Molecular chaperone which facilitates proper subunit assembly and surface trafficking of alpha-7 (CHRNA7) and alpha-8 (CHRNA8) nicotinic acetylcholine receptors (  ). May also promote functional expression of homomeric serotoninergic 5-HT3 receptors, and of heteromeric acetylcholine receptors alpha-3/beta-2, alpha-3/beta-4, alpha-4/beta-2 and alpha-4/beta-4.
Subcellular locations: Endoplasmic reticulum membrane
Subcellular locations: Endoplasmic reticulum membrane, Golgi apparatus membrane
Broadly expressed, with high levels in muscle, brain, heart, pancreas and testis. In the central nervous system, highest levels are detected in the cerebellum and pituitary gland. Over-expressed in brains from patients with bipolar disease or schizophrenia. Isoform 5 is predominantly expressed in the brain.