FIG 6.

PRRSV nsp5 reduces the STAT3 protein level. (A) nsp5 reduces STAT3 protein level in a dose-dependent manner. HEK293 cells were transfected with nsp5 plasmid in incremental amounts. WB analyses with antibodies against STAT3, HA, and tubulin were conducted at 48 hpt. The relative levels of STAT3 are shown below the images after normalization with tubulin. (B) 3-MA treatment is unable to rescue STAT3 protein level in HEK293 cells cotransfected with 0.5 μg of HA-nsp5 and 0.5 μg of STAT3 plasmid. Mock-treated cells were included as controls. The cells were treated with 3-MA for 24 h before being harvested for WB. The relative levels of STAT3 protein are shown below the images. (C) nsp5 has no effect on STAT1 protein level. HEK293 cells were transfected with 0.5 μg of pCAGEN-HA-nsp5 plasmid and 0.5 μg of pEGFP-C1-STAT1 plasmid. WB against STAT1 antibody was performed at 36 hpt. The relative levels of STAT1-GFP are shown below the images.