Figure 1.

Schematic diagram of some essential physiological functions and metabolic processes of copper. Copper is primarily transported into cells by CTR1. Upon entering the cell, copper is transferred to CCS, COX17, and ATOX1. CCS delivers copper to SOD1, which is involved in defense against oxygen toxicity. COX17 transfers copper to CCO, which participates in maintaining mitochondrial respiration. ATOX1 can carries copper into the cell nucleus, leading to the expression of G1/S-specific cyclin D1 and inducing cell proliferation. ATOX1 also transports copper to ATP7A and ATP7B across the Golgi network and regulates copper subcellular distribution through the complex transport mechanisms of the Golgi network. Excess copper in the cell is bound by MT and GSH to prevent copper toxicity. In addition, ATP7A and ATP7B primarily function in the efflux of copper ions from cells.