Clathrin is a major protein component of the cytoplasmic face of intracellular organelles, called coated vesicles and coated pits. These specialized organelles are involved in the intracellular trafficking of receptors and endocytosis of a variety of macromolecules. The basic subunit of the clathrin coat is composed of three heavy chains (192 kDa) and three light chains (LCa or LCb, 25-29 kDa) and self assembles into a polyhedral cytoskeletal element. Self assembly facilitates clathrin's central role in membrane sorting and selective transport within the cell.
