Figure 2.

Presenilins regulate PrP^c expression at a transcriptional level. A, Analysis of PrP^c and actin mRNA levels by semiquantitative PCR in wild-type (WT) and PS^−/− fibroblasts. B–D, PS^−/− fibroblasts were transiently transfected with either empty pcDNA3 vector (CT) or with PS1 and PS2 cDNA (PS1/PS2) as described in Materials and Methods. Thirty-six hours after transfection, protein expression (B), PrP^c promoter transactivation (C), and mRNA levels (D) were monitored. Bars in C and D express percentage of mock-transfected WT cells and represent the means ± SEM of 10 or 6 independent experiments, respectively. *p < 0.05; **p < 0.0001.