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La desacetilación de la cromatina por un complejo de remodelación de nucleosomas dependiente de ATP
J K Tong1, C A Hassig, G R Schnitzler
1Howard Hughes Medical Institute, Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA.
Nature
|November 6, 1998
Resumen
Los investigadores descubrieron un nuevo complejo de remodelación y desacetilación de nucleosomas (NRD) en las células humanas. Este complejo vincula la histona desacetilasa y las actividades de remodelación de nucleosomas dependientes de ATP, lo que afecta la transcripción génica y la estructura de la cromatina.
Área de la Ciencia:
- Biología Molecular Biología Molecular
- La epigenética es la epigenética.
- Biología de la cromatina Biología de la cromatina
Sus antecedentes:
- La dinámica de los cromosomas eucariotas, incluida la replicación del ADN y la transcripción génica, se basa en el ensamblaje y remodelación del núcleo del nucleosoma.
- La acetilación de histonas y la remodelación de nucleosomas dependientes de ATP son procesos enzimáticos clave que regulan la transcripción.
- Las desacetilasas de histona (HDAC) muestran limitaciones en la desacetilación de las histonas oligonucleosomales in vitro.
Objetivo del estudio:
- Identificar y caracterizar nuevas actividades de remodelación de nucleosomas dependientes de ATP dentro de los complejos de histona desacetilasa humana.
- Para investigar el acoplamiento potencial de distintas actividades modificadoras de la cromatina.
Principales métodos:
- Ensayos bioquímicos para identificar y caracterizar la actividad de remodelación de nucleosomas dependiente de ATP.
- Análisis funcional de los complejos de histona desacetilasa.
- Ensayos de desacetilación in vitro con histonas oligonucleosómicas.
Principales resultados:
- Identificación de una nueva actividad de remodelación de nucleosomas dependiente de ATP dentro de un complejo endógeno de histona desacetilasa humana.
- Esta actividad se atribuye a las proteínas CHD3 y CHD4, que poseen dominios helicasa/ATPasa.
- El complejo identificado, denominado complejo de remodelación y desacetilación de nucleosomas (NRD, por sus siglas en inglés), facilita la desacetilación in vitro de histonas oligonucleosómicas.
Conclusiones:
- Establece un vínculo físico y funcional entre la histona desacetilasa y las actividades de remodelación de nucleosomas.
- El complejo NRD integra distintas funciones modificadoras de la cromatina.
- Proporciona nuevos conocimientos sobre la regulación de la transcripción y la estructura de la cromatina.
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02:25Spreading of Chromatin Modifications
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