title: Lysine 63-linked ubiquitination is important for arachidonic acid-induced cellular adhesion and migration.
abstract: Arachidonic acid, a dietary cis-polyunsaturated fatty acid, stimulates adhesion and migration of human cancer cells on the extracellular matrix by activation of intracellular signaling pathways. Polyubiquitin chains bearing linkages through different lysine residues convey distinct structural and functional information that is important for signal transduction. We investigated whether ubiquitination was required for arachidonic acid-induced cellular adhesion and migration of MDA-MB-435 cells on collagen type IV. An E1 (ubiquitin-activating enzyme) inhibitor, PYR-431, completely abrogated arachidonic acid-stimulated adhesion. Additionally, expression of a lysine null mutant ubiquitin prevented activation of cellular adhesion. Cells expressing ubiquitin in which lysine 63 (K63) was mutated to arginine (K63R) were unable to adhere to collagen upon exposure to arachidonic acid. When K63 was the only lysine present, the cells retained the ability to adhere, indicating that K63-linked ubiquitin is both necessary and sufficient. Moreover, K63-linked ubiquitin was required for the induction of cell migration by arachidonic acid. The ubiquitin mutants and PYR-431 did not prevent arachidonic acid-induced phosphorylation of TGF-β activated kinase-1 (TAK1) and p38 MAPK, suggesting K63-linked ubiquitination occurs downstream of MAPK. These novel findings are the first to demonstrate a role for K63-linked ubiquitination in promoting cell adhesion and migration.
authors.affiliation: Laboratory of Molecular Carcinogenesis, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA.
authors.forename: Denise M
authors.initials: DM
authors.lastname: Ray
authors.forename: Brian A
authors.initials: BA
authors.lastname: Rogers
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Sunman
authors.forename: Steven K
authors.initials: SK
authors.lastname: Akiyama
authors.forename: Kenneth
authors.initials: K
authors.lastname: Olden
authors.forename: John D
authors.initials: JD
authors.lastname: Roberts
mesh_terms: D016718:Arachidonic Acid / Q000378:metabolism* / Q000494:pharmacology; D001943:Breast Neoplasms / Q000378:metabolism / Q000473:pathology*; D002448:Cell Adhesion / Q000187:drug effects; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000187:drug effects; D024141:Collagen Type IV; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005109:Extracellular Matrix / Q000378:metabolism; D006801:Humans; D008239:Lysine; D009362:Neoplasm Metastasis; D010766:Phosphorylation; D025801:Ubiquitin / Q000235:genetics / Q000378:metabolism*; D044764:Ubiquitin-Activating Enzymes / Q000378:metabolism; D054875:Ubiquitination; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
chemical_list: D024141:Collagen Type IV; D004791:Enzyme Inhibitors; C471538:UBA1 protein, human; D025801:Ubiquitin; D016718:Arachidonic Acid; D048051:p38 Mitogen-Activated Protein Kinases; D044764:Ubiquitin-Activating Enzymes; D008239:Lysine