Figure 8.

Depletion of hVps24 causes accumulation of small MVEs. EM of EGFR-labeled endosomes/MVEs. (A) EGFR labeling in control cell within a typical endosome with multivesicular appearance. Note that the MVE contains numerous intraluminal vesicles and that most of the labeling is found on these vesicles. (C) Overview of a group of endosomes illustrating the homogenous morphology of EGFR-positive endosomes. (B) In RNAi-treated cells, the EGFR-positive vesicles are significantly smaller than control MVEs and contain seemingly fewer intraluminal vesicles. EGFR labeling is found on these vesicles, which do not seem so homogeneous in size compared with control cells. (D) Overview of a group of endosomes and lysosomes in an RNAi-treated cell. Arrowheads in C and D indicate EGFR labeling. Bars, 200 nm. (E) Estimation of the mean vesicle diameter of EGFR-positive endosomes in control and RNAi-treated cells (control cells, n = 76; RNAi-treated cells, n = 68; 3 separate experiments). The difference in diameter between the two groups is ∼30%. Significance level by Student's t test (p ≤ 0.005).