HMA4 — Brassica juncea

Summary

BJUB05G58220S (HMA4, also known as BjHMA6) encodes a P-type ATPase with heavy-metal-associated domains, annotated with copper carrier activity, cadmium exporting ATPase activity, and P-type zinc transporter activity. In Indian mustard, this gene is associated with copper ion membrane transport, detoxification of copper ions, copper ion homeostasis, proton export across the plasma membrane, photosynthetic electron transport chain, cell pH regulation, response to toxic substances, and phenylpropanoid anabolism. It localises to the vacuolar membrane, Golgi membrane, chloroplast envelope, chloroplast stroma, plastid, and plasma membrane. The gene is linked to chlorophyll content and copper transport. Studies of related genes in other species connect the family to reduced growth, high chlorophyll fluorescence, and impaired photosynthesis.