Extended Data Fig. 2.

4A mutant Gα subunits sequester Gβγ dimers. BRET between the βγ sensor memGRKct-Rluc8 and Venus-βγ dimers decreased when 4A mutant Gα subunits were expressed, indicating formation of heterotrimers and sequestration of free Gβγ dimers; Gα:Gβγ refers to the ratio of plasmid DNA used for transfection. In most cases Gβγ sequestration was partially reversed by the addition of GTPγS (100 μM). P values represent one-way ANOVA, Dunnett’s multiple comparisons; n=5.