E2A and E2-2 are Subunits of B-Cell-Specific E2-Box DNA-Binding Proteins

• Published in: Molecular and cellular biology Vol. 13; no. 6; pp. 3522 - 3529
• Main Authors: Bain, Gretchen, Gruenwald, Stefan, Murre, Cornelis
• Format: Journal Article
• Language: English
• Published: Taylor & Francis 01.06.1993
• ISSN: 1098-5549; 1098-5549
• DOI: 10.1128/mcb.13.6.3522-3529.1993

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.