Abstract

Human doppel protein possesses inhibitory activity to superoxide dismutase

Author(s): Naoko Okumura, Yasuko Kitagishi, Yuka Nagata, Yuri Nishimura, Hitomi Yoshida, Satoru Matsuda

Doppel gene (PRND) is a paralogue of the mammalian prion gene (PRNP). As prion protein expressionmight aid cellular resistance to oxidative stress by influencing the activity of superoxide dismutase (SOD), cellular changes in the human PRND-transfected HEK293 cells were also investigated. The SOD activity of transfectants with doppel (Dpl) expression was significantly lower than that of parental cells at 48 h after transfection, while prion protein expression increased cellular SOD activity. The SOD activity in amino-terminal truncation of Dpl transfectant was also decreased. The glycosylphosphatidylinositol (GPI) anchor site at the carboxyl-terminus of Dpl appeared to be essential for the repression.