Regulation of the interleukin-7 receptor alpha promoter by the Ets transcription factors PU.1 and GA-binding protein in developing B cells.
Signaling through the IL-7 receptor (IL-7R) is required for development and maintenance of the immune system. The receptor for IL-7 is heterodimeric, consisting of a common gamma chain (gammac, encoded by Il2rg) and an alpha subunit (IL-7Ralpha, encoded by Il7r). The Il7r gene is expressed specifically in the immune system in a developmental stage-specific manner. It is not known how the Il7r gene is transcriptionally regulated during B cell development. The goal of this study is to elucidate the function of the Il7r promoter region in developing B cells. Using a combination of 5' rapid amplification of cDNA ends analysis, transient transfection assays, and DNase I hypersensitivity mapping, we identified the location of the Il7r promoter. Using a combination of electrophoretic mobility shift analysis, chromatin immunoprecipitation experiments, and RNA interference experiments, we found that the Ets transcription factors PU.1 and GA-binding protein (GABP) activate the Il7r promoter by interacting with a highly conserved Ets binding site. In committed B lineage cells, GABP can promote Il7r transcription in the absence of PU.1. However, the results of retroviral gene transfer experiments suggest that PU.1 is uniquely required to initiate transcription of the Il7r locus at the earliest stages of progenitor B cell generation. In summary, these results suggest that Il7r transcription is regulated by both PU.1 and GABP in developing B cells.
DeKoter
Rodney P
RP
Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA. dekoterp@ucmail.uc.edu
Schweitzer
Brock L
BL
Kamath
Meghana B
MB
Jones
Darrel
D
Tagoh
Hiromi
H
Bonifer
Constanze
C
Hildeman
David A
DA
Huang
Kelly J
KJ
D001402:B-Lymphocytes / Q000378:metabolism*; D001483:Base Sequence; D002467:Cell Nucleus / Q000378:metabolism; D047369:Chromatin Immunoprecipitation; D018983:DNA Footprinting; D024202:Electrophoretic Mobility Shift Assay; D005434:Flow Cytometry; D051268:GA-Binding Protein Transcription Factor / Q000378:metabolism*; D006801:Humans; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D020395:Receptors, Interleukin-7 / Q000235:genetics / Q000378:metabolism*; D012190:Retroviridae / Q000235:genetics; D012689:Sequence Homology, Nucleic Acid; D013601:T-Lymphocytes / Q000378:metabolism; D015534:Trans-Activators / Q000378:metabolism*; D014158:Transcription, Genetic; D015533:Transcriptional Activation; D014162:Transfection; D000099232:Proto-Oncogene Protein Spi-1
D051268:GA-Binding Protein Transcription Factor; D011518:Proto-Oncogene Proteins; D020395:Receptors, Interleukin-7; D015534:Trans-Activators; D000099232:Proto-Oncogene Protein Spi-1; C415350:interleukin-7 receptor, alpha chain