Figure 5.

Stac proteins do not affect Ca²⁺-dependent inactivation of the P/Q-type channel Ca_V2.1. Representative peak Ca²⁺ (red, vertically scaled by indicated factors) and Ba²⁺ (black) currents (A), fraction of peak current remaining 400 ms after the peak (R₄₀₀) as a function of test potential (B), and peak I–V relationships (C) in tsA201 cells transfected with YFP-Ca_V2.1, β_1a, and α₂-δ₁ either without or with Stac1, Stac2, or Stac3 (left to right, respectively). Ca²⁺ and Ba²⁺ test potentials in A: +25 mV and +10 mV, respectively. Scale bars in A: 5 pA/pF (unscaled Ba²⁺ currents, vertical), 100 ms (horizontal).