Figure 2.

NS5A specifically and directly interacts with Grb2. Cell lysates from HeLa cells stably expressing NS5A (A) or purified recombinant NS5A proteins (B) were incubated with GST or the indicated GST fusion protein immobilized on glutathione-agarose beads as described in Materials and Methods. Precipitates were washed and resolved by SDS/PAGE, immunoblotted with anti-NS5A (α-NS5A; Upper) or anti-GST (α-GST; Lower). (C) Reciprocal experiments by using GST-NS5A to precipitate endogenous Grb2. The position of NS5A is indicated by the arrow. The molecular size standards are shown in kilodaltons.