Plexins, comprising Plexin-A,-B,-C, and-D subfamilies, are receptors for semaphorins
governing cell adhesion, migration, and axon guidance. Among plexin subfamilies, Plexin-
A1 and Plexin-B1 have been shown to function as an R-Ras GAP, inducing repulsive
responses, and the expression of R-Ras GAP activity requires the binding of Rnd1, a
member of Rnd subfamily of Rho GTPases. However, signaling pathways of Plexin-D1 and
Plexin-C1 still remain obscure. Here, we found that Plexin-D1 displayed R-Ras GAP activity …