Clone REA159 recognizes the Y701 phosphorylated form (pY701) of STAT1, a member of signal transducers and activators of transcription (STAT) family. STAT family members play a critical role in activation of signaling pathways in response to the presence of various cytokines and growth factors (interferon (IFN)-α, IFN-γ, EGF, PDGF, and interleukin (IL)-6). In response to binding of IFNs to their respective receptors, STAT1, which is receptor bound, is activated by phosphorylation at the Y701 residue by Janus protein tyrosine kinases (Jaks). Activation of STAT1 is accompanied by its dissociation from the receptor and formation of homodimer and complex with STAT2 and p48 followed by translocation of the homodimer and complex to the nucleus. STAT1 is involved in positive regulation of IFN-stimulated genes, negatively regulates expression of genes for thyrotropin receptor, matrix metalloproteinase 1, 2, 13, etc. and constitutive expression of caspases 1, 2, 3, and LMP2 genes. STAT1 expression is found ubiquitously.

Additional information: Clone REA159 displays negligible binding to Fc receptors.