Figure 3: Protein folding regulation in the endoplasmic reticulum. Newly synthesized proteins are translocated into the endoplasmic reticulum, where they fold into their three-dimensional structure with the help of chaperones. Correctly folded proteins transported to golgi complex. However, incorrectly folded proteins are ubiquitinated and than degraded into cytoplasm by proteosomes (E2, ubiquitin-conjugating enzyme; E3, ubiquitin ligase).