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Las mutaciones de XPD impiden la transactivación dependiente de TFIIH por los receptores nucleares y la fosforilación
Anne Keriel1, Anne Stary, Alain Sarasin
1Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM/ULP, BP 163, 67404 Illkirch Cedex, C. U., Strasbourg, France.
Cell
|April 17, 2002
Resumen
Las mutaciones en el gen XPD, vinculadas a Xeroderma pigmentosum (XP), perjudican la función del receptor nuclear más allá de la reparación del ADN. Este estudio revela el XPD.
Área de la Ciencia:
- Biología Molecular Biología Molecular
- Genética La genética.
- La bioquímica es la bioquímica.
Sus antecedentes:
- Xeroderma pigmentosum (XP) es un trastorno genético raro causado por mutaciones en el gen XPD, un componente del factor de transcripción / reparación TFIIH.
- Los fenotipos XP sugieren roles para la XPD más allá de la reparación del ADN, pero estos no se comprenden completamente.
Objetivo del estudio:
- Para investigar las funciones de reparación no-ADN del gen XPD.
- Explorar el impacto de las mutaciones de XPD en la transactivación mediada por el receptor nuclear.
Principales métodos:
- Análisis de la transactivación del receptor nuclear en células de pacientes con XP-D.
- Investigando el papel de la XPD en la fosforilación del receptor nuclear RARalpha.
- Utilizando la sobreexpresión de XPD de tipo salvaje y un RARalpha mutado (RARalphaS77E) para evaluar la restauración funcional.
Principales resultados:
- Las mutaciones XPD reducen la transactivación dependiente de ligandos de los receptores nucleares como RARalpha, ERalpha y AR.
- La mutación XPD perjudica la actividad de la cinasa cdk7 dentro del TFIIH, afectando la fosforilación de RARalpha.
- Se observó la restauración de la transactivación con XPD o RARalphaS77E de tipo silvestre, lo que indica la importancia de una adecuada fosforilación de RARalpha.
Conclusiones:
- La subunidad XPD de TFIIH juega un papel crucial en la regulación de la actividad de los receptores nucleares a través de la fosforilación.
- Esta fosforilación, mediada por la cinasa cdk7, es esencial para la activación de genes dependientes de ligandos.
- La función de XPD se extiende más allá de la reparación del ADN, impactando la regulación hormonal de los genes y potencialmente contribuyendo a los fenotipos XP.
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