title: Oligospecificity of the cellular adhesion receptor Mac-1 encompasses an inducible recognition specificity for fibrinogen.
abstract: Mitogenesis, cellular aggregation, and motility follow upon the interaction of fibrinogen with certain defined cell surface receptors. In addition to circulating platelets and vascular endothelium, monocytes express what appears to be a receptor for fibrinogen. Evidence is presented here that the leukocyte adhesion receptor Mac-1 can be specifically induced to bind fibrinogen with characteristics immunochemically and functionally distinct from the established Arg-Gly-Asp-directed fibrinogen receptors. The competence of Mac-1 as a fibrinogen receptor is a general property of cells of monocyte and myeloid lineage acquired after maturational changes of some regions of the alpha subunit of Mac-1 during the process of cell differentiation. This ligand recognition specificity of Mac-1 is lacking for the resting cell. Rather, induction of fibrinogen binding capacity of Mac-1 is due to a cellular response to selected agonists characterized by inducing rapid transients of cytosolic Ca2+. Although different in activation pathways and recognition specificity, Mac-1 exhibits an oligospecific ligand versatility characteristic of other homologous Arg-Gly-Asp-directed adhesion receptors.
mesh_terms: D000595:Amino Acid Sequence; D000943:Antigens, Differentiation / Q000378:metabolism / Q000502:physiology*; D002448:Cell Adhesion; D002460:Cell Line; D005340:Fibrinogen / Q000378:metabolism*; D005455:Fluorescent Antibody Technique; D006801:Humans; D016177:Macrophage-1 Antigen; D008969:Molecular Sequence Data; D009000:Monocytes / Q000378:metabolism*; D010980:Platelet Membrane Glycoproteins / Q000378:metabolism; D011233:Precipitin Tests
chemical_list: D000943:Antigens, Differentiation; D016177:Macrophage-1 Antigen; D010980:Platelet Membrane Glycoproteins; D005340:Fibrinogen