FIGURE 5.
Positions 637 and 823 in the NR2A subunit interactively regulate NMDA receptor function and ethanol sensitivity. A and D, the graphs plot EC50 for glutamate activation of peak (A) and steady-state (B) current, maximal Iss/Ip (C), and ethanol IC50 (D) versus the substituent at position 823 for the series of mutants at NR2A(Phe-637/Met-823). Although the substituent at 637 did not by itself affect maximal Iss/Ip values (p > 0.05; ANOVA), there were highly significant effects of the substituents at 637 and 823 individually on all other measures (p < 0.0001; ANOVA), and highly significant interactions between the substituents at 637 and 823 on all measures (p < 0.0001; ANOVA). Note the departure from parallelism due to the values for subunits containing methionine at position 823.