Fig. 4

The endoribonuclease activity of nsp11 was important for nsp11 to enhance the PRRSV titers. MARC-145 cells cultured in 24-well plate were transfected with pcDNA3.1-FLAG-nsp11 (nsp11) (800 ng/well), pcDNA3.1-FLAG-nsp11 H129A (nsp11 H129A) (800 ng/well) or pcDNA 3.1-FLAG (Con). And 6 h later, the cells were infected with PRRSV at an MOI of 0.1 or mock infected, and 24 h later, the cells were lysed by freezing and thawing three times in three cycles, then the viral titers were measured by TCID50. Data represented means of three replicates, and experiments were repeated three times. Error bars represented the standard deviations. *: P <0.05 compared with the results in control. MOI, multiplicity of infection