Fig. 7. CD24 affects the localization of CXCR4 in lipid rafts. (A) Distribution of CD24 in membrane rafts isolated from CD24^+/+ 18H18+ cells. Gradient fractions were probed with mAb M1.69 to mouse CD24 followed by peroxidase-conjugated secondary antibody and ECL detection. (B) Distribution of CXCR4 in raft and non-raft fractions of the indicated pre-B-cell lines (upper panels). Note the presence of CXCR4 only in raft fraction 2 of CD24^–/– cells (*). Distribution of Fyn in raft and non-raft fractions of the indicated pre-B cell lines (lower panels). Note the presence of Fyn in raft fraction 2 of all cell lines. (C) Distribution of CXCR4 in raft and non-raft fractions of CD24^high and CD24^low MDA-MB-231 CXCR4-GFP cells. Note the presence of CXCR4 in raft fraction 2 of only CD24^low cells as indicated with (*) and the equal presence of Fyn in both cell lines.