CYP2S1 is highly expressed in epithelial tissues of the respiratory, gastrointestinal, urinary tracts, and skin and in leukocytes of the monocyte/macrophage and lymphocyte series; it is also expressed throughout Embryogenesis and, as discussed below, certain types of cancers.
Function
This gene encodes a member of the cytochrome P450 superfamily of enzymes. The cytochrome P450 proteins are monooxygenases which catalyze many reactions involved in drug metabolism and synthesis of cholesterol, steroids and other lipids. This protein localizes to the endoplasmic reticulum. In rodents, the homologous protein has been shown to metabolize certain carcinogens although its specific function in humans has not been clearly determined. In in vitro studies, the human enzyme has been found to metabolize all-trans-retinoic acid to 4-hydroxy-retinoic acid and 5, 6-epoxy-retinoic acid and therefore may play a role in processing retinoic acid in tissues where it is highly expressed such as the skin. CYP2S1 is significantly overexpressed and, perhaps directly related to this, its gene is significantly hypometylated arachidonic acid to its various epoxides, i.e., the epoxyeicosatrienoic acidsdocosahexaenoic acid to its various epoxides, i.e. the epoxydocosapentaenoic acids ''' linoleic acid to its various epoxides, i.e. vernolic acid and coronaric acid. It seems likely, although not yet tested, that CYP231 will also prove able to metabolize other polyunsaturated fatty acids to their epoxides; for example, the enzyme may metabolize eicosapentaenoic acid to epoxyeicosatetraenoic acids. Animal model studies implicate the EET, EDP, and EEQ epoxides in regulating blood pressure, tissue blood flow, new blood vessel formation. The CYP2S1-dependent production of EETs, which stimulate the growth of various types of cancer cells, including those of the colon, could contribute to the unfavorable effects of this CYP in the sited cancers. Vernolic and coronaric acids are potentially toxic, causing multiple organ failure and acute respiratory distress when injected into animals and suggested to be involved in causing these syndromes in humans. CYP2S1 has also been found to metabolize Prostaglandin G2 and Prostaglandin H2 to the biologically active product, 12-Hydroxyheptadecatrienoic acid.
