Physical and Functional Interaction of HIV-1 Tat with E2F-4, a Transcriptional Regulator of Mammalian Cell Cycle
| Autor: | Salvatore Venuta, Ileana Quinto, Antimina Puca, Francesca Di Leva, Camillo Palmieri, Concetta Ambrosino, Francesco Olimpico, Marco Schiavone, Giuseppe Scala, Maria Rosaria Ruocco, Francesca Trimboli, Mario Toriello |
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| Přispěvatelé: | C., Ambrosino, C., Palmieri, A., Puca, F., Trimboli, M., Schiavone, F., Olimpico, Ruocco, MARIA ROSARIA, F., DI LEVA, M., Toriello, I., Quinto, S., Venuta, G., Scala |
| Rok vydání: | 2002 |
| Předmět: |
Immunoprecipitation
E2F-4 LTR Recombinant Fusion Proteins Molecular Sequence Data Saccharomyces cerevisiae Biology Biochemistry Jurkat cells Cell Line Promoter Regions Genetic Transcriptional regulation Humans Cloning Molecular Promoter Regions Genetic E2F Molecular Biology Transcription factor Gene Library Glutathione Transferase HIV Long Terminal Repeat B-Lymphocytes Binding Sites Base Sequence Dimerization HIV-1 Plasmids Cell Biology Molecular Signal transducing adaptor protein Promoter Molecular biology Cell biology stomatognathic diseases biological phenomena cell phenomena and immunity Cloning |
| Zdroj: | Journal of Biological Chemistry. 277:31448-31458 |
| ISSN: | 0021-9258 |
| DOI: | 10.1074/jbc.m112398200 |
| Popis: | Tat protein of the human immunodeficiency virus type-1 (HIV-1) plays a critical role in the regulation of viral transcription and replication. In addition, Tat regulates the expression of a variety of cellular genes and could account for AIDS-associated diseases including Kaposi's Sarcoma and non-Hodgkin's lymphoma by interfering with cellular processes such as proliferation, differentiation, and apoptosis. The molecular mechanisms underlying the pleiotropic activities of Tat may include the generation of functional heterodimers of Tat with cellular proteins. By screening a human B-lymphoblastoid cDNA library in the yeast two-hybrid system, we identified E2F-4, a member of E2F family of transcription factors, as a Tat-binding protein. The interaction between Tat and E2F-4 was confirmed by GST pull-down experiments performed with cellular extracts as well as with in vitro translated E2F-4. The physical association of Tat and E2F-4 was confirmed by in vivo binding experiments where Tat.E2F-4 heterodimers were recovered from Jurkat cells by immunoprecipitation and immunoblotting. By using plasmids expressing mutant forms of Tat and E2F-4, the domains involved in Tat.E2F-4 interaction were identified as the regions encompassing amino acids 1-49 of Tat and amino acids 1-184 of E2F-4. Tat x E2F-4 complexes were shown to bind to E2F cis-regions with increased efficiency compared with E2F-4 alone and to mediate the activity of E2F-dependent promoters including HIV-1 long terminal repeat and cyclin A. The data point to Tat as an adaptor protein that recruits cellular factors such as E2F-4 to exert its multiple biological activities. |
| Databáze: | OpenAIRE |
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