A new pharmacology--drugging stressed folding pathways.

Folding in the endoplasmic reticulum (ER) must couple protein-synthesis pathways operating outside of the compartment with ER-assisted folding (ERAF) pathways in the lumen. Chaperone-mediated folding imbalances that are associated with numerous misfolding diseases, including diabetes, trigger the unfolded-protein response (UPR), using both transcriptional and translational pathways to correct the problem. Recent work suggests that small-molecule inhibitors could be useful to help rebalance protein synthesis with ERAF pathways through the ribosomal initiating factor eIF2alpha. Reprogramming stress pathways with drugs provides a potential new approach for balancing ER-protein load with cellular-folding capacity, thus correcting disease.