Ezrin and moesin co-localise with ICAM-1 in brain endothelial cells but are not directly associated.
The precise mechanism by which ICAM-1 transduces signals from adherent lymphocytes remains elusive. The ERM proteins ezrin and moesin were found to strongly co-localise with both ICAM-1 and F-actin in brain microvascular endothelial cells suggesting a potential role in mediating ICAM-1 signalling. Such strong co-localisation was maintained following treatment of cells with cytochalasin D, which inhibits actin polymerization and which is capable of inhibiting ICAM-1-induced signalling. Cross-linking of ICAM-1 demonstrated ICAM-1 clustering which no longer associated with ezrin or moesin. In addition immunoprecipitation analysis revealed that ICAM-1 was incapable of precipitating ERM proteins under conditions where ezrin was efficiently precipitated with anti-ICAM-2 antibodies. Fractionation of cell lysates on sucrose density gradients shows ICAM-1 and ezrin to sediment at different densities, whereas ICAM-2 co-sediments with ezrin. Together these data suggest that ICAM-1 is not directly associated with ezrin and moesin in brain microvascular endothelial cells.
Romero
Ignacio A
IA
Endothelial and Epithelial Cell Biology Unit, Department of Cell Biology, Institute of Ophthalmology, University College London, 11-43 Bath Street, London EC1V 9EL, UK. i.romero@open.ac.uk
Amos
Claire L
CL
Greenwood
John
J
Adamson
Peter
P
D000199:Actins / Q000276:immunology / Q000378:metabolism; D000818:Animals; D015703:Antigens, CD / Q000276:immunology / Q000378:metabolism; D001798:Blood Proteins / Q000276:immunology / Q000378:metabolism; D001812:Blood-Brain Barrier / Q000276:immunology*; D001921:Brain / Q000098:blood supply / Q000276:immunology* / Q000378:metabolism; D002448:Cell Adhesion / Q000276:immunology*; D015815:Cell Adhesion Molecules / Q000276:immunology / Q000378:metabolism; D002478:Cells, Cultured; D002634:Chemotaxis, Leukocyte / Q000276:immunology; D015638:Cytochalasin D / Q000494:pharmacology; D003598:Cytoskeletal Proteins / Q000276:immunology / Q000378:metabolism; D003599:Cytoskeleton / Q000276:immunology / Q000378:metabolism; D004660:Encephalitis / Q000276:immunology; D004730:Endothelium, Vascular / Q000276:immunology* / Q000378:metabolism; D007157:Immunologic Surveillance / Q000276:immunology; D018799:Intercellular Adhesion Molecule-1 / Q000276:immunology* / Q000378:metabolism; D008565:Membrane Proteins / Q000276:immunology / Q000378:metabolism; D008840:Microfilament Proteins / Q000276:immunology* / Q000378:metabolism; D019384:Nucleic Acid Synthesis Inhibitors / Q000494:pharmacology; D010750:Phosphoproteins / Q000276:immunology* / Q000378:metabolism; D011233:Precipitin Tests; D051381:Rats; D015398:Signal Transduction / Q000276:immunology; D016596:Vinculin / Q000276:immunology / Q000378:metabolism; D020741:rho GTP-Binding Proteins / Q000276:immunology / Q000378:metabolism; D000099149:Ezrin
D000199:Actins; D015703:Antigens, CD; D001798:Blood Proteins; D015815:Cell Adhesion Molecules; D015638:Cytochalasin D; D003598:Cytoskeletal Proteins; D018799:Intercellular Adhesion Molecule-1; D008565:Membrane Proteins; D008840:Microfilament Proteins; D019384:Nucleic Acid Synthesis Inhibitors; D010750:Phosphoproteins; D016596:Vinculin; D020741:rho GTP-Binding Proteins; D000099149:Ezrin; C065289:ICAM2 protein, human; C071058:moesin; C071776:radixin