Protein and lipid sorting from the trans-Golgi network to the plasma membrane in polarized cells

The targeting of proteins and lipids to the cell surface domains of polarized cells is not a simple bulk flow process but requires sorting into distinct apical and basolateral pathways from the trans-Golgi network. Here, we describe the sorting determinants in the cargo molecules, the cellular sorting machineries responsible for the hierarchical read-out of the signals, and the mechanisms of cargo delivery. Furthermore, we discuss the implications of these findings for protein-lipid interactions in other cellular machineries.