Ebola Virus Protein VP35 Impairs the Function of Interferon Regulatory Factor-Activating Kinases IKKε and TBK-1

Prins, Kathleen C.; Cárdenas, Washington B.; Basler, Christopher F.

doi:10.1128/jvi.01875-08

Cited by 218 publications

(220 citation statements)

References 54 publications

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“…Previous studies with zVP35 have shown that one mechanism underlying the ability of EBOV to suppress IFN-β production is through inhibition of IRF3/IRF7 phosphorylation by the IFN kinases IKKe/TBK-1 (11,13,25). Similar to zVP35, mVP35 is also able to block IFN-β promoter activity in a dose-dependent manner upon overexpression of IKKe or TBK-1 in 293T cells ( Fig.…”

supporting

confidence: 53%

“…mVP35 can also inhibit IFN-β induction when IFN kinases IKKe/ TBK-1 are expressed. Inhibition is lost when a constitutively active IRF3-5D is used, suggesting that mVP35 targets these kinases (25). Because all of the mVP35 dsRNA-binding mutants are functional in this assay, suppression of RLRs vs. the kinases likely requires different residues.…”

Section: Discussionmentioning

confidence: 99%

“…IFN-β promoter studies, IRF3 phosphorylation, and pI:C pull-down studies were carried out for WT and mutant mIID and zIID proteins as described previously (13,15,21,25).…”

Section: Methodsmentioning

confidence: 99%

“…EBOV VP35 interacts with several components of innate antiviral defenses, including retinoic-acid inducible gene-I (RIG-I)-like receptor (RLR) pathways that lead to IFN production (13-24). These include inhibition of IFN production through double-stranded (ds)RNA sequestration and inhibition of IFN regulatory factor (IRF) 3/IRF7 phosphorylation by direct association with kinases that activate IRF3/IRF7, IKKe/TBK-1 (13,15,21,25). Structural and biochemical studies on Zaire EBOV (ZEBOV) and Reston EBOV (REBOV) VP35 IFN inhibitory domains (IID) (termed zVP35 and zIID or rVP35 and rIID, for VP35 protein and IID, respectively) in free and dsRNA-bound forms identified a number of functionally critical basic residues (21, 26-28).…”

mentioning

confidence: 99%

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Structural basis for Marburg virus VP35–mediated immune evasion mechanisms

Ramanan

Edwards

Shabman

et al. 2012

Proc. Natl. Acad. Sci. U.S.A.

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120

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Filoviruses, marburgvirus (MARV) and ebolavirus (EBOV), are causative agents of highly lethal hemorrhagic fever in humans. MARV and EBOV share a common genome organization but show important differences in replication complex formation, cell entry, host tropism, transcriptional regulation, and immune evasion. Multifunctional filoviral viral protein (VP) 35 proteins inhibit innate immune responses. Recent studies suggest double-stranded (ds)RNA sequestration is a potential mechanism that allows EBOV VP35 to antagonize retinoic-acid inducible gene-I (RIG-I) like receptors (RLRs) that are activated by viral pathogen-associated molecular patterns (PAMPs), such as double-strandedness and dsRNA blunt ends. Here, we show that MARV VP35 can inhibit IFN production at multiple steps in the signaling pathways downstream of RLRs. The crystal structure of MARV VP35 IID in complex with 18-bp dsRNA reveals that despite the similar protein fold as EBOV VP35 IID, MARV VP35 IID interacts with the dsRNA backbone and not with blunt ends. Functional studies show that MARV VP35 can inhibit dsRNA-dependent RLR activation and interferon (IFN) regulatory factor 3 (IRF3) phosphorylation by IFN kinases TRAF family member-associated NFkb activator (TANK) binding kinase-1 (TBK-1) and IFN kB kinase e (IKKe) in cell-based studies. We also show that MARV VP35 can only inhibit RIG-I and melanoma differentiation associated gene 5 (MDA5) activation by double strandedness of RNA PAMPs (coating backbone) but is unable to inhibit activation of RLRs by dsRNA blunt ends (end capping). In contrast, EBOV VP35 can inhibit activation by both PAMPs. Insights on differential PAMP recognition and inhibition of IFN induction by a similar filoviral VP35 fold, as shown here, reveal the structural and functional plasticity of a highly conserved virulence factor.T he Filoviridae family of viruses, which includes marburgvirus (MARV) and ebolavirus (EBOV), can cause intermittent outbreaks that often result in high fatality rates (1). The family consists of five species of EBOV, Zaire, Reston, Sudan, Taï Forest, and Bundibugyo; one species of MARV; and a proposed genus Cuevavirus possessing a single species Lloviu cuevavirus (2). Despite overall similarities in genome size and organization, virion structure, and disease characteristics (3), EBOV and MARV exhibit important differences, including their strategies for immune evasion (4). For example, although EBOV viral protein (VP) 24 and MARV VP40 counter IFN signaling, neither MARV VP24 nor EBOV VP40 appears to function similarly to its corresponding counterparts with regard to immune evasion (5-10).Filoviruses also counteract innate immunity through the multifunctional VP35 proteins, which perform critical roles in viral RNA synthesis, virus assembly, and virus structure (reviewed in refs. 11 and 12). EBOV VP35 interacts with several components of innate antiviral defenses, including retinoic-acid inducible gene-I (RIG-I)-like receptor (RLR) pathways that lead to IFN production (13-24). These include inhibition of ...

