Previously, by a yeast 2-hybrid screen, we identified signal transducer and activator of transcription 5b (Stat5b) as a substrate of the insulin receptor (IR). We demonstrated that refeeding of fasted mice leads to rapid activation of Stat5 proteins in liver, skeletal muscle, and fat, suggesting that Stat5b is a physiological target of insulin. Here, we show that injection of glucose or insulin...

3-Methylcholanthrene (MC) activates the aryl hydrocarbon receptor and increases expression of cytochrome P450 (P450) enzymes such as CYP1A1. MC also decreases expression of CYP2C11, the major hepatic P450 in male rats that is regulated by pulsatile growth hormone (GH) secretion via a pathway partially dependent on signal transducer and activator of transcription 5b (STAT5b). If disruption of th...

The identification of susceptibility genes for inflammatory bowel disease (IBD) is key to understanding pathogenic mechanisms. Recently, the results of genetic association studies have highlighted many loci that are shared among several autoimmune diseases. We aimed to study the genetic epidemiology of polymorphisms in specific genes previously associated with other autoimmune diseases, namely ...

Signal transducer and activator of transcription (Stat)5a and Stat5b are critical for normal immune function. Progression of T cells through G(1)-S phase of cell cycle requires T cell receptor (TCR)- and/or cytokine-inducible tyrosine phosphorylation of Stat5a/b. Stat5a/b may also, in a cell-dependent manner, be constitutively or cytokine-inducibly phosphorylated on a Pro-Ser-Pro (PSP) motif lo...

STAT5 controls essential cellular functions and is encoded by two genes, Stat5a and Stat5b. To provide insight to the mechanisms linking hematologic malignancy to STAT5 activation/regulation of target genes, we identified STAT5 target genes and focused on Dpf3 gene, which encodes for an epigenetic factor. Dpf3 expression was induced upon IL-3 stimulation in Ba/F3 cells, while strong binding of ...

STAT transcription factors are expressed in many cell types and bind to similar sequences. However, different STAT gene knock-outs show very distinct phenotypes. To determine whether differences between the binding specificities of STAT proteins account for these effects, we compared the sequences bound by STAT1, STAT5A, STAT5B, and STAT6. One sequence set was selected from random oligonucleoti...

Exosomes (EVs) have relevance in cell-to-cell communication carrying pro-tumorigenic factors that participate in oncogenesis and drug resistance and are proposed to have potential as self-delivery systems. Advancing on our studies of EVs in triple-negative breast cancer, here we more comprehensively analysed isogenic cell line variants and their EV populations, tissues cell line variants and th...

Cytokine signals are known to contribute to CD8+ memory T cell homeostasis, but an exact understanding of the mechanism(s) has remained elusive. We have now investigated the role of Stat5 proteins in this process. Whereas Stat5a and Stat5b KO mice have decreased numbers of CD8+ T cells, Stat5-transgenic mice have an increased number of these cells. Stat5b-transgenic mice exhibit increased Ag-in...

Signal Transducers and Activators of Transcription (STATs) are key components of the JAK/STAT pathway. Of the seven STATs, STAT5A and STAT5B are of particular interest for their critical roles in cellular differentiation, adipogenesis, oncogenesis, and immune function. The interactions of STAT5A and STAT5B with cytokine/hormone receptors, nuclear receptors, transcriptional regulators, proto-onc...