FIGURE 5.

BCR ligation induces the association of Ag-μm, but not Ig-α, with clathrin-coated vesicles. Cells were fixed, then stained with PC₁₀BSA-gold (10 nm; large arrows) and clathrin (5 nm; small arrows; A) or stimulated for 5 min before preparation and staining of native membranes (B). Inset, Higher magnification of μm association with CCVs. The large and small arrows represent some of the large and small gold particles. C, Cells were prepared as described in A and then stained with an isotype-matched, polyclonal mouse IgG Ab (5 nm). Arrows depict 10 nm gold particles. D, Cells were stimulated with BSA-gold (10 nm) for 5 min before the preparation of native membranes and then stained for clathrin (5 nm). Arrows depict 5 nm particles staining CCVs. Cells were fixed and then stained for Ig-α (12 nm; large arrows) and clathrin (5 nm; small arrows; E) or stimulated with PC₁₀BSA for 5 min before preparation and staining of native membranes (F). The data are representative of 5–10 experiments. Bar = 100 nm.