FIG. 3.

LT injection in skeletal muscle induces GTPase glucosylation in vivo. Samples of EDL muscle tissue, harvested at various times after in vivo injection of LT and containing 50 μg of protein, were incubated with LT (50 ng/μl) and UDP-[¹⁴C]glucose, subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and autoradiographed. The intensities of the bands estimated by densitometry are plotted on the graph. The value of the control was assigned to 100%. Notice the decrease in the intensities at 1 to 24 h after LT injection, indicating an in vivo modification of the LT substrates. Data shown are representative of four independent determinations made at the times indicated.