scholarly journals A Single Adaptive Mutation in Sodium Taurocholate Cotransporting Polypeptide Induced by Hepadnaviruses Determines Virus Species-specificity

2018 ◽  
Author(s):  
Junko S Takeuchi ◽  
Kento Fukano ◽  
Masashi Iwamoto ◽  
Senko Tsukuda ◽  
Ryosuke Suzuki ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Positive Selection ◽  
Sodium Taurocholate ◽  
Arms Race ◽  
Adaptive Mutation ◽  
Molecular Evidence ◽  
Adaptive Mutations ◽  
Wide Range ◽  
B Virus ◽  
Coevolutionary Arms Race

AbstractHepatitis B virus (HBV) and its hepadnavirus relatives infect a wide range of vertebrates from fish to human. Hepadnaviruses and their hosts have a long history of acquiring adaptive mutations. However, there are no reports providing direct molecular evidence for such a coevolutionary “arms race” between hepadnaviruses and their hosts. Here, we present evidence suggesting the adaptive evolution of the sodium taurocholate cotransporting polypeptide (NTCP), an HBV receptor, has been influenced by virus infection. Evolutionary analysis of the NTCP-encoding genes from 20 mammals showed that most NTCP residues are highly conserved among species, exhibiting evolution under negative selection (dN/dS < 1); this observation implies that the evolution of NTCP is restricted by maintaining its original protein function. However, 0.7 % of NTCP amino acid (aa) residues exhibit rapid evolution under positive selection (dN/dS > 1). Notably, a substitution at aa 158, a positively selected residue, converting the human NTCP to a monkey-type sequence abrogated the capacity to support HBV infection; conversely, a substitution at this residue converting the monkey Ntcp to the human sequence was sufficient to confer HBV susceptibility. Together, these observations suggested that positive selection at aa 158 was induced by virus infection. Moreover, the aa 158 sequence determined attachment of the HBV envelope protein to host cell, demonstrating the mechanism whereby HBV infection would create positive selection at this residue in NTCP. In summary, we provide the first evidence in agreement with the function of hepadnavirus as a driver for inducing an adaptive mutation in host receptor.ImportanceHepatitis B virus (HBV) and its hepadnavirus relatives infect a wide range of vertebrates, with a long infectious history (hundreds of millions of years). Such a long history generally allows adaptive mutations in hosts to escape from infection, while simultaneously allowing adaptive mutations in viruses to overcome host barriers. However, there is no published molecular evidence for such a coevolutionary “arms race” between hepadnaviruses and hosts. In the present study, we performed coevolutionary phylogenetic analysis between hepadnaviruses and the sodium taurocholate cotransporting polypeptide (NTCP), an HBV receptor, combined with virological experimental assays for investigating the biological significance of NTCP sequence variation. Our data provide the first molecular evidences supporting that HBV-related hepadnaviruses drive adaptive evolution in the NTCP sequence, including a mechanistic explanation of how NTCP mutations determine host viral susceptibility. Our novel insights enhance our understanding of how hepadnaviruses evolved with their hosts, permitting the acquisition of strong species-specificity.

scholarly journals A Single Adaptive Mutation in Sodium Taurocholate Cotransporting Polypeptide Induced by Hepadnaviruses Determines Virus Species Specificity

2018 ◽  
Vol 93 (5) ◽  
Author(s):  
Junko S. Takeuchi ◽  
Kento Fukano ◽  
Masashi Iwamoto ◽  
Senko Tsukuda ◽  
Ryosuke Suzuki ◽  
...  
Keyword(s):  
Amino Acid ◽  
Virus Infection ◽  
Positive Selection ◽  
Sodium Taurocholate ◽  
Arms Race ◽  
Adaptive Mutation ◽  
Molecular Evidence ◽  
Adaptive Mutations ◽  
Wide Range ◽  
Coevolutionary Arms Race

