S727 phosphorylation of STAT1 in interferon-γ (IFN-γ)-treated mouse fibroblasts occurred without a need for p38 mitogen-activated protein kinase (MAPK), extracellular signal-regulated kinases 1 and 2 or c-Jun kinases, and required both an intact SH2 domain and phosphorylation of Y701.

IFN- γ signaling induces phosphorylation of two STAT1 residues: Tyr 701 (Y701), which facilitates dimerization, nuclear translocation, and DNA binding; and Ser 727 (S727), which enables maximal STAT1 transcription activity.

Jan 1, 2017 · STAT1 mediates proteasomal degradation of cyclin D1 by an unknown mechanism that requires the presence of S727 STAT1. Cell cycle arrest correlated with reduced phosphorylation of retinoblastoma protein (Rb), reduced levels of cyclin E and enhanced expression of p21WAF1 and p27 KIP1 [52].

Jul 1, 2008 · Here, we show that both Stat1 Y701 phosphorylation and nuclear translocation are required for IFN-induced S727 phosphorylation. We further show that Stat1 mutants lacking the ability to stably associate with chromatin are poorly serine-phosphorylated in response to IFN-γ.

Nov 23, 1999 · Relevant to the biology of macrophages, S727 can serve to feed IFN-γ-independent signals into STAT1. For example, macrophage-activating components of bacterial cell walls like lipopolysaccharide (LPS) strongly activate a STAT1 Ser727 kinase independently of Tyr701 phosphorylation.

Polyclonal Antibody for studying Stat1 (Ser727) phosphate. Validated for ChIP, IF, WB. Highly specific and rigorously validated in-house, Phospho-Stat1 (Ser727) Antibody (CST #9177) is ready to ship.

Aug 15, 2013 · NK cells with a phosphorylation-dead STAT1 mutant (Stat1-S727A) display signs of hyperactivity resulting in enhanced tumor surveillance in vivo. Correspondingly, the authors identify the upstream kinase as CDK8, and they find that targeting this kinase significantly enhances NK cell cytotoxicity.

Aug 15, 2013 · We show that mutation of a single phosphorylation site (Stat1-S727A) enhances NK cell cytotoxicity against a range of tumor cells, accompanied by increased expression of perforin and granzyme B. Stat1-S727A mice display significantly delayed disease onset in NK cell-surveilled tumor models including melanoma, leukemia, and metastasizing breast ...

Here we report that Mediator kinase inhibition with CA suppresses the growth of AML cells with hyper-activated JAK-STAT signaling in part by blocking STAT1 S727 phosphorylation. We also show that differentiation of these AML cells is mediated, in part, by CDK8 phosphorylation of …

Dec 8, 2014 · Recent data indicate that CDK8-mediated phosphorylation of signal transducer and activator of transcription 1 (STAT1) on S727 inhibits natural killer (NK) cell cytotoxicity and restrains tumor surveillance. These findings implicate CDK8 as a promising target for immunotherapy.