The unfolded protein response (UPR) senses stress in the endoplasmic reticulum (ER) and
initiates signal transduction cascades that culminate in changes to gene regulation. Long
recognized as a means for improving ER protein folding through up-regulation of ER
chaperones, the UPR is increasingly recognized to play a role in the regulation of metabolic
pathways. ER stress is clearly connected to altered metabolism in tissues such as the liver,
but the mechanisms underlying this connection are only beginning to be elucidated. Here …