This gene encodes a resident endoplasmic reticulum (ER), N-linked glycoprotein with an N-terminal ER targeting sequence, 2 putative N-glycosylation sites, and a C-terminal ER retention signal. This protein functions as a nucleotide exchange factor for another unfolded protein response protein. Mutations in this gene have been associated with Marinesco-Sjogren syndrome. Alternate transcriptional splice variants have been characterized. [provided by RefSeq, Jul 2008].