Transmembrane protein from translation to the plasma membrane (remains transmembrane) Cytosol -> er: translocation into the er membrane co-translational translocation (while you are translating it, you are trans locating it, requires a signal sequence. Ribosome binds to the mrna (in the cytosol) -> ribosome starts making the protein -> make the internal signal sequence which wants to go to the er. The srp and srp receptor are still involved in this process. Hydrophobic transmembrane segment this is the internal signal sequence -> from here, it is either step 1 followed by 2a, 3a, 4a or 1 followed by 2 and 3. Protein at the trans locator (charged) -> it will detect and look at the amino acids next to the internal signal sequence and essentially attract the opposite charge. Second case scenario: n terminal side is more while the cytosol side is more + -> n terminus stays in the er lumen and.