This gene encodes a member of a family of adenosine triphosphate(ATP)-metabolizing molecular chaperones with roles in stabilizing and folding other proteins. The encoded protein is localized to melanosomes and the endoplasmic reticulum. Expression of this protein is associated with a variety of pathogenic states, including tumor formation. There is a microRNA gene located within the 5 exon of this gene. There are pseudogenes for this gene on chromosomes 1 and 15. [provided by RefSeq, Aug 2012],function:Molecular chaperone that functions in the processing and transport of secreted proteins. Has ATPase activity.,PTM:Phosphorylated.,similarity:Belongs to the heat shock protein 90 family.,subcellular location:Identified by mass spectrometry in melanosome fractions from stage I to stage IV.,subunit:Homodimer, disulfide-linked. Component of an EIF2 complex at least composed of CUGBP1, CALR, CALR3, EIF2S1, EIF2S2, HSP90B1 and HSPA5 (By similarity). Part a large chaperone multiprotein complex comprising CABP1, DNAJB11, HSP90B1, HSPA5, HYOU, PDIA2, PDIA4, PPIB, SDF2L1, UGT1A1 and very small amounts of ERP29, but not, or at very low levels, CALR nor CANX.,
