scholarly journals Identification of Compounds Targeting Hepatitis B Virus Core Protein Dimerization through a Split Luciferase Complementation Assay

2018 ◽  
Vol 62 (12) ◽  
Author(s):  
Xia-Fei Wei ◽  
Chun-Yang Gan ◽  
Jing Cui ◽  
Ying-Ying Luo ◽  
Xue-Fei Cai ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Protein Interactions ◽  
Core Protein ◽  
Cell Model ◽  
Protein Protein Interactions ◽  
B Virus ◽  
Split Luciferase Complementation ◽  
Split Luciferase

ABSTRACTThe capsid of the hepatitis B virus is an attractive antiviral target for developing therapies against chronic hepatitis B infection. Currently available core protein allosteric modulators (CpAMs) mainly affect one of the two major types of protein-protein interactions involved in the process of capsid assembly, namely, the interaction between the core dimers. Compounds targeting the interaction between two core monomers have not been rigorously screened due to the lack of screening models. We report here a cell-based assay in which the formation of core dimers is indicated by split luciferase complementation (SLC). Making use of this model, 2 compounds, Arbidol (umifenovir) and 20-deoxyingenol, were identified from a library containing 672 compounds as core dimerization regulators. Arbidol and 20-deoxyingenol inhibit the hepatitis B virus (HBV) DNA replicationin vitroby decreasing and increasing the formation of core dimer and capsid, respectively. Our results provided a proof of concept for the cell model to be used to screen new agents targeting the step of core dimer and capsid formation.

scholarly journals Phosphorylation of hepatitis B virus Cp at Ser87 facilitates core assembly

2006 ◽  
Vol 398 (2) ◽  
pp. 311-317 ◽  
Author(s):  
Hee Yong Kang ◽  
Seungkeun Lee ◽  
Sung Gyoo Park ◽  
Jaehoon Yu ◽  
Youngsoo Kim ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Protein Kinase ◽  
Hepatitis B ◽  
Protein Interactions ◽  
Present Report ◽  
Protein Protein Interactions ◽  
B Virus ◽  
Dimeric Form ◽  
Genome Encapsidation

Protein–protein interactions can be regulated by protein modifications such as phosphorylation. Some of the phosphorylation sites (Ser155, Ser162 and Ser170) of HBV (hepatitis B virus) Cp have been discovered and these sites are implicated in the regulation of viral genome encapsidation, capsid localization and nucleocapsid maturation. In the present report, the dimeric form of HBV Cp was phosphorylated by PKA (protein kinase A), but not by protein kinase C in vitro, and the phosphorylation of dimeric Cp facilitated HBV core assembly. Matrix-assisted laser-desorption ionization–time-of-flight analysis revealed that the HBV Cp was phosphorylated at Ser87 by PKA. This was further confirmed using a mutant HBV Cp with S87G mutation. The S87G mutation inhibited the phosphorylation and, as a result, the in vitro HBV core assembly was not facilitated by PKA. In addition, when either pCMV/FLAG–Core(WT) or pCMV/FLAG–Core(S87G) was transfected into HepG2 cells, few mutant Cps (S87G) assembled into capsids compared with the wild-type (WT) Cps, although the same level of total Cps was expressed in both cases. In conclusion, PKA facilitates HBV core assembly through phosphorylation of the HBV Cp at Ser87.

Phosphorylation of hepatitis B virus core C-terminally truncated protein (Cp149) by PKC increases capsid assembly and stability

2008 ◽  
Vol 416 (1) ◽  
pp. 47-54 ◽  
Author(s):  
Hang Kang ◽  
Jaehoon Yu ◽  
Guhung Jung
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Core Protein ◽  
Virus Titre ◽  
Capsid Assembly ◽  
Human Hepatoma Cells ◽  
Virus Core ◽  
C Terminus ◽  
B Virus

