title: Interaction of plexin-B1 with PDZ domain-containing Rho guanine nucleotide exchange factors.
abstract: The Rho family GTPase has been implicated in plexin-B1, a receptor for Semaphorin 4D (Sema4D), mediating signal transduction. Rho may also play a function in this signaling pathway as well as Rac, but the mechanisms for Rho regulation are poorly understood. In this study, we have identified two kinds of PDZ domain-containing Rho-specific guanine nucleotide exchange factors (RhoGEFs) as proteins interacting with plexin-B1 cytoplasmic domain. These PDZ domain-containing RhoGEFs showed significant homology to human KIAA0380 (PDZ-RhoGEF) and LARG (KIAA0382), respectively. Both KIAA0380 and LARG could bind plexin-B1 and a deletion mutant analysis of plexin-B1, KIAA0380 and LARG revealed that KIAA0380 and LARG bound plexin-B1 cytoplasmic tail through their PDZ domains. The tissue distribution analysis indicated that plexin-B1 was co-localized with KIAA0380 and LARG in various tissues. Immunocytochemical analysis showed that LARG was recruited to plasma membrane by plexin-B1. These results suggest that PDZ domain-containing RhoGEFs play a role in Sema4D-plexin-B1 mediating signal transduction.
authors.affiliation: Group of Neurobiology, School of Allied Health Sciences, Osaka University Faculty of Medicine, Yamadaoka 1-7, Suita-shi, Osaka 565-0871, Japan.
authors.forename: Mutsumi
authors.initials: M
authors.lastname: Hirotani
authors.forename: Yoshiharu
authors.initials: Y
authors.lastname: Ohoka
authors.forename: Takahiro
authors.initials: T
authors.lastname: Yamamoto
authors.forename: Hiromi
authors.initials: H
authors.lastname: Nirasawa
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Furuyama
authors.forename: Mikihiko
authors.initials: M
authors.lastname: Kogo
authors.forename: Tokuzo
authors.initials: T
authors.lastname: Matsuya
authors.forename: Shinobu
authors.initials: S
authors.lastname: Inagaki
mesh_terms: D000818:Animals; D001665:Binding Sites; D002478:Cells, Cultured; D015870:Gene Expression; D020662:Guanine Nucleotide Exchange Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D011817:Rabbits; D011956:Receptors, Cell Surface / Q000378:metabolism*; D064067:Rho Guanine Nucleotide Exchange Factors; D014162:Transfection
chemical_list: C577234:ARHGEF11 protein, human; C577222:ARHGEF12 protein, human; C577356:ARHGEF2 protein, human; D020662:Guanine Nucleotide Exchange Factors; D009419:Nerve Tissue Proteins; C492119:PLXNB1 protein, human; D011956:Receptors, Cell Surface; D064067:Rho Guanine Nucleotide Exchange Factors