Abstract
Alternative promoter usage has been proposed as a mechanism regulating transcriptional and translational diversity in highly elaborated systems like the immune system in humans. Here, we report that transcription of human glycoprotein A repetitions predominant (GARP) in regulatory CD4 T cells (Tregs) is tightly regulated by two alternative promoters. An intragenic promoter contains several CpGs and acts as a weak promoter that is demethylated and initiates transcription Treg-specifically. The strong up-stream promoter containing a CpG-island is, in contrast, fully demethylated throughout tissues. Transcriptional activity of the strong promoter was surprisingly down-regulated upon demethylation of the weak promoter. This demethylation-induced transcriptional attenuation regulated the magnitude of GARP expression and correlated with disease activity in rheumatoid arthritis. Treg-specific GARP transcription was initiated by synergistic interaction of forkhead box protein 3 (Foxp3) with nuclear factor of activated T cells (NFAT) and was underpinned by permissive chromatin remodeling caused by release of the H3K4 demethylase, PLU-1. Our findings describe a novel function of alternative promoters in regulating the extent of transcription. Moreover, since GARP functions as a transporter of transforming growth factor beta (TGF beta), a cytokine with broad pleiotropic traits, GARP transcriptional attenuation by alternative promoters might provide a mechanism regulating peripheral TGF beta to avoid unwanted harmful effects. (C) 2015 Elsevier B.V. All rights reserved.
| Dokumententyp: | Zeitschriftenartikel |
|---|---|
| Fakultät: | Medizin |
| Themengebiete: | 600 Technik, Medizin, angewandte Wissenschaften > 610 Medizin und Gesundheit |
| ISSN: | 1874-9399 |
| Sprache: | Englisch |
| Dokumenten ID: | 44193 |
| Datum der Veröffentlichung auf Open Access LMU: | 27. Apr. 2018, 08:05 |
| Letzte Änderungen: | 04. Nov. 2020, 13:20 |
- Dokument bearbeiten