The HBV (hepatitis B virus) core is a phosphoprotein whose assembly, replication, encapsidation and localization are regulated by phosphorylation. It is known that PKC (protein kinase C) regulates pgRNA (pregenomic RNA) encapsidation by phosphorylation of the C-terminus of core, which is a component packaged into capsid. Neither the N-terminal residue phosphorylated by PKC nor the role of the C-terminal phosphorylation have been cleary defined. In the present study we found that HBV Cp149 (core protein C-terminally truncated at amino acid 149) expressed in Escherichia coli was phosphorylated by PKC at Ser106. PKC-mediated phosphorylation increased core affinity, as well as assembly and capsid stability. In vitro phosphorylation with core mutants (S26A, T70A, S106A and T114A) revealed that the Ser106 mutation inhibited phosphorylation of core by PKC. CD analysis also revealed that PKC-mediated phosphorylation stabilized the secondary structure of capsid. When either pCMV/FLAG-Cp149[WT (wild-type)] or pCMV/FLAG-S106A Cp149 was transfected into Huh7 human hepatoma cells, mutant capsid level was decreased by 2.06-fold with the S106A mutant when compared with WT, although the same level of total protein was expressed in both cases. In addition, when pUC1.2x and pUC1.2x/S106A were transfected, mutant virus titre was decreased 2.31-fold compared with WT virus titre. In conclusion, PKC-mediated phosphorylation increased capsid assembly, stability and structural stability.

Transbody against hepatitis B virus core protein inhibits hepatitis B virus replication in vitro

2015 ◽  
Vol 25 (2) ◽  
pp. 363-369 ◽  
Author(s):  
Yawen Wang ◽  
Yiping Li ◽  
Na Li ◽  
Qianqian Zhu ◽  
Lingyun Hui ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Virus Replication ◽  
Core Protein ◽  
Virus Core ◽  
B Virus

scholarly journals A Novel Pyridazinone Derivative Inhibits Hepatitis B Virus Replication by Inducing Genome-Free Capsid Formation

2015 ◽  
Vol 59 (11) ◽  
pp. 7061-7072 ◽  
Author(s):  
Ya-Juan Wang ◽  
Dong Lu ◽  
Yi-Bin Xu ◽  
Wei-Qiang Xing ◽  
Xian-Kun Tong ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Core Protein ◽  
Cell Model ◽  
Morphological Changes ◽  
Gradient Centrifugation ◽  
Hbv Dna ◽  
Capsid Formation ◽  
B Virus ◽  
Cell Model System

ABSTRACTHere we first identified a novel pyridazinone derivative, compound 3711, as a nonnucleosidic hepatitis B virus (HBV) inhibitor in a cell model system. 3711 decreased extracellular HBV DNA levels by 50% (50% inhibitory concentration [IC50]) at 1.5 ± 0.2 μM and intracellular DNA levels at 1.9 ± 0.1 μM, which demonstrated antiviral activity at levels far below those associated with toxicity. Both the 3TC/ETV dually resistant L180M/M204I mutant and the adefovir (ADV)-resistant A181T/N236T mutant were as susceptible to 3711 as wild-type HBV. 3711 treatment induced the formation of genome-free capsids, a portion of which migrated faster on 1.8% native agarose gel. The induced genome-free capsids sedimented more slowly in isopycnic CsCl gradient centrifugation without significant morphological changes. 3711 treatment decreased levels of HBV DNA contained in both secreted enveloped virion and naked virus particles in supernatant. 3711 could interfere with capsid formation of the core protein (Cp) assembly domain. A Cp V124W mutant, which strengthens capsid interdimer interactions, recapitulated the effect of 3711 on capsid assembly. Pyridazinone derivative 3711, a novel chemical entity and HBV inhibitor, may provide a new opportunity to combat chronic HBV infection.

The pregenome/C RNA of duck hepatitis B virus is not used for translation of core protein during the early phase of infection in vitro

2015 ◽  
Vol 196 ◽  
pp. 13-19 ◽  
Author(s):  
Qiang Liu ◽  
Juan Huang ◽  
Renyong Jia ◽  
Mingshu Wang ◽  
Dekang Zhu ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Early Phase ◽  
Core Protein ◽  
Duck Hepatitis B Virus ◽  
Duck Hepatitis ◽  
B Virus

scholarly journals Synergistic Interactions between Hepatitis B Virus RNase H Antagonists and Other Inhibitors

2016 ◽  
Vol 61 (3) ◽  
Author(s):  
Elena Lomonosova ◽  
Adam Zlotnick ◽  
John E. Tavis
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Core Protein ◽  
Index Theorem ◽  
Rnase H ◽  
Mass Action ◽  
Significant Activity ◽  
B Virus ◽  
Mass Action Law

