Figure 5. WDR26 selectively regulates Gβγ-mediated AKT phosphorylation.

MDA-MB231 cells were transiently transfected with a control siRNA (siCT) or siRNAs targeting WDR26 (siWDR26), and the effects on Gβγ-AKT phosphorylation and Gα-mediated cAMP accumulation or Ca²⁺ signaling were determined. A-B. LPA (10 μM)-, EGF (50 ng/ml) (A)- or SDF1α (100 nM)(B)-stimulated AKT and ERK phosphorylation determined by Western blotting. Data in A are expressed as the fold-increase over the unstimulated control (basal) after the levels of phosphorylated proteins are normalized to that of total proteins. *, ** p<0.05, versus siCT (n=5). C-D. LPA-stimulated Ca²⁺ signaling (C), SDF1α-mediated decrease in cAMP accumulation and isoproterenol (ISO)-stimulated increase in cAMP (D). Ca²⁺ signaling was measured using Fura-2/AM. Representative data and maximum Ca²⁺ concentration (n=3) are shown in C. To measure SDF1α- and ISO-induced decrease and incrase in cAMP accumulation, respectively, cells were treated with either forskolin (10 μM) alone or forskolin (10 μM) plus SDF1α (50 nM) or ISO (1 μM) (n=3).