A novel family of cys-rich membrane proteins mediates cadmium resistance in Arabidopsis.
Cadmium (Cd) is a widespread pollutant that is toxic to plant growth. However, only a few genes that contribute to Cd resistance in plants have been identified. To identify additional Cd(II) resistance genes, we screened an Arabidopsis cDNA library using a yeast (Saccharomyces cerevisiae) expression system employing the Cd(II)-sensitive yeast mutant ycf1. This screening process yielded a small Cys-rich membrane protein (Arabidopsis plant cadmium resistance, AtPcrs). Database searches revealed that there are nine close homologs in Arabidopsis. Homologs were also found in other plants. Four of the five homologs that were tested also increased resistance to Cd(II) when expressed in ycf1. AtPcr1 localizes at the plasma membrane in both yeast and Arabidopsis. Arabidopsis plants overexpressing AtPcr1 exhibited increased Cd(II) resistance, whereas antisense plants that showed reduced AtPcr1 expression were more sensitive to Cd(II). AtPcr1 overexpression reduced Cd uptake by yeast cells and also reduced the Cd contents of both yeast and Arabidopsis protoplasts treated with Cd. Thus, it appears that the Pcr family members may play an important role in the Cd resistance of plants.
Song
Won-Yong
WY
National Research Laboratory of Phytoremediation, Division of Molecular Life Science, POSTECH, Pohang, 790-784, Korea.
Martinoia
Enrico
E
Lee
Joohyun
J
Kim
Dongwoo
D
Kim
Do-Young
DY
Vogt
Esther
E
Shim
Donghwan
D
Choi
Kwan Sam
KS
Hwang
Inhwan
I
Lee
Youngsook
Y
D000222:Adaptation, Physiological / Q000187:drug effects / Q000502:physiology*; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D002104:Cadmium / Q000378:metabolism / Q000494:pharmacology*; D004351:Drug Resistance / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D008565:Membrane Proteins / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism*; D008969:Molecular Sequence Data; D005810:Multigene Family; D010802:Phylogeny; D012441:Saccharomyces cerevisiae / Q000235:genetics; D017386:Sequence Homology, Amino Acid
D029681:Arabidopsis Proteins; D008565:Membrane Proteins; D002104:Cadmium