Enables caspase binding activity; protein-macromolecule adaptor activity; and ubiquitin protein ligase activity. Involved in negative regulation of IRE1-mediated unfolded protein response; proteasome-mediated ubiquitin-dependent protein catabolic process; and protein ubiquitination. Acts upstream of or within negative regulation of apoptotic process. Located in endoplasmic reticulum and membrane. [provided by Alliance of Genome Resources, Apr 2022]