HMA4 — Arabidopsis thaliana

Summary

AT2G19110, also known as HMA4 or AtHMA4, encodes a P-type heavy metal ATPase on Arabidopsis thaliana chromosome 2, with cation-transporting ATPase activity, cadmium-exporting ATPase activity, P-type zinc transporter activity, and P-type divalent copper transporter activity. This gene is associated with metal ion transport and detoxification, particularly for cadmium, zinc, and copper. HMA4 is linked to cadmium uptake, xylem loading, and shoot accumulation, as well as seed zinc content and metal tolerance. It is also associated with zinc import, copper ion transport, and responses to cobalt and toxic substances. Localization evidence places the product at the vacuolar membrane, chloroplast envelope, and endomembrane system. Additionally, HMA4 is associated with traits including zinc and cadmium concentration, copper sensitivity, leaf chlorosis, root development, and flowering time. Studies of related genes in other species link this gene family to heavy metal tolerance and translocation.