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supporting

confidence: 53%

Section: Discussionmentioning

confidence: 99%

“…IFN-β promoter studies, IRF3 phosphorylation, and pI:C pull-down studies were carried out for WT and mutant mIID and zIID proteins as described previously (13,15,21,25).…”

Section: Methodsmentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

Structural basis for Marburg virus VP35–mediated immune evasion mechanisms

Ramanan

Edwards

Shabman

et al. 2012

Proc. Natl. Acad. Sci. U.S.A.

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120

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“…In response to different upstream signals, it also undergoes K48-and K63-linked ubiquitination that is modulated by other ubiquitin ligases and deubiquitinases (8)(9)(10)(11)(12). In line with its positive regulatory role in antiviral response, TRAF3 signaling complexes are targeted by various viral proteins as countermeasures to inhibit IFN production (13)(14)(15); however, it is not fully understood how the adaptor function of TRAF3 in innate IFN response is achieved and regulated in the cell.…”

mentioning

confidence: 99%

MIP-T3 Is a Negative Regulator of Innate Type I IFN Response

Kok

et al. 2011

The Journal of Immunology

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TNFR-associated factor (TRAF) 3 is an important adaptor that transmits upstream activation signals to protein kinases that phosphorylate transcription factors to induce the production of type I IFNs, the important effectors in innate antiviral immune response. MIP-T3 interacts specifically with TRAF3, but its function in innate IFN response remains unclear. In this study, we demonstrated a negative regulatory role of MIP-T3 in type I IFN production. Overexpression of MIP-T3 inhibited RIG-I-, MDA5-, VISA-, TBK1-, and IKKε-induced transcriptional activity mediated by IFN-stimulated response elements and IFN-β promoter. MIP-T3 interacted with TRAF3 and perturbed in a dose-dependent manner the formation of functional complexes of TRAF3 with VISA, TBK1, IKKε, and IFN regulatory factor 3. Consistent with this finding, retinoic acid-inducible gene I- and TBK1-induced phosphorylation of IFN regulatory factor 3 was significantly diminished when MIP-T3 was overexpressed. Depletion of MIP-T3 facilitated Sendai virus-induced activation of IFN production and attenuated the replication of vesicular stomatitis virus. In addition, MIP-T3 was found to be dissociated from TRAF3 during the course of Sendai virus infection. Our findings suggest that MIP-T3 functions as a negative regulator of innate IFN response by preventing TRAF3 from forming protein complexes with critical downstream transducers and effectors.

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Exploring the mechanism how Marburg virus VP35 recognizes and binds dsRNA by molecular dynamics simulations and free energy calculations

et al. 2014

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Filoviruses often cause terrible infectious disease which has not been successfully dealt with pharmacologically. All filoviruses encode a unique protein termed VP35 which can mask doubled-stranded RNA to deactivate interferon. The interface of VP35-dsRNA would be a feasible target for structure-based antiviral agent design. To explore the essence of VP35-dsRNA interaction, molecular dynamics simulation combined with MM-GBSA calculations were performed on Marburg virus VP35-dsRNA complex and several mutational complexes. The energetic analysis indicates that nonpolar interactions provide the main driving force for the binding process. Although the intermolecular electrostatic interactions play important roles in VP35-dsRNA interaction, the whole polar interactions are unfavorable for binding which result in a low binding affinity. Compared with wild type VP35, the studied mutants F228A, R271A, and K298A have obviously reduced binding free energies with dsRNA reflecting in the reduction of polar or nonpolar interactions. The results also indicate that the loss of binding affinity for one dsRNA strand would abolish the total binding affinity. Three important residues Arg271, Arg294, and Lys298 which makes the largest contribution for binding in VP35 lose their binding affinity significantly in mutants. The uncovering of VP35-dsRNA recognition mechanism will provide some insights for development of antiviral drug.

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Ebola Virus Protein VP35 Impairs the Function of Interferon Regulatory Factor-Activating Kinases IKKε and TBK-1

Cited by 218 publications

References 54 publications

Structural basis for Marburg virus VP35–mediated immune evasion mechanisms

Structural basis for Marburg virus VP35–mediated immune evasion mechanisms

MIP-T3 Is a Negative Regulator of Innate Type I IFN Response

Exploring the mechanism how Marburg virus VP35 recognizes and binds dsRNA by molecular dynamics simulations and free energy calculations

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