The antiviral mechanism of MxA revealed by a molecular docking-based structural model of the complex of MxA and influenza A virus NP/RNPs

Mapping Intimacies ◽

10.1101/219915 ◽

2017 ◽

Author(s):

Yeping Sun

Keyword(s):

Crystal Structure ◽

Influenza A Virus ◽

Influenza A ◽

Molecular Mechanisms ◽

Structural Model ◽

Restriction Factor ◽

Host Restriction ◽

Host Restriction Factor ◽

Rnp Complex ◽

Antiviral Mechanism

AbstractMxA, a member of the dynamin superfamily, is a potent host restriction factor for influenza A virus replication. The viral nucleoprotein (NP) of influenza A virus has been suggested to be a target of MxA. However, the molecular details of the interactions between NP and MxA remain unknown. In the present study, loop L4 of MxA, which was shown to target viral component and is missing in the crystal structure of MxA was modeled on a dimer of the MxA. The dimer was then docked onto NP. The resulting NP-MxA dimer complex is in agreement with previous studies, as the interface contains many residues that were previously identified to be associated with MxA resistance. And the model was the used to construct NP-MxA ring. We also constructed a structural model of the complex of influenza virus NP and polymerase, and the NP residues that interact with MxA in the NP-MxA model partly overlap with those in the NP-polymerase model, so MxA may competitively inhibit the binding of NP and the polymerase and disrupt the assembly of ribonucleoprotein (RNP) complex. These results of this work represent a putative molecular mechanisms for MxA antiviral activity.

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A double-stranded RNA platform is required for the interaction between a host restriction factor and the NS1 protein of influenza A virus

Nucleic Acids Research ◽

10.1093/nar/gkz1094 ◽

2019 ◽

Vol 48 (1) ◽

pp. 304-315 ◽

Cited By ~ 3

Author(s):

Guifang Chen ◽

Li-Chung Ma ◽

Shanshan Wang ◽

Ryan L Woltz ◽

Emily M Grasso ◽

...

Keyword(s):

Amino Acid ◽

Influenza A ◽

Binding Activity ◽

Restriction Factor ◽

Amino Acid Residues ◽

Ns1 Protein ◽

Double Stranded Rna ◽

Host Restriction ◽

Host Restriction Factor ◽

Dsrna Binding

Abstract Influenza A viruses cause widespread human respiratory disease. The viral multifunctional NS1 protein inhibits host antiviral responses. This inhibition results from the binding of specific cellular antiviral proteins at various positions on the NS1 protein. Remarkably, binding of several proteins also requires the two amino-acid residues in the NS1 N-terminal RNA-binding domain (RBD) that are required for binding double-stranded RNA (dsRNA). Here we focus on the host restriction factor DHX30 helicase that is countered by the NS1 protein, and establish why the dsRNA-binding activity of NS1 is required for its binding to DHX30. We show that the N-terminal 152 amino-acid residue segment of DHX30, denoted DHX30N, possesses all the antiviral activity of DHX30 and contains a dsRNA-binding domain, and that the NS1-DHX30 interaction in vivo requires the dsRNA-binding activity of both DHX30N and the NS1 RBD. We demonstrate why this is the case using bacteria-expressed proteins: the DHX30N-NS1 RBD interaction in vitro requires the presence of a dsRNA platform that binds both NS1 RBD and DHX30N. We propose that a similar dsRNA platform functions in interactions of the NS1 protein with other proteins that requires these same two amino-acid residues required for NS1 RBD dsRNA-binding activity.

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Inhibition of Avian Influenza A Virus Replication in Human Cells by Host Restriction Factor TUFM Is Correlated with Autophagy

mBio ◽

10.1128/mbio.00481-17 ◽

2017 ◽

Vol 8 (3) ◽

Cited By ~ 19

Author(s):

Shu-Ming Kuo ◽

Chi-Jene Chen ◽

Shih-Cheng Chang ◽

Tzu-Jou Liu ◽

Yi-Hsiang Chen ◽

...

