Article

Rice DEP1, encoding a highly cysteine-rich G protein γ subunit, confers cadmium tolerance on yeast cells and plants.

Kunihiro, S; Saito, T; Matsuda, T; Inoue, M; Kuramata, M; Taguchi-Shiobara, F; Youssefian, S; Berberich, T; Kusano, T

Journal of experimental botany 2013 14

PMID: 24163402

Rice DEP1, encoding a highly cysteine-rich G protein γ subunit, confers cadmium tolerance on yeast cells and plants.

A rice cDNA, OsDEP1, encoding a highly cysteine (Cys)-rich G protein γ subunit, was initially identified as it conferred cadmium (Cd) tolerance on yeast cells. Of the 426 aa constituting OsDEP1, 120 are Cys residues (28.2%), of which 88 are clustered in the C-terminal half region (aa 170-426). To evaluate the independent effects of these two regions, two truncated ve='term' data-tid='6369' href='#term-6369'>rsions of the OsDEP1-expressing plasmids pOsDEP1(1-169) and pOsDEP1(170-426) were used to examine their effects oata-tid='6372' hrerm' data-tid='6374' href='#term-6374'>ef='#term-6372'>='term' term' data-tid='6377' href='#term-6377'>data-tid='6371' href='#term-6371'>n yeast Cd tolerance. Although OsDEP1(170-426) conferred a similar level of Cd tolerance as the intact OsDEP1, OsDEP1(1-169) provided no such tolerance, indicating that the tolerance effect is localized to the aa 170-426 C-terminal peptide region. The Cd responses of transgenic Arabidopsis plants constitutively expressing OsDEP1, OsDEP1(1-169) or OsDEP1(170-426), were similar to the observations in yeast cells, with OsDEP1 and OsDEP1(170-426) transgenic plants displaying Cd tolerance but OsDEP1(1-169) plants showing no such tolerance. In addition, a positive correlation between the transcript levels of OsDEP1 or OsDEP1(170-426) in the transgenics and the Cd content of these plants upon Cd application was observed. As several Arabidopsis loss-of-function heterotrimeric G protein β and γ subunit gene mutants did not show differences in their Cd sensitivity compared with wild-type plants, we propose that the Cys-rich region of OsDEP1 may function directly as a trap for Cd ions.