(A-H) Western blots showing PC2 levels in PRE-WT (A, B), PRE-Pkd1KO (C, D), mIMCD3-WT (E, F) and mIMCD3- Pkd1KO (G, H) cells treated with cycloheximide (CHX), MG-132 (MG) or bafilomycin (Baf) for 24 hours as indicated. CHX inhibits protein translation, MG inhibits proteasomal degradation and Baf inhibits lysosomal degradation. (B, D, F, H) Quantification of corresponding Western Blot data. PC2 level in control/untreated cells was set to 1. The bars represent mean ± SEM. **p<0.01, ***p < 0.001, NS – not significant. MG rescued PC2 degradation in both wild type and Pkd1 mutant cells suggesting that PC2 is mainly degraded by the proteasomes.