Figure 1.

Overview of endosomal sorting pathways. Cargo in the endosome is sorted either into the degradative pathway, leading to its eventual delivery to the lysosome, or into an export pathway that returns it to another organelle for reuse. Recycling export pathways deliver cargo to the plasma membrane, and retrograde export pathways return cargo to the trans-Golgi network. Sorting devices that act in each of these export pathways are listed. Transport carriers of the export pathways bud from the tubular endosomal network, whereas sorting into the lysosomal degradation pathway results in packaging of cargo into vesicles that bud into the lumen of multivesicular endosomes.