Figure 8.

Isoproterenol-induced changes of Gαs splice variant ratios. Lymphoblasts (5 × 10⁶) from four different individuals were stimulated with isoproterenol (100 nM) and splice variant ratios were determined at indicated time points as described in Materials and Methods. Isoproterenol stimulation resulted in a slight decrease in Gαs_S/Gαs ratio with a maximum after 8 h (A) and a corresponding increase in Gαs_L/Gαs ratio (B). Within the short variant, the ratios of +/−CAG variants changed significantly after 4 h of isoproterenol treatment with an increase of +CAG variants and a decrease of −CAG variants. The Gαs_S+CAG/Gαs_S ratio increased from 0.55 ± 0.02 at baseline to a maximum of 0.64 ± 0.02 after 4 h (p < 0.05). After 24 h, baseline values were reached again (C). The same effect was observed for +/−CAG variants within the long variant. The Gαs_L+CAG/Gαs_L ratio increased from 0.08 ± 0.01 at baseline to a maximum of 0.17 ± 0.01 after 4 h (p < 0.05) and returned to baseline values after 24 h (D). All experiments were repeated at least twice at different time points with similar results. Data are expressed as means ± SEM.