Biology 2382B Lecture Notes - Lecture 6: Cholesteryl Ester, Transferrin Receptor, Clathrin
Document Summary
Macrophage engulfs and digests a large structure. Small indentation in membrane and take up small amounts of extracellular fluid. A method of selective internalization of specific extracellular molecules (ligands) Amphipathic shell composed of a phospholipid monolayer, and apolipoprotein. Lipids are transported in water soluble complexes called lipoproteins. Apolipoprotein wrapped around the polar surface to help with transport. Ldl receptors on plasma membrane (clathrin coated) Receptors in plasma membrane recognizes a unique ligand (ldl) Clathrin pit becomes a clathrin vesicle inside the cell (cytosol) Two layer coat: clathrin and adapter protein (ap) complexes: Ap complexes recognize sorting signals of cargo proteins or receptors. Clathrin-coated vesicles pinch of using dynamin and gtp hydrolysis. Dynamin forms rings around the vesicle neck, pinches and fuses it together to create a vesicle ph-dependent binding of ldl particles to the ldl receptor. Ldl receptor ligand-binding arm binds tightly to apob under normal ph conditions.