Fig. 1.
Restoration of cardiomyocyte sulfonylurea receptor 2 (SUR2)A protein in the SUR2 null heart. Top left: schematic map of MLC-2v SUR2A transgene construct. The 270-bp MLC-2v promoter (black box) is immediately proximal to the MLC2 gene and drives cardiomyocyte-specific expression. The SUR2A variant of SUR2 contains exon 39 and is the primary SUR2 splice variant expressed in heart and skeletal muscle. “Ter” represents the bovine growth hormone terminator. Restriction enzyme sites are indicated: X, XhoI; N, NotI; C, SacII; S, SalI. MLC2A transgene-bearing mice were bred to SUR2 null mice to restore cardiomyocyte SUR2-containing ATP-sensitive potassium (KATP) channels. Immunofluorescence microscopy of heart sections from wild-type (WT) control (top right), MLC2A (bottom left), and SUR2 null (bottom right) mice is also shown. All sections were stained with anti-SUR2 antibodies to visualize SUR2 (green) and DAPI (blue) to visualize nuclei. SUR2 staining was evident in control and MLC2A hearts but not in hearts from SUR2 null mice. Scale bars = 50 μm in all micrographs.