AtHMA3, a plant P1B-ATPase, functions as a Cd/Pb transporter in yeast.
The Arabidopsis thaliana AtHMA3 protein belongs to the P(1B)-adenosine triphosphatase (ATPase) transporter family, involved in heavy metal transport. Functional expression of AtHMA3 phenotypically complements the Cd/Pb-hypersensitive yeast strain Deltaycf1, but not the Zn-hypersensitive mutant Deltazrc1. AtHMA3-complemented Deltaycf1 cells accumulate the same amount of cadmium as YCF1-complemented Deltaycf1 cells or wild-type cells, suggesting that AtHMA3 carries out an intracellular sequestration of Cd. A mutant of AtHMA3 altered in the P-ATPase phosphorylation domain did not complement Deltaycf1, suggesting that metal transport rather than chelation is involved. The fusion protein AtHMA3::green fluorescent protein (GFP) is localized at the vacuole, consistent with a role in the influx of cadmium into the vacuolar compartment. In A. thaliana, the mRNA of AtHMA3 was detected mainly in roots, old rosette leaves and cauline leaves. The expression levels were not affected by cadmium or zinc treatments.
Gravot
Antoine
A
CEA Cadarache, DSV/DEVM/Laboratoire des Echanges Membranaires et Signalisation, UMR 6191 CNRS-CEA-Aix-Marseille II, Bat. 156, 13108 St Paul lez Durance Cedex, France.
Lieutaud
Aurélie
A
Verret
Frédéric
F
Auroy
Pascaline
P
Vavasseur
Alain
A
Richaud
Pierre
P
D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism*; D000595:Amino Acid Sequence; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D002104:Cadmium / Q000378:metabolism*; D007854:Lead / Q000378:metabolism*; D019216:Metals, Heavy / Q000378:metabolism; D008969:Molecular Sequence Data; D018515:Plant Leaves / Q000235:genetics; D018517:Plant Roots / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis; D016415:Sequence Alignment; D014617:Vacuoles / Q000378:metabolism; D015003:Yeasts / Q000235:genetics
D029681:Arabidopsis Proteins; D019216:Metals, Heavy; D012333:RNA, Messenger; D002104:Cadmium; D007854:Lead; D000251:Adenosine Triphosphatases; C484509:HMA3 protein, Arabidopsis