Figure 7. Proteoglycans and proteoglycan-binding ligands are trafficked to late endosomes independently of microtubule-dependent motion or PI(3)K-dependent sorting from early endosomes.

A) Fraction of polyplexes, lipoplexes, PA-QDs, anti-HSPG, and LDL colocalized with Rab5 (gray) and Rab9 (black) at 1 hour after incubation with nocodazole-treated cells (solid columns). The majority of polyplexes, lipoplexes, PA-QDs, and anti-HSPG accumulate in endosomes that contain only Rab 9 but not Rab5. In contrast, the majority of LDL particles colocalize with both Rab5 and Rab9. The dashed columns show results for LDL in untreated control cells for comparison. Error bars indicate standard deviation. G) PtdIns3P-dependent sorting from early endosomes is not required for late endosomal entry of cationic ligands and HSPG. Fraction of polyplexes, lipoplexes, PA-QDs, and anti-HSPG in late endosomes that contain Rab9, but not Rab5, is similar in untreated cells and in cells treated with wortmannin, an inhibitor of PI(3)K. In comparison, colocalization of LDL with Rab9 is substantially reduced by wortmannin treatment. Measurements were done 1 hour post-endocytosis. Error bars indicate standard deviation.