Rem overexpression does not alter targeting of CaV1.1 α1S or β1a subunits. Confocal images of FDB fibers expressing CFP-α1S alone (A), CFP-α1S coexpressed with V-Rem (B), CFP-β1a alone (C), or CFP-β1a coexpressed with V-Rem (D). For each panel, the left, left-middle, and right-middle images show CFP fluorescence (red), Venus fluorescence (green), and an overlay, respectively. Bars, 10 µm. The right images are blowups of the area indicated by the yellow boxes in the adjacent overlays; average image profile analyses are shown below. The green lines indicate Venus fluorescence and the red lines represent the fluorescence emitted by either CFP-α1S or CFP-β1a in arbitrary units. Note that the transverse-tubular targeting of CFP-α1S or β1a is intact both in the absence and in the presence of coexpressed V-Rem. For experiments with each channel subunit clone, images were acquired with nearly identical microscope settings.
