Levels of CD150, pERK1/2, and pAkt expressed in DT40 transfectants. (A) Cell surface expression of CD150 on DT40 transfectants. DT40 cells were transfected with CD150 alone or together with SH2D1A. Stable transfectants were stained with the anti-CD150 mAb IPO-3 or with isotype-matched mAb (dotted histograms) and evaluated by flow cytometry analysis. (B) Basal levels of ERK1/2 and Akt phosphorylation in DT40 transfectants. Transfection of CD150 with or without SH2D1A into DT40 cell line did not induce changes in the basal levels of ERK1/2 and Akt phosphorylation compared to WT DT40 cells and WT DT40 cells transfected with empty vector. Western blot analyses of cell lysates. Western blot with anti-actin serum served as a control for equal protein loading (bottom panel).