title: Identification of the protein HC receptor.
abstract: In the present study, we demonstrate for the first time the presence of a specific receptor for protein HC on the surface of human cells using the human histiocytic lymphoma cell line U937. Cells treated for 4 days with the maturation inducer phorbol 12-myristate 13-acetate, were found to increase both the number of cells binding protein HC (76% higher than for untreated cells) and the expression of protein HC receptors. Protein HC bound to these cells in a specific and saturable manner. Scatchard analysis at 4 degrees C, using radioiodinated protein HC, indicated a single class of low-affinity receptor (Ka = 2-5 x 10(7) M-1) and 20,000-30,000 receptors per cell. Monoclonal antibodies against protein HC abrogated specific binding of this protein to U937. In contrast, monoclonal antibodies that did not react with protein HC (anti-LFA-1 alpha, anti-MO1 alpha) were without effect on the binding reaction.
authors: Centro de Investigaciones Biologicas, CSIC, Madrid, Spain.
authors: J L
authors: JL
authors: Fernandez-Luna
authors: F
authors: F
authors: Leyva-Cobian
authors: F
authors: F
authors: Mollinedo
mesh_terms: D000510:Alpha-Globulins / Q000378:metabolism*; D000911:Antibodies, Monoclonal / Q000276:immunology; D006801:Humans; D009000:Monocytes / Q000378:metabolism*; D011485:Protein Binding; D011971:Receptors, Immunologic / Q000378:metabolism*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014407:Tumor Cells, Cultured
chemical_list: D000510:Alpha-Globulins; D000911:Antibodies, Monoclonal; D011971:Receptors, Immunologic; C057015:alpha(1)-microglobulin receptor; C016001:alpha-1-microglobulin; D013755:Tetradecanoylphorbol Acetate