LINA02H3 Lecture Notes - Lecture 6: Membrane Fusion Protein, Fusion Protein, Lipid Bilayer Fusion
Document Summary
Fusion- penetration of enveloped viruses involves a membrane fusion event mediated by viral glycoproteins. Synthesized, made, folded in the er of infected cell. Wait to be activated ( don t fuse continuously ) Fusion- active: cleaved at n-terminal (by the fusion peptide) makes the fusion activated. Which are part of class 1 fusion proteins. Trimer (make up of 3 polypeptides; alpha helical coiled coils) Step 1: in endosome, becomes matured when the ph drops. Step 2: this change: fusion peptides are exposed which insert themselves into the target membrane. Step 3: several ha molecules come together to form a cluster, they can move laterally if needed for the cluster. Step 4:to make a fusion, the ha fold back to bring themselves together. Step 5: hemifusion: the bilayers proceed to fuse. Step 6: they fully fuse to make a fusion channel. Once in the cytosol, they need to find the proper site for replication.
