Overexpression of 7a, a protein specifically encoded by the severe acute respiratory syndrome coronavirus, induces apoptosis via a caspase-dependent pathway.
Besides genes that are homologous to proteins found in other coronaviruses, the severe acute respiratory syndrome coronavirus genome also contains nine other potential open reading frames. Previously, we have characterized the expression and cellular localization of two of these "accessory" viral proteins, 3a (previously termed U274) and 7a (previously termed U122). In this study, we further examined whether they can induce apoptosis, which has been observed clinically. We showed that the overexpression of 7a, but not of 3a or the viral structural proteins, nucleocapsid, membrane, and envelope, induces apoptosis. 7a induces apoptosis via a caspase-dependent pathway and in cell lines derived from different organs, including lung, kidney, and liver.
Tan
Yee-Joo
YJ
Institute of Molecular and Cell Biology, Proteos, Singapore. mcbtanyj@imcb.a-star.edu.sg.
Fielding
Burtram C
BC
Goh
Phuay-Yee
PY
Shen
Shuo
S
Tan
Timothy H P
TH
Lim
Seng Gee
SG
Hong
Wanjin
W
D000818:Animals; D017209:Apoptosis; D019556:COS Cells; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism*; D002460:Cell Line; D002522:Chlorocebus aethiops; D006367:HeLa Cells; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D045473:Severe acute respiratory syndrome-related coronavirus / Q000235:genetics / Q000472:pathogenicity*; D014709:Vero Cells; D014763:Viral Matrix Proteins; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism*
D008565:Membrane Proteins; D014763:Viral Matrix Proteins; D014764:Viral Proteins; C488151:sars7a protein, SARS virus; C505407:CASP3 protein, human; D053148:Caspase 3; D020169:Caspases