Relationships between sorting in the exocytic and endocytic pathways of MDCK cells.

Epithelial cells use both the exocytic and endocytic pathways to generate and maintain the polarized distribution of membrane proteins. This review summarizes current information concerning the general features and functions of the exocytic and endocytic pathways in MDCK cells. We analyse the possible implications of similarities between signals for endocytosis and determinants for basolateral sorting in the TGN. Furthermore, we discuss the fundamental relationships that might also exist in the biochemical basis of membrane traffic in the two pathways.