Distinct promoters mediate the regulation of Ebf1 gene expression by interleukin-7 and Pax5.
Early differentiation of B lymphocytes requires the function of multiple transcription factors that regulate the specification and commitment of the lineage. Loss- and gain-of-function experiments have provided important insight into the transcriptional control of B lymphopoiesis, whereby E2A was suggested to act upstream of EBF1 and Pax5 downstream of EBF1. However, this simple hierarchy cannot account for all observations, and our understanding of a presumed regulatory network, in which transcription factors and signaling pathways operate, is limited. Here, we show that the expression of the Ebf1 gene involves two promoters that are differentially regulated and generate distinct protein isoforms. We find that interleukin-7 signaling, E2A, and EBF1 activate the distal Ebf1 promoter, whereas Pax5, together with Ets1 and Pu.1, regulates the stronger proximal promoter. In the absence of Pax5, the function of the proximal Ebf1 promoter and accumulation of EBF1 protein are impaired and the replication timing and subcellular localization of the Ebf1 locus are altered. Taken together, these data suggest that the regulation of Ebf1 via distinct promoters allows for the generation of several feedback loops and the coordination of multiple determinants of B lymphopoiesis in a regulatory network.
Roessler
Stephanie
S
Max Planck Institute of Immunobiology, Department of Cellular and Molecular Immunology, 79108 Freiburg, Germany.
Györy
Ildiko
I
Imhof
Sascha
S
Spivakov
Mikhail
M
Williams
Ruth R
RR
Busslinger
Meinrad
M
Fisher
Amanda G
AG
Grosschedl
Rudolf
R
D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D004261:DNA Replication; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D005786:Gene Expression Regulation; D017930:Genes, Reporter; D006801:Humans; D015851:Interleukin-7 / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D051757:PAX5 Transcription Factor / Q000502:physiology*; D011401:Promoter Regions, Genetic; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D050799:STAT5 Transcription Factor / Q000378:metabolism; D051820:TCF Transcription Factors / Q000378:metabolism; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D058125:Transcription Factor 7-Like 1 Protein; D000099232:Proto-Oncogene Protein Spi-1
D004268:DNA-Binding Proteins; D015851:Interleukin-7; D051757:PAX5 Transcription Factor; D011518:Proto-Oncogene Proteins; D050799:STAT5 Transcription Factor; D051820:TCF Transcription Factors; D015534:Trans-Activators; D058125:Transcription Factor 7-Like 1 Protein; D000099232:Proto-Oncogene Protein Spi-1; C081976:EBF1 protein, human; C489921:Ebf1 protein, mouse; C497282:Pax5 protein, mouse; C544912:TCF7L1 protein, human; C544913:Tcf7l1 protein, mouse