Involved in the unfolded protein response (UPR), a transcriptional response which up-regulates genes that enable cells to cope with misfolded, endoplasmic reticulum-retained proteins. UPR is part of the endoplasmic reticulum quality control (ERQC) which prevents the exit of misfolded secretory and membrane proteins from the endoplasmic reticulum. By the unfolded protein response (UPR). Present with 721 molecules/cell in log phase SD medium.