title: Dock4 is regulated by RhoG and promotes Rac-dependent cell migration.
abstract: Cell migration is essential for normal development and many pathological processes including tumor metastasis. Rho family GTPases play important roles in this event. In particular, Rac is required for lamellipodia formation at the leading edge during migration. Dock4 is a member of the Dock180 family proteins, and Dock4 mutations are present in a subset of human cancer cell lines. However, the function and the regulatory mechanism of Dock4 remain unclear. Here we show that Dock4 is regulated by the small GTPase RhoG and its effector ELMO and promotes cell migration by activating Rac1. Dock4 formed a complex with ELMO, and expression of active RhoG induced translocation of the Dock4-ELMO complex from the cytoplasm to the plasma membrane and enhanced the Dock4- and ELMO-dependent Rac1 activation and cell migration. On the other hand, RNA interference-mediated knockdown of Dock4 in NIH3T3 cells reduced cell migration. Taken together, these results suggest that Dock4 plays an important role in the regulation of cell migration through activation of Rac1, and that RhoG is a key upstream regulator for Dock4.
authors.affiliation: Laboratory of Molecular Neurobiology, Graduate School of Biostudies, Kyoto University, Yoshidakonoe-cho, Sakyo-ku, Kyoto 606-8501, Japan.
authors.forename: Kiyo
authors.initials: K
authors.lastname: Hiramoto
authors.forename: Manabu
authors.initials: M
authors.lastname: Negishi
authors.forename: Hironori
authors.initials: H
authors.lastname: Katoh
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism; D000818:Animals; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D002465:Cell Movement; D020690:GTPase-Activating Proteins / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D005786:Gene Expression Regulation; D006367:HeLa Cells; D006801:Humans; D051379:Mice; D041681:NIH 3T3 Cells; D011485:Protein Binding; D034622:RNA Interference; D015398:Signal Transduction; D014162:Transfection; D020744:rac GTP-Binding Proteins / Q000378:metabolism* / Q000502:physiology; D020741:rho GTP-Binding Proteins / Q000502:physiology*
chemical_list: D048868:Adaptor Proteins, Signal Transducing; C510122:DOCK4 protein, human; C465214:ELMO1 protein, human; D020690:GTPase-Activating Proteins; C075397:RHOG protein, human; D020744:rac GTP-Binding Proteins; D020741:rho GTP-Binding Proteins