Oligomerization in endoplasmic reticulum stress signaling

Abstract

Oligomerization of protein complexes has been involved in various mechanisms that play a major role in endoplasmic reticulum (ER) functions. In particular, in response to the accumulation of misfolded proteins in the ER, an adaptive response is activated and named the unfolded protein response (UPR). To facilitate recovery of ER homeostasis, both the inositol-requiring enzyme-1 (IRE1) and the protein kinase RNA-like ER kinase, two transmembrane ER stress transducers, oligomerize and activate UPR-specific transcription factors to adjust the folding and productive capacity of the ER, to direct misfolded proteins to ER-associated degradation or autophagy. Recent advances in the molecular characterization of how ER protein sensors transduce signals to orchestrate the adaptive cellular response have greatly unlocked the development of tools to dissect their functions in health and disease. Here, we focus on the advances concerning oligomerization of ER stress transducers and, in particular IRE1, describe the oligomerization-dependent mechanisms for modulating UPR signals on and off.