Clathrin is a protein and so is made on ribosomes outside th

Clathrin is a protein and so is made on ribosomes outside the ER. From what you know of its function, what localization sequence, if any, would you expect to find within the clathrin amino acid sequence? Why?

Solution

Clathrin-coated vesicles transport materials from the trans-Golgi network to endosomes, lysosomes, and plant vacuoles. They also move materials from the plasma membrane to cytoplasmic compartments via endocytic pathway. They have also been associated in trafficking from endosomes and lysosomes. Yeast and other organisms, make a single type of clathrin heavy chain and a single type of clathrin light chain; thus, they make a single type of clathrin coat. It is a trimer of three heavy chains, each with an associated light chain. The heavy chain has an amino-terminal, -propeller domain, followed in the polypeptide chain by 42 -helical zig-zags of approximately 30 amino acid residues each and a 45-residue carboxy-terminal segment with poorly defined structure. The carboxy-terminal segment comprises a short region with an amino acid sequence that is specially recognized by Hsc70 and prerequisite for Hsc70-facilitated uncoating. There are no specific localization sequences are observed in clathrin proteins.