FIGURE 1.
CaVα2bδ stimulated CaV1.2 whole cell currents. A, panel a, whole cell current traces recorded after the transient expression of the CaV1.2 wt channel in the stable CaVβ3 cell line. The charge carrier was 2 mm Ca2+. Panel b, whole cell current traces recorded after the transient expression of the CaV1.2-HA channel in the stable CaVβ3 cell line. Panel c, whole cell current traces recorded after the transient expression of the CaV1.2-HA channel and the CaVα2bδ in the stable CaVβ3 cell line. B, panel a, current-voltage relationships of CaV1.2 wt + CaVβ3 ± CaVα2bδ show a typical voltage-dependent activation with a mean current density of −7 ± 2 pA/pF (n = 6) for the wild type CaV1.2 channel in the stable CaVβ3 stable cell line as compared with a current density of −41 ± 9 pA/pF (n = 7) for the wild type CaV1.2 channel measured in the same cell line after transient transfection with CaVα2bδ subunit. The activation potential of 3 ± 3 mV for the CaV1.2 wt + CaVβ was shifted to −10 ± 2 mV in the presence of CaVα2bδ. Panel b, current-voltage relationships of CaV1.2-HA/CaVβ3 ± CaVα2bδ show a typical voltage-dependent activation with a mean current density of −9 ± 2 pA/pF (n = 5) for the CaV1.2-HA channel in the stable CaVβ3 stable cell line as compared with a current density of −36 ± 8 pA/pF (n = 7) for the CaV1.2-HA channel measured in the same cell line after transient transfection with CaVα2bδ subunit. The activation potential of 2 ± 3 mV for the CaV1.2-HA/CaVβ was shifted to −12 ± 2 mV in the presence of CaVα2bδ. Patch clamp experiments were carried out in the whole cell configuration in the presence of a 2 mm Ca2+ saline solution.