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La transcripción de bxd ARN no codificantes promovida por el trithorax reprime Ubx en cis por interferencia
Svetlana Petruk1, Yurii Sedkov, Kristen M Riley
1Department of Biochemistry, Thomas Jefferson University, Philadelphia, PA 19107, USA.
Cell
|December 19, 2006
Resumen
Los ARN largos no codificantes (ARNnc) transcritos de la región bithoraxoid (bxd) sorprendentemente reprimen la expresión génica Ultrabithorax (Ubx). Esta represión se produce a través de la transcripción de ncRNA en cis, mediada por el complejo Trithorax TAC1.
Área de la Ciencia:
- Biología del desarrollo Biología del desarrollo.
- Regulación genética Reglamento genético.
- ARN no codificante Biología Biología.
Sus antecedentes:
- Los ARN largos no codificantes (ARNnc) se transcriben a partir de grandes porciones del genoma.
- Anteriormente se pensaba que los ncRNA bitoraxoide (bxd) activaban la expresión de Ultrabithorax (Ubx) mediante el reclutamiento de proteínas del grupo trithorax (trxG).
- El papel preciso de los ncRNAs bxd en la regulación de la expresión de Ubx sigue sin estar claro.
Objetivo del estudio:
- Para investigar el papel de bxd ncRNAs en la regulación de la expresión de Ubx.
- Para dilucidar el mecanismo por el cual los bxd ncRNAs influyen en la transcripción de Ubx.
- Para entender la interacción entre bxd ncRNAs, Ubx y el complejo Trithorax.
Principales métodos:
- Análisis de patrones de expresión no superpuestos de los ncRNAs Ubx y bxd en embriones de Drosophila y discos de imagen.
- Investigación para descartar la represión mediada por ARN pequeño interferente (siRNA) o microARN (miRNA).
- Examen de los patrones de unión del complejo Trithorax (TAC1) en relación con la expresión de Ubx y bxd ncRNA.
Principales resultados:
- Los ncRNAs Ubx y bxd exhiben patrones de expresión no superpuestos, lo que sugiere un papel represivo para los ncRNAs.
- La represión de Ubx por bxd ncRNAs es independiente de las vías de siRNA o miRNA.
- La transcripción de ncRNA actúa en cis para reprimir la transcripción de Ubx.
- El complejo Trithorax (TAC1) une la región codificante de Ubx cuando se expresa Ubx y la región bxd cuando se reprime Ubx.
Conclusiones:
- Contrariamente a las hipótesis anteriores, los bxd ncRNAs reprimen, en lugar de activar, la expresión de Ubx.
- La propia transcripción de ncRNA, actuando en cis, es el mecanismo de la represión de Ubx.
- TAC1 facilita el patrón de expresión mosaico de Ubx promoviendo el alargamiento de bxd ncRNA, lo que lleva a la represión transcripcional de Ubx.
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