Skip to main content
Fig. 4 | Skeletal Muscle

Fig. 4

From: The ERG1a potassium channel increases basal intracellular calcium concentration and calpain activity in skeletal muscle cells

Fig. 4

Expression of mouse erg1a in mouse Gastrocnemius muscle increases Merg1a transcription and native calpain activity, but does not increase the number of centrally located nuclei or the abundance of laminin protein. a Quantitative PCR shows that electro-transfer of an expression plasmid encoding mouse erg1a (Merg1a) into mouse skeletal muscle produces Merg1a expression which is significantly higher than day 0 at days 3–5 (p < 0.05; n = 28). The enclosed circles of the line graph represent the mean while the error bars represent the standard error of the mean. b Merg1a transfection in mouse skeletal muscle increases calpain activity nearly 4-fold (over day 0) by day 3 and nearly 7.5-fold by day 4 (p < 0.05; n = 40). It returns to day 0 control levels by day 5 post transfection. Bars represent the mean calpain activity while error bars represent the standard error of the mean. c Positive assay for the β-galactosidase reporter (as an indicator of electro-transfer of plasmid encoding the Merg1a gene) produces a blue color. d Immunostain for MERG1 (green) of a serial section matched to the section in c demonstrates that there is indeed a greater amount of MERG1 in the fibers colored blue in c. There were no greater number of centrally located nuclei in the green fibers of any sections (n = 5 mice). e Representative of sections immunostained without primary antibody. f Over-expression of Merg1a does not produce a change in laminin abundance (p = 0.3; n = 5). Bars represent the mean single point laminin fluorescence while error bars represent the standard error of the mean. All scale bars = 50 μm

Back to article page