BIOL3006 Lecture Notes - Lecture 3: Secretion, Point Mutation, Immunology
Document Summary
Binds pip2, purified proteins spontaneously form rings in vitro, gtpase switches between conformations. In vitro assay: purify dynamin, add to liposomes, convert tubular structure of liposomes into tubular structures via dynamin, trigger gtp hydrolysis, tubules pinch off into small vesicles. Hsc70 (atpase) and synaptojanin (phosphatase on pip2) needed. Summary: adaptins bind to receptor cytoplasmic domain, clathrin binds adaptin which binds pip2, pip2 acts as a platform to recruit dynamin, dynamin needed for budding, synaptojanin is needed for uncoating. Sorts traffic via receptor-ligand systems following distinct pathways. Example 1: ldl-receptor system: ldl degraded, lrl-r recycles. Example 2: transferrin receptor recycling: transferrin bins iron, which associates with receptor. Iron released in early endosome (ph 6: transferrin + receptor is recycle to surface, unbound transferrin disassociates from receptor (ph 7) Example 4: m6pr being recycled back to golgi. Escrt 0, i, ii, iii self-assemble on surface of the endosome and push vesicles inside. Linked to ilv formation but not all are essential.
