Enables copper ion binding activity. Involved in negative regulation of neuron apoptotic process. Acts upstream of or within several processes, including cellular response to chromate; cellular response to zinc ion; and cellular zinc ion homeostasis. Located in cytosol and lysosome. Is expressed in several structures, including alimentary system; early conceptus; genitourinary system; liver; and nasal cavity epithelium. Orthologous to several human genes including MT1A (metallothionein 1A); MT1E (metallothionein 1E); and MT1F (metallothionein 1F). [provided by Alliance of Genome Resources, Apr 2022]