Enables magnesium ion transmembrane transporter activity and sodium ion transmembrane transporter activity. Acts upstream of or within enamel mineralization; magnesium ion homeostasis; and magnesium ion transport. Located in basolateral plasma membrane. Is expressed in colon and metanephros. Human ortholog(s) of this gene implicated in Jalili syndrome. Orthologous to human CNNM4 (cyclin and CBS domain divalent metal cation transport mediator 4). [provided by Alliance of Genome Resources, Apr 2022]