Cytosolic prostaglandin synthase that catalyzes the oxidoreduction of prostaglandin endoperoxide H2 (PGH2) to prostaglandin E2 (PGE2) (PubMed:10922363). Molecular chaperone that localizes to genomic response elements in a hormone-dependent manner and disrupts receptor-mediated transcriptional activation, by promoting disassembly of transcriptional regulatory complexes. Facilitates HIF alpha proteins hydroxylation via interaction with EGLN1/PHD2, leading to recruit EGLN1/PHD2 to the HSP90 pathway (By similarity). prostaglandin H2 = prostaglandin E2 Lipid metabolism; prostaglandin biosynthesis. Probably forms a complex composed of chaperones HSP90 and HSP70, co-chaperones STIP1/HOP, CDC37, PPP5C, PTGES3/p23, TSC1 and client protein TSC2. Binds to the progesterone receptor. Interacts with TERT; the interaction, together with HSP90AA1, is required for correct assembly and stabilization of the telomerase holoenzyme complex. Interacts (via PXLE motif) with EGLN1/PHD2, recruiting EGLN1/PHD2 to the HSP90 pathway to facilitate HIF alpha proteins hydroxylation. Interacts with HSP90AA1, FLCN, FNIP1 and FNIP2. Widely expressed with highest levels in testis. In brain, by LPS. Belongs to the p23/wos2 family.