Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, pr. Lavrentieva, 8, 630090 Novosibirsk, Russia; Department of Natural Sciences, Novosibirsk State University, ul. Pirogova, 2, 630090 Novosibirsk, Russia.
Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, pr. Lavrentieva, 8, 630090 Novosibirsk, Russia.
Biochimie. 2014 Apr;99:8-18. doi: 10.1016/j.biochi.2013.11.001. Epub 2013 Nov 13.
Ribosomal proteins from the S3 family are universal components of small ribosomal subunits in all three domains of life. In eukaryotes, ribosomal protein S3e (rpS3e) is one of 33 proteins of small subunit of the ribosome. It functions not only within the ribosome participating in translation but also as an extraribosomal player involved in a number of vitally important cellular events. RpS3e is directly implicated in translation initiation via participation in rearrangements of the small subunit structure occurring upon the binding of initiation factors eIF1 and eIF1A, which opens the ribosomal mRNA binding channel for incoming mRNA and allows scanning. Being located at the mRNA entry site of the ribosome, rpS3e is suggested to interact with mRNA part downstream of the codon at the decoding site and it could be implicated in helicase activity of the ribosome by analogy to its bacterial counterpart rpS3p. Extraribosomal functions of rpS3e are mainly based on its ability to bind to nucleic acids, although protein-protein interactions take place too. As an independent player, rpS3e is involved in DNA repair, selective gene regulation via implication in NF-κB signaling pathway, inducing apoptosis, control of expression of the own gene at the translation level and molecular interactions affecting half-life of the protein. Involvement of rpS3e in various cellular processes is mediated by specific mechanisms utilizing post-translational modifications of the protein. Here, we present accumulated to date information and current ideas concerning functions of rpS3e as a constituent of translational machinery and of the free protein as a key player in various events of the cell life.
核糖体蛋白 S3 家族是所有三个生命领域中小核糖体亚基的通用成分。在真核生物中，核糖体蛋白 S3e (rpS3e) 是核糖体小亚基的 33 种蛋白质之一。它不仅在核糖体中参与翻译，而且作为一种游离核糖体的参与者，参与许多至关重要的细胞事件。RpS3e 通过参与结合起始因子 eIF1 和 eIF1A 时小亚基结构的重排，直接参与翻译起始，这打开了核糖体 mRNA 结合通道，允许 mRNA 进入并进行扫描。由于位于核糖体的 mRNA 入口处，rpS3e 被认为与密码子下游的 mRNA 部分相互作用，并且可以通过类比其细菌对应物 rpS3p 来参与核糖体的解旋酶活性。RpS3e 的游离核糖体功能主要基于其与核酸结合的能力，尽管也发生蛋白质-蛋白质相互作用。作为一个独立的参与者，rpS3e 参与 DNA 修复、通过参与 NF-κB 信号通路的选择性基因调节、诱导细胞凋亡、控制翻译水平自身基因的表达以及影响蛋白质半衰期的分子相互作用。rpS3e 参与各种细胞过程是通过利用蛋白质的翻译后修饰来介导的。在这里，我们介绍了迄今为止积累的有关 rpS3e 作为翻译机制组成部分的功能以及游离蛋白作为细胞生命中各种事件的关键参与者的信息和当前观点。
