蛋白磷酸酶1催化HBV核心蛋白去磷酸化，并与病毒前基因组RNA

StephenW

Protein phosphatase 1 catalyzes HBV core protein dephosphorylation and is co-packaged with viral pregenomic RNA into nucleocapsids
Zhanying Hu  1 , Haiqun Ban  1 , Haiyan Zheng  2 , Mingliang Liu  3 , Jinhong Chang  1 , Ju-Tao Guo  1
Affiliations
Affiliations

    1
    Department of Experimental Medicine, Baruch S. Blumberg Institute, Doylestown, Pennsylvania, United States of America.
    2
    Biological mass spectrometry facility, Robert Wood Johnson Medical School and Rutgers, The State University of New Jersey. Piscataway, New Jersey, United States of America.
    3
    Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Tian-Tan Xi-Li, Beijing, China.

    PMID: 32702076 DOI: 10.1371/journal.ppat.1008669

Abstract

Hepatitis B virus (HBV) replicates its genomic DNA via viral DNA polymerase self-primed reverse transcription of a RNA pre-genome in the nucleocapsid assembled by 120 core protein (Cp) dimers. The arginine-rich carboxyl-terminal domain (CTD) of Cp plays an important role in the selective packaging of viral DNA polymerase-pregenomic (pg) RNA complex into nucleocapsid. Previous studies suggested that the CTD is initially phosphorylated at multiple sites to facilitate viral RNA packaging and subsequently dephosphorylated in association with viral DNA synthesis and secretion of DNA-containing virions. However, our recent studies suggested that Cp is hyper-phosphorylated as free dimers and its dephosphorylation is associated with pgRNA encapsidation. Herein, we provide further genetic and biochemical evidence supporting that extensive Cp dephosphorylation does take place during the assembly of pgRNA-containing nucleocapsids, but not empty capsids. Moreover, we found that cellular protein phosphatase 1 (PP1) is required for Cp dephosphorylation and pgRNA packaging. Interestingly, the PP1 catalytic subunits α and β were packaged into pgRNA-containing nucleocapsids, but not empty capsids, and treatment of HBV replicating cells with core protein allosteric modulators (CpAMs) promoted empty capsid assembly and abrogated the encapsidation of PP1 α and β. Our study thus identified PP1 as a host cellular factor that is co-packaged into HBV nucleocapsids, and plays an essential role in selective packaging of the viral DNA-polymerase-pgRNA complex through catalyzing Cp dephosphorylation.
Conflict of interest statement

JTG received research support and hold stock of Arbutus Biopharma, Inc. JC received research support from Arbutus Biopharma, Inc.

StephenW

蛋白磷酸酶1催化HBV核心蛋白去磷酸化，并与病毒前基因组RNA共包装到核衣壳中
胡占英1，海群版1，郑海燕2，刘明亮3，常金宏1，郭菊涛1
隶属关系
隶属关系

    1个
    美利坚合众国宾夕法尼亚州Doylestown的Baruch S. Blumberg研究所实验医学系。
    2
    罗伯特伍德·约翰逊医学院和新泽西州立大学罗格斯分校的生物质谱仪。美利坚合众国新泽西州皮斯卡塔维。
    3
    中国医学科学院北京协和医学院药物生物技术研究所，北京天坛西里

    PMID：32702076 DOI：10.1371 / journal.ppat.1008669

抽象

乙型肝炎病毒（HBV）通过病毒DNA聚合酶在120个核心蛋白（Cp）二聚体组装的核衣壳中RNA前基因组的自引发逆转录来复制其基因组DNA。 Cp的富含精氨酸的羧基末端结构域（CTD）在将病毒DNA聚合酶-前基因组（pg）RNA复合体选择性包装到核衣壳中起重要作用。先前的研究表明，CTD最初在多个位点被磷酸化以促进病毒RNA的包装，随后与病毒DNA的合成和含DNA的病毒粒子的分泌一起被去磷酸化。然而，我们最近的研究表明，Cp被过度磷酸化为游离二聚体，并且其去磷酸化与pgRNA衣壳化有关。本文中，我们提供了进一步的遗传和生化证据，证明在组装含pgRNA的核衣壳而不发生空衣壳的过程中确实发生了广泛的Cp去磷酸化。此外，我们发现细胞蛋白磷酸酶1（PP1）是Cp去磷酸化和pgRNA包装所必需的。有趣的是，PP1催化亚基α和β被包装到含pgRNA的核衣壳中，而不是空衣壳中，用核心蛋白变构调节剂（CpAM）处理HBV复制细胞促进了空衣壳组装并废除了PP1α和β的衣壳化。因此，我们的研究确定了PP1为宿主细胞因子，它被共同包装到HBV核衣壳中，并在通过催化Cp脱磷酸作用选择性包装病毒DNA-聚合酶-pgRNA复合物中起着至关重要的作用。
利益冲突声明

JTG获得了Arbutus Biopharma，Inc.的研究支持并持有股票。JC获得了Arbutus Biopharma，Inc.的研究支持。

StephenW

https://journals.plos.org/plospa ... ournal.ppat.1008669