ABSTRACTHepatitis B virus (HBV) and its hepadnavirus relatives infect a wide range of vertebrates, from fish to human. Hepadnaviruses and their hosts have a long history of acquiring adaptive mutations. However, there are no reports providing direct molecular evidence for such a coevolutionary “arms race” between hepadnaviruses and their hosts. Here, we present evidence suggesting that the adaptive evolution of the sodium taurocholate cotransporting polypeptide (NTCP), an HBV receptor, has been influenced by virus infection. Evolutionary analysis of the NTCP-encoding genes from 20 mammals showed that most NTCP residues are highly conserved among species, exhibiting evolution under negative selection (dN/dSratio [ratio of nonsynonymous to synonymous evolutionary changes] of <1); this observation implies that the evolution of NTCP is restricted by maintaining its original protein function. However, 0.7% of NTCP amino acid residues exhibit rapid evolution under positive selection (dN/dSratio of >1). Notably, a substitution at amino acid (aa) 158, a positively selected residue, converting the human NTCP to a monkey-type sequence abrogated the capacity to support HBV infection; conversely, a substitution at this residue converting the monkey Ntcp to the human sequence was sufficient to confer HBV susceptibility. Together, these observations suggested a close association of the aa 158 positive selection with the pressure by virus infection. Moreover, the aa 158 sequence determined attachment of the HBV envelope protein to the host cell, demonstrating the mechanism whereby HBV infection would create positive selection at this NTCP residue. In summary, we provide the first evidence in agreement with the function of hepadnavirus as a driver for inducing adaptive mutation in host receptor.IMPORTANCEHBV and its hepadnavirus relatives infect a wide range of vertebrates, with a long infectious history (hundreds of millions of years). Such a long history generally allows adaptive mutations in hosts to escape from infection while simultaneously allowing adaptive mutations in viruses to overcome host barriers. However, there is no published molecular evidence for such a coevolutionary arms race between hepadnaviruses and hosts. In the present study, we performed coevolutionary phylogenetic analysis between hepadnaviruses and the sodium taurocholate cotransporting polypeptide (NTCP), an HBV receptor, combined with virological experimental assays for investigating the biological significance of NTCP sequence variation. Our data provide the first molecular evidence supporting that HBV-related hepadnaviruses drive adaptive evolution in the NTCP sequence, including a mechanistic explanation of how NTCP mutations determine host viral susceptibility. Our novel insights enhance our understanding of how hepadnaviruses evolved with their hosts, permitting the acquisition of strong species specificity.

scholarly journals Smc5/6-antagonism by HBx is an evolutionary-conserved function of hepatitis B virus infection in mammals

2017 ◽  
Author(s):  
Fabien Filleton ◽  
Fabien Abdul ◽  
Laetitia Gerossier ◽  
Alexia Paturel ◽  
Janet Hall ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Antiviral Activity ◽  
Positive Selection ◽  
Host Species ◽  
Human Hepatocytes ◽  
Arms Race ◽  
Restriction Factor ◽  
Primary Human Hepatocytes ◽  
B Virus

AbstractInfection with Hepatitis B virus (HBV) is a major cause of liver disease and cancer in humans. HBVs (family Hepadnaviridae) have been associated with mammals for millions of years. Recently, the Smc5/6 complex, known for its essential housekeeping functions in genome maintenance, was identified as an antiviral restriction factor of human HBV. The virus has however developed a counteraction mechanism by degrading the complex via its regulatory HBx protein. Whether the antiviral activity of the Smc5/6 complex against hepadnaviruses is an important and evolutionary-conserved function is unknown. Here, we used a combined evolutionary and functional approach to address this question. We first performed phylogenetic and positive selection analyses of the six Smc5/6 complex subunits and found that they have been highly conserved in primates and mammals. Yet, the Smc6 subunit showed marks of adaptive evolution, potentially reminiscent of virus-host “arms-race” We then functionally tested the HBx from six very divergent hepadnaviruses now naturally infecting primates, rodents, and bats. Despite little sequence homology, we demonstrate that these HBx efficiently degraded mammalian Smc5/6 complexes, independently of the host species and of the sites under positive selection. Importantly, all also rescued the replication of an HBx-deficient HBV in primary human hepatocytes. These findings point to an evolutionary-conserved requirement for Smc5/6 inactivation by HBx, showing that the Smc5/6 antiviral activity has been an important defense mechanism against hepadnaviruses in mammals. Interestingly, Smc5/6 may further be a restriction factor of other yet unidentified viruses that have driven some of its adaptation.ImportanceInfection with hepatitis B virus (HBV) led to 887000 human deaths in 2015. HBV has been co-evolving with mammals for millions of years. Recently, the Smc5/6 complex, known for its essential housekeeping functions, was identified as a restriction factor of human HBV antagonized by the regulatory HBx protein. Here, we address whether the antiviral activity of Smc5/6 is an important evolutionary-conserved function. We found that all six subunits of Smc5/6 have been conserved in primates with only Smc6 showing signatures of “evolutionary arms-race” Using evolutionary-guided functional assays that include infections of primary human hepatocytes, we demonstrate that HBx from very divergent mammalian HBVs could all efficiently antagonize Smc5/6, independently of the host species and sites under positive selection. These findings show that the Smc5/6 antiviral activity against HBV is an important function in mammals. It also raises the intriguing possibility that Smc5/6 restricts other, yet unidentified viruses.

