title: RGD-containing ankyrin externalized onto the cell surface triggers αVβ3 integrin-mediated erythrophagocytosis.
abstract: The RGD motif on the extracellular matrix or cell surface, together with its integrin receptors, constitutes a major recognition system for cell adhesion. There are several erythrocyte major membrane skeletal proteins, e.g., α spectrin, ankyrin, and protein 4.2, that bear an RGD motif. However, it is not known whether the RGD/integrin recognition system is utilized in the erythrocyte-macrophage adhesion during erythrophagocytosis. Here we report that the RGD motif of ankyrin, but not others, is recognized by the α(v)β(3) integrin receptor. In addition, the RGD motif of ankyrin, a peripheral membrane protein, can be externalized onto the cell surface when erythrocytes are incubated with calcium and sheared both at physiological levels. Furthermore, the erythrocyte-macrophage adhesion can be specifically inhibited by ankyrin and/or α(v)β(3). Thus, externalization of ankyrin followed by RGD/integrin recognition may be a novel mechanism by which erythrocytes adhere to macrophages preceding phagocytosis.
authors.affiliation: Department of Bioengineering, University of California, San Diego, CA 92093-0412, USA.
authors.forename: Weiyan
authors.initials: W
authors.lastname: Peng
authors.forename: Lanping Amy
authors.initials: LA
authors.lastname: Sung
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D017487:Ankyrins / Q000378:metabolism*; D002448:Cell Adhesion; D002478:Cells, Cultured; D057899:Cytophagocytosis; D004910:Erythrocyte Membrane / Q000378:metabolism / Q000502:physiology*; D004912:Erythrocytes / Q000378:metabolism / Q000502:physiology*; D006801:Humans; D039302:Integrin alphaVbeta3 / Q000378:metabolism*; D008264:Macrophages / Q000502:physiology; D051379:Mice; D008856:Microscopy, Fluorescence; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000378:metabolism*
chemical_list: D017487:Ankyrins; D039302:Integrin alphaVbeta3; D009842:Oligopeptides; C047981:arginyl-glycyl-aspartic acid