BIOL 2021 Lecture Notes - Lecture 7: Heat Shock Protein, Signal Peptidase, Intermembrane Space
Document Summary
Some proteisn can shuttle in and out. Signal (ex: ca2+) changes conformation of proteins. Question: an individual nuclear pore can mediate transport in both direction at the same time, as many as 1000 macromolecules travelling through one pore per second. How does the cell avoid traffic congestion and collisions bw cargo going in and out of the same pore: a: we don"t know. Tim: translocase of inner membrane: don"t worry about the different types of tim. Sam: insert beta-barrel proteins into the outer membrane. Oxa: inserts some proteins into inner membrane. Events for import into the mitochondria: 1) precursor protein synthesis in cytosol post translational import. 1) atp hydrolysis to remove the hsp70 in the cytosol. 2) membrane potential across inner membrane: signal sequence is positively charged, electrophoresis. 3) atp hydrolysis by hsp70 inside the matrix pulls the protein into matrix import into other spaces fig 12-25a inner membrane.