fig1

Figure 1. Copper redox, oxidation, and absorbance in cells. ZnT1 directly transports extracellular Cu²⁺ into cells. Extracellular Cu²⁺ could be reduced to Cu⁺ via STEAP and then transported into cells via SLC31A1, while ATP7B opposes this process via excreting Cu⁺. Intracellular Cu⁺ is absorbed into lysosomes and mitochondria via SLC46A3 and ATP7A, respectively. ZnT1: Solute carrier family 30 member 1/Slc30a1, a zinc and copper transporter; STEAP: 6-transmembrane epithelial antigen of prostate, comprises STEAP1, STEAP2, STEAP3, and STEAP4; Dcytb: duodenal cytochrome b; SLC31A1: solute carrier family 31 member 1, Ctr1: copper transport protein 1; ATP7B: ATPase copper-transporting beta; SLC46A3: solute carrier family 46 member 3; ATP7A: ATPase copper-transporting alpha.