Receptor-Mediated Endocytosis

Schematic representation of the endocytic pathway and membrane trafficking. Ligands, such as hormones and growth factors, bind to specific surface receptors and are internalized in pinocytotic vesicles coated with clathrin and other proteins. After the liberation of the coating molecules, the pinocytotic vesicles fuse with the endosomal compartment, where the low pH causes the separation of the ligands from their receptors. Membrane with receptors is returned to the cell surface to be reused. The ligands typically are transferred to lysosomes. The cytoskeleton with motor proteins is responsible for all vesicle movements described.