Keyword(s):

Influenza Virus ◽

Avian Influenza ◽

Virus Replication ◽

Influenza A ◽

Inhibitory Effect ◽

Human Cells ◽

Restriction Factor ◽

Influenza A Viruses ◽

Host Restriction ◽

Host Restriction Factor

ABSTRACT Avian influenza A viruses generally do not replicate efficiently in human cells, but substitution of glutamic acid (Glu, E) for lysine (Lys, K) at residue 627 of avian influenza virus polymerase basic protein 2 (PB2) can serve to overcome host restriction and facilitate human infectivity. Although PB2 residue 627 is regarded as a species-specific signature of influenza A viruses, host restriction factors associated with PB2627E have yet to be fully investigated. We conducted immunoprecipitation, followed by differential proteomic analysis, to identify proteins associating with PB2627K (human signature) and PB2627E (avian signature) of influenza A/WSN/1933(H1N1) virus, and the results indicated that Tu elongation factor, mitochondrial (TUFM), had a higher binding affinity for PB2627E than PB2627K in transfected human cells. Stronger binding of TUFM to avian-signature PB2590G/591Q and PB2627E in the 2009 swine-origin pandemic H1N1 and 2013 avian-origin H7N9 influenza A viruses was similarly observed. Viruses carrying avian-signature PB2627E demonstrated increased replication in TUFM-deficient cells, but viral replication decreased in cells overexpressing TUFM. Interestingly, the presence of TUFM specifically inhibited the replication of PB2627E viruses, but not PB2627K viruses. In addition, enhanced levels of interaction between TUFM and PB2627E were noted in the mitochondrial fraction of infected cells. Furthermore, TUFM-dependent autophagy was reduced in TUFM-deficient cells infected with PB2627E virus; however, autophagy remained consistent in PB2627K virus-infected cells. The results suggest that TUFM acts as a host restriction factor that impedes avian-signature influenza A virus replication in human cells in a manner that correlates with autophagy. IMPORTANCE An understanding of the mechanisms that influenza A viruses utilize to shift host tropism and the identification of host restriction factors that can limit infection are both critical to the prevention and control of emerging viruses that cross species barriers to target new hosts. Using a proteomic approach, we revealed a novel role for TUFM as a host restriction factor that exerts an inhibitory effect on avian-signature PB2627E influenza virus propagation in human cells. We further found that increased TUFM-dependent autophagy correlates with the inhibitory effect on avian-signature influenza virus replication and may serve as a key intrinsic mechanism to restrict avian influenza virus infection in humans. These findings provide new insight regarding the TUFM mitochondrial protein and may have important implications for the development of novel antiviral strategies. IMPORTANCE An understanding of the mechanisms that influenza A viruses utilize to shift host tropism and the identification of host restriction factors that can limit infection are both critical to the prevention and control of emerging viruses that cross species barriers to target new hosts. Using a proteomic approach, we revealed a novel role for TUFM as a host restriction factor that exerts an inhibitory effect on avian-signature PB2627E influenza virus propagation in human cells. We further found that increased TUFM-dependent autophagy correlates with the inhibitory effect on avian-signature influenza virus replication and may serve as a key intrinsic mechanism to restrict avian influenza virus infection in humans. These findings provide new insight regarding the TUFM mitochondrial protein and may have important implications for the development of novel antiviral strategies.

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Host restriction factor A3G inhibits the replication of Enterovirus D68 through competitively binding 5’ UTR with PCBP1

Journal of Virology ◽

10.1128/jvi.01708-21 ◽

2021 ◽

Author(s):

Zhaolong Li ◽

Xu Yang ◽

Zhilei Zhao ◽

Xin Liu ◽

Wenyan Zhang

Keyword(s):

