Figure 3
GRIN2A mutations associated with DD/ID, but not epilepsy or SCZ, demonstrate a dominant-negative effect. (A) Western blot probing for GluN2A, insulin receptor beta, and β-ACTIN in the input, flowthrough, and elution samples of surface biotinylation experiment done on HEK cells transiently transfected with GRIN1-GRIN2A constructs to express wild-type or M653I mutant NMDARs. Input, flowthrough, and elution represent total, internal, and surface expression respectively. IR-B: insulin receptor beta. The blots presented here are cropped, and the original blots are presented in Supplementary Fig. 6. (B) Glutamate EC50 normalized to wild type EC50, for each mutant NMDAR. (C) Peak current density in response to 100 µM glutamate, normalized to wild type’s response, is plotted for each mutant NMDAR. In (B) and (C) data are displayed as mean + /- SEM; n = 80 (WT); 113 (1:1 WT:E58Ter); 27 (Y698C); 45 (1:1 WT:Y698C); 8 (A727T); 44 (1:1 WT:A727T); 74 (M653I); 39 (1:1 WT:M653I); 35 (S809R); 46 (1:1 WT:S809R) cells; statistical significance was assessed using Brown-Forsythe and Welch ANOVA with Dunnett’s T3 multiple comparisons test. *: p < 0.05, ***: p < 0.001, ****: p < 0.0001.
