title: Rho localization in cells and tissues.
abstract: Rho family small GTPases regulate cytoskeletal organization. Although their spatiotemporal activities appear to be important for cellular morphogenesis, there has been little characterization of the localization of Rho family GTPases in cells and tissues. Here we show precise localization of Rho subfamily proteins in mammalian cultured cells and tissues through evaluation of anti-Rho antibodies and fixation protocols. Although Rho is not a structural protein but functions as a switching molecule, it often localizes at several distinct domains or structures of cells. In cultured epithelial cells, Rho was highly accumulated at lateral membranes. However, in fibroblastic cells, Rho appeared to be distributed evenly in the cytoplasm. Rho concentration at the cleavage furrow at cytokinesis was generally observed. In A431 cells, Rho translocation from the cytoplasm to elongating microvilli at the apical membrane within 30 s after EGF stimulation was clearly demonstrated. Also, Myc- or GFP-tagged RhoA did not always reflect the localization of endogenous Rho, indicating a drawback of protein-tagging methods for localization research. In mouse tissues, Rho localization differed depending on cell type, probably reflecting the functional differences of each cell type.
authors.affiliation: Laboratory for Cellular Morphogenesis, RIKEN Center for Developmental Biology, Chuo, Kobe, Hyogo 650-0047, Japan. yonemura@cbd.riken.jp
authors.forename: Shigenobu
authors.initials: S
authors.lastname: Yonemura
authors.forename: Kazuyo
authors.initials: K
authors.lastname: Hirao-Minakuchi
authors.forename: Yukako
authors.initials: Y
authors.lastname: Nishimura
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000378:metabolism; D002455:Cell Division / Q000502:physiology; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000378:metabolism; D002477:Cells / Q000378:metabolism*; D003593:Cytoplasm / Q000378:metabolism; D003599:Cytoskeleton / Q000502:physiology; D004285:Dogs; D004789:Enzyme Activation / Q000187:drug effects; D004815:Epidermal Growth Factor / Q000494:pharmacology; D004847:Epithelial Cells / Q000378:metabolism; D005347:Fibroblasts / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D007739:L Cells; D051379:Mice; D008815:Mice, Inbred Strains; D008871:Microvilli / Q000187:drug effects / Q000378:metabolism; D009504:Neutrophils / Q000187:drug effects / Q000378:metabolism; D021381:Protein Transport; D013997:Time Factors; D014018:Tissue Distribution; D020741:rho GTP-Binding Proteins / Q000378:metabolism*
chemical_list: D000911:Antibodies, Monoclonal; D004815:Epidermal Growth Factor; D020741:rho GTP-Binding Proteins