Broad Spectrum ◽

Enterovirus 71 ◽

Host Protein ◽

General Mechanism ◽

Restriction Factor ◽

Nucleic Acid Binding ◽

Structural Protein ◽

Stem Loop ◽

Host Restriction ◽

Host Restriction Factor

The host restriction factor APOBEC3G (A3G) presents extensively inhibition on a variety of viruses, including retroviruses, DNA and RNA viruses. Our recent study showed that A3G inhibits enterovirus 71 (EV71) and coxsackievirus A16 (CA16) via competitively binding 5’UTR with the host protein poly(C)-binding protein 1 (PCBP1) that is required for multiple EVs replication. However, in addition to EV71 and CA16, whether A3G inhibits other EVs has not been investigated. Here, we demonstrate that A3G could inhibit EVD68 replication, which needs PCBP1 for its replication, but not CA6 that PCBP1 is dispensable for CA6 replication. Further investigation revealed that nucleic acid binding activity of A3G is required for EVD68 restriction, which is similar to the mechanism presented in EV71 restriction. Mechanistically, A3G competitively binds to the cloverleaf (1–123) and the stem-loop IV (234-446) domains of EVD68 5’UTR with PCBP1, thereby inhibiting the 5'UTR activity of EVD68, whereas A3G doesn’t interact with CA6 5’UTR results in no effect on CA6 replication. Moreover, non-structural protein 2C encoded by EVD68 overcomes A3G suppression through inducing A3G degradation via the autophagy-lysosome pathway. Our finding revealed that A3G might have broad spectrum antiviral activity against multiple EVs through the general mechanism, which might provide important information for the development of anti-EVs strategy. Importance As the two major pathogens causing hand, food, and mouth disease (HFMD), EV71 and CA16 attract more attention for the discovery of pathogenesis, the involvement of cellular proteins and so on. However, other EVs such as CA6 or EVD68 constantly occurred sporadic or might spread widely in recent years worldwide. Therefore, more information related to these EVs needs to be further investigated so as to develop broad-spectrum anti-EVs inhibitor. In this study, we first reveal that PCBP1 involved in PV and EV71 virus replication, also is required for the replication of EVD68 but not CA6. Then we found that the host restriction factor A3G specifically inhibits the replication of EVD68 but not CA6 via competitively binding to the 5’UTR of EVD68 with PCBP1. Our findings broaden the knowledge related to EVs replication and the interplay between EVs and host factors.

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Amphotericin b effect on the sensitivity to influenza infection of WI-38 VA-13 cells with IFITM3 gene knockout

Medical academic journal ◽

10.17816/maj76106 ◽

2021 ◽

Vol 21 (3) ◽

pp. 109-112

Author(s):

Kira S. Koryabina ◽

Mariya V. Sergeeva ◽

Andrey B. Komissarov ◽

Nataliya V. Eshchenko ◽

Grigoriy A. Stepanov

Keyword(s):

Amphotericin B ◽

Influenza A Virus ◽

Influenza A ◽

Gene Knockout ◽

Influenza Infection ◽

Restriction Factors ◽

Host Restriction ◽

Host Restriction Factors ◽

Infected Cells ◽

The Difference

BACKGROUND: The application of CRISPR/Cas9 is one of the most rapidly developing areas in biotechnology. This method was used to obtain clones of а human origin cell line with knockout of one or more genes of the IFITM family, representing host restriction factors for influenza infection. Amphotericin B has previously been shown to promote influenza infection by blocking IFITM3 function. AIM: The aim of this study was to evaluate the effect of amphotericin B on the sensitivity of IFITM knockout cells to influenza A virus infection. MATERIALS AND METHODS: WI-38 VA-13 cells and mutant clones with IFITM3 knockout (F3 clone) or IFITM1, IFITM3 knockout (clone E12) were infected with influenza virus A/PR/8/34 (H1N1) in the presence or absence of amphotericin B. Forty-four hours after infection, the culture medium was taken to determine the infectious activity of the virus by titration in the MDCK cell culture, as well as the hemagglutinating activity of the virus. The infected cells were stained with fluorescently labeled antibodies against the viral NP protein, and the number of NP-positive cells was determined by flow cytometry. RESULTS: The addition of amphotericin B increased the hemagglutinating and infectious activity of the virus in WI-38 VA-13cells, while the difference was insignificant for clones with IFITM gene knockout. A similar dependency was obtained for the percent of infected cells. CONCLUSIONS: Mutant cells with a knockout of one or several genes of the IFITM family were equally susceptible to influenza infection regardless of the addition of amphotericin B, which confirms the crucial importance of a defect in the IFITM3 protein in increasing the permissiveness of cells to influenza A virus.

