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Epac es un factor de intercambio de guanina y nucleótido Rap1 activado directamente por la AMP cíclica

J de Rooij¹, F J Zwartkruis, M H Verheijen

¹Laboratory for Physiological Chemistry and Centre for Biomedical Genetics, Utrecht University, The Netherlands.

|December 16, 1998

Resumen

Los investigadores descubrieron Epac, una nueva proteína activada directamente por el AMP cíclico (cAMP). Este factor de intercambio guanina-nucleótido (GEF) regula la actividad de Rap1, independiente de la proteína quinasa A, revelando una nueva vía de señalización cAMP.

Área de la Ciencia:

Biología Molecular Biología Molecular
La señalización celular de las células.

Sus antecedentes:

Rap1, una Ras-como GTPasa, juega un papel en la proliferación celular, la diferenciación y la activación.
La activación de Rap1 es desencadenada por mensajeros secundarios como el diacilglicerol, el calcio y la AMP cíclica (cAMP).
La comprensión previa sugería que el cAMP activaba el Rap1 indirectamente, potencialmente a través de la proteína quinasa A.

Objetivo del estudio:

Para investigar el mecanismo de activación de Rap1 por cAMP.
Para identificar nuevas proteínas involucradas en la señalización Rap1 mediada por cAMP.
Para caracterizar un nuevo factor de intercambio de guanina-nucleótido (GEF) activado por cAMP.

Principales métodos:

Clonar el gen para una nueva proteína de unión al cAMP.
Ensayos in vitro e in vivo para evaluar la actividad del APG.
Investigando el papel de la proteína quinasa A en la activación de Rap1 inducida por cAMP.

Principales resultados:

Identificó y clonó Epac (proteína de intercambio activada directamente por cAMP), un nuevo GEF.
Epac se une directamente a cAMP y exhibe actividad GEF hacia Rap1.
cAMP induce fuertemente la actividad GEF de Epac en Rap1, independientemente de la proteína quinasa A.

Conclusiones:

Epac es un GEF directamente regulado por el cAMP para Rap1.
Epac representa una nueva vía de señalización para cAMP.
Epac es una nueva proteína diana para el cAMP, mediando la activación de Rap1.

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