HMT, encoded by H-2M3, is a neoclassical major histocompatibility class I antigen.
H-2M3 encodes HMT, the major histocompatibility complex (MHC) class I heavy chain of the maternally transmitted antigen (Mta). Like classical MHC class I genes, the expression of M3 can be stimulated by gamma-interferon and its message can be detected from mid-gestational embryos (day 8) through adulthood. HMTb, a nonimmunogenic allelic form of HMT, differs from the common HMTa molecule by four amino acids, of which only two (residues 31 and 95) are located in the alpha 1 and alpha 2 domains that form the peptide-binding groove. Recognition of site-directed mutants by Mta-specific cytotoxic T lymphocytes was hardly affected by the substitution of Met for Val31 but was abolished by the substitution of Gln for Leu95, which is located in the beta-sheet floor of the peptide-binding groove. Thus a single amino acid difference is responsible for the immunological silence of HMTb.
Wang
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Howard Hughes Medical Institute, Department of Microbiology, University of Texas Southwestern Medical Center, Dallas 75235-9050.
Lindahl
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D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D003360:Cosmids; D004622:Embryo, Mammalian / Q000276:immunology; D005314:Embryonic and Fetal Development; D005091:Exons; D005260:Female; D015723:Gene Library; D015395:Histocompatibility Antigens Class I / Q000096:biosynthesis / Q000235:genetics*; D007371:Interferon-gamma / Q000494:pharmacology; D051379:Mice; D008807:Mice, Inbred BALB C; D008815:Mice, Inbred Strains; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009838:Oligodeoxyribonucleotides; D016133:Polymerase Chain Reaction / Q000379:methods; D012333:RNA, Messenger / Q000235:genetics; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D014162:Transfection
C078177:H2-M3 antigen; D015395:Histocompatibility Antigens Class I; D009838:Oligodeoxyribonucleotides; D012333:RNA, Messenger; D007371:Interferon-gamma