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Updated: Jan 6, 2026
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Cells and Secretions of the Pancreas
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Fosfatidilinositol 3-cinasa: estructura y expresión de la subunidad catalítica 110 kd
Cell
|August 7, 1992
Resumen
La subunidad p110 de la fosfatidilinositol 3-kinasa (Pl3-kinasa) posee actividad catalítica y se asocia con la subunidad del adaptador p85 alfa. Este complejo p85 alfa-p110 se une a las tirosinacinasas activadas, cruciales para la señalización celular.
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 (Pl3-kinasa) es una enzima clave en las vías de señalización celular.
- La pl3-cinasa existe como un complejo de subunidades reguladoras (p85 alfa) y catalíticas (p110).
- La subunidad alfa p85 actúa como un adaptador, uniendo p110 a las proteínas tirosinacinasas activadas.
Objetivo del estudio:
- Para caracterizar la subunidad p110 del cerebro bovino Pl3-kinasa.
- Para entender la relación funcional entre las subunidades alfa p110 y p85.
Principales métodos:
- La clonación del ADN complementario (ADNc) de la subunidad p110.
- Expresión de p110 en insectos y células COS-1.
- Análisis de la actividad de la Pl3-cinasa en proteínas y complejos expresados.
Principales resultados:
- La clonación de ADNc reveló que p110 es una proteína de 1068 aminoácidos homóloga a S. cerevisiae Vps34p.
- El p110 recombinante expresado en células de insectos exhibió actividad de Pl3-cinasa.
- p110 se asoció con p85 alfa para formar un complejo activo que se unía al receptor activado del factor estimulante de colonias 1.
- La actividad catalítica de p110 expresada en las células COS-1 dependía de la asociación con p85 alfa.
Conclusiones:
- La subunidad p110 es el componente catalítico de la Pl3-quinasa.
- La subunidad alfa p85 es esencial para acoplar p110 a las tirosinacinasas activadas y para su actividad catalítica.
- El complejo p85 alfa-p110 juega un papel en la señalización aguas abajo de los receptores del factor de crecimiento como el receptor del factor 1 estimulante de colonias.
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