Parasite-dependent exclusion of Csk from Hck-positive GEMs.

(Ai-v) GEMs were isolated from untreated or BW720c-cured TpM409 cells by Tx-100 solubilization and sucrose gradient centrifugation. Eleven fractions of the sucrose gradient were analyzed by Western blotting. The GEMs concentrate mainly in fraction 4, whereas Tx-100–soluble material accumulates in fractions 10 and 11. The antibodies used for Western blotting are indicated at the top of each panel (identical membrane was used for each panel shown). (B) GEM fractions are free of plasma membrane marker-transferrin receptor (TfR): Fractions 4 (GEM fraction) and 11 (Tx-100 soluble) were probed with anti-Hck (top), Csk (middle), and TfR (bottom).