This gene encodes a RING domain-containing protein that resides in the endoplasmic reticulum (ER) membrane. This protein functions as an E3 ubiquitin ligase and mediates ubiquitination and processing of inositol 1,4,5-trisphosphate (IP3) receptors via the ER-associated protein degradation pathway. It is recruited to the activated IP3 receptors by the ERLIN1/ERLIN2 complex to which it is constitutively bound. Mutations in this gene are associated with autosomal dominant sensory ataxia. Alternatively spliced transcript variants have been found for this gene. [provided by RefSeq, Jun 2012]