FIGURE 7:

αvβ8 integrin–RhoGDI1 protein complexes regulate Rho GTPase activation and drive GBM cell invasion. (A) αvβ8 integrin is expressed in GBM cells, where it interacts with RhoGDI1 via the β8 cytoplasmic tail. αvβ8 integrin–RhoGDI1 protein complexes recruit GDP-bound Rac1 and Cdc42 to control activation of Rho proteins, thus driving GBM cell polarity and invasion. In addition, αvβ8 integrin likely binds to ECM protein ligands, including latent TGFβs, to regulate intracellular signaling pathways involved in GBM cell invasion. (B) Uncoupling αvβ8 integrin–RhoGDI1 protein complexes by mutating the integrin cytoplasmic tail or silencing β8 integrin or RhoGDI1 gene expression leads to elevated levels of GTP-bound Rho proteins, resulting in diminished GBM cell polarity and invasion.