ABSTRACT Combination therapies are standard for management of human immunodeficiency virus (HIV) and hepatitis C virus (HCV) infections; however, no such therapies are established for human hepatitis B virus (HBV). Recently, we identified several promising inhibitors of HBV RNase H (here simply RNase H) activity that have significant activity against viral replication in vitro. Here, we investigated the in vitro antiviral efficacy of combinations of two RNase H inhibitors with the current anti-HBV drug nucleoside analog lamivudine, with HAP12, an experimental core protein allosteric modulator, and with each other. Anti-HBV activities of the compounds were tested in a HepG2-derived cell line by monitoring intracellular core particle DNA levels, and cytotoxicity was assessed by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay. The antiviral efficiencies of the drug combinations were evaluated using the median-effect equation derived from the mass-action law principle and combination index theorem of Chou and Talalay. We found that combinations of two RNase H inhibitors from different chemical classes were synergistic with lamivudine against HBV DNA synthesis. Significant synergism was also observed for the combination of the two RNase H inhibitors. Combinations of RNase H inhibitors with HAP12 had additive antiviral effects. Enhanced cytotoxicity was not observed in the combination experiments. Because of these synergistic and additive effects, the antiviral activity of combinations of RNase H inhibitors with drugs that act by two different mechanisms and with each other can be achieved by administering the compounds in combination at doses below the respective single drug doses.

scholarly journals Antiviral Properties and Mechanism of Action Studies of the Hepatitis B Virus Capsid Assembly Modulator JNJ-56136379

2020 ◽  
Vol 64 (5) ◽  
Author(s):  
Jan Martin Berke ◽  
Pascale Dehertogh ◽  
Karen Vergauwen ◽  
Wendy Mostmans ◽  
Koen Vandyck ◽  
...  
Keyword(s):  
Life Cycle ◽  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Core Protein ◽  
Hbv Dna ◽  
Size Exclusion ◽  
Capsid Assembly ◽  
Phase Ii Trials ◽  
B Virus

ABSTRACT Capsid assembly is a critical step in the hepatitis B virus (HBV) life cycle, mediated by the core protein. Core is a potential target for new antiviral therapies, the capsid assembly modulators (CAMs). JNJ-56136379 (JNJ-6379) is a novel and potent CAM currently in phase II trials. We evaluated the mechanisms of action (MOAs) and antiviral properties of JNJ-6379 in vitro. Size exclusion chromatography and electron microscopy studies demonstrated that JNJ-6379 induced the formation of morphologically intact viral capsids devoid of genomic material (primary MOA). JNJ-6379 accelerated the rate and extent of HBV capsid assembly in vitro. JNJ-6379 specifically and potently inhibited HBV replication; its median 50% effective concentration (EC50) was 54 nM (HepG2.117 cells). In HBV-infected primary human hepatocytes (PHHs), JNJ-6379, when added with the viral inoculum, dose-dependently reduced extracellular HBV DNA levels (median EC50 of 93 nM) and prevented covalently closed circular DNA (cccDNA) formation, leading to a dose-dependent reduction of intracellular HBV RNA levels (median EC50 of 876 nM) and reduced antigen levels (secondary MOA). Adding JNJ-6379 to PHHs 4 or 5 days postinfection reduced extracellular HBV DNA and did not prevent cccDNA formation. Time-of-addition PHH studies revealed that JNJ-6379 most likely interfered with postentry processes. Collectively, these data demonstrate that JNJ-6379 has dual MOAs in the early and late steps of the HBV life cycle, which is different from the MOA of nucleos(t)ide analogues. JNJ-6379 is in development for chronic hepatitis B treatment and may translate into higher HBV functional cure rates.

scholarly journals Hepatitis B virus upregulates host microRNAs that target apoptosis-regulatory genes in an in vitro cell model

2018 ◽  
Vol 371 (1) ◽  
pp. 92-103 ◽  
Author(s):  
Kirstine Overgaard Nielsen ◽  
Kari Stougaard Jacobsen ◽  
Aashiq Hussain Mirza ◽  
Thilde Nordmann Winther ◽  
Joachim Størling ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Cell Model ◽  
Regulatory Genes ◽  
B Virus

scholarly journals Intracellular Distribution of Hepatitis B Virus Core Protein Expressed In Vitro Depends on the Sequence of the Isolate and the Serologic Pattern

2004 ◽  
Vol 189 (9) ◽  
pp. 1634-1645 ◽  
Author(s):  
Mohammed S. Jazayeri ◽  
Edward S. Dornan ◽  
Winifred Boner ◽  
Giovanna Fattovich ◽  
Stephanos Hadziyannis ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Core Protein ◽  
Intracellular Distribution ◽  
Virus Core ◽  
B Virus
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