Interaction of the cytoplasmic region of CD43 with moesin and ezrin from Jurkat cell lysates. (A) Coomassie blue-stained SDS-PAGE of GST-CyD7CD43 fusion protein purified with glutathione Sepharose 4B beads. (B) Specific association of two proteins of 78 and 80 kD with GST-CyD7CD43. Jurkat cells were metabolically labeled and lysed. After discarding cell debris and nuclei, supernatants were collected and allowed to bind to equivalent amounts of GST and GST-CyD7CD43 proteins bound to glutathione Sepharose 4B beads by overnight incubation at 4°C. Bound proteins were sequentially washed with lysis buffer containing 0.1% SDS and 0.65 mol/L NaCl and then subjected to 8% SDS-PAGE. Before drying, the gel was incubated for 30 minutes in Amplify solution (Amersham Corp). (C) Precipitates from unlabeled Jurkat cells were performed as in (B), SDS-PAGE separated, and immunoblotted with the antimoesin 95/2 (lanes 1 and 2) or the antiezrin 90/3 (lanes 3 and 4) pAb. Molecular weights in kilodaltons are indicated at the right.