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艾滋病毒-1单个转录起点突变体表现出互补的复制功能,这些功能通过逆转恢复

K Gc¹, S Lesko², A Emery³

¹Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA.

bioRxiv : the preprint server for biology

|December 16, 2024

概括

人类免疫缺陷病毒1型 (HIV-1) 使用两个转录起点,产生不同的RNA 5'端. 虽然两者都可以作为mRNA和基因组RNA发挥作用,但cap3G形式显示了复制缺陷,突显了双重转录起点使用对高效的HIV-1复制的重要性.

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:

艾滋病毒-1转录始于两个不同的位置,产生具有cap1G或cap3G5'末端的RNA.
这些RNA异型具有不同的复制命运:cap1GRNAs优先被包装成病毒颗粒,而cap3GRNAs留在细胞中,富含在多体和结合的病毒RNA中.

研究的目的:

研究仅产生cap1G或cap3GRNA异型的HIV-1促进子突变的复制特性.
评估每个RNA异形单独和组合在病毒复制和传播感染期间的功能作用.

主要方法:

构建和分析产生单一RNA5'异型 (仅cap1G或仅cap3G) 的HIV-1促进子突变.
评估RNA翻译,拼接和包装效率.
在细胞系 (MT-4) 和人类CD4+T细胞中评估病毒复制动力学,包括在传播感染期间.

主要成果:

当cap1G和cap3GRNA作为唯一形式存在时,它们可以作为mRNA和基因组RNA发挥作用.
cap3G RNA表现出更高效的翻译和拼接,而cap1G RNA显示出稍微更好的包装成新生的病毒.
只有cap3G的病毒在允许细胞和初级细胞中表现出严重的复制延迟,而只有cap1G的病毒显示出轻微的缺陷. 只有cap3G病毒的穿越导致恢复双重转录起点使用和复制效率恢复的复原体.

结论:

虽然这两种RNA异型都能支持病毒复制,但cap3G异型在体内效率较低,导致仅生产时的复制延迟.
cap1G RNA的优惠包装和cap3G RNA的高效翻译/拼接有助于野生型HIV-1的整体适应性.
在复原体中恢复双重转录起点的使用,强调了两种异构体对于最佳的HIV-1复制和发病的重要性.

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