title: Spatial control of Rho (Rac-Rop) signaling in tip-growing plant cells.
abstract: Spatially restricted signaling by Rho GTPases is essential for the polarization of eukaryotic cells, which is required for the morphogenesis, mobility and division of single cells, and for the development of multicellular organisms. Rac-Rop GTPases, which constitute a plant-specific Rho GTPase subfamily, accumulate at the apical plasma membrane of pollen tubes and root hairs, where they control rapid polar cell expansion by a process known as tip growth. Here, recent insights into the spatial control of Rac-Rop-dependent signaling in tip-growing plant cells by regulatory proteins (i.e. Rho GTPase-activating proteins, Rho guanine nucleotide dissociation inhibitors, Rho guanine nucleotide-exchange factors and phosphoinositide-specific phospholipase C) and lipids [phosphatidylinositol (4,5)-bisphosphate and diacyl glycerol] are summarized. A model is presented, which integrates the current knowledge concerning the molecular mechanisms that maintain the polarization of Rho signaling in plant cells.
authors.affiliation: Warwick HRI, University of Warwick, Wellesbourne, Warwickshire, CV35 9EF, UK. b.kost@warwick.ac.uk
authors.forename: Benedikt
authors.initials: B
authors.lastname: Kost
mesh_terms: D002462:Cell Membrane / Q000378:metabolism; D016764:Cell Polarity; D049109:Cell Proliferation; D004075:Diglycerides / Q000378:metabolism; D004705:Endocytosis; D020730:Guanine Nucleotide Dissociation Inhibitors / Q000378:metabolism; D020662:Guanine Nucleotide Exchange Factors / Q000378:metabolism; D018519:Meristem / Q000166:cytology / Q000201:enzymology / Q000378:metabolism*; D019269:Phosphatidylinositol 4,5-Diphosphate; D018129:Phosphatidylinositol Phosphates / Q000378:metabolism; D010940:Plant Proteins / Q000378:metabolism*; D053205:Pollen Tube / Q000166:cytology / Q000201:enzymology / Q000378:metabolism*; D015398:Signal Transduction; D010738:Type C Phospholipases / Q000378:metabolism; D020764:cdc42 GTP-Binding Protein / Q000378:metabolism; D020744:rac GTP-Binding Proteins / Q000378:metabolism*; D020741:rho GTP-Binding Proteins / Q000378:metabolism*; D062947:rho-Specific Guanine Nucleotide Dissociation Inhibitors
chemical_list: D004075:Diglycerides; D020730:Guanine Nucleotide Dissociation Inhibitors; D020662:Guanine Nucleotide Exchange Factors; D019269:Phosphatidylinositol 4,5-Diphosphate; D018129:Phosphatidylinositol Phosphates; D010940:Plant Proteins; D062947:rho-Specific Guanine Nucleotide Dissociation Inhibitors; D010738:Type C Phospholipases; D020764:cdc42 GTP-Binding Protein; D020744:rac GTP-Binding Proteins; D020741:rho GTP-Binding Proteins