Figure 6.

Immunogold labeling of endocytic compartments isolated by sucrose gradient with anti-MMIα antibodies and antibodies directed against specific markers of endocytic compartments (transferrin receptor and lgp 120). Fractions collected after separating the postnuclear supernatant from BWTG3 cells by a sucrose density gradient and enriched in endocytic markers (see Figure 5B, lane E) were loaded onto EM grids. These membrane vesicles were double immunogold labeled (A) with anti-Myr 1 antibodies (Tu 30, PAG 15) and anti-transferrin receptor antibody (PAG 10; B), with anti-Myr 1 antibodies (PAG 15) and anti-cytoplasmic tail lgp 120 antibodies (PAG 10), and (C and D) with anti-BBMI antibody (CX-1; PAG 15) and anti-β-actin antibodies (PAG 10). (D) Cells were treated with cytochalasin D before fractionation. Bars, 200 nm