Metallothionein (MT) (MT)

Metallothioneins (MTs) are a family of low-molecular-weight, cysteine-rich proteins that serve as the primary intracellular zinc-binding proteins in mammals. They play a critical role in maintaining zinc and copper homeostasis, detoxifying heavy metals like cadmium and mercury, and protecting cells against oxidative stress by scavenging reactive oxygen species. MTs regulate the availability of zinc ions, which are essential cofactors for thousands of proteins, including transcription factors and enzymes. In disease states, MT dysregulation is linked to cancer progression and resistance to platinum-based chemotherapy, as well as neurodegenerative disorders like Alzheimer's and Parkinson's disease due to their role in metal-mediated proteotoxicity. Therapeutically, MTs are targeted through zinc supplementation to induce their expression for treating copper overload or as potential biomarkers for environmental toxicity and disease prognosis. Their ability to sequester both essential and toxic metals makes them central to cellular metal metabolism and a significant factor in drug efficacy and toxicity.

Other names

Intracellular zinc-binding proteinsMetallothioneinsMTsMetal-binding proteinsZinc-binding protein

Induction of protein expression to sequester excess metals, direct sequestration of metal ions and platinum-based drugs, and scavenging of reactive oxygen species via thiol groups.