title: Characterization of the laminin binding domains of the Lutheran blood group glycoprotein.
abstract: Lutheran (Lu) blood group antigens and the basal cell adhesion molecule antigen reside on two glycoproteins that belong to the Ig superfamily (IgSF) and carry five Ig-like extracellular domains. These glycoproteins act as widely expressed adhesion molecules and represent the unique receptors for laminin-10/11 in erythroid cells. Here, we report the mapping of IgSF domains responsible for binding to laminin. In plasmonic resonance surface experiments, only recombinant Lu proteins containing the N-terminal IgSF domains 1-3 were able to bind laminin-10/11 and to inhibit binding of laminin to Lu-expressing K562 cells. Mutant recombinant proteins containing only IgSF domain 1, domains 1 + 2, domains 1 + 3, domains 2 + 3, domain 3, domain 4, domain 5, and domains 4 + 5 failed to bind laminin as well as a construct containing all of the extracellular domains except domain 3. Altogether, these results indicate that IgSF domains 1-3 are involved in laminin binding and that a specific spatial arrangement of these three first domains is most probably necessary for interaction. Neither the RGD nor the N-glycosylation motifs present in IgSF domain 3 were involved in laminin binding.
authors.affiliation: INSERM U76, Institut National de la Transfusion Sanguine, Paris 75015, France and CNRS UMR7590, Universités Paris 6 et Paris 7, Paris 75005, France.
authors.forename: W
authors.initials: W
authors.lastname: El Nemer
authors.forename: P
authors.initials: P
authors.lastname: Gane
authors.forename: Y
authors.initials: Y
authors.lastname: Colin
authors.forename: A M
authors.initials: AM
authors.lastname: D'Ambrosio
authors.forename: I
authors.initials: I
authors.lastname: Callebaut
authors.forename: J P
authors.initials: JP
authors.lastname: Cartron
authors.forename: C L
authors.initials: CL
authors.lastname: Van Kim
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D001667:Binding, Competitive; D015374:Biosensing Techniques; D006801:Humans; D007141:Immunoglobulin Fc Fragments / Q000235:genetics; D020014:K562 Cells; D007797:Laminin / Q000378:metabolism*; D008188:Lutheran Blood-Group System / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008969:Molecular Sequence Data; D009154:Mutation; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D017386:Sequence Homology, Amino Acid
chemical_list: D007141:Immunoglobulin Fc Fragments; D007797:Laminin; D008188:Lutheran Blood-Group System; D011993:Recombinant Fusion Proteins; C119013:laminin 10