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Basic Characteristics of Mutations
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Mutation Site
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G1896A |
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Mutation Site Sentence
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It is reported that the hepatitis B e antigen (HBeAg) can interfere with NF-kappaB activity, which then leads to high viral loads, while HBV with the G1896A mutation remains infectious without the production of HBeAg but can induce more severe proinflammatory response and liver damage. |
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Mutation Level
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Nucleotide level |
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Mutation Type
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Nonsense mutation |
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Gene/Protein/Region
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PreC |
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Standardized Encoding Gene
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C
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Genotype/Subtype
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- |
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Viral Reference
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-
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Functional Impact and Mechanisms
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Disease
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Liver Diseases
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Immune
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- |
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Target Gene
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IKBKG
NFKB1
TRAF6
IL1B
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Clinical and Epidemiological Correlations
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Clinical Information
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- |
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Treatment
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- |
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Location
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- |
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Literature Information
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PMID
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30404796
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Title
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Hepatitis B e Antigen Inhibits NF-kappaB Activity by Interrupting K63-Linked Ubiquitination of NEMO
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Author
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Wang Y,Cui L,Yang G,Zhan J,Guo L,Chen Y,Fan C,Liu D,Guo D
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Journal
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Journal of virology
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Journal Info
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2019 Jan 4;93(2):e00667-18
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Abstract
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Viruses have adopted diverse strategies to suppress antiviral responses. Hepatitis B virus (HBV), a virus that is prevalent worldwide, manipulates the host's innate immune system to evade scavenging. It is reported that the hepatitis B e antigen (HBeAg) can interfere with NF-kappaB activity, which then leads to high viral loads, while HBV with the G1896A mutation remains infectious without the production of HBeAg but can induce more severe proinflammatory response and liver damage. The aim of current work was to study the molecular mechanism by which HBeAg suppresses interleukin-1beta (IL-1beta)-stimulated NF-kappaB activity, which leads to the suppression of the innate immune responses to HBV infection. Our study revealed that HBeAg could interact with NEMO, a regulatory subunit associated with IkappaB kinase, which regulates the activation of NF-kappaB. HBeAg suppressed the IL-1beta-induced tumor necrosis factor (TNF)-associated factor 6 (TRAF6)-dependent K63-linked ubiquitination of NEMO, thereby downregulating NF-kappaB activity and promoting virus replication. We further demonstrated the inhibitory effect of HBeAg on the NF-kappaB signaling pathway using primary human hepatocytes, HBV-infected HepG2-NTCP cells, and clinical liver samples. Our study reveals a molecular mechanism whereby HBeAg suppresses IL-1beta-induced NF-kappaB activation by decreasing the TRAF6-dependent K63-linked ubiquitination of NEMO, which may thereby enhance HBV replication and promote a persistent infection.IMPORTANCE The role of HBeAg in inflammatory responses during the infection of hepatitis B virus (HBV) is not fully understood, and several previous reports with regard to the NF-kappaB pathway are controversial. In this study, we showed that HBeAg could suppress both Toll-like receptor 2 (TLR2)- and IL-1beta-induced activation of NF-kappaB in cells and clinical samples, and we further revealed novel molecular mechanisms. We found that HBeAg can associate with NEMO, the regulatory subunit for IkappaB kinase (IKK) that controls the NF-kappaB signaling pathway, and thereby inhibits TRAF6-mediated K63-linked ubiquitination of NEMO, resulting in downregulation of NF-kappaB activity and promotion of virus replication. In contrast, the HBeAg-negative HBV mutant can induce higher levels of NF-kappaB activity. These results are important for understanding the HBV-induced pathogenesis of chronic hepatitis and indicate that different clinical measures should be considered to treat HBeAg-positive and HBeAg-negative infections. Our findings represent a conceptual advance in HBV-related suppression of NF-kappaB signaling.
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Sequence Data
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-
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