B-MYB transactivates its own promoter through SP1-binding sites
| Autor: | Arturo Sala, Maria Neve Cervellera, I Casella, Cesare Peschle, Robert E. Lewis, P. De Luca, Biagio Saitta, Roger J. Watson |
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| Rok vydání: | 1999 |
| Předmět: |
Transcriptional Activation
Cancer Research Saccharomyces cerevisiae Proteins animal structures Transcription Genetic Sp1 Transcription Factor Recombinant Fusion Proteins Oligonucleotides Cell Cycle Proteins Biology Transfection Cell Line Fungal Proteins Proto-Oncogene Proteins c-myb Transactivation Sp3 transcription factor Transcription (biology) Proto-Oncogene Proteins Coactivator Genetics Humans MYB Promoter Regions Genetic Molecular Biology Sp1 transcription factor Binding Sites fungi NF-kappa B Herpes Simplex Virus Protein Vmw65 Fusion protein Molecular biology DNA-Binding Proteins Sp3 Transcription Factor Trans-Activators Adenovirus E1A Proteins Protein Binding Transcription Factors |
| Zdroj: | Oncogene. 18:1333-1339 |
| ISSN: | 1476-5594 0950-9232 |
| DOI: | 10.1038/sj.onc.1202421 |
| Popis: | B-MYB is an ubiquitous protein required for mammalian cell growth. In this report we show that B-MYB transactivates its own promoter through a 120 bp segment proximal to the transcription start site. The B-MYB-responsive element does not contain myb-binding sites and gel-shift analysis shows that SP1, but not B-MYB, protein contained in SAOS2 cell extracts binds to the 120 bp B-myb promoter fragment. B-MYB-dependent transactivation is cooperatively increased in the presence of SP1, but not SP3 overexpression. When the SP1 elements of the B-myb promoter are transferred in front of a heterologous promoter, an increased response to B-MYB results. In contrast, c-MYB, the prototype member of the Myb family, is not able to activate the luciferase construct containing the SP1 elements. With the use of an SP1-GAL4 fusion protein, we have determined that the cooperative activation occurs through the domain A of SP1. These observations suggest that B-MYB functions as a coactivator of SP1, and that diverse combinations of myb and SP1 sites may dictate the responsiveness of myb-target genes to the various members of the myb family. |
| Databáze: | OpenAIRE |
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