HMA4 — Brassica juncea

Summary

BJUA01G39590S (HMA4, also known as BjHMA6) encodes a P-type ATPase with heavy-metal-associated domains, annotated with copper carrier, cadmium-exporting ATPase, and P-type zinc transporter activities. 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, cell pH regulation, and phenylpropanoid anabolism. It is linked to chlorophyll content and copper transport. The encoded protein localises to the vacuolar membrane, Golgi membrane, chloroplast envelope, chloroplast stroma, plastid, and plasma membrane. Studies of related genes in other species connect the family to reduced growth, high chlorophyll fluorescence, impaired photosynthesis, and defective electron transport.