Receptor-Mediated Endocytosis and Differentiation in Proximal Tubule Cell Systems.

The epithelial cells lining the proximal tubule (PT) of the kidney rely on multiligand receptors and vesicular membrane pathways to efficiently reabsorb essential nutrients and low–mol wt proteins (Figure 1A).1 The endolysosome stands at the crossroads of this network, processing incoming solutes, sorting receptors and/or transporters, and regulating balance between proliferation and differentiation in PT cells, hence their role in homeostasis.2,3 A major concern is to use PT cell systems that recapitulate these crucial properties, which are relevant for congenital and acquired disorders targeting the PT.