Prostaglandin-endoperoxide synthase 2 (prostaglandin G/H synthase and cyclooxygenase)
Prostaglandin-endoperoxide synthase (PTGS), also known as cyclooxygenase, is the key enzyme in prostaglandin biosynthesis, and acts both as a dioxygenase and as a peroxidase. There are two isozymes of PTGS: a constitutive PTGS1 and an inducible PTGS2, which differ in their regulation of expression and tissue distribution. This gene encodes PTGS2, which shows 86% - 89% amino acid sequence identity with mouse, rat, sheep, bovine, horse and rabit PTGS2 proteins, respectively. Human PTGS2 is expressed in a limited number of cell types and regulated by specific stimulatory events, suggesting that it is responsible for the prostanoid biosynthesis involved in inflammation and mitogenesis. The expression of this gene is deregulated in epithelial tumors.