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Updated: Jul 9, 2026
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Quantitative Comparison of cis-Regulatory Element (CRE) Activities in Transgenic Drosophila melanogaster
Published on: December 19, 2011
La activación independiente de CBP de CREM y CREB por la proteína ACT sólo LIM
G M Fimia1, D De Cesare, P Sassone-Corsi
1Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS-INSERM-ULP, Illkirch, Strasbourg, France.
Nature
|March 23, 1999
Resumen
Los investigadores descubrieron ACT, una nueva proteína que activa la transcripción CREM (modulador del elemento de respuesta CAMP) en los testículos. Este activador evita la fosforilación tradicional y la interacción de la CBP, lo que sugiere una nueva vía para la regulación génica en las células germinales masculinas.
Área de la Ciencia:
- Biología Molecular Biología Molecular
- Regulación genética Reglamento genético.
- Biología Reproductiva Biología Reproductiva.
Sus antecedentes:
- La activación transcripcional por CREB (proteína de unión del elemento de respuesta CAMP) y CREM (modulador del elemento de respuesta CAMP) generalmente requiere fosforilación e interacción del coactivador CBP.
- CREM es crucial para la expresión génica en las células germinales masculinas durante las etapas post-meióticas.
Objetivo del estudio:
- Identificar nuevas proteínas involucradas en la activación transcripcional mediada por CREM en los testículos.
- Para caracterizar la función y el mecanismo de un activador testículo-específico recientemente identificado.
Principales métodos:
- Se empleó una pantalla de dos híbridos para aislar las proteínas que interactúan con CREM de una biblioteca de ADNc del testículo.
- Se utilizaron ensayos funcionales en levaduras y células de mamíferos para evaluar el impacto de la proteína identificada en la actividad transcripcional CREM.
- Los patrones de expresión de la nueva proteína se analizaron de una manera específica para el tejido y el desarrollo.
Principales resultados:
- Se aisló un cDNA derivado de los testículos que codificaba una proteína LIM-sólo, denominada ACT (activador de CREM en los testículos).
- ACT se asocia específicamente con CREM y se expresa coordinadamente con CREM de una manera regulada en el tejido y el desarrollo.
- ACT estimula fuertemente la actividad transcripcional CREM, evitando la necesidad de la fosforilación de Ser 117 y la interacción de CBP.
Conclusiones:
- ACT representa una nueva vía para la activación transcripcional por CREM y CREB, independiente de los mecanismos canónicos.
- ACT puede constituir una nueva clase de coactivadores específicos de tejidos involucrados en distintos programas de diferenciación celular, particularmente en el desarrollo de células germinales masculinas.
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