- 1999
50. [The Philadelphia chromosome: from the gene to therapeutic methods].
- Author
-
Pérez-Losada J, González-Sarmiento R, and Sánchez-García I
- Subjects
- Apoptosis physiology, Cell Division physiology, Cell Transformation, Neoplastic genetics, Chromosomes, Human, Pair 22 genetics, Chromosomes, Human, Pair 9 genetics, DNA, Neoplasm genetics, Fusion Proteins, bcr-abl chemistry, Fusion Proteins, bcr-abl physiology, Gene Expression Regulation, Leukemic, Genes, abl, Genetic Therapy, Hematopoietic Stem Cells cytology, Hematopoietic Stem Cells metabolism, Humans, Leukemia, Myelogenous, Chronic, BCR-ABL Positive therapy, Neoplastic Stem Cells metabolism, Neoplastic Stem Cells pathology, Phosphorylation, Protein Processing, Post-Translational, Protein-Tyrosine Kinases chemistry, Protein-Tyrosine Kinases physiology, Proto-Oncogene Proteins chemistry, Proto-Oncogene Proteins physiology, Proto-Oncogene Proteins c-abl chemistry, Proto-Oncogene Proteins c-abl physiology, Proto-Oncogene Proteins c-bcr, Fusion Proteins, bcr-abl genetics, Leukemia, Myelogenous, Chronic, BCR-ABL Positive genetics, Philadelphia Chromosome
- Published
- 1998
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