E2A and E2-2 are subunits of B-cell-specific E2-box DNA-binding proteins.
A class of helix-loop-helix (HLH) proteins, including E2A (E12 and E47), E2-2, and HEB, that bind in vitro to DNA sequences present in the immunoglobulin (Ig) enhancers has recently been identified. E12, E47, E2-2, and HEB are each present in B cells. The presence of many different HLH proteins raises the question of which of the HLH proteins actually binds the Ig enhancer elements in B cells. Using monoclonal antibodies specific for both E2A and E2-2, we show that both E2-2 and E2A polypeptides are present in B-cell-specific Ig enhancer-binding complexes. E2-box-binding complexes in pre-B cells contain both E2-2 and E2A HLH subunits, whereas in mature B cells only E2A gene products are present. We show that the difference in E2-box-binding complexes in pre-B and mature B cells may be caused by differential expression of E2A and E2-2.
Department of Biology, University of California, San Diego, La Jolla 92130.
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Bain
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Gruenwald
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Murre
D000918:Antibody Specificity; D001402:B-Lymphocytes / Q000378:metabolism*; D015152:Blotting, Northern; D002467:Cell Nucleus / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000096:biosynthesis / Q000235:genetics / Q000302:isolation & purification*; D004586:Electrophoresis; D006801:Humans; D015151:Immunoblotting; D046911:Macromolecular Substances; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051820:TCF Transcription Factors; D058125:Transcription Factor 7-Like 1 Protein; D014157:Transcription Factors; D014158:Transcription, Genetic; D014407:Tumor Cells, Cultured
D004268:DNA-Binding Proteins; D046911:Macromolecular Substances; D012333:RNA, Messenger; D051820:TCF Transcription Factors; C544912:TCF7L1 protein, human; D058125:Transcription Factor 7-Like 1 Protein; D014157:Transcription Factors