FIGURE 1.

Gadd45a TAP, a functional Gadd45a construct designed for tandem affinity purification in mouse skeletal muscle. A, schematic of the Gadd45a TAP construct. B–E, mouse TA muscle fibers were transfected with 20 μg of Gadd45a TAP plasmid plus 2.5 μg of eGFP plasmid. In each mouse, the contralateral TA muscle fibers (Control) were transfected with 20 μg of empty TAP plasmid plus 2.5 μg of eGFP plasmid. Bilateral TA muscles were harvested for analysis 7 days post-transfection. B, skeletal muscle protein extracts were subjected to immunoblot analysis using monoclonal anti-FLAG IgG. C, representative fluorescence microscopy images of muscle cross-sections. D, average diameters of skeletal muscle fibers. Each data point represents the mean of >450 muscle fibers from one muscle, and horizontal bars denote average of the means ± S.E. p value was determined with a paired t test. E, size distribution of all muscle fibers from D.