Redistribution of Gαi subunits in AtT-20 cells overexpressing calnuc-GFP. In parental AtT-20 cells (NT), the majority of the endogenous Gαi1/2 (70%) is found in heavy fractions (3–8) containing ER and secretory granules, whereas most of the endogenous Gαi3 (72%) is present in light fractions (10–12) containing Golgi and PM. In cells overexpressing calnuc-GFP (CNG) the % of the total Gαi1/2 found in heavy fractions is reduced (55%), that in light fractions is correspondingly increased (41%), and Gαi3 is more broadly distributed in fractions 3–12. No obvious change in the distribution of Gβ is observed following calnuc-GFP overexpression. Similar distribution change of indicated proteins was observed in 3 separate experiments depicted. The quantitative analysis shown by bar graph which was calculate based on the dot curve in left panel represent the result from the same illustrated experiment as indicated above. The experimental protocol is the same as for Figure 6. "B" and "C" were calculated and plotted as in Figure 8A.