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Identificación de secuencias en un promotor de histona de levadura involucrado en la transcripción periódica
Cell
|May 23, 1986
Resumen
La transcripción periódica de los genes de las histonas de levadura está controlada por elementos promotores, no por una secuencia de replicación autónoma (ARS). El análisis de eliminación reveló dos funciones clave: activación dependiente del ciclo celular y represión periódica, lo que sugiere que la regulación negativa es dominante.
Área de la Ciencia:
- Biología Molecular Biología Molecular
- Genética de la levadura Genética de la levadura
- Regulación del ciclo celular Reglamento del ciclo celular.
Sus antecedentes:
- Los genes de la histona en Saccharomyces cerevisiae (levadura) exhiben una transcripción periódica durante el ciclo celular.
- La hipótesis anterior sugirió que una secuencia de replicación autónoma (ars) aguas abajo de los genes histónicos actuaba como un temporizador de transcripción.
Objetivo del estudio:
- Identificar los elementos reguladores responsables de la transcripción periódica del gen de la histona.
- Para investigar los mecanismos que controlan la expresión génica específica del ciclo celular en la levadura.
Principales métodos:
- Análisis de eliminación de secuencias de promotores aguas arriba de genes de histona transcritos de manera divergente.
- Inserción de elementos promotores aislados en un sistema de promotores heterólogo.
- Análisis de los patrones de expresión génica en respuesta a la progresión del ciclo celular.
Principales resultados:
- Secuencias específicas de promotores, no las ars, confieren transcripción periódica.
- Se identificaron dos funciones promotoras distintas específicas del ciclo celular: activación y represión.
- La eliminación de la función reprimente condujo a una expresión constitutiva y no periódica.
Conclusiones:
- Los elementos promotores específicos del ciclo celular regulan directamente la transcripción del gen de la histona.
- La represión periódica parece ser un mecanismo importante para el control del ciclo celular de la expresión génica de la histona.
- Los hallazgos revisan la comprensión de la regulación génica de las histonas de levadura.
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