HBV core protein allosteric modulators differentially alter cccDNA biosynthesis from de novo infection and intracellular amplification pathways

PLoS Pathogens

Andrea Cuconati¹  Qiong Zhao²  Qing Su²  Ju-Tao Guo²  Jinhong Chang²  Fang Guo²  Junjun Cheng²  Yanming Du²  Lai Wei³  Muhammad Sheraz⁴  Yonghe Qi⁵  Wenhui Li⁵ 

[1] Arbutus Biopharma Inc., Doylestown, Pennsylvania, United States of America;Baruch S. Blumberg Institute, Doylestown, Pennsylvania, United States of America;Hepatology Institute, Peking University People’s Hospital, Beijing, China;Microbiology and Immunology graduate program, Drexel University College of Medicine, Philadelphia, Pennsylvania, United States of America;National Institute of Biological Sciences, Beijing, China

关键词: Nucleocapsids;    Capsids;    DNA hybridization;    Circular DNA;    Viral core;    Deoxyribonucleases;    DNA polymerase;    Virions;   

DOI  :  10.1371/journal.ppat.1006658

学科分类：生物科学（综合）

来源: Public Library of Science

【 摘 要 】

Hepatitis B virus (HBV) core protein assembles viral pre-genomic (pg) RNA and DNA polymerase into nucleocapsids for reverse transcriptional DNA replication to take place. Several chemotypes of small molecules, including heteroaryldihydropyrimidines (HAPs) and sulfamoylbenzamides (SBAs), have been discovered to allosterically modulate core protein structure and consequentially alter the kinetics and pathway of core protein assembly, resulting in formation of irregularly-shaped core protein aggregates or “empty” capsids devoid of pre-genomic RNA and viral DNA polymerase. Interestingly, in addition to inhibiting nucleocapsid assembly and subsequent viral genome replication, we have now demonstrated that HAPs and SBAs differentially modulate the biosynthesis of covalently closed circular (ccc) DNA from de novo infection and intracellular amplification pathways by inducing disassembly of nucleocapsids derived from virions as well as double-stranded DNA-containing progeny nucleocapsids in the cytoplasm. Specifically, the mistimed cuing of nucleocapsid uncoating prevents cccDNA formation during de novo infection of hepatocytes, while transiently accelerating cccDNA synthesis from cytoplasmic progeny nucleocapsids. Our studies indicate that elongation of positive-stranded DNA induces structural changes of nucleocapsids, which confers ability of mature nucleocapsids to bind CpAMs and triggers its disassembly. Understanding the molecular mechanism underlying the dual effects of the core protein allosteric modulators on nucleocapsid assembly and disassembly will facilitate the discovery of novel core protein-targeting antiviral agents that can more efficiently suppress cccDNA synthesis and cure chronic hepatitis B.

【 授权许可】

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