Immunoglobulin Transcription Factor 1 (ITF1)

The TCF3 gene, also called E2A, encodes 2 basic helix-loop-helix (bHLH) transcription factors, E12 and E47, through alternative splicing. E12 and E47 are involved in regulation of immunoglobulin gene expression .

Expression of immunoglobulin genes depends on various sequence motifs in their enhancer and promoter regions. One class of such sequences is the E box, which is found in both heavy and light chain enhancers. The kappa-E2 site has been shown to be important for light chain gene transcription. To isolate cDNAs encoding kappa-E2-binding proteins, Murre et al. (1989) screened a cDNA expression library derived from a human B-cell lymphoma cell line (BJAB) with an oligonucleotide containing a trimerized kappa-E2 site. They identified a partial cDNA encoding a protein that they designated E12.