一个具有构成性运输元素的内子被保留在Tap信使RNA中
Ying Li1, Yeou-Cherng Bor, Yukiko Misawa
1Myles H. Thaler Center for AIDS & Human Retrovirus Research and Department of Microbiology, University of Virginia, Charlottesville, Virginia 22908, USA.
Nature
|September 15, 2006
概括
构成性运输元件 (CTEs) 能够使哺乳动物中的内部保留mRNAs表达. 塔普基因利用内部的CTE调节自身的表达,揭示了有效处理哺乳动物mRNA的机制.
科学领域:
- 分子生物学分子生物学
- 在RNA生物学,RNA生物学.
- 基因规则 基因规则
背景情况:
- 替代拼接,特别是内子保留,对于遗传多样性至关重要,但由于mRNA出口和降解途径,在较高的真核生物中通常受到限制.
- 细胞机制通常会降解具有保留内子的mRNA,特别是那些含有过早停止子的mRNA,从而限制它们的表达.
- 复原病毒,比如梅森-泽子病毒,使用cis-acting RNA元素,如构成性运输元素 (CTE),以克服这些限制并促进mRNA出口.
研究的目的:
- 调查具有保留内子的细胞mRNA是否利用CTE类元素来克服表达限制.
- 为了确定Tap基因,mRNA出口的关键调节器,是否含有功能性的CTE.
- 阐明Tap调节其自身内子含有mRNA表达的机制.
主要方法:
- 生物信息分析用于识别Tap基因内的潜在CTEs.
- 在Tap mRNA出口和翻译中对CTE函数的实验验证.
- 在人类和子细胞中检测来自内子含有mRNA的Tap蛋白表达.
主要成果:
- 塔普基因在其替代拼接的10号内具有功能性的CTE.
- 含有这种内子的TAPmRNA被有效地输出到细胞质中,并在多核糖体中发现,表明活性翻译.
- 一个小的Tap蛋白被这种含有内子的mRNA编码,可以在人类和子细胞中检测到.
结论:
- Tap通过一种CTE介导的机制自我调节自己的表达,该机制涉及一个包含内子的转录.
- 构成性运输元素 (CTEs) 可能对具有保留内子的哺乳动物mRNAs的有效表达很重要.
- 这一发现挑战了在较高的真核生物中内核保留总是导致非功能转录的观念.
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