scholarly journals Smc5/6 Antagonism by HBx Is an Evolutionarily Conserved Function of Hepatitis B Virus Infection in Mammals

2018 ◽  
Vol 92 (16) ◽  
Author(s):  
Fabien Abdul ◽  
Fabien Filleton ◽  
Laetitia Gerossier ◽  
Alexia Paturel ◽  
Janet Hall ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Antiviral Activity ◽  
Positive Selection ◽  
Defense Mechanism ◽  
Human Hepatocytes ◽  
Arms Race ◽  
Restriction Factor ◽  
Evolutionarily Conserved ◽  
B Virus

ABSTRACT Chronic infection with hepatitis B virus (HBV) is a major cause of liver disease and cancer in humans. HBVs (family Hepadnaviridae) have been associated with mammals for millions of years. Recently, the Smc5/6 complex, known for its essential housekeeping functions in genome maintenance, was identified as an antiviral restriction factor of human HBV. The virus has, however, evolved to counteract this defense mechanism by degrading the complex via its regulatory HBx protein. Whether the antiviral activity of the Smc5/6 complex against hepadnaviruses is an important and evolutionarily conserved function is unknown. In this study, we used an evolutionary and functional approach to address this question. We first performed phylogenetic and positive selection analyses of the Smc5/6 complex subunits and found that they have been conserved in primates and mammals. Yet, Smc6 showed marks of adaptive evolution, potentially reminiscent of a virus-host “arms race.” We then functionally tested the HBx proteins from six divergent hepadnaviruses naturally infecting primates, rodents, and bats. We demonstrate that despite little sequence homology, these HBx proteins efficiently degraded mammalian Smc5/6 complexes, independently of the host species and of the sites under positive selection. Importantly, all HBx proteins also rescued the replication of an HBx-deficient HBV in primary human hepatocytes. These findings point to an evolutionarily conserved requirement for Smc5/6 inactivation by HBx, showing that Smc5/6 antiviral activity has been an important defense mechanism against hepadnaviruses in mammals. It will be interesting to investigate whether Smc5/6 may further be a restriction factor of other, yet-unidentified viruses that may have driven some of its adaptation. IMPORTANCE Infection with hepatitis B virus (HBV) led to 887,000 human deaths in 2015. HBV has been coevolving with mammals for millions of years. Recently, the Smc5/6 complex, which has essential housekeeping functions, was identified as a restriction factor of human HBV antagonized by the regulatory HBx protein. Here we address whether the antiviral activity of Smc5/6 is an important evolutionarily conserved function. We found that all six subunits of Smc5/6 have been conserved in primates, with only Smc6 showing signatures of an “evolutionary arms race.” Using evolution-guided functional analyses that included infections of primary human hepatocytes, we demonstrated that HBx proteins from very divergent mammalian HBVs could all efficiently antagonize Smc5/6, independently of the host species and sites under positive selection. These findings show that Smc5/6 antiviral activity against HBV is an important function in mammals. They also raise the intriguing possibility that Smc5/6 may restrict other, yet-unidentified viruses.

NTCP oligomerization occurs downstream of the NTCP-EGFR interaction during hepatitis B virus internalization

2021 ◽  
Author(s):  
Kento Fukano ◽  
Mizuki Oshima ◽  
Senko Tsukuda ◽  
Hideki Aizaki ◽  
Mio Ohki ◽  
...  
Keyword(s):  
Epidermal Growth Factor Receptor ◽  
Bile Acid ◽  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Viral Entry ◽  
Sodium Taurocholate ◽  
Growth Factor Receptor ◽  
Host Cells ◽  
B Virus ◽  
Epidermal Growth

