BIOC 212 Lecture Notes - Lecture 7: Integral Membrane Protein, Membrane Protein, Biological Membrane
14 Oct 2015
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Document Summary
Which amino acids are modified? amino acid reversible? modification disulfide phosphorylation acetylation methylation ubiquitination lipidation glycosylation. Targeting signals: the sequence of a protein can encode a signal or signals that specify its organelle localization, targeting signals: Are often independent from the structure or biochemical function of proteins. Recognized by their pattern, but usually not an exact sequence. May be removed by proteolysis after targeting is complete, or form part of the native structure: targeting steps, recognize a signal on a protein, connect protein to the membrane. 3. translocate protein into or across the membrane. Secretory proteins and er: all secretory pathway proteins are inserted into or across the endoplasmic reticulum (er) membrane. Transport to further compartments by vesicles golgi, pm, endosomes, lysosomes. Outer and inner nuclear membranes are continuous with er: rough er: many attached ribosomes, secretory protein synthesis, smooth er: no ribosomes, sites of lipid synthesis. Signal peptide must start mechanism to connect ribosome to translocation pore.
