title: A single gene encodes soluble and membrane-bound forms of the major histocompatibility Qa-2 antigen: anchoring of the product by a phospholipid tail.
abstract: The H-2, Qa, and Tla genes of the murine major histocompatibility complex are related to each other by DNA sequence homology. The H-2 genes encode ubiquitously expressed transplantation antigens that serve as recognition structures for cytotoxic T cells. The identities of the Qa and Tla products, their sites of expression, and their functions are largely unknown. We report here that the Qa region gene Q7 encodes a membrane-bound as well as a secreted form of the serologically defined antigen Qa-2. The Q7 gene introduced into liver-derived cells is expressed as a membrane-bound and as a secreted molecule. In transfected L cells it is expressed only as a soluble protein. Biochemical analysis suggests that the Q7 product is anchored to the liver cell membranes by a phospholipid tail. This feature may be responsible for cell type-specific expression of the two forms of the Qa-2 molecules.
mesh_terms: D000818:Animals; D000954:Antigens, Surface / Q000096:biosynthesis / Q000235:genetics*; D002460:Cell Line; D002462:Cell Membrane / Q000276:immunology / Q000378:metabolism; D004274:DNA, Recombinant; D000939:Epitopes / Q000235:genetics; D006183:H-2 Antigens / Q000235:genetics; D015395:Histocompatibility Antigens Class I; D007739:L Cells; D008099:Liver / Q000276:immunology / Q000378:metabolism; D008114:Liver Neoplasms, Experimental / Q000276:immunology; D008285:Major Histocompatibility Complex; D008565:Membrane Proteins / Q000235:genetics*; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D010743:Phospholipids / Q000378:metabolism*; D010957:Plasmids; D051381:Rats; D014162:Transfection; D010738:Type C Phospholipases / Q000378:metabolism
chemical_list: D000954:Antigens, Surface; D004274:DNA, Recombinant; D000939:Epitopes; D006183:H-2 Antigens; D015395:Histocompatibility Antigens Class I; D008565:Membrane Proteins; D010743:Phospholipids; C032907:Q surface antigens; D010738:Type C Phospholipases