1. Protein translation starts on free ribosomes.
2. SRP (signal recognition particle) blinds to the translation apparatus.
3. This complex binds to an SRP receptor in the RER membrane, and the signal sequence enters the translocation pore.
4. Translation continues, and the growing protein is translocated as it is being made.
5. Enzymes such as dolichol phosphate on the luminal surface add carbohydrates to the protein.
6. Once the whole protein is translocated, signal peptidase cleaves the signal sequence, and the mature protein is released into the RER lumen.