Cross Talk between Expression of the Human T-Cell Leukemia Virus Type 1 Tax Transactivator and the Oncogenic bHLH Transcription Factor TAL1
| Autor: | Pierre Jalinot, Louis Gazzolo, Madeleine Duc Dodon, Jean-Michel Terme, Arnaud Favre-Bonvin, Mélanie Wencker, Françoise Bex |
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| Rok vydání: | 2008 |
| Předmět: |
Gene Expression Regulation
Viral Immunology Thymus Gland CREB Models Biological Proto-Oncogene Mas Microbiology Transformation and Oncogenesis Cell Line Transactivation Transcription (biology) Proto-Oncogene Proteins hemic and lymphatic diseases Virology Basic Helix-Loop-Helix Transcription Factors medicine Humans Leukemia-Lymphoma Adult T-Cell Promoter Regions Genetic Transcription factor T-Cell Acute Lymphocytic Leukemia Protein 1 Feedback Physiological Genetics Human T-lymphotropic virus 1 Binding Sites biology NF-kappa B Promoter Gene Products tax biology.organism_classification medicine.disease Leukemia Insect Science Cancer research biology.protein HeLa Cells TAL1 |
| Zdroj: | Journal of Virology. 82:7913-7922 |
| ISSN: | 1098-5514 0022-538X |
| DOI: | 10.1128/jvi.02414-07 |
| Popis: | The human T-cell leukemia virus type 1 (HTLV-1) Tax transactivator is known to induce or repress various cellular genes, several of them encoding transcription factors. As Tax is known to deregulate various basic bHLH factors, we looked more specifically at its effect on TAL1 (T-cell acute lymphoblastic leukemia 1), also known as SCL (stem cell leukemia). Indeed, TAL1 is deregulated in a high percentage of T-cell acute lymphoblastic leukemia cells, and its oncogenic properties are well-established. Here we show that Tax induces transcription of this proto-oncogene by stimulating the activity of the TAL1 gene promoter 1b, through both the CREB and NF-κB pathways. It was also observed that TAL1 upregulates HTLV-1 promoter activity, in either the presence or the absence of Tax. The viral promoter is inhibited in trans by expression of the E2A protein E47, and TAL1 is able to abrogate this inhibition. These data show the existence of a positive feedback loop between Tax and TAL1 expression and support the notion that this proto-oncogene participates in generation of adult T-cell leukemia/lymphoma by increasing the amount of the Tax oncoprotein but also possibly by its own transforming activities. |
| Databáze: | OpenAIRE |
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