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Identification of Kinase-substrate Pairs Using High Throughput Screening
Published on: August 29, 2015
Caracterización de dos proteínas de 85 kd que se asocian con las receptoras de las tirosinacinasas, los complejos
Cell
|April 5, 1991
Resumen
La fosfatidilinositol 3-kinasa (PI3-kinasa) del cerebro bovino incluye 85 kDa de proteínas (p85 alfa/beta) con dominios SH2. Estas proteínas se unen a las tirosinacinasas pero carecen de actividad de la PI3-cinasa, lo que sugiere un papel regulador en las vías de señalización.
Área de la Ciencia:
- La bioquímica es la bioquímica.
- Biología Molecular Biología Molecular
- La señalización celular de las células.
Sus antecedentes:
- La fosfatidilinositol 3-kinasa (PI3-kinasa) es una enzima clave en la señalización celular.
- La PI3-cinasa del cerebro bovino se compone de subunidades de 85 kDa y 110 kDa.
Objetivo del estudio:
- Para caracterizar las subunidades de 85 kDa (p85 alfa y p85 beta) de la PI3-cinasa del cerebro bovino.
- Investigar los roles funcionales de p85 alfa y p85 beta en la actividad de la PI3-cinasa y las interacciones de los receptores.
Principales métodos:
- Purificación por afinidad de la PI3-quinasa del cerebro bovino.
- Secuenciación de aminoácidos y clonación de ADNc de las subunidades de PI3-cinasa.
- Expresión y análisis funcional de las proteínas p85.
- Estudios de inmunoprecipitación con el uso de antiseróticos específicos.
- Análisis del complejo PI3-cinasa que se une a las receptoras de las tirosinacinasas.
Principales resultados:
- Se identificaron dos proteínas relacionadas de 85 kDa, p85 alfa y p85 beta, cada una de las cuales contiene dominios SH3 y SH2.
- Los p85 alfa y p85 beta expresados se unen a las proteínas fosforiladas por tirosina, pero carecen de actividad intrínseca de la PI3-cinasa.
- Un antisuero contra p85 beta inmunoprecipitó la actividad de la PI3-cinasa, lo que indica su participación.
- El complejo activo de PI3-cinasa, que contiene p85 alfa o p85 beta y la proteína de 110 kDa, se une a los receptores de PDGF pero no a los receptores de EGF.
Conclusiones:
- p85 alfa y p85 beta son subunidades reguladoras de la PI3-cinasa que carecen de actividad catalítica.
- Estas subunidades median la interacción de la PI3-cinasa con las tirosinacinasas específicas, incluidos los receptores de PDGF.
- p85 alfa y p85 beta juegan un papel crucial en la dirección de la señalización de la PI3-cinasa a las distintas receptoras tirosina-cinasas.
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