Recognition of sorting signals by clathrin adaptors

Sorting of membrane proteins is generally mediated by cytosolic coats, whic h create a scaffold to form coated buds and vesicles and to selectively con centrate cargo by interacting with cytosolic signals. The classical paradig m is the interaction between clathrin coats and associated adaptor proteins , which cluster receptors with characteristic tyrosine and dileucine motifs during endocytosis. Clathrin in association with different sets of adaptor s is found in addition at the trans-Golgi network and endosomes. Sequences similar to internalization signals also direct lysosomal and basolateral so rting, which implicates related clathrin-adaptor coats in the respective so rting pathways. This review concentrates on the recognition of sorting sign als by clathrin-associated adaptor proteins, an area of significant recent progress due to new methodological and conceptual approaches. (C) 1999 John Wiley & Sons, Inc.