MMTV RNA包装需要扩展的远程相互作用，以与包装信号结合生产性堵嘴
MMTV RNA packaging requires an extended long-range interaction for productive Gag binding to packaging signals
影响因子:7.20000
分区:生物学1区 Top / 生化与分子生物学1区 生物学1区
发表日期:2024 Oct
作者:
Suresha G Prabhu, Vineeta N Pillai, Lizna Mohamed Ali, Valérie Vivet-Boudou, Akhil Chameettachal, Serena Bernacchi, Farah Mustafa, Roland Marquet, Tahir A Rizvi
摘要
基因组RNA（GRNA）在逆转录病毒颗粒中的包装取决于包装信号（PSI）的GAG前体（PSI）的特定识别，该插入前体通过长期相互作用（LRIS）维持复杂的二级结构。但是，目前尚不清楚单独使用PSI与PSI的结合是否足以促进RNA包装以及LRI在此过程中的作用。使用小鼠乳腺肿瘤病毒（MMTV），我们研究了4个提出的LRI对GRNA结构和功能的突变的影响。我们的发现揭示了存在未使用的扩展LRI，HShape表明，保持野生型PSI结构对于有效的包装至关重要。出乎意料的是，滤波器结合测定表明，大多数突变体无论其包装能力如何，都表现出与PR77GAG的显着结合，这表明与PSI的GAG结合不足以有效包装。足迹实验表明，当PR77GAG与PSI内的2个特定位点结合时，促进了有效的RNA包装，而PSI中其他地方的结合不会导致有效的包装。综上所述，我们的结果表明，PSI/PR77GAG复合物的3D结构调节围绕GRNA的病毒颗粒组装，从而有效歧视其他病毒和细胞RNA，也可以有效地结合GAG。
Abstract
The packaging of genomic RNA (gRNA) into retroviral particles relies on the specific recognition by the Gag precursor of packaging signals (Psi), which maintain a complex secondary structure through long-range interactions (LRIs). However, it remains unclear whether the binding of Gag to Psi alone is enough to promote RNA packaging and what role LRIs play in this process. Using mouse mammary tumor virus (MMTV), we investigated the effects of mutations in 4 proposed LRIs on gRNA structure and function. Our findings revealed the presence of an unsuspected extended LRI, and hSHAPE revealed that maintaining a wild-type-like Psi structure is crucial for efficient packaging. Surprisingly, filter-binding assays demonstrated that most mutants, regardless of their packaging capability, exhibited significant binding to Pr77Gag, suggesting that Gag binding to Psi is insufficient for efficient packaging. Footprinting experiments indicated that efficient RNA packaging is promoted when Pr77Gag binds to 2 specific sites within Psi, whereas binding elsewhere in Psi does not lead to efficient packaging. Taken together, our results suggest that the 3D structure of the Psi/Pr77Gag complex regulates the assembly of viral particles around gRNA, enabling effective discrimination against other viral and cellular RNAs that may also bind Gag efficiently.