Protein Insertion into the Endoplasmic Reticulum Membrane
4 types of transmembrane proteins
- Type I membrane proteins have a signal sequence at their N-terminus and an internal stop-transfer sequence.
- Type II membrane proteins have an internal signal sequence instead of a terminal one.
- Type III also have an internal signal sequence instead of a terminal one.
- Type IV are multipass membrane proteins that have multiple hydrophobic regions embedded in the bilayer. We will focus on a 2-pass protein, which has an internal signal sequence and a stop-transfer sequence.