title: Arachidonic acid stimulates formation of a novel complex containing nucleolin and RhoA.
abstract: Arachidonic acid (AA) stimulates cell adhesion through a p38 mitogen activated protein kinase-mediated RhoA signaling pathway. Here we report that a proteomic screen following AA-treatment identified nucleolin, a multifunctional nucleolar protein, in a complex with the GTPase, RhoA, that also included the Rho kinase, ROCK. AA-stimulated cell adhesion was inhibited by expression of nucleolin-targeted shRNA and formation of the multiprotein complex was blocked by expression of dominant-negative RhoA. AA-treatment also induced ROCK-dependent serine phosphorylation of nucleolin and translocation of nucleolin from the nucleus to the cytoplasm, where it appeared to co-localize with RhoA. These data suggest the existence of a new signaling pathway through which the location and post-translational state of nucleolin are modulated.
authors.affiliation: Laboratory of Molecular Carcinogenesis, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA.
authors.forename: Melissa C
authors.initials: MC
authors.lastname: Garcia
authors.forename: Jason
authors.initials: J
authors.lastname: Williams
authors.forename: Katina
authors.initials: K
authors.lastname: Johnson
authors.forename: Kenneth
authors.initials: K
authors.lastname: Olden
authors.forename: John D
authors.initials: JD
authors.lastname: Roberts
mesh_terms: D019943:Amino Acid Substitution; D016718:Arachidonic Acid / Q000378:metabolism*; D002448:Cell Adhesion; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D020868:Gene Silencing; D006801:Humans; D047468:Immunoprecipitation; D050505:Mutant Proteins / Q000235:genetics / Q000378:metabolism; D010750:Phosphoproteins / Q000037:antagonists & inhibitors / Q000378:metabolism*; D010766:Phosphorylation; D047428:Protein Kinase Inhibitors; D021381:Protein Transport; D040901:Proteomics / Q000379:methods; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012694:Serine / Q000378:metabolism; D054460:rho-Associated Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D020742:rhoA GTP-Binding Protein / Q000235:genetics / Q000378:metabolism*; D000097796:Nucleolin
chemical_list: D016718:Arachidonic Acid; D050505:Mutant Proteins; D010750:Phosphoproteins; D047428:Protein Kinase Inhibitors; D034741:RNA, Small Interfering; D016601:RNA-Binding Proteins; D011993:Recombinant Fusion Proteins; D012694:Serine; D054460:rho-Associated Kinases; D020742:rhoA GTP-Binding Protein; D000097796:Nucleolin; C066737:RHOA protein, human