The G-switch? Direct Modulators have been developed with an emphasis on creating highly potent cell permeable reagents that directly target the Rho family of small G-proteins. Our Direct Activator reagents are based on the catalytic domain of the bacterial CNF toxins, which are covalently attached to a proprietary cell penetrating moiety. Rho Activator II (Cat# CN03) enters the cell and activates Rho GTPase isoforms by deamidating glutamine-63, which is located in the Switch II region of these GTPases (1). This modification converts glutamine-63 to glutamate, which blocks intrinsic and GAP stimulated GTPase activity resulting in constitutively active Rho (2). Rho Activator II robustly increases the level of GTP bound RhoA within 2-4 h after addition to the culture medium, providing a more rapid alternative to transfection based methods for introducing activators like GEFs into cells. Moreover, the targeted action of Rho Activator II makes it far more attractive tool for the study of Rho GTPase signaling than classic indirect activators (e.g. LPA) that concomitantly activate other signaling pathways (e.g. Ras, PI3K and PLC).