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Una estructura intramolecular G-cuadruplex con hebras G paralelas / antiparalelas mixtas formadas en la región
Jixun Dai1, Thomas S Dexheimer, Ding Chen
1College of Pharmacy, University of Arizona, Tucson, 85721, USA.
Journal of the American Chemical Society
|January 26, 2006
Resumen
Los investigadores descubrieron la primera estructura G-cuadruplex en el promotor humano bcl-2. Esta nueva estructura, con hebras G mixtas, ofrece un nuevo objetivo para los medicamentos contra el cáncer que modulan la expresión génica bcl-2.
Área de la Ciencia:
- Biología Estructural Biología estructural.
- Oncología Molecular Oncología Molecular
- La bioquímica es la bioquímica.
Sus antecedentes:
- Bcl-2 es una oncoproteína que inhibe la apoptosis, sobreexpresada en muchos tumores humanos.
- Una región rica en GC en el promotor bcl-2 regula su transcripción.
- Esta región puede formar múltiples G-cuadruplexos intramoleculares.
Objetivo del estudio:
- Para determinar la estructura del G-cuadruplex predominante en el promotor Bcl-2 humano.
- Para entender cómo este G-cuadruplex influye en la expresión génica bcl-2.
Principales métodos:
- Se utilizó la espectroscopia de Resonancia Magnética Nuclear (RMN) para estudiar la estructura G-cuadruplex.
- Análisis de las formaciones de plegado y bucle G-cuadruplex.
Principales resultados:
- Se identificó un nuevo G-cuadruplex intramolecular con hebras G mixtas paralelas / antiparalelas.
- La estructura cuenta con tres tetras G, un bucle de doble cadena de inversión y dos bucles laterales.
- Un bucle CGC único de tres nucleótidos en el promotor bcl-2 dicta su plegamiento.
Conclusiones:
- El identificado promotor de bcl-2 G-quadruplex tiene un patrón de plegado único.
- Esta estructura difiere de motivos similares en otros oncogenes como el c-MYC.
- El bcl-2 G-quadruplex es un objetivo terapéutico potencial para el desarrollo de fármacos contra el cáncer.
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