Cytochrome b5 reductase 4 (CYB5R4)

Cytochrome b5 reductase 4 (CYB5R4) is a flavohemoprotein enzyme encoded by the CYB5R4 gene in humans. It contains functional domains found in both cytochrome b5 and cytochrome b5 reductase, and is involved primarily in electron transfer reactions, using NADH or NADPH to reduce membrane-bound electron acceptors. CYB5R4 is expressed in various subcellular membranes including the endoplasmic reticulum and mitochondria. In pancreatic beta-cells, CYB5R4 is critical for protecting cells against oxidative stress by preventing excessive buildup of reactive oxygen species. It also plays roles in lipid metabolism, xenobiotic detoxification, and glucose homeostasis. Mutations impacting the structural protein dynamics can lead to diseases such as methemoglobinemia. The enzyme is relevant to metabolic and oxidative stress-related disease mechanisms but is not currently targeted by approved drugs.

Other names

NCB5ORcb5/cb5RdJ676J13.1cytochrome b5 reductase 4CYB5R4

Drug mechanisms, if any, would involve modulation of redox activity or modulation of downstream oxidative stress pathways through enzyme inhibition or enhancement. However, no drugs are currently cited as acting directly on cytochrome b5 reductase 4 in the sources provided.