Expression of complementary DNA and genomic clones for carcinoembryonic antigen and nonspecific cross-reacting antigen in Chinese hamster ovary and mouse fibroblast cells and characterization of the membrane-expressed products.

摘要: Complementary DNA clones coding for both carcinoembryonic antigen (CEA), a well characterized colonic tumor marker, and nonspecific cross-reacting (NCA), related antigen, were expressed in Chinese hamster ovary (CHO) cells L-cells (mouse fibroblasts). A genomic clone CEA was also CHO cells. Positive identified by fluorescence flow cytometry enzyme-linked immunosorbent assay. Membrane location of the recombinant NCA confirmed indirect immunofluorescence labeling transfectants, followed visualization under microscope. The apparent molecular weight 180,000 96,000, respectively, cell lines, as determined immunoblot analysis. on sensitive to treatment with phosphatidylinositol-specific phospholipase C (PI-PLC), whereas proteins resistant removal PI-PLC. Unlike NCA, which contains three methionine residues, only is C-terminal hydrophobic domain. This domain shown be removed replaced phosphatidylinositol glycan (PI-G) anchor (Hefta et al., Proc. Natl. Acad. Sci. USA, 85: 4648-4652, 1988). from could labeled [3H]-ethanolamine (a component PI-G anchor) but not [35S] methionine, [3H]ethanolamine [35S]methionine. studies PI-PLC results are consistent possessing anchor. L-cell transfectants may contain cleavage In addition, membrane-bound secreted levels determined.