Subtlety is underrated: Physiological UPR activation in meiosis

Abstract

In this issue, Bartolutti et al. (https://doi.org/10.1083/jcb.202509100) identify a physiological function for the unfolded protein response (UPR). The UPR has long been viewed as a coping mechanism for protein misfolding in the endoplasmic reticulum (ER). The authors here show that budding yeast naturally use this response to reorganize their ER during meiosis and sporulation, suggesting an ancient origin for the UPR as an adaptive developmental program.