Signal transducer and transcription activator that mediates cellular responses to interferons , cytokine KITLG/SCF and other cytokines and other growth factors . Following type I IFN binding to cell surface receptors, signaling via protein kinases leads to activation of Jak kinases and to tyrosine phosphorylation of STAT1 and STAT2. The phosphorylated STATs dimerize and associate with ISGF3G/IRF-9 to form a complex termed ISGF3 transcription factor, that enters the nucleus . ISGF3 binds to the IFN stimulated response element to activate the transcription of IFN-stimulated genes , which drive the cell in an antiviral state . In response to type II IFN , STAT1 is tyrosine- and serine-phosphorylated . It then forms a homodimer termed IFN-gamma-activated factor , migrates into the nucleus and binds to the IFN gamma activated sequence to drive the expression of the target genes, inducing a cellular antiviral state . Becomes activated in response to KITLG/SCF and KIT signaling . May mediate cellular responses to activated FGFR1, FGFR2, FGFR3 and FGFR4 . Following bacterial lipopolysaccharide -induced TLR4 endocytosis, phosphorylated at Thr-749 by IKBKB which promotes binding of STAT1 to the 5'-TTTGAGGC-3' sequence in the ARID5A promoter, resulting in transcriptional activation of ARID5A and subsequent ARID5A-mediated stabilization of IL6 . Phosphorylation at Thr-749 also promotes binding of STAT1 to the 5'-TTTGAGTC-3' sequence in the IL12B promoter and activation of IL12B transcription . Involved in food tolerance in small intestine: associates with the Gasdermin-D, p13 cleavage product and promotes transcription of CIITA, inducing type 1 regulatory T cells in upper small intestine .

Signal transducer and activator of transcription 1-alpha/beta (Transcription factor ISGF-3 components p91/p84)

p42224

Human

WB

WB 1:1000-1:5000

~88 kD

Rabbit

50mM Tris-Glycine(pH 7.4), 0.15M NaCl, 40% Glycerol, 0.01% sodium azide and 0.05% BSA.

Store at -20°C. Stable for 12 months from date of receipt.