Adaptin is a protein mediating the formation of clathrin-coated pits, through interaction with membrane-bound receptors. There are several types of adaptin, each related to a different group of such receptors.
Adaptin shows sequence similarity to some COPI subunits, thus they are thought to have a common evolutionary origin.
References
Alberts, Johnson, Lewis, Raff, Roberts, Walter: Molecular Biology of the Cell, 4th edition (2002), Garland Science.
