BIOL 2021 Chapter Notes - Chapter 13.8: Clathrin, Dynamin, Hsp70
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Q: many organisms make only one kind of clathrin and therefore only a single type of clathrin coat, but there are 3 different transport pathways that use clathrin coats. How can the same coat be used for different transport pathways carrying different cargo? (where does the specificity come from?) A: different types of adaptins allow different cargo receptors to be transported. Specificity is maintained by: adaptor proteins select different receptors, receptors select different cargo. The coat forms the correct shape spontaneously. Dynamin helix and associated proteins pinches off the vesicle by forming a helix and wrapping around it. Uses gtp for energy (dynamin is a gtpase) Hsp70 chaperones use atp to remove clathrin. Free clathrin stores energy in its conformation. Clathrin is now in a high energy state and when it meets up with other clathrins, it will spontaneously form a coat to go into its low energy form. Lipids and proteins are responsible for this.