Trafficking of lysosomal membrane proteins in polarized kidney cells.

Segregation of lysosomal membrane proteins into the endosomal system occurs via clathrin coated vesicles, either from the trans-Golgi network or the cell surface. In both cases, cytosolic signals present in these proteins interact with clathrin adaptor proteins. In polarized kidney MDCK cells, transport of lysosomal membrane proteins via the plasma membrane occurs in a polarized fashion through the basolateral domain. Here, we discuss recent developments on lysosomal membrane protein trafficking, with a particular focus on the transport of these proteins in polarized MDCK cells.