Agol V I
Chumakov Institute of Poliomyelitis and Virus Encephalites, Russian Academy of Medical Sciences, and, Moscow State University, Moscow, Russia.
Mol Biol. 2001;35(4):591-599. doi: 10.1023/A:1010531228348.
Picornaviruses are small animal viruses with positive-strand genomic RNA, which is translated using cap-independent internal translation initiation. The key role in this is played by elements of the 5"-untranslated region (5"-UTR) and, in particular, by the internal ribosome entry site (IRES). The function of translational elements requires both canonical translation initiation factors (eIFs) and additional IRES -acting factors (ITAFs). All known ITAFs are cell RNA-binding proteins which play a variety of functions in noninfected cells. Specific features of translational elements substantially affect the phenotype and, in particular, tissue tropism and pathogenic properties of picornaviruses. It is clear that, in some cases, the molecular mechanism involved is a change in interactions between viral elements and ITAFs. The properties and tissue distribution of ITAFs may determine the biological properties of other viruses that also use the IRES-dependent translation initiation. Since this mechanism is also involved in translation of several cell mRNAs, ITAF may contribute to the regulation of the most important aspects of the living activity in noninfected cells.
小核糖核酸病毒是一类具有正链基因组RNA的小型动物病毒，其通过不依赖帽子结构的内部翻译起始进行翻译。在这一过程中，5’非翻译区（5’-UTR）的元件，特别是内部核糖体进入位点（IRES）发挥着关键作用。翻译元件的功能既需要经典的翻译起始因子（eIFs），也需要额外的IRES作用因子（ITAFs）。所有已知的ITAFs都是细胞RNA结合蛋白，它们在未感染的细胞中发挥着多种功能。翻译元件的特定特征会显著影响小核糖核酸病毒的表型，尤其是组织嗜性和致病特性。很明显，在某些情况下，涉及的分子机制是病毒元件与ITAFs之间相互作用的改变。ITAFs的特性和组织分布可能决定其他也使用IRES依赖性翻译起始的病毒的生物学特性。由于这一机制也参与了几种细胞mRNA的翻译，ITAF可能有助于调节未感染细胞中生命活动的最重要方面。
