Plays a role in regulation of the unfolded protein response triggered by endoplasmic reticulum (ER) stress resulting from the presence of unfolded proteins in the ER lumen. Homooligomer (PubMed:31653868). Interacts (via C-terminus) with endoplasmic reticulum (ER) protein CLCC1; the interaction occurs at the mitochondria-associated ER membrane, a zone of contact between the ER and mitochondrial membranes, but does not appear to play a role in ER-mitochondria tethering and is not affected by ER stress (PubMed:31653868).