The mammalian copper transporters CTR1 and CTR2 and their roles in development and disease

Copper is vital to cell function. The influx of reduced copper ions is controlled by two functionally homologous transmembrane solute carrier transporters CTR1 (encoded by SLC31A1) and CTR2 (encoded by SLC31A2). These copper transporters vary in their expression profiles and intracellular localisation patterns. CTR1 plays roles in the developing embryo as well as regulating homeostasis in the adult mammal. In contrast, the regulation, expression and function of CTR2 is poorly defined. Both are capable of transporting other divalent metal ions and are the primary transporters for platinum-based chemotherapeutic drugs such as cisplatin. This review summarises our current understanding of these two copper transporters and highlights their roles in cellular processes, embryonic development, differentiation, cancer, immunity and disease.