Figure 1

<p>Proteasome activities following lentiviral gene transfer of PA28γ and S5a, in control and HD fibroblasts. (A) Expression levels of gene and protein of S5a and PA28γ were determined using RT-PCR and Western blot after viral gene transfer to HD fibroblasts (lane 1 and 3; lenti-GFP transduced cells, lane 2; S5a transduced cells, and lane 4; PA28γ transduced cells). (B–G) Proteasome activities were increased by lentiviral gene transduction of PA28γ. Chymotrypsin-like (B, E), PGPH (C, F) and trypsin-like (D, G) activities were detected in normal control (<36 CAG) and HD patients' skin fibroblasts, which overexpress PA28γ (B–D) or S5a (E–G). The overexpression of PA28γ increased chymotrypsin and PGPH-like, but not trypsin proteasome activities in both normal control and HD fibroblasts compared to lenti-GFP transduction. Chymotrypsin activities and PGPH activities were increased in control fibroblasts by overexpression of S5a. However, in HD patients' fibroblasts, S5a did not increase PGPH activities and slightly decreased chymotrypsin-like activities (§, p<0.05 between control and HD fibroblasts. *, p<0.05 between the gene transferred groups of control protein GFP and PA28γ or S5a). The experiments were repeated three times in triplicate.