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Poly (((A) polimerasa y un factor estimulante de poliadenilación disociable codificado por el virus de la vacuna
P D Gershon1, B Y Ahn, M Garfield
1Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892.
Cell
|September 20, 1991
Resumen
Los investigadores identificaron dos proteínas del virus de la vacuna, VP55 y VP39, esenciales para agregar colas poli (A) al ARNm. La VP55 actúa como la enzima, mientras que la VP39 se une a la poli (A) y estimula la formación de colas, revelando un nuevo mecanismo para el procesamiento del ARNm.
Área de la Ciencia:
- Virología Virología.
- Biología Molecular Biología Molecular
- Expresión génica de la expresión génica.
Sus antecedentes:
- El ARNm eucariótico típicamente presenta una cola de 3' poli (A) añadida post-transcripcionalmente.
- Los mecanismos precisos de la formación de la cola 3' poly ((A) no se comprenden completamente.
Objetivo del estudio:
- Para investigar los mecanismos de la formación de la cola 3 'poly (A).
- Identificar y caracterizar las proteínas virales responsables de la poliadenilación en el virus de la vacuna.
Principales métodos:
- Identificación y purificación de los polipéptidos del virus de la vacuna VP55 y VP39.
- Análisis de la actividad de poliadenilación utilizando proteínas y anticuerpos purificados.
- Análisis de las interacciones de las proteínas y las propiedades de unión de poli (A).
Principales resultados:
- La actividad de poliadenilación dependiente del primer estaba exclusivamente relacionada con el heterodimero VP55-VP39.
- La actividad de la poli (A) polimerasa residía en VP55, mientras que la VP39 era necesaria para la síntesis de moléculas largas de poli (A) y la unión de poli (A) libre.
- No se encontraron homólogos para VP55 o VP39 en las bases de datos de secuencias.
Conclusiones:
- La formación de la cola poli-A implica un polipéptido catalítico (VP55) y un factor estimulante disociable de unión al poli-A (VP39).
- Estas proteínas virales representan una nueva clase de factores de poliadenilación, distintos de las conocidas enzimas procarióticas o eucarióticas.
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