Activator for CDC42 by directly engaging this Rho GTPase and acting as potent guanine nucleotide exchange factor (GEF). This activation results in actin cytoskeleton rearrangements and stimulates membrane ruffling, promoting bacterial entry into non-phagocytic cells. Chaperone InvB is required for secretion, translocation and stabilization of intracellular levels of sopE2 (By similarity). Secreted via the type III secretion system 1 (SPI-1 TTSS). Belongs to the GEF (guanine exchange factor) SopE family.