title: Cloning and characterization of a promoter flanking the early B cell factor (EBF) gene indicates roles for E-proteins and autoregulation in the control of EBF expression.
abstract: The early B cell factor (EBF) is a transcription factor shown crucial for the development of B lymphocytes. The protein is expressed from the earliest stages of B cell development until the mature B cell stage, but the control elements responsible for the regulation of the gene are unknown. In this study, we report of the identification of a promoter region flanking the EBF gene. Several transcription start sites were identified by primer extension analysis in a region approximately 3.1 kb from the predicted ATG. Transient transfections revealed that this region was able to stimulate transcription of a reporter gene in B lymphoid and to a lesser extent, myeloid cells, but not in a pre-T cell line. The promoter was also able to functionally interact with E47, suggesting that the EBF gene may be a direct target for activation by E-proteins. In addition, functional binding of EBF to its own promoter was confirmed by EMSA and transfection assays indicating that the EBF protein may be involved in an autoregulatory loop. Finally, a tissue-restricted factor was able to bind an upstream regulatory region in B-lineage cells, further supporting the idea that the cloned promoter participates in the regulation of stage and lineage specific expression of the EBF gene.
authors.affiliation: Laboratory of Cellular Differentiation, Department of Stem Cell Biology, Lund University, Lund, Sweden.
authors.forename: Emma M K
authors.initials: EM
authors.lastname: Smith
authors.forename: Ramiro
authors.initials: R
authors.lastname: Gisler
authors.forename: Mikael
authors.initials: M
authors.lastname: Sigvardsson
mesh_terms: D020121:5' Untranslated Regions / Q000235:genetics / Q000276:immunology; D000595:Amino Acid Sequence; D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology / Q000378:metabolism; D001482:Base Composition; D001483:Base Sequence; D002478:Cells, Cultured; D003001:Cloning, Molecular; D004268:DNA-Binding Proteins / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics* / Q000502:physiology; D024721:E-Box Elements / Q000235:genetics / Q000276:immunology; D005091:Exons / Q000235:genetics / Q000276:immunology; D006367:HeLa Cells; D018257:Helix-Loop-Helix Motifs / Q000235:genetics* / Q000276:immunology*; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D009928:Organ Specificity / Q000235:genetics / Q000276:immunology; D011401:Promoter Regions, Genetic / Q000276:immunology*; D011485:Protein Binding / Q000235:genetics / Q000276:immunology; D051820:TCF Transcription Factors; D015534:Trans-Activators / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics* / Q000502:physiology; D058125:Transcription Factor 7-Like 1 Protein; D014157:Transcription Factors / Q000502:physiology*
chemical_list: D020121:5' Untranslated Regions; D004268:DNA-Binding Proteins; C081976:EBF1 protein, human; C489921:Ebf1 protein, mouse; D009687:Nuclear Proteins; D051820:TCF Transcription Factors; C544912:TCF7L1 protein, human; C544913:Tcf7l1 protein, mouse; D015534:Trans-Activators; D058125:Transcription Factor 7-Like 1 Protein; D014157:Transcription Factors