Fig. 1
From: Cavβ surface charged residues contribute to the regulation of neuronal calcium channels
Cavβ3 surface charged residues contribute to the modulation of Cav2.1 channels. a Cartoon representation of secondary structural elements of the rat Cavβ3 subunit in complex with the Cavβ1 interacting domain (AID) (PDB 1VYT). b Position of surface charged residues within the Cavβ3 subunit. Positively (H, histidine; R, arginine) and negatively (E, glutamic acid; D, aspartic acid) charged residues are shown in blue and red, respectively. c Mean current–voltage (I/V) relationship for Cav2.1 expressed alone (filled circles) and in combination with wild-type Cavβ3 (open circles). d Corresponding mean maximal macroscopic conductance (Gmax) obtained from the fit of the I/V curves with the modified Boltzmann function (1) for Cav2.1 alone and in combination with WT and mutant Cavβ3 (ANOVA results: F = 26.6; p < 0.0001 and F = 10.15; p < 0.0001 for Cav2.1 expressed alone versus in the presence of Cavβ3 variants and Cav2.1 expressed with Cavβ3 wild-type versus with Cavβ3 variants, respectively. e Mean normalized voltage-dependence of activation for Cav2.1 expressed alone (filled circles) and in combination with WT Cavβ3 (open circles). f Corresponding mean half-activation potential values obtained from the fit of the activation curves with the modified Boltzmann function (1) for Cav2.1 alone and in combination with WT and mutant Cavβ3 (ANOVA results: F = 34.29; p < 0.0001 and F = 9.965; p < 0.0001 for Cav2.1 expressed alone versus in the presence of Cavβ3 variants and Cav2.1 expressed with Cavβ3 wild-type versus with Cavβ3 variants, respectively). g Mean normalized voltage-dependence of inactivation for Cav2.1 expressed alone (filled circles) and in combination with WT Cavβ3 (open circles). h Corresponding mean half-inactivation potential values obtained from the fit of the activation curves with the two-state Boltzmann function (3) for Cav2.1 alone and in combination with WT and mutant Cavβ3 (ANOVA results: F = 47.9; p < 0.0001 and F = 27.84; p < 0.0001 for Cav2.1 expressed alone versus in the presence of Cavβ3 variants and Cav2.1 expressed with Cavβ3 wild-type versus with Cavβ3 variants, respectively. Statistical analysis (ANOVA followed by Dunnett’s post hoc multiple comparisons test) was performed for all Cavβ3 variants either against Cav2.1 expressed alone (black statistical symbols) or Cav2.1 expressed with WT Cavβ3 (red statistical symbols): * p < 0.05. The exact p values of the Dunnett’s post hoc analysis are provided in Additional file 3: Table S2