Project description:Signal Transducers and Activators of Transcription (STAT) 5A/B regulate cytokine-inducible genes upon binding to GAS motifs. It is not known what percentage of genes with GAS motifs bind to and are regulated by STAT5. Moreover, it is not clear whether genome-wide STAT5 binding is modulated by its concentration. To clarify these issues we established genome-wide STAT5 binding upon growth hormone (GH) stimulation of wild type mouse embryonic fibroblasts (MEFs) and MEFs overexpressing STAT5A more than 20-fold. Upon GH stimulation 23,827 and 111,939 STAT5A binding sites were detected in wild type and STAT5A overexpressing MEFs, respectively. 13,278 and 71,561 peaks contained at least one GAS motif. 1,586 and 8,613 binding sites were located within 2.5 kbp of promoter sequences, respectively. Stringent filtering revealed 78 genes in which the promoter/upstream region (-10kbp to +0.5kbp) was recognized by STAT5 both in wt and STAT5 overexpressing MEFs and 347 genes that bound STAT5 only in overexpressing cells. Genome-wide expression analyses identified that the majority of STAT5-bound genes was not under GH control. Up to 40% of STAT5-bound genes were not expressed. For the first time we demonstrate the magnitude of opportunistic genomic STAT5 binding that does not translate into transcriptional activation of neighboring genes. Genome-wide mapping of STAT5 binding in MEF cells (WT, KO; Stat5-/- and overexpression; STAT5A-Stat5-/-) upon growth hormone induction
Project description:Signal Transducers and Activators of Transcription (STAT) 5A/B regulate cytokine-inducible genes upon binding to GAS motifs. It is not known what percentage of genes with GAS motifs bind to and are regulated by STAT5. Moreover, it is not clear whether genome-wide STAT5 binding is modulated by its concentration. To clarify these issues we established genome-wide STAT5 binding upon growth hormone (GH) stimulation of wild type mouse embryonic fibroblasts (MEFs) and MEFs overexpressing STAT5A more than 20-fold. Upon GH stimulation 23,827 and 111,939 STAT5A binding sites were detected in wild type and STAT5A overexpressing MEFs, respectively. 13,278 and 71,561 peaks contained at least one GAS motif. 1,586 and 8,613 binding sites were located within 2.5 kbp of promoter sequences, respectively. Stringent filtering revealed 78 genes in which the promoter/upstream region (-10kbp to +0.5kbp) was recognized by STAT5 both in wt and STAT5 overexpressing MEFs and 347 genes that bound STAT5 only in overexpressing cells. Genome-wide expression analyses identified that the majority of STAT5-bound genes was not under GH control. Up to 40% of STAT5-bound genes were not expressed. For the first time we demonstrate the magnitude of opportunistic genomic STAT5 binding that does not translate into transcriptional activation of neighboring genes.
Project description:Interleukin 2 (IL-2), a cytokine linked to human autoimmune diseases, limits IL-17 production. We show that deletion of Stat3 in T cells abrogates IL-17 production and attenuates autoimmunity associated with IL-2 deficiency. While STAT3 induces IL-17 and RORγt and inhibits Foxp3, IL-2 inhibited IL-17 independently of Foxp3 and RORγt. We found that STAT3 and STAT5 bound to multiple common sites across the Il17 genetic locus. The induction of STAT5 binding by IL-2 was associated with a reduction in STAT3 binding at these sites and the inhibition of associated active epigenetic marks. Titrating the relative activation of STAT3 and STAT5 modulated TH17 cell specification. Thus, the balance rather than the absolute magnitude of these signals determines the propensity of cells to make a key inflammatory cytokine. The genome-wide binding of STAT3 and STAT5 under Th17 conditions was investigated by CHIP-seq.