title: An enhancer-blocking element between alpha and delta gene segments within the human T cell receptor alpha/delta locus.
abstract: T cell receptor (TCR) alpha and delta gene segments are organized within a single genetic locus but are differentially regulated during T cell development. An enhancer-blocking element (BEAD-1, for blocking element alpha/delta 1) was localized to a 2.0-kb region 3' of TCR delta gene segments and 5' of TCR alpha joining gene segments within this locus. BEAD-1 blocked the ability of the TCR delta enhancer (Edelta) to activate a promoter when located between the two in a chromatin-integrated construct. We propose that BEAD-1 functions as a boundary that separates the TCR alpha/delta locus into distinct regulatory domains controlled by Edelta and the TCR alpha enhancer, and that it prevents Edelta from opening the chromatin of the TCR alpha joining gene segments for VDJ recombination at an early stage of T cell development.
authors.affiliation: Department of Immunology, P.O. Box 3010, Duke University Medical Center, Durham, NC 27710, USA.
authors.forename: X P
authors.initials: XP
authors.lastname: Zhong
authors.forename: M S
authors.initials: MS
authors.lastname: Krangel
mesh_terms: D000818:Animals; D002455:Cell Division; D004254:DNA Nucleotidyltransferases / Q000378:metabolism; D004330:Drosophila; D004742:Enhancer Elements, Genetic; D006801:Humans; D019169:Jurkat Cells; D011401:Promoter Regions, Genetic; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000096:biosynthesis / Q000235:genetics*; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000096:biosynthesis / Q000235:genetics*; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D015183:Restriction Mapping; D013601:T-Lymphocytes / Q000276:immunology; D014157:Transcription Factors / Q000096:biosynthesis / Q000502:physiology*; D014158:Transcription, Genetic; D014162:Transfection; D045567:VDJ Recombinases
chemical_list: D016693:Receptors, Antigen, T-Cell, alpha-beta; D016692:Receptors, Antigen, T-Cell, gamma-delta; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; D004254:DNA Nucleotidyltransferases; D045567:VDJ Recombinases