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CPEB es un factor de especificidad que media la poliadenilación citoplasmática durante la maduración de los ovocitos

L E Hake¹, J D Richter

¹Worcester Foundation for Experimental Biology Shrewsbury, Massachusetts 01545.

|November 18, 1994

Resumen

La poliadenilación citoplasmática requiere una proteína específica (CPEB) que se une a los elementos de ARN. Esta proteína es esencial para la poliadenilación durante la maduración de los ovocitos de Xenopus.

Área de la Ciencia:

Biología Molecular Biología Molecular
Biología del desarrollo Biología del desarrollo.
ARN Biología Biología ARN

Sus antecedentes:

La poliadenilación citoplasmática es crucial para la activación traslacional de los ARNm maternos durante la maduración de los ovocitos de Xenopus.
Este proceso depende del elemento de poliadenilación del citoplasma (CPE) y de la secuencia de hexanucleótidos AAUAAA.

Objetivo del estudio:

Para identificar y caracterizar la proteína que se une a la CPE.
Para determinar el papel de esta proteína de unión a la CPE (CPEB) en la poliadenilación citoplasmática.

Principales métodos:

La cromatografía de afinidad de ARN se utilizó para enriquecer el CPEB.
Se obtuvo y se analizó el cDNA de CPEB.
Se realizaron experimentos de inmunodepleción y reconstitución utilizando extractos de huevo.

Principales resultados:

Se identificó una proteína CPEB de 62 kDa, que contiene motivos de reconocimiento de ARN y muestra homología con Drosophila orb.
CPEB es abundante en los ovocitos y disminuye en etapas embrionarias posteriores.
La fosforilación de CPEB coincide con la inducción de poliadenilación durante la maduración de los ovocitos.
El agotamiento de CPEB abolió la poliadenilación en extractos de huevo, que fue restaurada tras la adición de CPEB.

Conclusiones:

CPEB es una proteína clave requerida para la poliadenilación citoplasmática en los ovocitos de Xenopus.
La fosforilación de CPEB durante la maduración de los ovocitos está relacionada con la activación de la poliadenilación.

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