The human T-cell receptor α-chain gene maps to chromosome 14

Abstract

The T-cell receptor for antigen has been identified as a disulphide-linked heterodimeric glycoprotein of relative molecular mass (M_r) 90,000 comprising an α- and a β-chain^1–3. The availability of complementary DNA clones encoding mouse⁴ and human⁵ β-chains has allowed a detailed characterization of the genomic organization of the β-chain gene family and has revealed that functional β-chain genes in T cells are generated from recombination events involving variable (V), diversity (D), joining (J) and constant (C) gene segments^6,7. Recently, cDNA clones encoding mouse^8,9 and human¹⁰ α-chains have been described; the sequences of these clones have indicated that functional α-chain genes are also generated from multiple gene segments. It is possible that chromosomal translocations involving T-cell receptor α- and β-chain genes have a role in T-cell neoplasms in much the same way as translocations involving immunoglobulin genes are associated with oncogenic transformation in B cells¹¹. In the latter case, the chromosomal localization of the immunoglobulin genes provided one of the first indications of the involvement of such translocations in oncogenic transformation. The chromosomal assignment of the α- and β-chain genes may, therefore, provide equally important clues for T-cell neoplastic transformation. The chromosomal location of the mouse and human β-chain gene family has been determined: the murine gene lies on chromosome 6 (refs 12, 13) whereas the human gene is located on chromosome 7 (refs 13,14). Here we use a cDNA clone encoding the human α-chain to map the corresponding gene to chromosome 14.