title: A novel serine-rich motif in the intercellular adhesion molecule 3 is critical for its ezrin/radixin/moesin-directed subcellular targeting.
abstract: Intercellular adhesion molecule 3 (ICAM-3) is a leukocyte-specific receptor involved in primary immune responses. We have investigated the interaction between ICAM-3 and ezrin/radixin/moesin (ERM) proteins and its role in LFA-1-induced cell-cell interactions and membrane positioning of ICAM-3 in polarized migrating lymphocytes. Protein-protein binding assays demonstrated a phosphatidylinositol 4,5-bisphosphate-induced association between ICAM-3 and the amino-terminal domain of ERM proteins. This interaction was not essential for the binding of ICAM-3 to LFA-1. Dynamic fluorescence videomicroscopy studies of cells demonstrated that moesin and ICAM-3 coordinately redistribute on the plasma membrane during lymphocyte migration. Furthermore, overexpression of the amino-terminal domain of moesin, which lacks the consensus moesin actin-binding site, caused the subcellular mislocalization of ICAM-3. A CD4 chimerical protein containing the cytoplasmic tail of ICAM-3 was targeted to the trailing edge. Point mutation of Ser(487), Ser(489), and Ser(496) to alanine in the juxtamembrane region of ICAM-3 significantly impaired both ERM binding and polarization of ICAM-3. ERM-directed polarization of ICAM-3 was also impaired by phosphorylation-like mutation of Ser(487) and Ser(489), but not of Ser(496). Our results underscore the key role of specific serine residues within the cytoplasmic region of ICAM-3 for its ERM-directed positioning at the trailing edge of motile lymphocytes.
authors.affiliation: Servicio de Inmunologia, Hospital de la Princesa, Universidad Autónoma de Madrid, Madrid 28006, Spain.
authors.forename: Juan M
authors.initials: JM
authors.lastname: Serrador
authors.forename: Miguel
authors.initials: M
authors.lastname: Vicente-Manzanares
authors.forename: Javier
authors.initials: J
authors.lastname: Calvo
authors.forename: Olga
authors.initials: O
authors.lastname: Barreiro
authors.forename: Maria C
authors.initials: MC
authors.lastname: Montoya
authors.forename: Reinhard
authors.initials: R
authors.lastname: Schwartz-Albiez
authors.forename: Heinz
authors.initials: H
authors.lastname: Furthmayr
authors.forename: Francisco
authors.initials: F
authors.lastname: Lozano
authors.forename: Francisco
authors.initials: F
authors.lastname: Sánchez-Madrid
mesh_terms: D000409:Alanine / Q000737:chemistry; D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D015703:Antigens, CD; D000943:Antigens, Differentiation; D001798:Blood Proteins / Q000378:metabolism*; D015153:Blotting, Western; D015704:CD4 Antigens / Q000378:metabolism; D015815:Cell Adhesion Molecules / Q000737:chemistry* / Q000378:metabolism*; D002450:Cell Communication; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D002465:Cell Movement; D003593:Cytoplasm / Q000378:metabolism; D003598:Cytoskeletal Proteins / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D005982:Glutathione Transferase / Q000378:metabolism; D049452:Green Fluorescent Proteins; D006801:Humans; D020014:K562 Cells; D008164:Luminescent Proteins / Q000378:metabolism; D008214:Lymphocytes / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism*; D051379:Mice; D008840:Microfilament Proteins / Q000378:metabolism*; D008856:Microscopy, Fluorescence; D018715:Microscopy, Video; D008969:Molecular Sequence Data; D010750:Phosphoproteins / Q000378:metabolism*; D010766:Phosphorylation; D010957:Plasmids / Q000378:metabolism; D011233:Precipitin Tests; D011485:Protein Binding; D014176:Protein Biosynthesis; D017434:Protein Structure, Tertiary; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D012694:Serine / Q000737:chemistry; D014162:Transfection; D000099149:Ezrin
chemical_list: D000409:Alanine; D015703:Antigens, CD; D000943:Antigens, Differentiation; D001798:Blood Proteins; D015704:CD4 Antigens; D015815:Cell Adhesion Molecules; D003598:Cytoskeletal Proteins; D005982:Glutathione Transferase; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins; D008565:Membrane Proteins; D008840:Microfilament Proteins; D010750:Phosphoproteins; D011993:Recombinant Fusion Proteins; D012694:Serine; D000099149:Ezrin; C483616:ICAM3 protein, human; C071058:moesin; C071776:radixin