Effects of the Sabin-like mutations in domain V of the internal ribosome entry segment on translational efficiency of the Coxsackievirus B3
Effects of the Sabin-like mutations in domain V of the internal ribosome entry segment on translational efficiency of the Coxsackievirus B3
复制标题
DOI：
10.1007/s00438-006-0155-3
复制
发表时间：
2006-10-01
影响因子：
3.1
通讯作者：
Kean, Katherine M.
中科院分区：
文献类型：
--
作者：
Ben M'hadheb-Gharbi, Manel;Gharbi, Jawhar;Kean, Katherine M.
脊髓灰质炎病毒 (PV) 内部核糖体进入片段 (IRES) 内的结构域 V 预计对其自身的神经毒力很重要，因为它在每种萨宾疫苗株中都包含减毒突变。在这项研究中，我们试图找出在PV Sabin疫苗株中观察到的结果是否可以推断到属于同一肠道病毒属但具有不同向性的另一种病毒。为了检验这一假设，我们使用了柯萨奇病毒 B3 (CVB3)，它是病毒性心肌炎最常见的病原体。在 CVB3 IRES 结构域 V 的等效位置（核苷酸 484、485 和 473）引入三个 PV Sabin 样突变会导致 Sabin3 样突变体（Sab3 样）的病毒滴度显着降低，但 Sab1 和 Sab2 样突变体的病毒滴度不会显着降低。当所有突变体在兔网织红细胞裂解物中翻译时，这种低效价与体外翻译效率差相关。然而，通过生物化学探测对Sabin样突变体的IRES的整个结构域V的二级结构进行的阐明并未揭示与野生型对应物相比没有明显的特征。 MFOLD 程序对二级结构的预测表明含有 Sab3 样突变的茎的结构扰动，表明特定的蛋白质-病毒 RNA 相互作用被破坏，从而阻止了有效的病毒翻译。
The domain V within the internal ribosome entry segment (IRES) of poliovirus (PV) is expected to be important in its own neurovirulence because it contains an attenuating mutation in each of the Sabin vaccine strains. In this study, we try to find out if the results observed in the case of Sabin vaccine strains of PV can be extrapolated to another virus belonging to the same genus of enteroviruses but with a different tropism. To test this hypothesis, we used the coxsackievirus B3 (CVB3), known to be the most common causal agent of viral myocarditis. The introduction of the three PV Sabin-like mutations in the equivalent positions (nucleotides 484, 485, and 473) to the domain V of the CVB3 IRES results in significant reduced viral titer of the Sabin3-like mutant (Sab3-like) but not on those of Sab1- and Sab2-like mutants. This low titer was correlated with poor translation efficiency in vitro when all mutants were translated in rabbit reticulocyte lysates. However, elucidation by biochemical probing of the secondary structure of the entire domain V of the IRES of Sabin-like mutants reveals no distinct proWles in comparison with the wild-type counterpart. Prediction of secondary structure by MFOLD program indicates a structural perturbation of the stem containing the Sab3-like mutation, suggesting that specific protein-viral RNA interactions are disrupted, preventing efficient viral translation.