《生命科学》 2024, 36(3): 291-301

eIF4A在帽依赖和IRES介导的翻译起始中的作用

郭可盈 , 周　杰^*

浙江大学生命科学研究院，杭州 310058

摘　要：

生物体内翻译起始机制分为两类：帽依赖性翻译起始和内部核糖体进入位点(internal ribosome entry sites, IRES) 介导的翻译起始。真核生物的翻译起始为经典的帽依赖性翻译起始模型，而大多数正链RNA 病毒选择依赖于IRES 的翻译机制。真核翻译起始因子4A (eukaryotic initiation factor 4A, eIF4A) 是DEAD-box RNA 解旋酶家族的成员，具有依赖于RNA 的ATP 酶活性和RNA 解旋酶活性，而eIF4A 具体的解旋机制至今仍不清晰。同时，eIF4A 与其他翻译因子有着复杂而紧密的联系，在帽依赖性与IRES 介导的翻译起始过程中扮演着至关重要的角色。本文主要对eIF4A 的功能、结构以及eIF4A 在帽依赖性与IRES介导的翻译起始过程中的机制作一综述。

通讯作者：周　杰 , Email:jiezh@zju.edu.cn

The role of eIF4A in cap- and IRES-dependent translation initiation

GUO Ke-Ying , ZHOU Jie^*

Life Sciences Institute, Zhejiang University, Hangzhou 310058, China

Abstract:

In biological systems, there are two primary translation initiation mechanisms: cap-dependent translation initiation and internal ribosome entry sites (IRES)-mediated translation initiation. Cap-dependent translation initiation is the classical model in eukaryotic organisms, while most positive-strand RNA viruses employ an IRESdependent translation mechanism. The eukaryotic initiation factor 4A (eIF4A), a member of the DEAD-box RNA helicase family, features RNA-dependent ATPase and RNA helicase activities, yet the specific unwinding mechanism of eIF4A remains unclear. Additionally, eIF4A engages in complex and close interactions with other eukaryotic initiation factors, playing a key role in both cap-dependent and IRES-mediated translation initiation processes. This article primarily reviews the functions and structures of eIF4A, and the mechanisms of eIF4A in cap-dependent and IRES-mediated translation initiation.

Communication Author：ZHOU Jie , Email:jiezh@zju.edu.cn