Ferric Chelate Reductase 1 (FRRS1)

Members of the cytochrome b561 (CYB561) family, including FRRS1, reduce ferric to ferrous iron before its transport from the endosome to the cytoplasm . Northern blot analysis detected Sdr2 predominantly in rat liver and kidney with lower levels in lung, heart, stomach, small intestine, spleen, testis, and skin. In situ hybridization showed that Sdr2 expression was localized in adult mouse brain to the choroid plexus of the fourth, third, and lateral ventricles and to ependymal cells that line the ventricles.Sdr2 has significant ferric reductase activity. Sdr2 expression was decreased in kidney and liver of hypotransferrinemic (hpx) mice, which have iron overload of the liver and pancreas, compared to wildtype mice, suggesting that Sdr2 expression in kidney and liver is regulated by iron.