Bifunctional enzyme which catalyzes both the conversion of PGH2 to PGD2, a prostaglandin involved in smooth muscle contraction/relaxation and a potent inhibitor of platelet aggregation, and the conjugation of glutathione with a wide range of aryl halides and organic isothiocyanates. Also exhibits low glutathione-peroxidase activity towards cumene hydroperoxide.
Expressed in a number of megakaryocytic cell lines but not in platelets. Highly expressed in adipose tissue, macrophages and placenta. Also expressed at lower levels in lung, heart, lymph nodes, appendix, bone marrow and fetal liver.
Belongs to the GST superfamily. Sigma family. Contains 1 GST C-terminal domain. Contains 1 GST N-terminal domain.
Highest levels in immature megakaryocytic cells. Disappears after final differentiation to platelets.