Figure 3.

RID-α induces formation of a hybrid organelle with characteristics of both endocytic and autophagic vesicles. (a) CHO–RID-α cells stained with LAMP1 and RID-α antibodies after incubation with DiI-LDL. Arrows denote the RID-α compartment. (b) CHO–RID-α cells stained for LC3 and RID-α after incubation with MDC. (c) Parental CHO or CHO–RID-α cells stained for LC3 or LC3 and RID-α under basal conditions (left) or after 6-h incubation in Earl’s balanced salt solution to induce autophagy (middle and right). (d and e) CHO–RID-α cells stained for RID-α and β-COP (d) or ORP1L (e). (f and g) Magnified images of single and merged channels of CHO–RID-α cells triple stained for RID-α and ORP1L and either β-COP (f) or LC3 (g). Arrowheads denote compartments with colocalized markers. (h) Parental CHO cells stained for β-COP and ORP1L. (i–k) CHO–RID-α (C67S) cells stained for RID-α and LC3 (i), β-COP (j), or ORP1L (k). (a–e and h–k) Cell and nucleus (Nu) boundaries were drawn using MetaMorph software. Boxed areas show regions of the image that were magnified. Bars, 10 µm.