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La especificidad de la secuencia de la interacción homeodomain-ADN
C Desplan1, J Theis, P H O'Farrell
1Department of Biochemistry and Biophysics, University of California, San Francisco 94143-0448.
Cell
|September 23, 1988
Resumen
El gen grabado.
Área de la Ciencia:
- Biología del desarrollo Biología del desarrollo.
- Genética La genética.
- Biología molecular La biología molecular.
Sus antecedentes:
- Se sabe que el gen de desarrollo de Drosophila melanogaster, engrailed, codifica la actividad de unión al ADN.
- Esta actividad es crucial para la regulación génica durante el desarrollo.
Objetivo del estudio:
- Para identificar el dominio específico responsable de la unión al ADN en el gen grabado.
- Para caracterizar los sitios de unión al ADN y la especificidad del homeodomain grabado.
- Para comparar las propiedades de unión del homeodomain grabado con un homeodomain relacionado.
Principales métodos:
- Utilizó construcciones de eliminación del gen grabado.
- Proteínas de fusión expresadas en E. coli para el análisis funcional.
- Secuencias de consenso del sitio de unión del ADN determinado. secuencias de consenso.
- Realizó ensayos de unión y experimentos de competencia.
Principales resultados:
- Localizó la actividad de unión del ADN en el homeodomain conservado (HD).
- Identificó el consenso de sitio vinculante como TCAATTAAAT, que se encuentra en grupos en la región reguladora engrailed.
- Se observó una mayor unión a copias adyacentes de la secuencia de consenso.
- Se encontró que el homeodomain fushi tarazu (Ftz) se une a sitios similares a los engrailed (En) HD, con algunas diferencias en la preferencia.
- Tanto En como Ftz HDs se unen a un segundo tipo de secuencia: una repetición de TAA.
Conclusiones:
- La similitud en la especificidad de la secuencia entre En y Ftz HDs sugiere que las proteínas de unión al ADN relacionadas comparten especificidades similares.
- La competencia entre proteínas reguladoras relacionadas para sitios de unión puede determinar los resultados de la regulación génica.
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