Table 1.

Fractional Ca2+ currents (Pf) and Ca2+ permeability (PCa/PCs) in mutant NMDAR channels containing substitutions of the M2 loop or M3 segment

Subunit combinationPCa/PCsnPf(%)n
NR1–NR2A6.4  ± 0.1813.6  ± 0.233
NR1(N0Q)–NR2AND7.8  ± 0.5*5
NR1(N0G)–NR2A1.5  ± 0.1*57.8  ± 0.6*4
NR1–NR2A(N0Q)ND13.7  ± 0.84
NR1–NR2A(N0G)6.1  ± 0.1612.8  ± 0.44
NR1–NR2A(N+1G)2.9  ± 0.1*48.8  ± 0.3*7
NR1(T630C)–NR2A6.2  ± 0.23ND
NR1(N632C)–NR2A4.9  ± 0.1*6ND
NR1(N632A)–NR2A4.8  ± 0.1*410.3  ± 0.2*6
  • Values are shown as mean ± SEM and were measured as in Figure 2. The N0 and N+1 designation corresponds to the N sites (N598 in NR1 and N595 in NR2A) and to an adjacent asparagine (N596) in NR2A, respectively (Kuner et al., 1996). NR1(N0), NR2A(N0), and NR2A(N+1) are located in the M2 loop, whereas T630 and N632 are located in the M3 segment proper (Fig. 1). ND, Not determined.

  • * Significantly different from wild type.