Anti-Stat3, Rabbit Monoclonal (RM465)

STAT3 belongs to the family of STAT (signal transducers and activators of transcription) proteins which are phosphorylated by receptor associated kinases, translocate to the nucleus, and act as transcription factors in response to cytokines and growth factors. Coactivators such as CREB-binding protein are required for the transcriptional activation by STAT3. STAT3 can also be activated by interferon-alpha, interferon-gamma, EGF, PDGF and IL6. Phosphorylation on tyrosine 705 by JAK1 and JAK2 is essential for STAT3 dimer formation, nuclear translocation and DNA binding activity. Transcriptional activation seems to be regulated by phosphorylation at Ser727 through the MAPK or mTOR pathways. The transcription factors associated with STAT3 are c-Jun and cyclic AMP-responsive enhancer binding protein (CREB). STAT3 mediates the expression of a variety of genes in response to cell stimuli, and thus plays a key role in many cellular processes such as cell growth and apoptosis. The small GTPase Rac1 has been shown to bind and regulate the activity of STAT3 while the PIAS3 protein is a specific inhibitor of STAT3. Three alternatively spliced transcript variants encoding distinct isoforms of STAT3 have been described. Deletion of the STAT3 gene in knock-out mice was lethal at the early embryonic stage. STAT3 is essential for the differentiation of the TH17 helper T cells, which have been implicated in a variety of autoimmune diseases. STAT3 can promote oncogenesis by being constitutively active through various pathways and increased activity of STAT3 in cancer cells, leads to changes in the function of protein complexes that control expression of inflammatory genes. Protein function: Signal transducer and transcription activator that mediates cellular responses to interleukins, KITLG/SCF, LEP and other growth factors (PubMed:10688651, PubMed:12359225, PubMed:12873986, PubMed:15194700, PubMed:17344214, PubMed:18242580, PubMed:23084476). 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 (PubMed:12873986). Upon activation of IL6ST/gp130 signaling by interleukin-6 (IL6), binds to the IL6-responsive elements identified in the promoters of various acute-phase protein genes (PubMed:12359225). Activated by IL31 through IL31RA (PubMed:15194700). Acts as a regulator of inflammatory response by regulating differentiation of naive CD4(+) T-cells into T-helper Th17 or regulatory T-cells (Treg): deacetylation and oxidation of lysine residues by LOXL3, leads to disrupt STAT3 dimerization and inhibit its transcription activity (PubMed:28065600). 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. May play an apoptotic role by transctivating BIRC5 expression under LEP activation (PubMed:18242580). Cytoplasmic STAT3 represses macroautophagy by inhibiting EIF2AK2/PKR activity (PubMed:23084476). Plays a crucial role in basal beta cell functions, such as regulation of insulin secretion. [The UniProt Consortium]