Key features and details
- Assay type: Semi-quantitative
- Detection method: Colorimetric
- Platform: Microplate reader
- Assay time: 3 hr 30 min
- Sample type: Nuclear Extracts
- Sensitivity: 600 ng/well
Product nameSTAT3 Transcription Factor Assay Kit (Colorimetric)
See all STAT3 kits
Sample typeNuclear Extracts
Sensitivity< 600 ng/well
Assay time3h 30m
Species reactivityReacts with: Mouse, Rat, Human
STAT3 Transcription Factor Assay Kit (Colorimetric) (ab207229) is a high throughput assay to quantify STAT3 activation in nuclear extracts. This assay combines a quick ELISA format with a sensitive and specific non-radioactive assay for transcription factor activation.
A specific double stranded DNA sequence containing the STAT3 consensus binding site (5’ – TTCCCGGAA – 3’) has been immobilized onto a 96-well plate. Active STAT3 present in the nuclear extract specifically binds to the oligonucleotide. STAT3 is detected by a primary antibody that recognizes an epitope of STAT3 accessible only when the protein is activated and bound to its target DNA. An HRP-conjugated secondary antibody provides sensitive colorimetric readout that at OD 450 nm. This product detects human, mouse and rat STAT3.
Key performance and benefits:
- Assay time: 3.5 hours (cell extracts preparation not included).
- Detection limit: < 0.6 µg nuclear extract/well.
- Detection range: 0.3 – 10 µg nuclear extract/well.
STAT (signal transducers and activators of transcription) transcription factors were discovered fourteen years ago as mediators of interferon-induced gene expression. They comprise a family of latent cytoplasmic proteins that are activated to participate in gene control when cells encounter various extracellular polypeptides. Their critical role in development and normal cell signaling has been largely determined through the analysis of transgenic mice lacking individual STAT genes. The STAT family consists of seven members that are activated by virtually every cytokine and growth factor.
The STAT proteins are unique among transcription factors in containing an SH2 (src-homology 2), phosphotyrosine-binding domain, a common protein-protein interaction domain among signaling proteins. Tyrosine phosphorylation around residue 700 is essential for the dimerization of STATs and the concomitant nuclear translocation of the dimer. Ligand-activated receptors that catalyze this phosphorylation include receptors with intrinsic tyrosine kinase activity (epidermal growth factor (EGF), platelet-derived growth factor (PDGF) and colony-stimulating factor-1) as well as receptors that lack intrinsic tyrosine kinase activity but to which Janus kinases (JAKs) are noncovalently associated. Receptors to which JAKs are bound are often referred to as cytokine receptors. Their ligands include IFN-α, -β and -γ; interleukins (IL) 2 to 7, 10 to 13, and 15; and erythropoietin, growth hormone, prolactin, thrombopoietin and other polypeptides. STAT dimers and heterodimers, but not monomers, are competent to bind DNA. The known DNA binding heterodimers are STAT1:2 (strong binding requires the joint presence of another protein, p48) and STAT1:3. STATs that form homodimers that bind DNA include STAT 1, 3, 4, 5 (STAT5A and 5B interact in a manner equivalent to a heterodimer) and 6.
In most cases, STAT activation is transient. Inactivation of STAT proteins is carried out by several mechanisms, including dephosphorylation of STAT proteins in the nucleus and degradation through the ubiquitin-proteosome pathway. A novel family of negative feedback inhibitors of the JAK-STAT pathway has been identified, referred to as suppressor-of-cytokine-signaling (SOCS) proteins/JAK binding (JAB) proteins, and STAT-induced STAT inhibitors (SSIs). In addition, a family of protein inhibitors of activated STAT (PIAS) proteins has been identified.
Storage instructionsPlease refer to protocols.
