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Co-immunoprecipitation Assay for Studying Functional Interactions Between Receptors and Enzymes
Published on: September 28, 2018
La dimerización inhibe la actividad de la proteína tipo receptor tirosina fosfatasa alfa
1Molecular Biology and Virology Laboratory, The Salk Institute for Biological Studies, La Jolla, California 92037, USA. gjiang@aim.salk.edu
Nature
|October 19, 1999
Resumen
La dimerización regula negativamente la actividad de la receptor-como la proteína tirosina fosfatasa alfa (RPTPalpha) en vivo. Esta regulación es estereocímicamente consistente con las estructuras cristalinas, lo que sugiere un mecanismo para controlar el crecimiento y la diferenciación celular.
Área de la Ciencia:
- Biología Molecular Biología Molecular
- La señalización celular de las células.
- La bioquímica es la bioquímica.
Sus antecedentes:
- Las fosfatasas de proteína-tirosina (PTP) son cruciales para los procesos celulares.
- La regulación de la PTP parecida a los receptores (RPTP) no se entiende completamente.
- Las estructuras cristalinas sugieren que la dimerización de RPTPalpha puede inhibir la actividad.
Objetivo del estudio:
- Para investigar la regulación in vivo de la actividad de RPTPalpha de longitud completa por dimerización.
- Para determinar si la dimerización tiene un impacto negativo en la función RPTPalpha.
- Para confirmar la base estructural de la inhibición mediada por la dimerización de RPTPalpha.
Principales métodos:
- Se generaron homodímeros RPTPalpha estables enlazados con disulfuro utilizando mutantes de cisteína.
- RPTPalpha de tipo salvaje y mutante expresado en células embrionarias de ratón RPTPalpha-nulo.
- Evaluado c-Src Tyr 529 desfosforilación y actividad.
Principales resultados:
- Se demostró que la dimerización inhibe la actividad completa de RPTPalpha in vivo.
- Las mutaciones específicas de cisteína (Phe135Cys, Thr141Cys) permitieron la dimerización y el aumento de la actividad c-Src.
- La mutación de la cuña inhibidora (Pro210/211 a Leu) restauró la activación de c-Src en un mutante con defecto de dimerización.
Conclusiones:
- La actividad de RPTPalpha puede ser regulada negativamente por la dimerización in vivo.
- El mecanismo inhibidor es consistente con los datos estructurales de RPTPalpha.
- La dimerización proporciona un mecanismo de regulación potencial para el RPTPalfa en la señalización celular.
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