BIOL 200 Lecture Notes - Lecture 21: Vesicle Fusion, Signal Transducing Adaptor Protein, Lipid Bilayer Fusion
Document Summary
4 stages of vesicle transport: formation, transport, docking, fusion. Stages of vesicle for(cid:373)atio(cid:374) : budding (adaptin binds to cargo receptors which binds cargo molecules, pinching off (clathrin coat is formed, coat is shed (uncoating, naked transport vesicle is ready for transport (from cytosol to extracellular space) Cop-coated and clathrin-coated vesicle formation involve similar components: cargo receptor, adaptor protein interacts with the cytosolic side of the cargo receptor, coat protein, gtpase binds gtp and helps assemble membrane coat. Step 3 & 4: vesicle docking & fusion. Proteins that direct vesicles to the right place for docking: Rabs & tethers: active rab-gtpases are present on both vesicles and target membranes. If the right rab binding/tethering protein is present on the target membrane, the vesicle will tether: this brings the vesicle in close enough proximity to begin membrane fusion. Proteins that mediate vesicle fusion: snares v-snares: on vesicle membrane t-snares: on target membranes.
