Publications

• Homologous 2',5'-phosphodiesterases from disparate RNA viruses antagonize antiviral innate immunity.

  Zhang R., Jha B.K., Ogden K.M., Dong B., Zhao L., Elliott R., Patton J.T., Silverman R.H., Weiss S.R.

  Efficient and productive virus infection often requires viral countermeasures that block innate immunity. The IFN-inducible 2',5'-oligoadenylate (2-5A) synthetases (OASs) and ribonuclease (RNase) L are components of a potent host antiviral pathway. We previously showed that murine coronavirus (MHV ... >> More

  Efficient and productive virus infection often requires viral countermeasures that block innate immunity. The IFN-inducible 2',5'-oligoadenylate (2-5A) synthetases (OASs) and ribonuclease (RNase) L are components of a potent host antiviral pathway. We previously showed that murine coronavirus (MHV) accessory protein ns2, a 2H phosphoesterase superfamily member, is a phosphodiesterase (PDE) that cleaves 2-5A, thereby preventing activation of RNase L. The PDE activity of ns2 is required for MHV replication in macrophages and for hepatitis. Here, we show that group A rotavirus (RVA), an important cause of acute gastroenteritis in children worldwide, encodes a similar PDE. The RVA PDE forms the carboxy-terminal domain of the minor core protein VP3 (VP3-CTD) and shares sequence and predicted structural homology with ns2, including two catalytic HxT/S motifs. Bacterially expressed VP3-CTD exhibited 2',5'-PDE activity, which cleaved 2-5A in vitro. In addition, VP3-CTD expressed transiently in mammalian cells depleted 2-5A levels induced by OAS activation with poly(rI):poly(rC), preventing RNase L activation. In the context of recombinant chimeric MHV expressing inactive ns2, VP3-CTD restored the ability of the virus to replicate efficiently in macrophages or in the livers of infected mice, whereas mutant viruses expressing inactive VP3-CTD (H718A or H798R) were attenuated. In addition, chimeric viruses expressing either active ns2 or VP3-CTD, but not nonfunctional equivalents, were able to protect ribosomal RNA from RNase L-mediated degradation. Thus, VP3-CTD is a 2',5'-PDE able to functionally substitute for ns2 in MHV infection. Remarkably, therefore, two disparate RNA viruses encode proteins with homologous 2',5'-PDEs that antagonize activation of innate immunity. << Less

  Proc. Natl. Acad. Sci. U.S.A. 110:13114-13119(2013) [PubMed] [EuropePMC]

  This publication is cited by 2 other entries.

• Crystal structure of the C-terminal 2',5'-phosphodiesterase domain of group A rotavirus protein VP3.

  Brandmann T., Jinek M.

  In response to viral infections, the mammalian innate immune system induces the production of the second messenger 2'-5' oligoadenylate (2-5A) to activate latent ribonuclease L (RNase L) that restricts viral replication and promotes apoptosis. A subset of rotaviruses and coronaviruses encode 2',5' ... >> More

  In response to viral infections, the mammalian innate immune system induces the production of the second messenger 2'-5' oligoadenylate (2-5A) to activate latent ribonuclease L (RNase L) that restricts viral replication and promotes apoptosis. A subset of rotaviruses and coronaviruses encode 2',5'-phosphodiesterase enzymes that hydrolyze 2-5A, thereby inhibiting RNase L activation. We report the crystal structure of the 2',5'-phosphodiesterase domain of group A rotavirus protein VP3 at 1.39 Å resolution. The structure exhibits a 2H phosphoesterase fold and reveals conserved active site residues, providing insights into the mechanism of 2-5A degradation in viral evasion of host innate immunity. << Less

  Proteins 83:997-1002(2015) [PubMed] [EuropePMC]

  This publication is cited by 2 other entries.

• Crystal structure of the mouse hepatitis virus ns2 phosphodiesterase domain that antagonizes RNase L activation.

  Sui B., Huang J., Jha B.K., Yin P., Zhou M., Fu Z.F., Silverman R.H., Weiss S.R., Peng G., Zhao L.

  Prior studies have demonstrated that the mouse hepatitis virus (MHV) A59 strain ns2 protein is a member of the 2H phosphoesterase family and exhibits 2',5'-phosphodiesterase (PDE) activity. During the IFN antiviral response, ns2 cleaves 2',5'-oligoadenylate (2-5A), a key mediator of RNase L activa ... >> More

  Prior studies have demonstrated that the mouse hepatitis virus (MHV) A59 strain ns2 protein is a member of the 2H phosphoesterase family and exhibits 2',5'-phosphodiesterase (PDE) activity. During the IFN antiviral response, ns2 cleaves 2',5'-oligoadenylate (2-5A), a key mediator of RNase L activation, thereby subverting the activation of RNase L and evading host innate immunity. However, the mechanism of 2-5A cleavage by ns2 remains unclear. Here, we present the crystal structure of the MHV ns2 PDE domain and demonstrate a PDE fold similar to that of the cellular protein, a kinase anchoring protein 7 central domain (AKAP7(CD)) and rotavirus VP3 carboxy-terminal domain. The structure displays a pair of strictly conserved HxT/Sx motifs and forms a deep, positively charged catalytic groove with β-sheets and an arginine-containing loop. These findings provide insight into the structural basis for 2-5A binding of MHV ns2. << Less

  J Gen Virol 97:880-886(2016) [PubMed] [EuropePMC]

  This publication is cited by 2 other entries.