Fig. 3.

Interactions of 8a, 8b and 8ab with other SARS-CoV proteins. Cell lysates containing myc-GST (lane 1), 8a-myc (lane 2), 8b-myc (lane 3) or 8ab-myc (lane 4) and another SARS-CoV protein (S, E, M-HA, N, 3a or 7a) were immunoprecipitated with an anti-myc polyclonal antibody and protein A-agarose beads. (A) The amounts of S protein co-immunoprecipitated (IP) by the myc-tagged proteins were determined using an anti-S monoclonal antibody (top panel). The amounts of S and myc-tag proteins in the lysates before co-immunoprecipitation were also determined by Western blot (WB) with anti-S and anti-myc monoclonal antibodies, respectively (middle and bottom panels). The same experiments were performed for panels B–F except that different antibodies against the specific viral proteins were used, namely (B) anti-E mouse polyclonal; (C) anti-HA monoclonal (as the M protein fused with a HA tag at the C terminus); (D) anti-N mouse polyclonal; (E) anti-3a mouse polyclonal; (F) anti-7a mouse polyclonal.