Regulation of T-cell antigen receptor (TCR) alpha-chain expression by TCR beta-chain transcripts.
The TCR is an alpha beta heterodimer, a part of the multimeric structure through which physiological T-cell activation occurs. The expression of TCR alpha chain is greatly diminished in a beta-chain-deficient mutant Jurkat cell line (J.RT3-T3.5). The relationship between the expression of the TCR alpha and beta chains has been examined by stable transfection of a series of TCR beta-chain mutant constructs into this mutant cell line. The level of alpha-chain transcript was dramatically upregulated by the expression of the beta chain and specifically by a transcript of the beta-chain variable region alone, including a transcript in which the ATG start codon was mutated. The downregulation of the endogenous alpha-chain transcripts in mutants cells lacking complete beta-chain transcripts occurred primarily at the posttranscriptional level. This evidence for a regulatory function of the TCR beta-chain gene represents an unusual regulatory pathway in which the transcript of one gene is required for the optimal expression of another gene.
Chung
S
S
Department of Biochemistry and Molecular Biology, Harvard University, Cambridge, MA 02138, USA.
Strominger
J L
JL
D000595:Amino Acid Sequence; D001483:Base Sequence; D002460:Cell Line; D002462:Cell Membrane / Q000276:immunology; D003062:Codon; D017931:DNA Primers; D005434:Flow Cytometry; D005786:Gene Expression Regulation; D006801:Humans; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D016133:Polymerase Chain Reaction; D017260:Receptor-CD3 Complex, Antigen, T-Cell / Q000032:analysis / Q000096:biosynthesis; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000096:biosynthesis* / Q000378:metabolism; D013601:T-Lymphocytes / Q000276:immunology*; D014158:Transcription, Genetic; D014162:Transfection; D014407:Tumor Cells, Cultured; D015854:Up-Regulation
D003062:Codon; D017931:DNA Primers; D017260:Receptor-CD3 Complex, Antigen, T-Cell; D016693:Receptors, Antigen, T-Cell, alpha-beta