PMID- 32461321
OWN - NLM
STAT- MEDLINE
DCOM- 20200804
LR  - 20221207
IS  - 1098-5514 (Electronic)
IS  - 0022-538X (Print)
IS  - 0022-538X (Linking)
VI  - 94
IP  - 16
DP  - 2020 Jul 30
TI  - Porcine Epidemic Diarrhea Virus Deficient in RNA Cap Guanine-N-7 Methylation Is 
      Attenuated and Induces Higher Type I and III Interferon Responses.
LID - 10.1128/JVI.00447-20 [doi]
LID - e00447-20
AB  - The 5' cap methylation of viral RNA plays important roles in RNA stability, 
      efficient translation, and immune evasion. Thus, RNA cap methylation is an 
      attractive target for antiviral discovery and development of new live attenuated 
      vaccines. For coronaviruses, RNA cap structure is first methylated at the 
      guanine-N-7 (G-N-7) position by nonstructural protein 14 (nsp14), which 
      facilitates and precedes the subsequent ribose 2'-O methylation by the 
      nsp16-nsp10 complex. Using porcine epidemic diarrhea virus (PEDV), an 
      Alphacoronavirus, as a model, we showed that G-N-7 methyltransferase (G-N-7 
      MTase) of PEDV nsp14 methylated RNA substrates in a sequence-unspecific manner. 
      PEDV nsp14 can efficiently methylate RNA substrates with various lengths in both 
      neutral and alkaline pH environments and can methylate cap analogs (GpppA and 
      GpppG) and single-nucleotide GTP but not ATP, CTP, or UTP. Mutations to the 
      S-adenosyl-l-methionine (SAM) binding motif in the nsp14 abolished the G-N-7 
      MTase activity and were lethal to PEDV. However, recombinant rPEDV-D350A with a 
      single mutation (D350A) in nsp14, which retained 29.0% of G-N-7 MTase activity, 
      was viable. Recombinant rPEDV-D350A formed a significantly smaller plaque and had 
      significant defects in viral protein synthesis and viral replication in Vero 
      CCL-81 cells and intestinal porcine epithelial cells (IPEC-DQ). Notably, 
      rPEDV-D350A induced significantly higher expression of both type I and III 
      interferons in IPEC-DQ cells than the parental rPEDV. Collectively, our results 
      demonstrate that G-N-7 MTase activity of PEDV modulates viral replication, gene 
      expression, and innate immune responses.IMPORTANCE Coronaviruses (CoVs) include a 
      wide range of important human and animal pathogens. Examples of human CoVs 
      include severe acute respiratory syndrome coronavirus (SARS-CoV-1), Middle East 
      respiratory syndrome coronavirus (MERS-CoV), and the most recently emerged 
      SARS-CoV-2. Examples of pig CoVs include porcine epidemic diarrhea virus (PEDV), 
      porcine deltacoronavirus (PDCoV), and swine enteric alphacoronavirus (SeACoV). 
      There are no vaccines or antiviral drugs for most of these viruses. All known 
      CoVs encode a bifunctional nsp14 protein which possesses ExoN and guanine-N-7 
      methyltransferase (G-N-7 MTase) activities, responsible for replication fidelity 
      and RNA cap G-N-7 methylation, respectively. Here, we biochemically characterized 
      G-N-7 MTase of PEDV nsp14 and found that G-N-7 MTase-deficient PEDV was defective 
      in replication and induced greater responses of type I and III interferons. These 
      findings highlight that CoV G-N-7 MTase may be a novel target for rational design 
      of live attenuated vaccines and antiviral drugs.
CI  - Copyright (c) 2020 American Society for Microbiology.
FAU - Lu, Yunjian
AU  - Lu Y
AD  - College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 
      Jiangsu, People's Republic of China.
AD  - Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio 
      State University, Columbus, Ohio, USA.
FAU - Cai, Hui
AU  - Cai H
AD  - Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio 
      State University, Columbus, Ohio, USA.
FAU - Lu, Mijia
AU  - Lu M
AD  - Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio 
      State University, Columbus, Ohio, USA.
FAU - Ma, Yuanmei
AU  - Ma Y
AD  - Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio 
      State University, Columbus, Ohio, USA.
FAU - Li, Anzhong
AU  - Li A
AD  - Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio 
      State University, Columbus, Ohio, USA.
FAU - Gao, Youling
AU  - Gao Y
AD  - Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio 
      State University, Columbus, Ohio, USA.
FAU - Zhou, Jiyong
AU  - Zhou J
AUID- ORCID: 0000-0002-8852-1227
AD  - MOA Key Laboratory of Animal Virology, Department of Veterinary Medicine and 
      Center of Veterinary Medical Science, Zhejiang University, Hangzhou, People's 
      Republic of China.
FAU - Gu, Howard
AU  - Gu H
AD  - Department of Biological Chemistry and Pharmacology, College of Medicine, The 
      Ohio State University, Columbus, Ohio, USA.
FAU - Li, Jianrong
AU  - Li J
AD  - Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio 
      State University, Columbus, Ohio, USA li.926@osu.edu gjy@zju.edu.cn.
FAU - Gu, Jinyan
AU  - Gu J
AD  - College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 
      Jiangsu, People's Republic of China li.926@osu.edu gjy@zju.edu.cn.
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20200730
PL  - United States
TA  - J Virol
JT  - Journal of virology
JID - 0113724
RN  - 0 (Interferon Type I)
RN  - 0 (RNA Caps)
RN  - 0 (RNA, Viral)
RN  - 0 (Viral Nonstructural Proteins)
RN  - 5Z93L87A1R (Guanine)
RN  - 7LP2MPO46S (S-Adenosylmethionine)
RN  - 9008-11-1 (Interferons)
RN  - EC 3.1.- (Exoribonucleases)
RN  - 0 (Interferon Lambda)
SB  - IM
MH  - Animals
MH  - Binding Sites
MH  - Cell Line
MH  - Chlorocebus aethiops
MH  - Exoribonucleases/genetics/*metabolism
MH  - Gene Expression
MH  - Guanine/metabolism
MH  - Immunity, Innate
MH  - Interferon Type I/*biosynthesis
MH  - Interferons/*biosynthesis
MH  - Methylation
MH  - Mutation
MH  - Porcine epidemic diarrhea virus/enzymology/genetics/pathogenicity/*physiology
MH  - RNA Caps/*metabolism
MH  - RNA, Viral/metabolism
MH  - S-Adenosylmethionine/metabolism
MH  - Swine
MH  - Vero Cells
MH  - Viral Nonstructural Proteins/genetics/*metabolism
MH  - Virus Replication
MH  - Interferon Lambda
PMC - PMC7394890
OTO - NOTNLM
OT  - Porcine epidemic diarrhea virus
OT  - RNA methylation
OT  - coronavirus
EDAT- 2020/05/29 06:00
MHDA- 2020/08/05 06:00
PMCR- 2021/01/30
CRDT- 2020/05/29 06:00
PHST- 2020/03/13 00:00 [received]
PHST- 2020/05/16 00:00 [accepted]
PHST- 2020/05/29 06:00 [pubmed]
PHST- 2020/08/05 06:00 [medline]
PHST- 2020/05/29 06:00 [entrez]
PHST- 2021/01/30 00:00 [pmc-release]
AID - JVI.00447-20 [pii]
AID - 00447-20 [pii]
AID - 10.1128/JVI.00447-20 [doi]
PST - epublish
SO  - J Virol. 2020 Jul 30;94(16):e00447-20. doi: 10.1128/JVI.00447-20. Print 2020 Jul 
      30.