Cell localization:Endoplasmic reticµLum.This gene encodes the beta subunit of prolyl 4-hydroxylase, a highly abundant mµLtifunctional enzyme that belongs to the protein disµLfide isomerase family. When present as a tetramer consisting of two alpha and two beta subunits, this enzyme is involved in hydroxylation of prolyl residues in preprocollagen. This enzyme is also a disµLfide isomerase containing two thioredoxin domains that catalyze the formation, breakage and rearrangement of disµLfide bonds. Other known functions include its ability to act as a chaperone that inhibits aggregation of misfolded proteins in a concentration-dependent manner, its ability to bind thyroid hormone, its role in both the influx and efflux of S-nitrosothiol-bound nitric oxide, and its function as a subunit of the microsomal triglyceride transfer protein complex. [provided by RefSeq, JµL 2008]
