FIGURE 6.

Exon 1 overexpression inhibits surface trafficking and whole cell Ca_V1.2 currents in cerebral artery smooth muscle cells. A, upper panel, representative Western blot illustrating surface Ca_V1.2 and α₂δ-1 proteins in lysates from control arteries (pEGFP-N3 vector) or arteries expressing e1b-EGFP or e1c-EGFP. Lower panel, bar graph illustrating the percentage of Ca_V1.2 (black bars) and α₂δ-1 (white bars) surface protein remaining relative to control (pEGFP-N3 vector) in arteries expressing e1b-EGFP or e1c-EGFP. *, significance compared with control (pEGFP-N3 vector); #, significance compared with arteries overexpressing e1b-EGFP (p < 0.05, n = 4 for each). B, representative Western blot showing that e1c-EGFP overexpression does not alter total or surface expression of BK_Ca channel α subunits when compared with control (pEGFP-N3 vector) in cerebral arteries. C, exon 1c overexpression inhibits Ca_V1.2 currents in cerebral artery smooth muscle cells. Upper panel, representative whole cell currents from smooth muscle cells isolated from arteries treated with either control vector (pEGFP-N3) or vectors that express e1c-EGFP. Lower panel, current-voltage relationships of voltage-dependent Ba²⁺ currents from control (pEGFP-N3 vector, filled symbols) and e1c-EGFP treated (open symbols) cerebral artery myocytes (n = 4–5 for each). *, significance compared with scrmV (p < 0.05).