VeroE6 cells were mock-infected or infected with MP-12 or recombinant MP-12 encoding partially truncated NSs at an moi of 4 in 6-well plate. At 16 hpi, cells were collected, and washed once in PBS. Then, cytoplasmic fraction was lyzed with PBS containing 1% TritonX-100 on ice for 5 min. After centrifugation at 10,000 xg at 4 u C for 5 min, nuclear fraction was washed once with cold PBS, and resuspended in PBS containing 1% TritonX-100. Both cytoplasmic and nuclear fractions were mixed with 26 SDS sample buffer, and subjected to SDS-PAGE and Western blot analysis.