Atlas of Genetics and Cytogenetics in Oncology and Haematology
TCF3 (transcription factor 3 (E2A immunoglobulin enhancer binding factors E12/E47))
| Identity |
| Other names | E2A |
| TCF3 (Trancription Factor 3); | |
| ITF1 Immunoglobulin Enhancer Binding | |
| Factors E12/E47 | |
| HGNC | TCF3 |
| Location | 19p13.3 |
| Local_order | not far from ENL also in 19p13.3; LYL1 is in 19p13.2-p13.1 and ELL in 19p13.1 |
| DNA/RNA |
 | |
| c-E2A (19p13.3) in normal cells: PAC 1116F22 - Courtesy Mariano Rocchi, Resources for Molecular Cytogenetics. Laboratories willing to validate the probes are wellcome: contact M Rocchi | |
| Description | 17 exons; 15a and 15b alternative |
| Transcription | 4.4kb mRNA; coding sequence: 2.0 kb; alternate splicing --> E12 and E47, having different bHLH encoding exons (+ also E2-5) |
| Protein |
 | |
| c-E2A (19p13.3) in normal cells: PAC 1116F22 - Courtesy Mariano Rocchi, Resources for Molecular Cytogenetics. Laboratories willing to validate the probes are wellcome: contact M Rocchi | |
| Description | this gene encodes E12 and E47, which are proteins which bind specifically to the immunoglobulin k chain enhancer kE2; 648-654 amino acids; 68 KDa; domains: 2 transcriptional activation domains (-> transcription factor) in the NH2-terminal, and a basic helix-loop-helix (bHLH) DNA binding site in the C-term |
| Expression | widely expressed |
| Localisation | nuclear |
| Function | transcription regulation; heterodimerizes with tissue-specific bHLH proteins; homodimers are only found so far in B-lineage lymphocytes; essential for normal B-cell hematopoiesis |
| Homology | with other proteins with a Helix-Loop-Helix dimerization domain signature, MYC type (MYC family, of which is C-MYC, LYL1, TAL1 (link)) |
| Implicated in |
| Entity | t(1;19)(q23;p13)/B-ALL --> hybrid gene: E2A/PBX1 |
| Disease | pre B ALL mainly; CD19+, CD10+, CD9+ |
| Prognosis | controversial data; associated with poor prognostic features |
| Cytogenetics | two different forms: - the balanced t(1;19); - the unbalanced form, with 2 normal chromosomes 1, a der(19), and a normal chromosome19: --> partial trisomy for 1q23-1qter and monosomy for 19p13.3-pter ; additional anomalies: in half of the cases; they are various |
| Hybrid/Mutated Gene | 5' E2A from 19p13 fused to 3' PBX1; breakpoints are clustered on both genes |
| Abnormal Protein | N-term transcriptional activation domains from E2A fused to the Hox cooperative motif and homeodomain of C-term PBX1 |
| Oncogenesis | potent transcriptional activator; pleiotropic transforming activity |
| Entity | t(17;19)(q22;p13)/B-ALL --> hybrid gene: E2A/HLF |
| Disease | childhood B-ALL |
| Prognosis | poor prognosis is likely |
| Hybrid/Mutated Gene | 5' E2A - 3' HLF |
| Abnormal Protein | N-term transcriptional activation domains from E2A fused to the basic leucine zipper from HLF C-term |
| Oncogenesis | E2A/HLF homodimers bind to promoter/enhancer elements of downstream target genes |
| Breakpoints |
 | |
 | |
| Note | breakpoints: 1- in t(1;19): are located (and dispersed) in the intron 13, and remove the bHLH domain; 2- in t(17;19) type I: are so far located at a given nucleotide in intron 13; in t(17;19) type II: are located in intron 12 |
| External links |
| Bibliography |
| Chromosomal translocations involving the E2A gene in acute lymphoblastic leukemia: clinical features and molecular pathogenesis. |
| Hunger SP |
| Blood. 1996 ; 87 (4) : 1211-1224. |
| PMID 8608207 |
| REVIEW articles | automatic search in PubMed |
| Last year publications | automatic search in PubMed |
| Contributor(s) |
| Written | 12-1997 | Jean-Loup Huret |
| Citation |
| This paper should be referenced as such : |
| Huret JL . TCF3 (transcription factor 3 (E2A immunoglobulin enhancer binding factors E12/E47)). Atlas Genet Cytogenet Oncol Haematol. December 1997 . URL : http://AtlasGeneticsOncology.org/Genes/E2A.html |
| © Atlas of Genetics and Cytogenetics in Oncology and Haematology | indexed on : Mon Aug 11 21:13:23 2008 |
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