Cell Signaling Technology

Product Pathways - Jak/Stat Pathway

Phospho-Stat1 (Tyr701) Antibody #9171

Applications Reactivity Sensitivity MW (kDa) Source
W IP ChIP H M R (B) (Dg) Endogenous 84, 91 Rabbit

Applications Key:  W=Western Blotting  IP=Immunoprecipitation  ChIP=Chromatin IP
Reactivity Key:  H=Human  M=Mouse  R=Rat  B=Bovine  Dg=Dog
Species cross-reactivity is determined by western blot. Species enclosed in parentheses are predicted to react based on 100% sequence homology.

Protocols

Specificity / Sensitivity

Phospho-Stat1 (Tyr701) Antibody detects endogenous levels of Stat1 only when phosphorylated at tyrosine 701. The antibody detects phosphorylated tyrosine 701 of p91 Stat1 and also the p84 splice variant. It does not cross-react with the corresponding phospho-tyrosines of other Stat proteins.

Source / Purification

Polyclonal antibodies are produced by immunizing animals with a synthetic phosphopeptide corresponding to residues surrounding Tyr701 of human Stat1. Antibodies are purified by protein A and peptide affinity chromatography.

Western Blotting

Western Blotting

Western blot analysis of extracts from HeLa cells, untreated or IFN-alpha-treated (100 ng/ml), using Phospho-Stat1 (Tyr701) Antibody.

Chromatin IP

Chromatin IP

Chromatin immunoprecipitations were performed with cross-linked chromatin from 4 x 106 HT-1080 cells treated with IFN-γ (50 ng/ml) for 30 minutes and either 20 μl of Phospho-Stat1 (Tyr701) Antibody or 2 μl of Normal Rabbit IgG #2729 using SimpleChIP® Enzymatic Chromatin IP Kit (Magnetic Beads) #9003. The enriched DNA was quantified by real-time PCR using human IRF-1 promoter primers, SimpleChIP® Human TAP1 Promoter Primers #5148, and SimpleChIP® Human α Satellite Repeat Primers #4486. The amount of immunoprecipitated DNA in each sample is represented as signal relative to the total amount of input chromatin, which is equivalent to one.

Background

The Stat1 transcription factor is activated in response to a large number of ligands (1) and is essential for responsiveness to IFN-α and IFN-γ (2,3). Phosphorylation of Stat1 at Tyr701 induces Stat1 dimerization, nuclear translocation, and DNA binding (4). Stat1 protein exists as a pair of isoforms, Stat1α (91 kDa) and the splice variant Stat1β (84 kDa). In most cells, both isoforms are activated by IFN-α, but only Stat1α is activated by IFN-γ. The inappropriate activation of Stat1 occurs in many tumors (5). In addition to tyrosine phosphorylation, Stat1 is also phosphorylated at Ser727 through a p38 mitogen-activated protein kinase (MAPK)-dependent pathway in response to IFN-α and other cellular stresses (6). Serine phosphorylation may be required for the maximal induction of Stat1-mediated gene activation.

  1. Heim, M.H. (1999) J. Recept. Signal. Transduct. Res. 19, 75-120.
  2. Durbin, J.E. et al. (1996) Cell 84, 443-450.
  3. Meraz, M.A. et al. (1996) Cell 84, 431-442.
  4. Ihle, J.N. et al. (1994) Trends Biochem. Sci. 19, 222-227.
  5. Frank, D.A. (1999) Mol. Med. 5, 432-456.
  6. Wen, Z. et al. (1995) Cell 82, 241-250.

Application References

Have you published research involving the use of our products? If so we'd love to hear about it. Please let us know!

Companion Products


This product is intended for research purposes only. The product is not intended to be used for therapeutic or diagnostic purposes in humans or animals.

Products