Metal Homeostasis

Abstract

AbstractTransition metals are a key component of biological systems. Because of their special properties, they are incorporated into proteins functioning in dioxygen transport, electron transfer, redox transformations, and regulatory control. The metals used in biological systems have been selected throughout evolution based on their availability in the environment and their kinetic lability, resulting in preferential use of first‐row transition metals in biology. These essential metals must be obtained from the environment and concentrated within the cell for use in biochemical pathways. Once appropriated, metals must be directed to metalloenzymes or metal storage proteins within the cell. In addition, organisms must be able to distinguish between essential and toxic metals and must have mechanisms for minimizing the toxicity of both essential and toxic metals that are present in excess. Metal homeostasis is broadly defined as the metal uptake, trafficking, efflux, and sensing pathways that allow organisms to maintain an appropriate (often narrow) intracellular concentration range of essential transition metals. This review will introduce several unifying concepts of metal homeostasis with brief illustrative examples for each concept.