A cloned prokaryotic Cd2+ P-type ATPase increases yeast sensitivity to Cd2+.
CadA, the P1-type ATPase involved in Listeria monocytogenes resistance to Cd(2+), was expressed in Saccharomyces cerevisiae and did just the opposite to what was expected, as it strikingly decreased the Cd(2+) tolerance of these cells. Yeast cells expressing the non-functional mutant Asp(398)Ala could grow on selective medium containing up to 100 microM Cd(2+), whereas those expressing the functional protein could not grow in the presence of 1 microM Cd(2+). The CadA-GFP fusion protein was localized in the endoplasmic reticulum membrane, suggesting that yeast hyper-sensitivity was due to Cd(2+) accumulation in the reticulum lumen. CadA is also known to transport Zn(2+), but Zn(2+) did not protect the cells against Cd(2+) poisoning. In the presence of 10 microM Cd(2+), transformed yeasts survived by rapid loss of their expression vector.
Laboratoire de Biophysique Moléculaire et Cellulaire, UMR 5090 CEA-CNRS, Université Joseph Fourier, CEA/DRDC/BMC, 17 rue des Martyrs, 38054 Grenoble Cedex 9, France.
Chen-Chou
CC
Wu
Nathalie
N
Bal
Julien
J
Perard
Jennifer
J
Lowe
Cécile
C
Boscheron
Elisabeth
E
Mintz
Patrice
P
Catty
D000251:Adenosine Triphosphatases / Q000737:chemistry / Q000378:metabolism* / Q000502:physiology*; D000255:Adenosine Triphosphate / Q000737:chemistry; D000409:Alanine / Q000737:chemistry; D001224:Aspartic Acid / Q000737:chemistry; D002104:Cadmium / Q000737:chemistry / Q000378:metabolism; D003470:Culture Media / Q000378:metabolism / Q000494:pharmacology; D004721:Endoplasmic Reticulum / Q000378:metabolism; D005822:Genetic Vectors; D049452:Green Fluorescent Proteins / Q000378:metabolism; D008089:Listeria monocytogenes / Q000201:enzymology / Q000378:metabolism*; D008670:Metals / Q000737:chemistry; D010641:Phenotype; D010766:Phosphorylation; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D015032:Zinc / Q000737:chemistry
D003470:Culture Media; D008670:Metals; D002104:Cadmium; D049452:Green Fluorescent Proteins; D001224:Aspartic Acid; D000255:Adenosine Triphosphate; D000251:Adenosine Triphosphatases; C059771:cadmium translocating ATPase; D015032:Zinc; D000409:Alanine