The 7a accessory protein of severe acute respiratory syndrome coronavirus acts as an RNA silencing suppressor.
RNA silencing suppressors (RSSs) are well studied for plant viruses but are not well defined to date for animal viruses. Here, we have identified an RSS from a medically important positive-sense mammalian virus, Severe acute respiratory syndrome coronavirus. The viral 7a accessory protein suppressed both transgene and virus-induced gene silencing by reducing the levels of small interfering RNA (siRNA). The suppression of silencing was analyzed by two independent assays, and the middle region (amino acids [aa] 32 to 89) of 7a was responsible for suppression. Finally, the RNA suppression property and the enhancement of heterologous replicon activity by the 7a protein were confirmed for animal cell lines.
Karjee
Sumona
S
Virology & Plant Molecular Biology Groups, International Center for Genetic Engineering and Biotechnology, Aruna Asaf Ali Road, New Delhi 110067, India.
Minhas
Ankita
A
Sood
Vikas
V
Ponia
Sanket S
SS
Banerjea
Akhil C
AC
Chow
Vincent T K
VT
Mukherjee
Sunil K
SK
Lal
Sunil K
SK
D002460:Cell Line; D005814:Genes, Viral; D006801:Humans; D010942:Plant Viruses / Q000235:genetics / Q000502:physiology; D030821:Plants, Genetically Modified / Q000235:genetics / Q000821:virology; D034622:RNA Interference / Q000502:physiology*; D034741:RNA, Small Interfering / Q000235:genetics; D012367:RNA, Viral / Q000235:genetics; D045473:Severe acute respiratory syndrome-related coronavirus / Q000235:genetics* / Q000472:pathogenicity / Q000502:physiology*; D013489:Suppression, Genetic; D014763:Viral Matrix Proteins / Q000737:chemistry / Q000235:genetics* / Q000502:physiology*
D034741:RNA, Small Interfering; D012367:RNA, Viral; D014763:Viral Matrix Proteins; C488151:sars7a protein, SARS virus