隐秘的内源转录启动产生有效的内源mRNA模板,用于C9orf72-关联的RAN翻译
Shannon L Miller1,2, Katelyn M Green1,2, Bradley Crone3
1Department of Neurology, University of Michigan, Ann Arbor, MI 48109.
概括
在C9orf72中,内部的重复扩张会导致ALS和FTD. 新的研究确定了神秘的,内源启动的C9orf72mRNAs是通过重复关联的非AUG转化产生有毒二重复蛋白质的主要来源.
科学领域:
- 神经科学是一个神经科学.
- 遗传学 遗传学 是一个
- 分子生物学分子生物学
背景情况:
- C9orf72重复扩张是肌缩侧面硬化症 (ALS) 和前性痴呆症 (FTD) 的主要遗传原因.
- 致病性二聚重复 (DPR) 蛋白质通过重复关联的非AUG (RAN) 翻译产生,但内源性RNA模板仍然未确定.
- 了解这些有毒蛋白质的来源对于开发有效疗法至关重要.
研究的目的:
- 在C9orf72相关的神经退行性疾病中确定负责DPR蛋白合成的内源RNA模板.
- 调查不同C9orf72转录物种在RAN翻译中的作用.
- 通过阐明DPR生产的机制来探索潜在的治疗点.
主要方法:
- 利用长读5'RNA连接酶介导的cDNA末端的快速放大 (5'重复-RLM-RACE) 来识别C9orf72的转录.
- 雇员记者测试以评估不同内和外C9orf72转录的翻译效率.
- 通过在患者衍生的iNeurons中击倒Dbr1酶来操纵拉里亚特RNA稳定性.
主要成果:
- 在小鼠模型和人类神经元中鉴定出神秘的,引入子1启动的C9orf72mRNAs (m7G覆盖和多基化).
- 证明这些内子启动转录物比其他潜在模板 (如内子保留或拉里亚特RNAs) 更丰富,更有效地转化为DPR.
- 发现增强拉里亚特RNA稳定性不会影响DPR产生,这表明拉里亚特RNA在内源DPR合成中的作用很小.
结论:
- 隐秘的,线性,内部启动C9orf72mRNAs作为RAN转化和DPR产生的主要内源模板.
- 这些发现为C9orf72相关的ALS和FTD的分子病原发生提供了关键的见解.
- 这种新型RNA模板的识别为针对C9orf72介导的神经退行症的治疗策略开辟了新的途径.
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