FIGURE 1.

Co-expression of PREP increases levels of aSyn in N2A cells. A, the expression of PREP and PREP(S554A) together with GLuc-fragment- and HA-tagged aSyn was studied by Western blot. aSyn-GLuc1 and aSyn-GLuc2 were transfected at 0.75 μg of plasmid DNA per well (each plasmid), whereas PREP and PREP(S554A) were transfected either at 0.75 μg or 1.5 μg. The total amount of plasmid DNA was set at 3 μg per well and was adjusted by mock plasmid when needed. Cells transfected with aSyn-GLuc1 and aSyn-GLuc2 plasmids only were used as the control. Blots were stained with antibodies to PREP, HA-tag (aSyn-GLuc1/2), and GAPDH as a loading control. B, optical density-based quantification of aSyn levels in four replicate experiments (as in Fig. 1A). Both PREP and PREP(S554A) showed a trend toward increased aSyn levels, but the difference did not reach significance. The average values are displayed as the percent change as compared with control-transfected cells (mean ± S.E.; n = 4 independent experiments).