Tristetraprolin down-regulates IL-2 gene expression through AU-rich element-mediated mRNA decay
| Autor: | Michelle Abelson, Irina A. Vlasova, Rachel L. Ogilvie, Perry J. Blackshear, Paul R. Bohjanen, Heidi H. Hau |
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| Rok vydání: | 2005 |
| Předmět: |
Cell Extracts
Transcription Genetic MRNA destabilization RNA Stability T-Lymphocytes Immunology Tristetraprolin Down-Regulation Biology Regulatory Sequences Nucleic Acid Lymphocyte Activation Transfection Cell Line Immediate-Early Proteins Mice hemic and lymphatic diseases Gene expression Immunology and Allergy Animals Humans Electrophoretic mobility shift assay RNA Messenger AU-rich element Mice Knockout Messenger RNA T-cell receptor CD28 Molecular biology DNA-Binding Proteins Mice Inbred C57BL Interleukin-2 HeLa Cells Protein Binding |
| Zdroj: | Journal of immunology (Baltimore, Md. : 1950). 174(2) |
| ISSN: | 0022-1767 |
| Popis: | Posttranscriptional regulation of IL-2 gene expression at the level of mRNA decay is mediated by an AU-rich element (ARE) found in the 3′-untranslated region. We hypothesized that the ARE-binding protein tristetraprolin (TTP) regulates T lymphocyte IL-2 mRNA decay by interacting with the IL-2 ARE and targeting the transcript for decay. rTTP protein expressed in HeLa cells bound specifically to the IL-2 ARE with high affinity in a gel shift assay. In primary human T lymphocytes, TTP mRNA and protein expression were induced by TCR and CD28 coreceptor stimulation. Using a gel shift assay, we identified a cytoplasmic RNA-binding activity that was induced by TCR and CD28 coreceptor stimulation and bound specifically to the IL-2 ARE sequence. Using anti-TTP Abs, we showed by supershift that this inducible activity contained TTP. We also showed that insertion of the IL-2 ARE sequence into the 3′-untranslated region of a β-globin reporter construct conferred TTP-dependent mRNA destabilization on the β-globin reporter. To determine whether TTP also regulates IL-2 gene expression in vivo, we examined IL-2 expression in primary cells from wild-type and TTP knockout mice. Compared with their wild-type counterparts, TCR- and CD28-activated splenocytes and T cells from TTP knockout mice overexpressed IL-2 mRNA and protein. Also, IL-2 mRNA was more stable in activated splenocytes from TTP knockout mice compared with wild-type mice. Taken together, these data suggest that TTP functions to down-regulate IL-2 gene expression through ARE-mediated mRNA decay. |
| Databáze: | OpenAIRE |
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