Mutations that impair a posttranscriptional step in expression of HLA-A and -B antigens.
Mutations can interfere with posttranscriptional expression of the HLA-A and -B genes. B-lymphoblastoid cells that contain one copy of the major histocompatibility complex (MHC) were subjected to mutagenesis and immunoselection for MHC antigen-loss mutants. Some mutations partially reduced surface expression of HLA-A and eliminated HLA-B expression concurrently, although the HLA-A and -B genes were present and transcribed. Antigen expression was fully restored in hybrids of these mutants with other B-lymphoblastoid cells. Therefore, normal cell surface expression of the HLA-A and -B antigens on B lymphoblasts requires (i) execution of at least one trans-active step in the production of the antigens after transcription of the HLA-A and -B genes or (ii) association of the class I antigens with other molecules. DNA analysis of one mutant suggests the possibility that a locus required for the normal expression of the HLA-A and -B antigens is located between the MHC complement genes and the HLA-DP alpha II locus.
D000911:Antibodies, Monoclonal; D002478:Cells, Cultured; D005720:Gamma Rays; D005786:Gene Expression Regulation; D005796:Genes; D005816:Genetic Complementation Test; D006680:HLA Antigens / Q000235:genetics*; D006801:Humans; D007791:Lactoylglutathione Lyase / Q000235:genetics; D009154:Mutation / Q000528:radiation effects; D012323:RNA Processing, Post-Transcriptional; D014158:Transcription, Genetic; D001613:beta 2-Microglobulin / Q000235:genetics
D000911:Antibodies, Monoclonal; D006680:HLA Antigens; D001613:beta 2-Microglobulin; D007791:Lactoylglutathione Lyase