Complete reconstitution of clathrin basket formation with recombinant protein fragments: Adaptor control of clathrin self-assembly

Clathrin polymerization into a polyhedral basket, surrounding budding membr ane vesicles, mediates protein sorting during endocytosis and organelle bio genesis. Adaptor proteins target clathrin assembly to specific membrane sit es and sequester receptors into the clathrin coat. We have reconstituted co mplete clathrin basket formation from recombinantly expressed fragments of clathrin and adaptors. This reconstitution reveals a hierarchy of clathrin self-assembly interactions and demonstrates that adaptors control basket fo rmation by alignment of the distal domains of the clathrin triskelion leg t hrough their binding to the terminal domain.