LIFE 210 Lecture Notes - Lipid Bilayer Fusion, Copii, Endocytosis
Document Summary
Lumen components can be passed to another compartment without having to cross a membrane. Balanced flow of membrane and proteins retrieval pathways. Protein coats assemble on the cytosolic face of organelle membrane. They concentrate specific membrane proteins in a specialized membrane patch that will form the vesicle. Triskelion: 3 heavy chains + 3 light chains. Natural tendency to form cages (pentagons + hexagons) Adaptor proteins recruit selected transmembrane proteins such as receptors. Not all coats form basket-like structures (e. g. retromer) Different types of phospholipids label the various organelles. Family with more than 60 members, specific organelle/vesicle markers. Rab effectors facilitate vesicle transport, tethering, and/or fusion. Additional layer of specificity in the transport process. The biosynthetic-secretory pathway involves transport from the er to the golgi apparatus. Proteins leave the er in copii-coated transport vesicles. Copii vesicles form in er exit sites (smooth er) Entry into copii vesicles is a selective process (signals) The retrieval pathway to the er uses sorting signals.
