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.
Copyright © 2011. Published by Elsevier B.V.
Publication types
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Research Support, N.I.H., Intramural
MeSH terms
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Amino Acid Substitution
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Arachidonic Acid / metabolism*
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Cell Adhesion
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Cell Line
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Cell Nucleus / metabolism
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Cytoplasm / metabolism
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Gene Silencing
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Humans
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Immunoprecipitation
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Mutant Proteins / genetics
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Mutant Proteins / metabolism
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Nucleolin
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Phosphoproteins / antagonists & inhibitors
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Phosphoproteins / metabolism*
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Phosphorylation
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Protein Kinase Inhibitors
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Protein Transport
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Proteomics / methods
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RNA, Small Interfering / genetics
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RNA, Small Interfering / metabolism
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RNA-Binding Proteins / antagonists & inhibitors
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RNA-Binding Proteins / metabolism*
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Recombinant Fusion Proteins / metabolism
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Serine / metabolism
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rho-Associated Kinases / antagonists & inhibitors
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rho-Associated Kinases / metabolism
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rhoA GTP-Binding Protein / genetics
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rhoA GTP-Binding Protein / metabolism*
Substances
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Mutant Proteins
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Phosphoproteins
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Protein Kinase Inhibitors
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RNA, Small Interfering
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RNA-Binding Proteins
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Recombinant Fusion Proteins
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RHOA protein, human
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Arachidonic Acid
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Serine
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rho-Associated Kinases
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rhoA GTP-Binding Protein