HBV前基因组RNA 5′端Epsilon结构的功能研究进展

Function of the Epsilon stem loop in HBV pre-genomic RNA

慢性乙型肝炎病毒(hepatitis B virus, HBV)感染是乙型肝炎、肝纤维化和肝细胞癌等疾病的重要病因。HBV的生命周期中存在着独特的逆转录过程,在这一过程中HBV前基因组RNA(pre-genomic RNA,pgRNA)发挥着极其重要的作用。pgRNA不仅是病毒逆转录的模板,还可作为mRNA翻译产生核心蛋白和聚合酶(P)蛋白。HBV pgRNA 5′端存在一特殊的茎环结构,被命名为Epsilon(ε)。研究发现,ε结构不仅能启动pgRNA衣壳化、激活P蛋白并启动HBV逆转录,其自身还能形成特异性核酶在肝细胞内发挥作用。ε结构有望成为有潜力的抗病毒药物靶点。本文旨在对ε结构特点及功能的研究进展进行综述。

Human hepatitis B virus(HBV) is an important cause of viral hepatitis, liver fibrosis and hepato-cellular carcinoma. Reverse transcription is a key process in HBV life cycle, in which pre-genomic RNA(pgRNA) plays a critical role. pgRNA is not only the template for translation of the HBV core protein and polymerase protein but also the key to initiating virus assembly and reverse transcription. There is a special stem loop structure at the 5′ end of HBV pgRNA, which is named Epsilon. After synthesis, HBV polymerase can recognize and bind to Epsilon to start the assembly of the virus capsid and reverse transcription to form mature progeny viruses which release from cells later.The Epsilon stem loop can initiate pgRNA encapsidation, activate the P protein, start HBV reverse transcription as well as to form a specific ribozyme. This review aims to conclude the functional research progress of the HBV pgRNA Epsilon structure.