該基因編碼脯氨酰4-羥化酶的β亞單位，脯氨酰4-羥化酶是一種非常豐富的多功能酶，屬于蛋白質二硫化物異構酶家族當以包含兩個α和兩個β亞單位的四聚體存在時，這種酶參與前膠原中脯氨酰殘基的羥基化這種酶也是二硫鍵異構酶，含有兩個硫氧還蛋白域，催化二硫鍵的形成、斷裂和重排。其他已知功能包括其作為伴侶的能力，其以濃度依賴性方式抑制錯折疊蛋白的聚集，其結合甲狀腺激素的能力，其在S-亞硝基硫醇結合的一氧化氮的流入和流出中的作用，以及其作為微粒體甘油三酯轉移蛋白復合物的亞基的功能。[由RefSeq提供，2008年7月]
This gene encodes the beta subunit of prolyl 4-hydroxylase, a highly abundant multifunctional enzyme that belongs to the protein disulfide 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 disulfide isomerase containing two thioredoxin domains that catalyze the formation, breakage and rearrangement of disulfide 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, Jul 2008]