title: Ephexin4 and EphA2 mediate cell migration through a RhoG-dependent mechanism.
abstract: EphA2, a member of the Eph receptor family, is frequently overexpressed in a variety of human cancers, including breast cancers, and promotes cancer cell motility and invasion independently of its ligand ephrin stimulation. In this study, we identify Ephexin4 as a guanine nucleotide exchange factor (GEF) for RhoG that interacts with EphA2 in breast cancer cells, and knockdown and rescue experiments show that Ephexin4 acts downstream of EphA2 to promote ligand-independent breast cancer cell migration and invasion toward epidermal growth factor through activation of RhoG. The activation of RhoG recruits its effector ELMO2 and a Rac GEF Dock4 to form a complex with EphA2 at the tips of cortactin-rich protrusions in migrating breast cancer cells. In addition, the Dock4-mediated Rac activation is required for breast cancer cell migration. Our findings reveal a novel link between EphA2 and Rac activation that contributes to the cell motility and invasiveness of breast cancer cells.
authors.affiliation: Laboratory of Molecular Neurobiology, Graduate School of Biostudies, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan.
authors.forename: Nao
authors.initials: N
authors.lastname: Hiramoto-Yamaki
authors.forename: Shingo
authors.initials: S
authors.lastname: Takeuchi
authors.forename: Shuhei
authors.initials: S
authors.lastname: Ueda
authors.forename: Kohei
authors.initials: K
authors.lastname: Harada
authors.forename: Satoshi
authors.initials: S
authors.lastname: Fujimoto
authors.forename: Manabu
authors.initials: M
authors.lastname: Negishi
authors.forename: Hironori
authors.initials: H
authors.lastname: Katoh
mesh_terms: D001943:Breast Neoplasms / Q000378:metabolism* / Q000473:pathology; D045744:Cell Line, Tumor; D002465:Cell Movement; D005260:Female; D020662:Guanine Nucleotide Exchange Factors / Q000737:chemistry / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D036104:Receptor, EphA2 / Q000378:metabolism*; D020741:rho GTP-Binding Proteins / Q000378:metabolism*
chemical_list: D020662:Guanine Nucleotide Exchange Factors; C075397:RHOG protein, human; D036104:Receptor, EphA2; D020741:rho GTP-Binding Proteins