FIGURE 5.
CaVβ3 Δ57–123 stimulated CaV1.2 whole cell currents. A, whole cell current traces recorded after the transient expression of the CaV1.2-HA channel with CaVα2bδ and CaVβ3 wt (left panel) or with CaVα2bδ and CaVβ3 Δ57–123 (right panel) in HEKT cells. All of the subunits were transiently expressed. B, current-voltage relationships of CaV1.2-HA + CaVα2bδ + CaVβ3 wt (filled circles) and CaV1.2-HA + CaVα2bδ + CaVβ3 Δ57–123 (open triangles) show a typical voltage-dependent activation with a mean current density of −21 ± 2 pA/pF (n = 5) for CaV1.2-HA + CaVα2bδ + CaVβ3 wt as compared with a current density of −23 ± 4 pA/pF (n = 4) for CaV1.2-HA + CaVα2bδ + CaVβ3 Δ57–123 measured under the same conditions. Patch clamp experiments were carried out in the whole cell configuration in the presence of a 2 mm Ca2+ saline solution.