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Table 3 Parameters for ACh action at WT or variant hα6hβ4*- nAChRs

From: Analysis of rare variations reveals roles of amino acid residues in the N-terminal extracellular domain of nicotinic acetylcholine receptor (nAChR) alpha6 subunit in the functional expression of human alpha6*-nAChRs

  Potency Peak response
nAChR subunit combinations n EC50(μM) (95% CI) nH± SE nH n Mean Imax± SE (nA) Imaxconc. (μM)
hα6 + hβ4   181 - 5 30 ± 3 1000
hα6(R96H) + hβ4 3 - - 3 31 ± 4 1000
hα6(A184D) + hβ4 3 11 (9.3-13) 1.3 ± 0.16 5 86 ± 5 ⬆ 1000
hα6(D199Y) + hβ4 3 16 (14–19) 1.1 ± 0.04 5 73 ± 12⬆ 1000
hα6(S233C) + hβ4 3 14 (11–17) 0.95 ± 0.08 4 90 ± 23 1000
hα6 + hβ4 + hβ3 4 40 (29–56) 1.1 ± 0.1 4 502 ± 60▲ 1000
hα6(R96H) + hβ4 + hβ3 3 21 (17–26) ⬇ 0.96 ± 0.07 6 905 ± 146▲ 1000
hα6(A184D) + hβ4 + hβ3 3 17 (14–22) ⬇ ▲ 0.97 ± 0.04 7 788 ± 202▲ 1000
hα6(D199Y) + hβ4 + hβ3 3 24 (20–28) ⬇ ▲ 1.1 ± 0.07 7 494 ± 51▲ 1000
hα6(S233C) + hβ4 + hβ3 3 16 (12–21) ⬇ 0.98 ± 0.1 3 771 ± 150▲ 1000
  1. 1From Kuryatov et al. (2000).
  2. Potencies [micromolar EC50 values with 95% confidence intervals (CI)], Hill coefficients (nH ± SE), mean ± SE peak response (Imax in nanoamps) and concentrations (μM) where maximal peak current amplitudes (Imax) achieved are provided for ACh acting at nAChR composed of the indicated subunits and from the indicated number of independent experiments (n) based on studies as shown in Figure 8. ⬆ or ⬇ indicate a significant (p < 0.05) increase or decrease in indicated parameter at the indicated nAChR subtype relative to nAChR containing the same subunits but in the presence of the WT hα6 subunit (i.e., hα6hβ4- vs. variant-hα6hβ4- nAChR; hα6hβ4hβ3- vs. variant-hα6hβ4hβ3- nAChR). ▲ or indicate a significant (p < 0.05) increase or decrease, respectively, in indicated parameter at the indicated nAChR subtype relative to nAChR containing the same subunits but in the absence WT β3 subunits (i.e., hα6hβ4- vs. hα6hβ4hβ3- nAChR; variant-hα6hβ4- vs. variant-hα6hβ4hβ3- nAChR). ‘-‘ indicates that inconsistent functional responses in two electrode voltage clamp studies precluded determination of the parameter of interest.