FIG 9.

PRRSV nsp11 interacts with STAT2 in infected cells, and residue K59 is essential for STAT2 reduction. (A) STAT2 IP precipitates nsp11 in PRRSV-infected MARC-145 cells. The cells were infected with PRRSV VR-2385 at an MOI of 1 and harvested at 36 hpi for IP with STAT2 antibody, followed by WB with rabbit antibodies against PRRSV nsp11 and nsp1β. WB of input was included as s control. (B) Sequencing of the cDNA of mutant VR-2385 with nsp11 K59A confirms the presence of codon mutation in its genome. The numbers above the sequence indicate nucleotide positions in the cDNA of the VR-2385 genome. The bar below the chromatogram indicates the codon change from AAA(Lys) to GCA(Ala) in nsp11. (C) Mutant PRRSV VR-2385 with nsp11 K59A has much less effect on STAT2 than does the wild-type (WT) virus in MARC-145 cells. The cells were infected with the mutant virus and WT VR-2385 at an MOI of 1 and harvested at 36 hpi for WB.