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Las estructuras del proteasoma 26S comprometidas con el sustrato revelan mecanismos para la translocación impulsada

Andres H de la Peña¹, Ellen A Goodall^2,3, Stephanie N Gates^2,3,4

¹Department of Integrative Structural and Computational Biology, The Scripps Research Institute, 10550 N. Torrey Pines Road, La Jolla, CA 92037, USA.

Science (New York, N.Y.)

|October 13, 2018

Resumen

El proteasoma 26S

Área de la Ciencia:

Biología molecular
Biología celular
La bioquímica

Sus antecedentes:

El proteosoma 26S es un mecanismo de degradación eucariota crucial.
Desempeña un papel vital en varios procesos celulares mediante la degradación de las proteínas.
Comprender su mecanismo es clave para la función celular.

Objetivo del estudio:

Para aclarar el mecanismo de los cambios conformacionales impulsados por la hidrólisis de ATP en el proteosoma 26S.
Para revelar cómo el proteasoma se despliega y transloca sustratos.
Comprender la coordinación de los eventos de unión, hidrólisis y liberación de ATP.

Principales métodos:

Se utilizó la microscopía criolectrónica (crio-EM) para capturar estados conformacionales distintos.
Se determinaron las estructuras del proteasoma 26S hidrolizante de ATP comprometido con el sustrato.
El análisis se centró en el motor de la ATPasa AAA+ y su interacción con sustratos.

Principales resultados:

Se visualizaron cuatro estados conformacionales distintos del proteosoma 26S.
Las estructuras muestran cómo la translocación mecánica del sustrato acelera la deubiquitinación.
Se reveló la coordinación de los eventos de hidrólisis de ATP dentro del motor AAA+.

Conclusiones:

El estudio proporciona conocimientos estructurales sin precedentes sobre la función del proteosoma 26S.
Aclara cómo la hidrólisis de ATP impulsa la translocación y la deubiquitinación del sustrato.
Este trabajo avanza nuestra comprensión de esta máquina celular esencial.

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