Figure 6. CXCR4 activates the RhoA signaling pathway via Gα₁₃.

(A) Western Blot showing the levels of Gα₁₂ and Gα₁₃ in transfected HCT116 and SW480 cells. GAPDH served as the internal control. (B, C) In vitro co-immunoprecipitation (co-IP) confirmed the interactions between CXCR4, RhoA, and the Gα₁₂/Gα₁₃ complex and revealed a complex composed of CXCR4 and Gα₁₃. Total protein was extracted from untransfected HCT116 and SW480 cells. Total (input) and eluted (co-IP) proteins were subjected to Western Blot, which was performed with anti-Gα₁₂, anti-RhoA, and anti-Gα₁₃. (D) Western Blot was used to confirm the expression of Gα₁₃ (right), and the G-LISA assay was used to measure RhoA activity in HCT116 cells after knocking down Gα₁₃ expression with siRNA-Gα₁₃ (left). The control group was exposed to the non-specific siRNA, **p < 0.01.