title: Different requirement for Rnd GTPases of R-Ras GAP activity of Plexin-C1 and Plexin-D1.
abstract: 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 and inhibited migration of COS-7 cells, and these actions required Rnd2, another Rnd subfamily GTPase. Rnd2 bound to Plexin-D1 in cortical neurons, and Sema3E/Plexin-D1-induced inhibition of axon outgrowth of cortical neurons required Rnd2 and down-regulation of R-Ras activity. On the other hand, Plexin-C1 displayed R-Ras GAP activity and inhibited cell migration of COS-7 cells without Rnd proteins. Therefore, R-Ras GAP activity is a common function of plexin subfamilies but the regulation of R-Ras GAP activity of plexins by Rnd proteins is different among plexin subfamilies.
authors.affiliation: Laboratory of Molecular Neurobiology, Graduate School of Biostudies, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan.
authors.forename: Kanami
authors.initials: K
authors.lastname: Uesugi
authors.forename: Izumi
authors.initials: I
authors.lastname: Oinuma
authors.forename: Hironori
authors.initials: H
authors.lastname: Katoh
authors.forename: Manabu
authors.initials: M
authors.lastname: Negishi
mesh_terms: D000818:Animals; D001369:Axons / Q000378:metabolism*; D019556:COS Cells; D002465:Cell Movement / Q000502:physiology; D002540:Cerebral Cortex / Q000166:cytology / Q000378:metabolism; D002522:Chlorocebus aethiops; D003598:Cytoskeletal Proteins; D006023:Glycoproteins / Q000235:genetics / Q000378:metabolism; D047908:Intracellular Signaling Peptides and Proteins; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism*; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D051379:Mice; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism*; D039961:Semaphorins; D015398:Signal Transduction / Q000502:physiology*; D018631:ras Proteins / Q000378:metabolism*; D020741:rho GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D003598:Cytoskeletal Proteins; D006023:Glycoproteins; D047908:Intracellular Signaling Peptides and Proteins; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; C492112:Plxna3 protein, mouse; C473552:Plxnd1 protein, mouse; D011956:Receptors, Cell Surface; C111871:Rnd1 protein, mouse; C111150:Sema3e protein, mouse; D039961:Semaphorins; C475019:Rnd2 protein, mouse; C513254:Rras protein, mouse; D018631:ras Proteins; D020741:rho GTP-Binding Proteins