Interplay between repressing and activating domains defines the transcriptional activity of IRF-1
| Autor: | S, Kirchhoff, A, Oumard, M, Nourbakhsh, B Z, Levi, H, Hauser |
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| Rok vydání: | 2000 |
| Předmět: |
Chloramphenicol O-Acetyltransferase
Transcriptional Activation Saccharomyces cerevisiae Proteins Sequence Homology Amino Acid Transcription Genetic Recombinant Fusion Proteins Molecular Sequence Data Enzyme-Linked Immunosorbent Assay Phosphoproteins Cell Line Protein Structure Tertiary DNA-Binding Proteins Fungal Proteins Mice Enhancer Elements Genetic Gene Expression Regulation Genes Reporter Animals Amino Acid Sequence Amino Acids Luciferases Interferon Regulatory Factor-1 Plasmids Transcription Factors |
| Zdroj: | European journal of biochemistry. 267(23) |
| ISSN: | 0014-2956 |
| Popis: | Interferon regulatory factor-1 (IRF-1) is a transcriptional activator with weak activation capacity. By defining the transcriptional activation domain of IRF-1 we identified two activator fragments located between amino acids 185 and 256 functioning in an additive manner. Another fragment of IRF-1, which has no activator function alone, acts as a strong enhancer element of these activator sequences. This enhancer element resides between the activator domains and the C-terminus. In addition, we identified a novel type of inhibitory domain in the N-terminal 60 amino acids of IRF-1 which strongly inhibits its transcriptional activity. Because this fragment is conserved in all interferon regulatory factors, we found similar repression effects in the corresponding fragments in IRF-2, IRF-3 and interferon consensus sequence binding protein (ICSBP/IRF-8). Interestingly, the corresponding sequence in p48/IRF-9 is divergent, so that it does not show this inhibitory activity. A five-amino-acid sequence distinguishes the p48/IRF-9 N-terminus from the homologous parts in other interferon regulatory factors containing the repressing function. Replacing the diverged amino acids in IRF-1 with the corresponding sequence of p48/IRF-9 resulted in a loss of inhibitory activity within IRF-1. The opposing activities within interferon regulatory factors may contribute to balanced or tuned regulation of gene activation, depending on the promoter context. |
| Databáze: | OpenAIRE |
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