Duodenal cytochrome b (Dcytb)

Duodenal cytochrome b (Dcytb) is a transmembrane hemoprotein enzyme encoded by the CYBRD1 gene and primarily expressed on the brush-border membrane of duodenal enterocytes[1][5][6]. Dcytb catalyzes the ascorbate-dependent reduction of dietary nonheme ferric iron (Fe^3+) to ferrous iron (Fe^2+), facilitating its absorption by the divalent metal transporter 1 (DMT1)[1][5][8]. It is a member of the cytochrome b561 family and contains two heme groups that enable electron transfer across the membrane[2][4][5]. Dcytb is regulated by iron status and hypoxia (via HIF2α), with expression upregulated in iron deficiency to enhance iron uptake[1][3]. Besides iron metabolism, Dcytb participates in ascorbate recycling in certain tissues (notably erythrocytes and some epithelial cells), and aberrant expression has been implicated in various cancers—often associated with altered tumor growth or prognosis depending on the tissue context[1][4]. No drugs are currently clinically approved that directly target Dcytb, but it is of ongoing interest for enhancing iron therapy or as a biomarker in specific cancers. There are no major reported safety concerns, though manipulating Dcytb activity could impact iron metabolism and related diseases.

Other names

cytochrome b reductase 1CYBRD1duodenal cytochrome bCybrd1

Ferric (Fe^3+) reduction to ferrous (Fe^2+) for uptake by iron transporters, Ascorbate-dependent electron transfer