A structural somatic variant of the Kk antigen is generated by point mutation.
We have previously selected structural variants of the Kk antigen from a (C3 X D2)F1 T-cell lymphoma. Those mutants were identified by the loss of certain epitopes defined by monoclonal antibodies. The variant Kk molecule from HK13.S3 cells is no longer recognized by 40% of the trinitrophenyl-specific, Kk-restricted cytotoxic T lymphocytes. Here we report on the primary structure of the altered Kk molecules from the cell line HK13.S3. Comparison with the parental Kk reveals a single base pair exchange, GCG to GTG, that results in an alanine to valine exchange in position 40 of the protein. This observation emphasizes that minor structural alterations in class I molecules may have a strong effect on the H-2-restricted T-cell response.
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D005796:Genes; D006183:H-2 Antigens / Q000235:genetics*; D051379:Mice; D009154:Mutation; D010446:Peptide Fragments / Q000032:analysis
D006183:H-2 Antigens; D010446:Peptide Fragments