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La hipermutación inducida por la enzima AID en un gen activamente transcrito en los fibroblastos
Kiyotsugu Yoshikawa1, Il-Mi Okazaki, Tomonori Eto
1Department of Medical Chemistry and Molecular Biology, Graduate School of Medicine, Kyoto University, Yoshida Konoe-cho, Sakyo-ku, Kyoto, 606-8501, Japan.
Science (New York, N.Y.)
|June 18, 2002
Resumen
La desaminasa citidina inducida por activación (AID) por sí sola puede desencadenar una hipermutación génica en los genes transcritos dentro de las células fibroblásticas. Esto sugiere que AID es suficiente para la generación de hipermutación somática (SHM) en varios tipos de células.
Área de la Ciencia:
- Inmunología Inmunología.
- Biología Molecular Biología Molecular
- Genética La genética.
Sus antecedentes:
- La desaminasa citidina inducida por activación (AID) es crucial para la diversificación genética de las inmunoglobulinas.
- La AID es esencial para la hipermutación somática (SHM), la recombinación del interruptor de clase y la conversión génica.
Objetivo del estudio:
- Investigar si el AID por sí solo es suficiente para inducir hipermutación en células no B.
- Determinar el papel de la AID en la generación de mutaciones en genes transcritos activamente.
Principales métodos:
- La expresión ectópica de AID en las células de fibroblastos murinos NIH 3T3.
- Utilizó un gen reportero GFP artificial para evaluar la frecuencia y distribución de la mutación.
- La frecuencia de mutación correlacionada con el nivel de transcripción del gen objetivo.
Principales resultados:
- La expresión ectópica de AID indujo una hipermutación en el sustrato GFP dentro de los fibroblastos.
- La frecuencia de mutación se correlaciona directamente con los niveles de transcripción del gen objetivo.
- La distribución de la mutación en los fibroblastos reflejó la observada en los linfocitos B durante la SHM.
Conclusiones:
- AID es suficiente para generar hipermutación somática (SHM) en los genes transcritos activamente en los fibroblastos.
- Los cofactores necesarios para la actividad de AID están presentes en los fibroblastos murinos.
- Estos hallazgos sugieren un mecanismo molecular común para SHM en diferentes tipos de células.
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