title: Coronavirus nsp10/nsp16 Methyltransferase Can Be Targeted by nsp10-Derived Peptide In Vitro and In Vivo To Reduce Replication and Pathogenesis.
abstract: The 5' cap structures of eukaryotic mRNAs are important for RNA stability and protein translation. Many viruses that replicate in the cytoplasm of eukaryotes have evolved 2'-O-methyltransferases (2'-O-MTase) to autonomously modify their mRNAs and carry a cap-1 structure (m7GpppNm) at the 5' end, thereby facilitating viral replication and escaping innate immune recognition in host cells. Previous studies showed that the 2'-O-MTase activity of severe acute respiratory syndrome coronavirus (SARS-CoV) nonstructural protein 16 (nsp16) needs to be activated by nsp10, whereas nsp16 of feline coronavirus (FCoV) alone possesses 2'-O-MTase activity (E. Decroly et al., J Virol 82:8071-8084, 2008, http://dx.doi.org/10.1128/JVI.00407-08; M. Bouvet et al., PLoS Pathog 6:e1000863, 2010, http://dx.doi.org/10.1371/journal.ppat.1000863; E. Decroly et al., PLoS Pathog 7:e1002059, 2011, http://dx.doi.org/10.1371/journal.ppat.1002059; Y. Chen et al., PLoS Pathog 7:e1002294, 2011, http://dx.doi.org/10.1371/journal.ppat.1002294) . In this study, we demonstrate that stimulation of nsp16 2'-O-MTase activity by nsp10 is a universal and conserved mechanism in coronaviruses, including FCoV, and that nsp10 is functionally interchangeable in the stimulation of nsp16 of different coronaviruses. Based on our current and previous studies, we designed a peptide (TP29) from the sequence of the interaction interface of mouse hepatitis virus (MHV) nsp10 and demonstrated that the peptide inhibits the 2'-O-MTase activity of different coronaviruses in biochemical assays and the viral replication in MHV infection and SARS-CoV replicon models. Interestingly, the peptide TP29 exerted robust inhibitory effects in vivo in MHV-infected mice by impairing MHV virulence and pathogenesis through suppressing virus replication and enhancing type I interferon production at an early stage of infection. Therefore, as a proof of principle, the current results indicate that coronavirus 2'-O-MTase activity can be targeted in vitro and in vivo.
  
  
  OBJECTIVE
  Coronaviruses are important pathogens of animals and human with high zoonotic potential. SARS-CoV encodes the 2'-O-MTase that is composed of the catalytic subunit nsp16 and the stimulatory subunit nsp10 and plays an important role in virus genome replication and evasion from innate immunity. Our current results demonstrate that stimulation of nsp16 2'-O-MTase activity by nsp10 is a common mechanism for coronaviruses, and nsp10 is functionally interchangeable in the stimulation of nsp16 among different coronaviruses, which underlies the rationale for developing inhibitory peptides. We demonstrate that a peptide derived from the nsp16-interacting domain of MHV nsp10 could inhibit 2'-O-MTase activity of different coronaviruses in vitro and viral replication of MHV and SARS-CoV replicon in cell culture, and it could strongly inhibit virus replication and pathogenesis in MHV-infected mice. This work makes it possible to develop broad-spectrum peptide inhibitors by targeting the nsp16/nsp10 2'-O-MTase of coronaviruses.
authors.affiliation: State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Pathogen Biology, Henan University of TCM, Zhengzhou, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Sun
authors.affiliation: State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, China.
authors.forename: Andong
authors.initials: A
authors.lastname: Wu
authors.affiliation: State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, China.
authors.forename: Shan
authors.initials: S
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, China.
authors.forename: Ruangang
authors.initials: R
authors.lastname: Pan
authors.affiliation: State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, China.
authors.forename: Cong
authors.initials: C
authors.lastname: Zeng
authors.affiliation: State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, China.
authors.forename: Xu
authors.initials: X
authors.lastname: Jin
authors.affiliation: Center for Emerging Infectious Diseases, State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China.
authors.forename: Xingyi
authors.initials: X
authors.lastname: Ge
authors.affiliation: Center for Emerging Infectious Diseases, State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China.
authors.forename: Zhengli
authors.initials: Z
authors.lastname: Shi
authors.affiliation: Department of Food and Environmental Sciences, University of Helsinki, Helsinki, Finland.
authors.forename: Tero
authors.initials: T
authors.lastname: Ahola
authors.affiliation: State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, China chenyu@whu.edu.cn dguo@whu.edu.cn.
authors.forename: Yu
authors.initials: Y
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, China chenyu@whu.edu.cn dguo@whu.edu.cn.
authors.forename: Deyin
authors.initials: D
authors.lastname: Guo
mesh_terms: D000410:Alanine Transaminase / Q000378:metabolism; D000818:Animals; D002460:Cell Line; D006801:Humans; D008156:Luciferases; D008780:Methyltransferases / Q000378:metabolism*; D051379:Mice; D006517:Murine hepatitis virus / Q000235:genetics / Q000472:pathogenicity*; D010455:Peptides / Q000235:genetics / Q000494:pharmacology*; D051381:Rats; D045473:Severe acute respiratory syndrome-related coronavirus / Q000201:enzymology*; D017361:Viral Nonstructural Proteins / Q000378:metabolism*; D014779:Virus Replication / Q000187:drug effects*
chemical_list: C558878:Nsp10 protein, SARS virus; D010455:Peptides; D017361:Viral Nonstructural Proteins; D008156:Luciferases; D008780:Methyltransferases; C558879:Nsp16 protein, SARS virus; D000410:Alanine Transaminase