Bat severe acute respiratory syndrome-like coronavirus ORF3b homologues display different interferon antagonist activities.
The ORF3b protein of severe acute respiratory syndrome coronavirus (SARS-CoV) has a nuclear localization signal (NLS) at its C terminus and antagonizes interferon (IFN) function by modulating the activity of IFN regulatory factor 3 (IRF3). SARS-like coronaviruses (SL-CoVs) found in bats share an identical genome organization and high sequence identity for most of their gene products. In this study, ORF3b homologues were identified from three bat SL-CoV strains. These ORF3b homologues were C-terminally truncated and lacked the C-terminal NLS of SARS-CoV. IFN antagonist activities analysis demonstrated that one SL-CoV ORF3b still possessed IFN antagonist and IRF3-modulating activities. These results indicate that different ORF3b proteins display different IFN antagonist activities and this function is independent of the protein's nuclear localization, suggesting a potential link between bat SL-CoV ORF3b function and viral pathogenesis.
State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, Republic of China.
Peng
P
Zhou
State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, Republic of China.
Hongxia
H
Li
State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, Republic of China.
Hanzhong
H
Wang
Australian Animal Health Laboratory, Commonwealth Scientific and Industrial Research Organisation Livestock Industries, Geelong, Victoria, Australia.
Lin-Fa
LF
Wang
State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, Republic of China.
Zhengli
Z
Shi
D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D002685:Chiroptera / Q000821:virology*; D006801:Humans; D057131:Immune Evasion; D050838:Interferon Regulatory Factor-3 / Q000378:metabolism*; D007372:Interferons / Q000037:antagonists & inhibitors*; D008969:Molecular Sequence Data; D019913:Nuclear Localization Signals; D045473:Severe acute respiratory syndrome-related coronavirus / Q000276:immunology* / Q000302:isolation & purification / Q000472:pathogenicity; D017386:Sequence Homology, Amino Acid; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism*; D014774:Virulence; D037521:Virulence Factors / Q000235:genetics / Q000378:metabolism*
D050838:Interferon Regulatory Factor-3; D019913:Nuclear Localization Signals; D014764:Viral Proteins; D037521:Virulence Factors; D007372:Interferons