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Isolation of Labile Multi-protein Complexes by in vivo Controlled Cellular Cross-Linking and Immuno-magnetic Affinity Chromatography
Published on: March 10, 2010
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El cuarto dominio inmunoglobulínico del receptor del factor de la célula madre se combina con ligandos que se unen a
1Department of Chemical Immunology, Weizmann Institute of Science, Rehovot, Israel.
Cell
|January 13, 1995
Resumen
Las receptoras de las tirosina quinasas se dimerizan a través de un sitio específico en el cuarto dominio similar a la inmunoglobulina, no solo se unen a los ligandos. Este hallazgo revela un mecanismo de dimerización intrínseco crucial para la señalización del receptor del factor de las células madre.
Área de la Ciencia:
- Biología molecular La biología molecular.
- La señalización celular de las células.
- La bioquímica es la bioquímica.
Sus antecedentes:
- Las receptoras tirosina quinasas (RTKs) median la señalización celular a través de la dimerización.
- La dimerización inducida por ligandos es un paso clave en la activación de RTK.
- La dimerización del receptor del factor de células madre (SCF) se atribuía previamente a la bivalencia del ligando.
Objetivo del estudio:
- Para identificar el dominio específico responsable de la dimerización del receptor SCF.
- Para dilucidar el mecanismo de acoplamiento de ligando que se une a la dimerización del receptor.
- Para investigar el papel del dominio identificado en la transducción de señales.
Principales métodos:
- Utilizó un anticuerpo monoclonal inhibidor de la dimerización contra el receptor SCF.
- Mutantes generados en el receptor de SCF mediante la eliminación del supuesto dominio de dimerización (cuarto dominio similar a la inmunoglobulina).
- Se evaluó la dimerización inducida por ligandos y la transducción de señales aguas abajo en mutantes receptores.
Principales resultados:
- Se localizó un sitio específico de dimerización en el cuarto dominio de tipo inmunoglobulina del receptor de SCF.
- La eliminación de este dominio abolió la dimerización inducida por ligandos y inhibió por completo la transducción de la señal.
- Los resultados proporcionan una visión mecanicista de cómo la unión de ligandos desencadena la dimerización del receptor.
Conclusiones:
- El receptor de SCF posee un sitio de dimerización intrínseco dentro de su cuarto dominio similar a la inmunoglobulina.
- Este sitio intrínseco, en lugar de solo la bivalencia del ligando, impulsa la dimerización y la señalización del receptor.
- Mecanismos de dimerización intrínseca similares pueden estar presentes en otras receptoras de tirosina quinasa.
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