Parvulin 14和Parvulin 17结合HBx和cccDNA并以HBx依赖性方式上调HBV从c

StephenW

Parvulin 14 and Parvulin 17 bind HBx and cccDNA and up-regulate HBV replication from cccDNA to virion in a HBx-dependent manner
Umar Saeed, Jumi Kim, Zahra Zahid Piracha, Hyeonjoong Kwon, Jaesung Jung, Yong-Joon Chwae, Sun Park, Ho-Joon Shin, Kyongmin Kim
J.-H. James Ou, editor
DOI: 10.1128 / JVI.01840-18


abstract

The parvulin 14 (Par14) and parvulin 17 (Par17) proteins encoded by the PIN4 gene play a role in protein folding, chromatin remodeling, DNA binding, ribosomal biogenesis and cell cycle progression. However, the effects of Par14 and Par17 on viral replication have never been explored. In the present study, we found that in the presence of HBx, Par14 or Par17 upregulates hepatitis B virus (HBV) replication, whereas in the absence of HBx, neither Par14 nor Par17 would have any effect on replication. Overexpression of Par14/Par17 significantly increased the formation of covalently closed circular DNA (cccDNA), the synthesis of HBV RNA and DNA, and the secretion of virions. In contrast, PIN4 knockdown significantly reduced HBV replication in HBV transfected and infected cells. Co-immunoprecipitation showed that Par14/Par17 interacted directly with HBx in cytoplasm, nucleus and mitochondria, possibly mediated by substrate binding residues on Par14/Par17 (E46 / D74 and E71 / D99, respectively) and conserved 19R20P-28R29P motif. On the HBx. In addition, these interactions enhance HBx stability, promote HBx translocation to the nuclear and mitochondrial parts, and increase HBV replication. Chromatin immunoprecipitation assays showed that Par14/Par17 was efficiently recruited to cccDNA in the presence of HBx and promoted transcriptional activation by specific DNA-binding residues (S19/44). In contrast, in the absence of HBx, Par14/Par17 binds cccDNA only at the basal level and does not promote transcriptional activation. In conclusion, our results demonstrate that Par14 and Par17 up-regulate HBV RNA transcription and DNA synthesis by forming a cccDNA-Par14/17-HBx complex, thereby increasing HBV cccDNA levels.

Importance HBx proteins play an important regulatory role in HBV replication. We found a substrate-binding residue on the human fine protein peptidyl-prolyl cis/trans isomerase proteins Par14 and Par17 and the arginine-proline (RP) motif conserved in the cytoplasm, nucleus and mitochondria in HBx Combine. The HBx-Par14/Par17 interaction stabilizes HBx; promotes its translocation to the nucleus and mitochondria; and stimulates multiple steps of HBV replication, including cccDNA formation, HBV RNA and DNA synthesis, and virion secretion. Furthermore, Par14 and Par17 proteins bind to cccDNA and promote transcriptional activation in the presence of HBx. Our results indicate that inhibition or knockdown of Par14 and Par17 may represent a novel therapeutic option for HBV infecti

StephenW

Parvulin 14和Parvulin 17结合HBx和cccDNA并以HBx依赖性方式上调HBV从cccDNA到病毒粒子的复制
Umar Saeed，Jumi Kim，Zahra Zahid Piracha，Hyeonjoong Kwon，Jaesung Jung，Yong-Joon Chwae，Sun Park，Ho-Joon Shin，Kyongmin Kim
J.-H. James Ou，编辑
DOI：10.1128 / JVI.01840-18


抽象

由PIN4基因编码的parvulin 14（Par14）和parvulin 17（Par17）蛋白在蛋白质折叠，染色质重塑，DNA结合，核糖体生物发生和细胞周期进程中起作用。然而，Par14和Par17对病毒复制的影响从未被探索过。在本研究中，我们发现在HBx存在时，Par14或Par17上调乙型肝炎病毒（HBV）复制，而在没有HBx的情况下，Par14和Par17都不会对复制产生任何影响。 Par14 / Par17的过表达显着增加了共价闭合环状DNA（cccDNA）的形成，HBV RNA和DNA的合成以及病毒粒子的分泌。相反，PIN4敲低显着降低了HBV转染和感染细胞中的HBV复制。共免疫沉淀显示Par14 / Par17与细胞质，细胞核和线粒体中的HBx直接相互作用，可能由Par14 / Par17上的底物结合残基（分别为E46 / D74和E71 / D99）和保守的19R20P-28R29P基序介导。在HBx上。此外，这些相互作用增强HBx稳定性，促进HBx易位至核和线粒体部分，并增加HBV复制。染色质免疫沉淀测定显示Par14 / Par17在HBx存在下有效募集到cccDNA，并通过特异性DNA结合残基促进转录激活（S19 / 44）。相反，在没有HBx的情况下，Par14 / Par17仅在基础水平上结合cccDNA并且不促进转录激活。总之，我们的结果表明Par14和Par17通过形成cccDNA-Par14 / 17-HBx复合物上调HBV RNA转录和DNA合成，从而增加HBV cccDNA水平。

重要性HBx蛋白在HBV复制中起重要的调节作用。我们在人类细蛋白肽 - 脯氨酰顺/反异构酶蛋白Par14和Par17上发现了底物结合残基，并且在HBx Combine的细胞质，细胞核和线粒体中保守了精氨酸 - 脯氨酸（RP）基序。 HBx-Par14 / Par17相互作用稳定了HBx;促进其向细胞核和线粒体的易位;并刺激HBV复制的多个步骤，包括cccDNA形成，HBV RNA和DNA合成以及病毒粒子分泌。此外，Par14和Par17蛋白与cccDNA结合并在HBx存在下促进转录激活。我们的结果表明Par14和Par17的抑制或敲低可能代表HBV感染的新治疗选择。