Figure 4.

UBE3A^T485A depletes multiple endogenous proteasome subunits. A, protein lysates from HEK293T cells expressing UBE3A^T485A or UBE3A^T485E mutants were analyzed by Western blotting for proteasome subunit protein levels. Analysis was performed on cells grown in L-cell CM or Wnt3a CM. B and C, quantification of Western blots for cells grown in L-cell CM (B) or Wnt3a CM (C). Mean percent abundance values in UBE3A^T485A samples relative to UBE3A^T485E samples are shown (n = 6). Error bars indicate S.D. Statistical analysis was performed using a one-sample t test (two-tailed). *, p < 0.05; **, p < 0.005. PSMD11 was not analyzed due to its low abundance in HEK293T cells. D and E, representative Western blot (D) and quantification (E) of proteasome subunits in immortalized lymphocyte cell lines from the father, mother, and autism proband (Simon's Simplex Collection; Family ID 13873). Mean percent values are shown relative to the father's level (n = 3). Error bars indicate S.D. *, p < 0.05, one-sample t test.