The AP-1 adaptor complex has been cast as the major player in clathrin coat
formation for vesicular transpirt from the trans-Golgi to the endocytic pa
thway. But new results on 'GGA' proteins have raised doubts about this para
digm and suggest both a new sorting mechanism and an unexpected complexity
in the roles of clathrin. (C) 2001 Elsevier Science Ltd. All rights reserve
d.