Intra- and intermolecular distances between the Cav1.2 calcium channel α1C and β subunits measured by three-color FRET microscopy.

*

P<0.002 vs. β3.

P<0.05 vs. β2d.

P<0.05 vs. β3.

§

P<0.05 vs. rV-R in Vα1C1CC+Rβ2d.

FRET efficiency between the indicated fluorophores fused to the α1C and β1b, β2d or β3 subunits was measured in the plasma membrane of expressing COS1 cells and fitted to a Gaussian function. In cases when the routine curve fit showed two significantly different Gaussian distributions, the corresponding dispersion coefficients c (mean±SEM) are shown for both distances (see Experimental Procedures). V – mVenus, C- mCerulean, R – tagRFP. Shown values of r are mean±SEM. Number of cells is shown in parentheses.