The Ep152R ORF of African Swine Fever Virus strain Georgia encodes for an essential gene that interacts with host protein BAG6

Authors: Borca, Manuel; O'DONNELL, VIVIAN - University Of Connecticut; Holinka-Patterson, Lauren; RAI, DEVENDRA - University Of Connecticut; SANFORD, BRENTON - Former ARS Employee; ALFANO, MARIALEXIA - Oak Ridge Institute For Science And Education (ORISE); CARLSON, JOLENE - Kansas State University Agricultural Research Center-Hays; AZZINARO, PAUL - Oak Ridge Institute For Science And Education (ORISE); ALONSO, COVADONGA - Department Of Biotechnology - Spain; Gladue, Douglas

Submitted to: Virus Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/29/2016
Publication Date: 8/3/2016
Publication URL: http://handle.nal.usda.gov/10113/63049
Citation: Borca, M.V., O'Donnell, V., Holinka-Patterson, L.G., Rai, D., Sanford, B., Alfano, M., Carlson, J., Azzinaro, P., Alonso, C., Gladue, D.P. 2016. The Ep152R ORF of African Swine Fever Virus strain Georgia encodes for an essential gene that interacts with host protein BAG6. Virus Research. 223:181-189. doi: 10.1016/j.virusres.2016.07.013.

Interpretive Summary: African swine fever virus (ASFV) causes lethal disease in swine. The virus DNA codes for many different genes. However, very few of these genes have been studied and their function remains largely unknown. We used computer based studies of some of these unknown proteins to predict their potential function. One such protein called Ep152R, is similar to proteins in other viruses whose function is to interfere with immune responses. In ASFV Ep152R is an essential protein and viruses in which this protein was deleted were not viable. We found that this protein, made early during viral infection, interacts with a cellular protein that is essential for viral replication. This information is important in our continued quest for effective vaccines against African swine fever.

Technical Abstract: African swine fever virus (ASFV) is the etiological agent of a contagious and often lethal disease of domestic pigs that has significant economic consequences for the swine industry. The viral genome encodes for more than 150 genes, and only a select few have been studied in some detail. Here we report the characterization of open reading frame Ep152R predicted to have a complement control module/SCR domain which similar to Vaccinia virus proteins involved in blocking the immune response during viral infection. A recombinant ASFV harboring a HA tagged version of the EP152R protein was developed (ASFV-G-EP152R-HA) and used to demonstrate that EP152R is an early virus protein. Attempts to construct recombinant viruses having a deleted EP152R gene, were consistently unsuccessful indicating that EP152R is an essential gene. Interestingly, analysis of host-protein interactions between EP152R with using a yeast two-hybrid screen, identified BAG6, a protein previously identified as being required for ASFV replication. Furthermore, fluorescent microscopy analysis confirms that EP152R-BAG6 interaction actually occurs in cells infected with ASFV.