Metallothionein-4 (MT4)

Metallothionein-4 (MT4) is a member of the metallothionein family of intracellular, cysteine-rich, low molecular weight proteins with a strong ability to bind metal ions, especially copper and zinc[1][2][3]. In mammals, MT4 exhibits a unique tissue- and developmental stage–specific expression, being found primarily in differentiating stratified squamous epithelial cells, including developing skin and hair follicles[1][3]. Its primary biological roles involve the regulation of essential metal ions (such as zinc and copper), protection against metal toxicity, and functioning as part of the cellular antioxidant defense[1][2][3]. MT4's unique structure gives it a preference for monovalent copper ions relative to other isoforms that prefer divalent zinc or cadmium[1]. Metallothioneins, including MT4, are considered important biomarkers for monitoring metal exposure and environmental toxicity due to their inducibility by various heavy metals and stress conditions[1][3]. However, unlike many traditional therapeutic targets (such as receptors or enzymes), there are no established drugs that selectively target MT4, and MT4 is not considered a current therapeutic target but rather a functional biomarker and metal-regulatory protein[1][2][3].

Other names

Metallothionein-4MT4MT-4MT-IVMTIVMetallothionein-IVmetallothionein-4metallothionein-IV