DNA-mediated gene transfer of a human cell surface 170-kilodalton glycoprotein. Evidence for association with an endogenous murine protein.

We have previously reported the identification and characterization of two related human cell surface protein complexes, very common antigens 1 and 2 (VCA-1, VCA-2) (Kantor, R. R. S., Mattes, M. J., Lloyd, K. O., Old, L. J., and Albino, A. P. (1987) J. Biol. Chem. 262, 15158-15165). We now report the transfection of DNA sequences encoding the 170-kilodalton heterodimer of VCA-2 from human SK-RC-41 renal cancer cells to B78H1 mouse melanoma cells. B78H1 cells were cotransfected with high molecular weight renal cancer DNA and a plasmid vector containing the neomycin resistance gene. Antibiotic-resistant transfectants were screened for the expression of the 170-kDa heterodimer with mouse monoclonal antibody (mAb) J143. Analysis of mAb J143-positive (J143+) transfectants showed that they expressed a 170-kDa heterodimer with an identical molecular weight, isoelectric point, two-dimensional peptide map, and spatial orientation of surface-exposed epitopes to the homologous 170-kDa species seen in human donor cells. The 170-kDa heterodimer in SK-RC-41 cells is associated with a 140-kDa (designated 140(1] polypeptide to form the VCA-2 complex. The 170-kDa complex and the 140(1)-kDa polypeptides are encoded by genes located on different human chromosomes. J143+ transfectants display a molecule of 140 kDa associated with the 170-kDa complex which is biochemically similar, but non-identical, to the human 140(1)-kDa polypeptide on VCA-2. This evidence supports our interpretation that the transfected human 170-kDa heterodimer associates with a murine counterpart of the human 140(1)-kDa polypeptide in J143+ transfectants.