A mannose receptor mediates mannosyl-rich glycoprotein-induced mitogenesis in bovine airway smooth muscle cells.

摘要: The putative mannose receptor (MR), previously implicated in mannosyl-rich glycoprotein-induced mitogenesis bovine airway smooth muscle (ASM) cells, was studied to determine its properties. Specific binding of the mitogenic neoglycoprotein, mannosylated serum albumin (Man-BSA) ASM cells saturable, with an apparent Kd = 5.0 x 10(-8) M. Cell-bound ManBSA-colloidal gold conjugate localized by electron microscopy clathrin-coated pits on cell surface, and found undergo internalization endosomes; this inhibitable weak bases swainsonine, that also inhibited ligand-induced mitogenesis. ASM-MR, isolated mannose-affinity chromatography, had same molecular mass as macrophage (Mo) MR (M(r) 175 kD), immunoprecipitated anti-MoMR immune serum. This antiserum blocked 125I-labeled-ManBSA intact stimulated mitogenesis, immunolocalized ASM-MR cytoplasmic vesicles compatible endosomes. A monoclonal antibody directed against MoMR reacted ASM-MR; like polyclonal antibodies, it effectively beta-hexosaminidases. These data indicate shares a number functional structural properties suggest similar receptors may have different main functions cells.