Components 1 x 96 tests 5 x 96 tests 10X Antibody Binding Buffer 1 x 2.2ml 1 x 11ml 10X Wash Buffer 1 x 22ml 1 x 110ml 96-well IRF-3 assay plate 1 unit 5 units Anti-rabbit HRP-conjugated IgG (0.25 μg/μL) 1 x 11µl 1 x 55µl Binding Buffer 1 x 10ml 1 x 50ml Developing Solution 1 x 11ml 1 x 55ml Dithiothreitol (DTT) (1 M) 1 x 100µl 1 x 500µl Hep G2 (IL-6, 100 ng/ml) nuclear extract (2.5 μg/μL) 1 x 40µl 1 x 200µl Herring sperm DNA (1 μg/μL) 1 x 100µl 1 x 500µl Lysis Buffer 1 x 10ml 1 x 50ml Plate sealer 1 unit 5 units Protease Inhibitor Cocktail 1 x 100µl 1 x 500µl STAT mutated oligonucleotide (10 pmol/μL) 1 x 100µl 1 x 500µl STAT Wild-type oligonucleotide (10 pmol/µL) 1 x 100µl 1 x 500µl STAT3 antibody 1 x 20µl 1 x 100µl Stop Solution 1 x 11ml 1 x 55ml
FunctionSignal transducer and transcription activator that mediates cellular responses to interleukins, KITLG/SCF, LEP and other growth factors. Once activated, recruits coactivators, such as NCOA1 or MED1, to the promoter region of the target gene (PubMed:17344214). May mediate cellular responses to activated FGFR1, FGFR2, FGFR3 and FGFR4. Binds to the interleukin-6 (IL-6)-responsive elements identified in the promoters of various acute-phase protein genes. Activated by IL31 through IL31RA. Involved in cell cycle regulation by inducing the expression of key genes for the progression from G1 to S phase, such as CCND1 (PubMed:17344214). Mediates the effects of LEP on melanocortin production, body energy homeostasis and lactation (By similarity). May play an apoptotic role by transctivating BIRC5 expression under LEP activation (PubMed:18242580). Cytoplasmic STAT3 represses macroautophagy by inhibiting EIF2AK2/PKR activity.
Tissue specificityHeart, brain, placenta, lung, liver, skeletal muscle, kidney and pancreas.
Involvement in diseaseHyperimmunoglobulin E recurrent infection syndrome, autosomal dominant
Autoimmune disease, multisystem, infantile-onset
Sequence similaritiesBelongs to the transcription factor STAT family.
Contains 1 SH2 domain.
modificationsTyrosine phosphorylated upon stimulation with EGF. Tyrosine phosphorylated in response to constitutively activated FGFR1, FGFR2, FGFR3 and FGFR4 (By similarity). Activated through tyrosine phosphorylation by BMX. Tyrosine phosphorylated in response to IL6, IL11, LIF, CNTF, KITLG/SCF, CSF1, EGF, PDGF, IFN-alpha, LEP and OSM. Activated KIT promotes phosphorylation on tyrosine residues and subsequent translocation to the nucleus. Phosphorylated on serine upon DNA damage, probably by ATM or ATR. Serine phosphorylation is important for the formation of stable DNA-binding STAT3 homodimers and maximal transcriptional activity. ARL2BP may participate in keeping the phosphorylated state of STAT3 within the nucleus. Upon LPS challenge, phosphorylated within the nucleus by IRAK1. Upon erythropoietin treatment, phosphorylated on Ser-727 by RPS6KA5. Phosphorylation at Tyr-705 by PTK6 or FER leads to an increase of its transcriptional activity. Dephosphorylation on tyrosine residues by PTPN2 negatively regulates IL6/interleukin-6 signaling.
Cellular localizationCytoplasm. Nucleus. Shuttles between the nucleus and the cytoplasm. Translocated into the nucleus upon tyrosine phosphorylation and dimerization, in response to signaling by activated FGFR1, FGFR2, FGFR3 or FGFR4. Constitutive nuclear presence is independent of tyrosine phosphorylation. Predominantly present in the cytoplasm without stimuli. Upon leukemia inhibitory factor (LIF) stimulation, accumulates in the nucleus. The complex composed of BART and ARL2 plays an important role in the nuclear translocation and retention of STAT3. Identified in a complex with LYN and PAG1.
- Information by UniProt
- Acute Phase Response Factor
- Acute-phase response factor
ab207229 has not yet been referenced specifically in any publications.