Figure 2.

Multiple fates for an endoplasmic reticulum (ER)-destined mislocalized protein. Protein import into the ER can fail, resulting in a mislocalized protein in the cytosol (inside the red oval in the center). This failure occurs constitutively at a low level under normal conditions (red arrows, left side) but can be enhanced for some proteins during acute ER stress (red arrows, right side). The mislocalized protein can be degraded, aggregate with itself or other proteins, or mistarget to another organelle.