title: A third polypeptide associated with heavy and light chain subunits of class I HLA antigens in immune interferon-treated human melanoma cells.
abstract: Recombinant immune interferon (IFN-gamma) increases the synthesis, expression and shedding of class I HLA antigens by the cultured human melanoma cell line Colo 38. The magnitude of the IFN-gamma-induced changes in class I HLA antigens is dependent on both the dose and the time of exposure to IFN-gamma and is more pronounced on the heavy chain subunit than on beta 2-microglobulin (beta 2m). In addition, a third, distinct polypeptide with a molecular mass of 14 kDa is present as a major component of the class I HLA molecular pool in IFN-gamma-treated melanoma cells. As IFN-gamma preferentially increases the synthesis of the heavy chain over that of beta 2m, the newly induced 14-kDa component appears to quantitatively replace beta 2m. The stoichiometric relationship between the three molecules suggests that the IFN-gamma-induced 14-kDa component may be involved in the insertion of the heavy chain subunit into the plasma membrane.
mesh_terms: D000937:Antigen-Antibody Reactions; D000954:Antigens, Surface / Q000032:analysis / Q000096:biosynthesis; D002460:Cell Line; D006680:HLA Antigens / Q000032:analysis / Q000096:biosynthesis; D006801:Humans; D007143:Immunoglobulin Heavy Chains / Q000096:biosynthesis; D007147:Immunoglobulin Light Chains / Q000096:biosynthesis; D007371:Interferon-gamma / Q000494:pharmacology*; D008545:Melanoma / Q000276:immunology*; D008970:Molecular Weight; D010452:Peptide Biosynthesis; D011233:Precipitin Tests
chemical_list: D000954:Antigens, Surface; D006680:HLA Antigens; D007143:Immunoglobulin Heavy Chains; D007147:Immunoglobulin Light Chains; D007371:Interferon-gamma