PIP2 binding is required for the association of moesin with the cytoplasmic tails of CD44, CD43, ICAM2, and ICAM3. (A) Effects of phospholipids or IP3 on the interaction between moesin and cytoplasmic tails of CD44, CD43, ICAM2, and ICAM3. The bound proteins by GST-tagged tails in the pellet were detected with antimoesin antibody and are shown in the top panel. Arrowheads indicate the intact protein in the lanes where degredation products also exist. (B) The effects of T558D mutation mimicking phosphorylation, K4N mutations, or their combination on the activation of moesin for CD44 tail binding. The bound proteins shown in the top panel were detected by WB. Further characterization of the recombinant protein is shown in Fig. S2 (available). GST (as control) or GST fusion proteins in the pellet were detected with Coomassie blue staining and are shown in the bottom panels. Each lane represents 40% of the amount of protein in the pellet. PI, phosphatidylinositol; PS, phosphatidylserine.