Tpo-mediated internalization of c-Mpl is dependent on clathrin, Jak2 and SFKs. (A) BaF-Mpl cells were stimulated with 50 ng/mL rhTpo for increasing periods of time, and cell-surface expression of c-Mpl was analyzed by flow cytometry. Error bars represent SE. Receptor internalization was determined in the presence of inhibitors to clathrin (B) and a panel of protein kinases (C). (D,E) The effects of JAKI and SU6656 were further determined by concentration response. The percentage of baseline c-Mpl cell-surface expression is determined by comparing Tpo-treated cells with unstimulated cells. All data are representative of at least 3 independent experiments using 2 BaF-Mpl clones.