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HDAC6 Restricts Influenza A Virus by Deacetylation of the RNA Polymerase PA Subunit

Journal of Virology ◽

10.1128/jvi.01896-18 ◽

2018 ◽

Vol 93 (4) ◽

Cited By ~ 12

Author(s):

Huan Chen ◽

Yingjuan Qian ◽

Xin Chen ◽

Zhiyang Ruan ◽

Yuetian Ye ◽

...

Keyword(s):

Life Cycle ◽

Rna Polymerase ◽

Influenza A Virus ◽

Influenza A ◽

Molecular Mechanisms ◽

Polymerase Activity ◽

Negative Regulator ◽

Host Protein ◽

Spectrometric Analysis ◽

Rna Polymerase Activity

ABSTRACT The life cycle of influenza A virus (IAV) is modulated by various cellular host factors. Although previous studies indicated that IAV infection is controlled by HDAC6, the deacetylase involved in the regulation of PA remained unknown. Here, we demonstrate that HDAC6 acts as a negative regulator of IAV infection by destabilizing PA. HDAC6 binds to and deacetylates PA, thereby promoting the proteasomal degradation of PA. Based on mass spectrometric analysis, Lys(664) of PA can be deacetylated by HDAC6, and the residue is crucial for PA protein stability. The deacetylase activity of HDAC6 is required for anti-IAV activity, because IAV infection was enhanced due to elevated IAV RNA polymerase activity upon HDAC6 depletion and an HDAC6 deacetylase dead mutant (HDAC6-DM; H216A, H611A). Finally, we also demonstrate that overexpression of HDAC6 suppresses IAV RNA polymerase activity, but HDAC6-DM does not. Taken together, our findings provide initial evidence that HDAC6 plays a negative role in IAV RNA polymerase activity by deacetylating PA and thus restricts IAV RNA transcription and replication. IMPORTANCE Influenza A virus (IAV) continues to threaten global public health due to drug resistance and the emergence of frequently mutated strains. Thus, it is critical to find new strategies to control IAV infection. Here, we discover one host protein, HDAC6, that can inhibit viral RNA polymerase activity by deacetylating PA and thus suppresses virus RNA replication and transcription. Previously, it was reported that IAV can utilize the HDAC6-dependent aggresome formation mechanism to promote virus uncoating, but HDAC6-mediated deacetylation of α-tubulin inhibits viral protein trafficking at late stages of the virus life cycle. These findings together will contribute to a better understanding of the role of HDAC6 in regulating IAV infection. Understanding the molecular mechanisms of HDAC6 at various periods of viral infection may illuminate novel strategies for developing antiviral drugs.

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Host Restriction Factor Screening: Let the Virus Do the Work

Cell Host & Microbe ◽

10.1016/j.chom.2013.08.014 ◽

2013 ◽

Vol 14 (3) ◽

pp. 229-231 ◽

Cited By ~ 2

Author(s):

Michael S. Diamond ◽

John W. Schoggins

Keyword(s):

Restriction Factor ◽

Factor Screening ◽

Host Restriction ◽

Host Restriction Factor

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Molecular Events Involved in Influenza A Virus-Induced Cell Death

Frontiers in Microbiology ◽

10.3389/fmicb.2021.797789 ◽

2022 ◽

Vol 12 ◽

Author(s):

Rui Gui ◽

Quanjiao Chen

Keyword(s):

Cell Death ◽

Influenza A Virus ◽

Influenza A ◽

Regulatory Networks ◽

Molecular Mechanisms ◽

Tissue Destruction ◽

Inflammatory Reactions ◽

Molecular Events ◽

Host Death

Viral infection usually leads to cell death. Moderate cell death is a protective innate immune response. By contrast, excessive, uncontrolled cell death causes tissue destruction, cytokine storm, or even host death. Thus, the struggle between the host and virus determines whether the host survives. Influenza A virus (IAV) infection in humans can lead to unbridled hyper-inflammatory reactions and cause serious illnesses and even death. A full understanding of the molecular mechanisms and regulatory networks through which IAVs induce cell death could facilitate the development of more effective antiviral treatments. In this review, we discuss current progress in research on cell death induced by IAV infection and evaluate the role of cell death in IAV replication and disease prognosis.

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