Biology 2382B Lecture Notes - Lecture 3: Ester, Glycerophospholipid, Sphingosine
Document Summary
Closed compartments: exoplasmic face always faces exoplasm (ecm or lumen!, cytoplasmic face always faces the cytoplasm. 20 25 amino acids: arg and lys near cytosolic face interact w/ polar heads of bilayer. Lipid-linked proteins: cytosolic: oacylation links an n-terminal glycine to a lipid in the membrane oprenylation links a cysteine at or near the c-terminus to a lipid, exoplasmic: oa gpi anchor links the protein to phosphoethanolamine (blue), Proteins: proteins are attached through non-covalent forces, they can associate with the cytoskeleton and ecm components all are translated in the cytosol and require sorting signals, topogenic sequences are specific protein folding patterns recognized by stuff . Sa (signal anchor) internal (uncleaved) sequence. Hydrophobic c-terminus these all determine the orientation of a protein in a membrane. Tail-anchored proteins: hydrophobic c-terminus (topogenic) is recognized by get3 associates with get1 and get2 of the membrane uses atp hydrolysis to embed the c-terminus in the membrane, no exoplasmic domain.