Copper Homeostasis in Humans and Bacteria

An increasing number of studies highlight the importance of copper homeostasis in humans and bacteria. In this article, the best-characterized soluble and membrane-embedded proteins acting in copper transport are reviewed. These proteins are not only necessary to maintain copper levels needed for the maturation of essential cuproenzymes but also to mobilize copper among different intracellular compartments and storage pools and the extracellular space. Dynamic fluctuations of copper levels, under physiological or pathological conditions, are at the basis of important processes, such as angiogenesis and cell migration. Some of these processes are related to cancer and cardiovascular diseases. Moreover, the maintenance of copper homeostasis is related to oxidative stress defense, immune response, and susceptibility to microbial infections. For this reason, it is also essential to widen our knowledge on the mechanisms of copper tolerance in bacteria, for which we illustrate some examples that reveal some similarities with human systems