Physical interaction of Epi and 2OST. (A) CHO cells expressing GlcATI-GFP, Epi-Myc, or 2OST-GFP were extracted in buffer containing 50 mM Mes (pH 6.5), 0.5% Triton X-100, and 0, 150, or 300 mM NaCl as indicated. The cell extracts were centrifuged, separated by SDS/gel electrophoresis, and analyzed by immunoblotting (Materials and Methods). (B) Samples of cells containing Epi-Myc and 2OST-GFP were immunoprecipitated with antibody to GFP and analyzed by SDS/PAGE. Lane 1, Western blot using mouse anti-Myc mAb. Lane 2, Western blot using mouse anti-GFP mAb.