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Respuesta diferencial de múltiples sitios de la capa de epsilon-globina a los controles de acción cis y trans
Cell
|September 1, 1984
Resumen
Los investigadores descubrieron que el gen epsilon-globina utiliza un sitio aguas arriba (sitio de la tapa 200) para la iniciación de la transcripción en las células no eritroides. Este sitio es este sitio.
Área de la Ciencia:
- Biología Molecular Biología Molecular
- Reglamento genético Reglamento genético.
- Genética La genética.
Sus antecedentes:
- El gen humano de la epsilon-globina exhibe sitios alternativos de iniciación de la transcripción aguas arriba del sitio principal de la tapa del ARNm.
- Las líneas celulares no eritroides muestran una transcripción "perdida" del gen epsilon-globina, principalmente en el sitio de la tapa -200.
Objetivo del estudio:
- Investigar la regulación independiente de la iniciación de la transcripción en el sitio de la tapa -200 y el sitio de la tapa principal del gen humano de la epsilon-globina.
- Para explorar el papel del sitio de la tapa -200 como un sitio de entrada de la polimerasa debido a su estructura de cromatina.
Principales métodos:
- Se emplearon ensayos de expresión transitoria para estudiar la transcripción génica.
- Análisis de la iniciación de la transcripción en respuesta a la replicación del plásmido, los elementos potenciadores SV40 y el gen E1A del adenovirus.
- Ensayos de sensibilidad de la nucleasa S1 para mapear regiones de ADN con estructura alterada.
Principales resultados:
- La iniciación de la transcripción desde el sitio de la cápsula -200 y el sitio de la cápsula mayor se puede regular de forma independiente.
- El sitio de la tapa -200 se encuentra en una región de hipersensibilidad S1 dentro de los plásmidos superenrollados.
- En ausencia de potenciadores virales, el sitio de la tapa -200 es el sitio de iniciación predominante después de la transfección.
Conclusiones:
- El sitio de la tapa -200 probablemente funcione como un sitio de entrada de la polimerasa debido a su estructura de cromatina accesible.
- Las moléculas reguladoras pueden modular la eficiencia de unión de la polimerasa en el sitio de la tapa -200.
- La regulación independiente de sitios de inicio alternativos de la transcripción ofrece flexibilidad en el control de la expresión génica.
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