Sodium taurocholate cotransporting polypeptide (NTCP) is a receptor that is essential for hepatitis B virus (HBV) entry into the host cell. A number of HBV entry inhibitors targeting NTCP have been reported to date; these inhibitors have facilitated a mechanistic analysis of the viral entry process. However, the mechanism of HBV internalization into host cells after interaction of virus with NTCP remains largely unknown. Recently, we reported that troglitazone, a thiazolidinedione derivative, specifically inhibits both HBV internalization and NTCP oligomerization, resulting in inhibition of HBV infection. Here, using troglitazone as a chemical probe to investigate entry process, the contribution of NTCP oligomerization to HBV internalization was evaluated. Using surface plasmon resonance and transporter kinetics, we found that troglitazone directly interacts with NTCP and non-competitively interferes with NTCP-mediated bile acid uptake, suggesting that troglitazone allosterically binds to NTCP, rather than to the bile acid-binding pocket. Additionally, alanine scanning mutagenesis showed that a mutation at phenylalanine 274 of NTCP (F274A) caused a loss of HBV susceptibility and disrupted both the oligomerization of NTCP and HBV internalization without affecting viral attachment to the cell surface. An inhibitor of the interaction between NTCP and epidermal growth factor receptor (EGFR), another host cofactor essential for HBV internalization, impeded NTCP oligomerization. Meanwhile, co-immunoprecipitation analysis revealed that neither troglitazone nor the F274A mutation in NTCP affect the NTCP-EGFR interaction. These findings suggest that NTCP oligomerization is initiated downstream of the NTCP-EGFR interaction, and then triggers HBV internalization. This study provides significant insight into the HBV entry mechanisms. Importance Hepatitis B virus (HBV) infection is mediated by a specific interaction with sodium taurocholate cotransporting polypeptide (NTCP), a viral entry receptor. Although the virus-receptor interactions are believed to trigger viral internalization into host cells, the exact molecular mechanisms of HBV internalization are not understood. In this study, we revealed the mode of action whereby troglitazone, a specific inhibitor of HBV internalization, impedes NTCP oligomerization, and identified NTCP phenylalanine 274 as a residue essential for this oligomerization. We further analyzed the association between NTCP oligomerization and HBV internalization, a process that is mediated by epidermal growth factor receptor (EGFR), another essential host cofactor for HBV internalization. Our study provides critical information on the mechanism of HBV entry, and suggests that oligomerization of the viral receptor serves as an attractive target for drug discovery.

scholarly journals An Effective Antiviral Approach Targeting Hepatitis B Virus with NJK14047, a Novel and Selective Biphenyl Amide p38 Mitogen-Activated Protein Kinase Inhibitor

2017 ◽  
Vol 61 (8) ◽  
Author(s):  
So-Young Kim ◽  
Hong Kim ◽  
Sang-Won Kim ◽  
Na-Rae Lee ◽  
Chae-Min Yi ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Protein Kinase ◽  
Hepatitis B ◽  
P38 Mapk ◽  
Sodium Taurocholate ◽  
Therapeutic Strategies ◽  
Host Factors ◽  
Mitogen Activated Protein Kinase ◽  
B Virus ◽  
Mitogen Activated Protein

ABSTRACT Despite recent advances in therapeutic strategies against hepatitis B virus (HBV) infection, chronic hepatitis B remains a major global health burden. Recent studies have shown that targeting host factors instead of viral factors can be an effective antiviral strategy with low risk of the development of resistance. Efforts to identify host factors affecting viral replication have identified p38 mitogen-activated protein kinase (MAPK) as a possible target for antiviral strategies against various viruses, including HBV. Here, a series of biphenyl amides were synthesized as novel p38 MAPK selective inhibitors and assessed for their anti-HBV activities. The suppression of HBV surface antigen (HBsAg) production by these compounds was positively correlated with p38 MAPK-inhibitory activity. The selected compound NJK14047 displayed significant anti-HBV activity, as determined by HBsAg production, HBeAg secretion, and HBV production. NJK14047 efficiently suppressed the secretion of HBV antigens and HBV particles from HBV genome-transfected cells and HBV-infected sodium taurocholate cotransporting polypeptide-expressing human hepatoma cells. Furthermore, NJK14047 treatment resulted in a significant decrease of pregenomic RNA and covalently closed circular DNA (cccDNA) of HBV in HBV-harboring cells, indicating its ability to inhibit HBV replication. Considering that suppression of HBsAg secretion and elimination of cccDNA of HBV are the major aims of anti-HBV therapeutic strategies, the results suggested the potential use of these compounds as a novel class of anti-HBV agents targeting host factors critical for viral infection.

scholarly journals Sodium taurocholate cotransporting polypeptide inhibition efficiently blocks hepatitis B virus spread in mice with a humanized liver

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Tasuku Nakabori ◽  
Hayato Hikita ◽  
Kazuhiro Murai ◽  
Yasutoshi Nozaki ◽  
Yugo Kai ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Sodium Taurocholate ◽  
Virus Spread ◽  
B Virus
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