Enables ubiquitin protein ligase activity. Involved in immature B cell differentiation; protein stabilization; and proteolysis involved in cellular protein catabolic process. Acts upstream of or within in utero embryonic development and negative regulation of endoplasmic reticulum stress-induced intrinsic apoptotic signaling pathway. Located in endoplasmic reticulum quality control compartment. Is expressed in rib. Orthologous to human SYVN1 (synoviolin 1). [provided by Alliance of Genome Resources, Apr 2022]