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| | Protein diagram |
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| Description | 295 amino acids, MW 43 kDa |
| Expression | HLF is normally expressed in hepatocytes and liver-derived cell lines, and, to a lesser extent, in lung, kidney and neurons of the central nervous system; it is not expressed in hematopoietic tissues or cell lines |
| Localisation | nuclear |
| Function | the normal function of HLF is largely unknown; HLF is a member of the PAR (proline and acidic amino acid-rich region) subfamily of b/ZIP (basic region leucine zipper) transcription factors; PAR and b/ZIP proteins bind to the DNA as dimers; HLF acts as a transcriptionnal transactivator; there are evidences that HLF protein transactivates factor VIII and factor IX genes, by binding as a homodimer (HLF/HLF) or a heterodimer with one albumin D-element binding protein sub unit (HLF/DBP), to multiple sites in the promoter of these genes; in the mouse central nervous system ontogeny, HLF expression increases markedly with synaptogenesis, suggesting that HLF plays a role in the function of adult differentiated neurons |
| Homology | other members of the b/ZIP PAR subfamily; in mammals: albumin D-element binding protein (DBP) and thyrotroph embryonic factor / vitellogenin gene binding protein (TEF/VBP); like HLF, they are transcription activators; the three proteins have an ability to form heterodimers with one another through the leucine-zipper domain; in other species : vitellogenin binding protein (VBP) in the chicken and Ces-2 gene in the nematode Caenorhabditis elegans |
| Fusion of the leucine zipper gene HLF to the E2A gene in human acute B-lineage leukemia. |
| Inaba T, Roberts WM, Shapiro LH, Jolly KW, Raimondi SC, Smith SD, Look AT |
| Science (New York, N.Y.). 1992 ; 257 (5069) : 531-534. |
| PMID 1386162 |
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| The proto-oncogene HLF and the related basic leucine zipper protein TEF display highly similar DNA-binding and transcriptional regulatory properties. |
| Hunger SP, Li S, Fall MZ, Naumovski L, Cleary ML |
| Blood. 1996 ; 87 (11) : 4607-4617. |
| PMID 8639829 |
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| 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 |
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| Cell transformation mediated by homodimeric E2A-HLF transcription factors. |
| Inukai T, Inaba T, Yoshihara T, Look AT |
| Molecular and cellular biology. 1997 ; 17 (3) : 1417-1424. |
| PMID 9032268 |
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| Regulation of the DBP promoter by PAR proteins and in leukemic cells bearing an E2A/HLF translocation. |
| Newcombe K, Glassco T, Mueller C |
| Biochemical and biophysical research communications. 1998 ; 245 (2) : 633-639. |
| PMID 9571207 |
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| Enhanced binding of HLF/DBP heterodimers represents one mechanism of PAR protein transactivation of the factor VIII and factor IX genes. |
| Begbie M, Mueller C, Lillicrap D |
| DNA and cell biology. 1999 ; 18 (2) : 165-173. |
| PMID 10073576 |
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| Expression patterns of the hepatic leukemia factor gene in the nervous system of developing and adult mice. |
| Hitzler JK, Soares HD, Drolet DW, Inaba T, O'Connel S, MG Rosenfeld, Morgan JI, Look AT |
| Brain research. 1999 ; 820 (1-2) : 1-11. |
| PMID 10023025 |
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