在酵母和哺乳动物细胞中错误翻译遗传密码的白
Josephine Davey-Young1, Farah Hasan1, Rasangi Tennakoon1
1Department of Biochemistry, The University of Western Ontario, London, Ontario, Canada.
RNA biology
|April 17, 2024
概括
错误翻译转移RNAs (tRNAs) 可能导致细胞缺陷,但细胞可以容忍一些错误. 这项研究表明,特定的氨基酸,tRNA类型和抗序列决定了细胞如何处理错误翻译.
科学领域:
- 分子生物学分子生物学
- 遗传学 是一个遗传学.
- 生物化学 生物化学
背景情况:
- 翻译忠实性对于细胞功能至关重要,因为它取决于通过氨基酸-tRNA合成酶 (AARS) 精确的转移RNA (tRNA) 的氨基酸化.
- 一些AARS不识别抗基,使得tRNA易于从抗变体中错误翻译.
- 人类基因组含有tRNA变异,可能导致错误翻译,影响蛋白质合成.
研究的目的:
- 调查罕见的人类tRNA (Leu) 抗变异对蛋白质生产和细胞活力的影响.
- 通过创建和分析酵母中所有可能的tRNA (Leu) 抗变体,全面评估遗传密码对白错误整合的耐受性.
- 为了比较细胞对白素的耐受性与氨酸错误整合.
主要方法:
- 在神经母细胞瘤细胞中表达人类tRNA (Leu) 抗变异,以评估表型效应.
- 利用tRNA测序和质谱测量来确认变体表达和错误翻译.
- 产生了64种酵母菌株,表达了所有可能的tRNA (Leu) 抗变体,在可诱导多克西环素的系统中评估生长缺陷.
主要成果:
- 人类tRNA (Leu) 变异导致了氨酸在氨酸或氨酸编码子的错误翻译,导致光蛋白的生产缺陷没有显著的细胞毒性.
- 许多酵母tRNA (Leu) 抗变体,特别是那些在位置35和36的G/C变体,导致严重的生长减少,这表明对白错误纳入的耐受性有限.
- 氨酸错误整合通常比几乎所有编码子的氨酸错误整合更容易忍受.
结论:
- 细胞对错误翻译tRNA的耐受性受到特定氨基酸替代,tRNA基因和抗序列的影响.
- 遗传密码对不同氨基酸的错误结合具有差异性灵活性,白素的耐受性低于氨酸.
- 了解tRNA变异效应对于理解翻译忠实性和潜在的疾病机制至关重要.
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