title: Tyrosine phosphorylation and dissociation of occludin-ZO-1 and E-cadherin-beta-catenin complexes from the cytoskeleton by oxidative stress.
abstract: The oxidative-stress-induced alteration in paracellular junctional complexes was analysed in Caco-2 cell monolayer. Oxidative stress induced a rapid increase in tyrosine phosphorylation of occludin, zonula occludens (ZO)-1, E-cadherin and beta-catenin. An oxidative-stress-induced decrease in transepithelial electrical resistance was associated with a redistribution of occludin-ZO-1 and E-cadherin-beta-catenin complexes from the intercellular junctions. Genistein, a tyrosine kinase inhibitor, prevented the oxidative-stress-induced decrease in resistance and redistribution of protein complexes. Occludin, ZO-1, E-cadherin and beta-catenin in the Triton-insoluble cytoskeletal fraction were reduced by oxidative stress, which was prevented by genistein. Oxidative stress also reduced the co-immunoprecipitation of ZO-1 with occludin, which was prevented by genistein. Co-immunoprecipitation of beta-catenin with E-cadherin was unaffected by oxidative stress or genistein. ZO-1, E-cadherin and beta-catenin in the plasma membrane or membrane-cytoskeleton were either slightly reduced or unaffected by oxidative stress or genistein. These results show that oxidative stress induces tyrosine phosphorylation and cellular redistribution of occludin-ZO-1 and E-cadherin-beta-catenin complexes by a tyrosine-kinase-dependent mechanism.
authors.affiliation: Department of Physiology, University of Tennessee Health Sciences Center, 894 Union Avenue, Memphis, TN 38163, U.S.A. rkrao@physio1.utmem.edu
authors.forename: Radhakrishna K
authors.initials: RK
authors.lastname: Rao
authors.forename: Shyamali
authors.initials: S
authors.lastname: Basuroy
authors.forename: Vijay U
authors.initials: VU
authors.lastname: Rao
authors.forename: Karl J
authors.initials: KJ
authors.lastname: Karnaky
authors.forename: Akshay
authors.initials: A
authors.lastname: Gupta
mesh_terms: D018938:Caco-2 Cells / Q000187:drug effects / Q000378:metabolism; D015820:Cadherins / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D003598:Cytoskeletal Proteins / Q000187:drug effects / Q000378:metabolism; D003599:Cytoskeleton / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D019833:Genistein / Q000494:pharmacology; D006801:Humans; D007365:Intercellular Junctions / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism*; D062793:Occludin; D018384:Oxidative Stress; D010750:Phosphoproteins / Q000378:metabolism*; D010766:Phosphorylation / Q000187:drug effects; D011505:Protein-Tyrosine Kinases / Q000187:drug effects / Q000378:metabolism; D015534:Trans-Activators / Q000187:drug effects / Q000378:metabolism; D014443:Tyrosine / Q000378:metabolism*; D019820:Xanthine / Q000494:pharmacology; D014969:Xanthine Oxidase / Q000494:pharmacology; D062826:Zonula Occludens-1 Protein; D051176:beta Catenin
chemical_list: C495270:CTNNB1 protein, human; D015820:Cadherins; D003598:Cytoskeletal Proteins; D004791:Enzyme Inhibitors; D008565:Membrane Proteins; C568985:OCLN protein, human; D062793:Occludin; D010750:Phosphoproteins; C569042:TJP1 protein, human; D015534:Trans-Activators; D062826:Zonula Occludens-1 Protein; D051176:beta Catenin; D019820:Xanthine; D014443:Tyrosine; D019833:Genistein; D014969:Xanthine Oxidase; D011505:Protein-Tyrosine Kinases