Western blot analysis of untransfected primary mouse neuron and glia cell cultures (lane 1), the same cells transduced with human ubiquilin 2 wild type (lane 2), with ubiquilin 2 P506T mutant (lane 3), with ubiquilin 2 P497S mutant (lane 4) and with enhanced GFP control (lane 5), all probed with Ubiquilin 2 / UBQLN2 antibody. Also seen is Ubiquilin 2 / UBQLN2 antibody staining in HeLa cells (lane 6) and 3T3 cells (lane 7). In primary mouse neuron and glia cell culture, endogenous ubiquilin 2 appears as a weak band at 68 kDa in all transduced and non-transduced cells, indicating low endogenous expression of mouse ubiquilin 2. Strong bands are seen in the cells transduced with human wild type or mutant ubiquilin 2. Small proteins run at 50 kDa in these cells are the fragments of ubiquilin 2. Note, ubiquilin 2 run at ~66 kDa in human HeLa cells and 68 kDa in rodent 3T3 cells.