title: T cell receptor beta gene has two downstream DNase I hypersensitive regions. Possible mechanisms of tissue- and stage-specific gene regulation.
abstract: Two DNase I-hypersensitive regions were identified downstream of the TCR gene constant region. One of these regions is located at the site of a putative enhancer element and was observed only in T cell lines and not in cell lines derived from other tissues. The other DNase-hypersensitive region was also detected only in T cell lines but only in those expressing TCR-beta RNA. Thus, the first region is probably tissue specific, while the second region is probably tissue and stage specific. The DNA sequence of the second DNase I-hypersensitive region revealed several stretches of nucleotides that are characteristic of consensus sequences for regulatory elements. These results, together with the observations in transgenic mice that indicate a requirement for two distinct regions for optimal TCR gene expression, suggest the presence of at least two regulatory regions downstream of the C-beta-2 region; one is an enhancer region and the other is a transcriptionally related regulatory region. The tissue/stage specificity of these DNase I-hypersensitive regions supports the notion that changes in chromatin structure control tissue-specific gene expression.
authors.affiliation: Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia 19104.
authors.forename: Y
authors.initials: Y
authors.lastname: Hashimoto
mesh_terms: D000818:Animals; D001483:Base Sequence; D002454:Cell Differentiation; D002460:Cell Line; D003850:Deoxyribonuclease I; D004742:Enhancer Elements, Genetic; D051379:Mice; D008805:Mice, Inbred A; D008806:Mice, Inbred AKR; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D015345:Oligonucleotide Probes; D009928:Organ Specificity; D011948:Receptors, Antigen, T-Cell / Q000235:genetics* / Q000502:physiology; D016693:Receptors, Antigen, T-Cell, alpha-beta; D015183:Restriction Mapping; D013601:T-Lymphocytes / Q000378:metabolism* / Q000502:physiology
chemical_list: D015345:Oligonucleotide Probes; D011948:Receptors, Antigen, T-Cell; D016693:Receptors, Antigen, T-Cell, alpha-beta; D003850:Deoxyribonuclease I