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La proteína prión del Scrapie contiene un fosfatidilinositol glucolipídico

N Stahl¹, D R Borchelt, K Hsiao

¹Department of Neurology, University of California, San Francisco 94143.

|October 23, 1987

Resumen

La proteína priónica celular (PrPC) está anclada a las superficies celulares a través de un glicolípido de fosfatidilinositol. Este hallazgo arroja luz sobre la estructura de la proteína priónica y las interacciones de la membrana celular.

Área de la Ciencia:

La bioquímica es la bioquímica.
Biología celular Biología celular.
La neurociencia es la neurociencia.

Sus antecedentes:

La proteína priónica celular (PrPC) y la proteína priónica de la tembladera (PrPSc) comparten un gen común pero exhiben propiedades distintas.
Se supone que las modificaciones posttraducionales causan estas diferentes propiedades.

Objetivo del estudio:

Para investigar la base molecular de las diferencias entre PrPC y PrPSc.
Para identificar el mecanismo de anclaje de PrPC a la superficie celular.

Principales métodos:

Purificación en gel del PrP 27-30 (derivado del PrPSc).
Identificación de los componentes de los glucolipidos mediante análisis bioquímico.
Digestión enzimática con fosfolipasa C (PIPLC) específica para el fosfatidilinositol.
Ensayos inmunológicos que utilizan antiseróticos específicos.

Principales resultados:

Se identificó un glicolipido de fosfatidilinositol tanto en PrPC como en PrP 27-30.
Se confirmó que la etanolamina, el myo-inositol, el fosfato y el ácido esteárico eran componentes de los glucolipidos.
El tratamiento con PIPLC liberó ácido esteárico unido y facilitó reacciones antiserum específicas.
El tratamiento PIPLC liberó PrPC de células de mamíferos cultivadas en el medio.

Conclusiones:

El PrPC está anclado a la superficie celular por un glicolípido de fosfatidilinositol.
Este enlace de glicolipidos es una característica clave de la localización de la superficie celular de PrPC.

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