翻译的重叠开放的读取框架促进的2型IRES在鸟类病毒基因组
Yani Arhab1, Tatyana V Pestova1, Christopher U T Hellen1
1Department of Cell Biology, SUNY Downstate Health Sciences University, Brooklyn, NY 11203, USA.
Viruses
|September 28, 2024
概括
鸟类病毒具有独特的内部核糖体进入点 (IRES),使其能够独立于帽子的翻译. 这些IRES在新的上游ORF (uORF) 和主要ORF中启动转换,由特定的IRES转换作用因子 (ITAF) 调节.
科学领域:
- 病毒学 病毒学
- 分子生物学分子生物学
- 遗传学 遗传学 是一个
背景情况:
- 卡利西病毒通常具有短5'UTR,但一些鸟类菌株具有长5'UTR,具有类似皮科纳病毒的内部核糖体进入点 (IRES).
- 这些IRES被认为是通过横向基因转移获得的,这代表了病毒基因表达的不寻常机制.
研究的目的:
- 调查IRES在禽类病毒中的患病率和功能.
- 描述由这些IRES调解的翻译启动机制,包括识别新型开放阅读框架 (ORF) 和特定蛋白质因子的作用.
主要方法:
- 基因组分析以识别含有IRES和上游ORF (ORF1*) 的鸟类calicivirus基因组.
- 在体外翻译试验以确认IRES活动.
- 脚印测试以确定核糖体结合部位和启动密码的使用.
- 对参与转化启动的真核细胞启动因子 (eIF) 和IRES转作用因子 (ITAF) 的分析.
主要成果:
- 确定了许多具有2型IRES的鸟类病毒基因组,其中许多含有上游ORF (ORF1*),重叠于主ORF1.
- 在体外翻译证实了代表性2型IRESs的活性.
- 在IRES下游的ORF1*启动和ORF1内部组装的核糖体启动复合体.
- 所有地点的启动都需要特定的eIF (eIF4A,eIF4G,eIF1/eIF1A),并通过ITAF (Ebp1/ITAF45,PTB或PCBP2) 增强.
结论:
- 鸟类卡利西病毒利用IRES介导的翻译启动,允许独立于帽子的表达.
- 已识别的IRES在新的上游ORF (ORF1*) 和主要ORF1中促进翻译启动,扩大病毒基因组的编码能力.
- 特定的ITAF在调节IRES驱动的翻译方面发挥着至关重要的作用,突出了病毒蛋白合成的复杂监管机制.
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