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El aflojamiento de la cromatina por la poli (ADP) -ribosa polimerasa (PARP) en los loci de la hinchazón de Drosophila
Alexei Tulin1, Allan Spradling
1Howard Hughes Medical Research Laboratories, Embryology Department, Carnegie Institution of Washington, 115 West University Parkway, Baltimore, MD 21210, USA.
Science (New York, N.Y.)
|January 25, 2003
Resumen
La actividad de la poli (ADP) -ribosa polimerasa (PARP) es esencial para crear hinchazos, que son estructuras de cromatina aflojadas que permiten la inducción génica en Drosophila. PARP ayuda a regular la expresión del gen de choque térmico Hsp70 mediante la modificación de la cromatina durante el desarrollo.
Área de la Ciencia:
- Biología Molecular Biología Molecular
- Genética La genética.
- Biología de la cromatina Biología de la cromatina
Sus antecedentes:
- Los genes activados por esteroides y el estrés, como la proteína de choque térmico 70 (Hsp70), se inducen a través de la expresión génica.
- La inducción génica en los cromosomas politenos de Drosophila se asocia con regiones de cromatina hinchadas.
- Las bocanadas cromosómicas de polietileno representan una descondensación localizada de la estructura de la cromatina.
Objetivo del estudio:
- Para investigar el papel de la poli-ADP-ribosa polimerasa (PARP) en la formación de hinchazos y la inducción de genes.
- Para determinar la participación de la modificación de adenosina difosfato (ADP) -ribosa en la remodelación de la cromatina durante la respuesta al estrés.
Principales métodos:
- Análisis de la formación de hinchazones en las glándulas salivales larvales de Drosophila.
- Cuantificación de las proteínas modificadas por adenosina difosfato (ADP) y ribosa en puffs.
- Evaluación de la expresión del gen Hsp70 y el tamaño de la boquilla en Drosophila de tipo silvestre y con deficiencia de PARP después de un choque térmico.
Principales resultados:
- Los puffs, sitios de inducción génica, acumulan niveles elevados de proteínas modificadas por ADP-ribosa.
- La poli (ADP) -ribosa polimerasa (PARP) es crucial para la formación de hinchazos de tamaño normal.
- La deficiencia de PARP conduce a una reducción de la expresión de Hsp70 y a estructuras anormales de la boquilla después de la exposición al calor.
Conclusiones:
- Se propone que la activación cromosómica de PARP, desencadenada por señales de desarrollo o ambientales, facilite la formación de hinchazos mediante la eliminación de proteínas unidas al ADN.
- Este aflojamiento de la cromatina localizada por PARP puede mejorar la transcripción génica y la accesibilidad de las proteínas para su modificación.
- La remodelación de la cromatina mediada por PARP es un mecanismo clave en la regulación genética del desarrollo y la respuesta al estrés.
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