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Santa Cruz discontinued a large number of its polyclonal products as a result of the USDA settlement that was made public May 19th 2016

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Specificity / Sensitivity

Phospho-Stat3 (Tyr705) (D3A7) XP® Rabbit mAb detects endogenous levels of Stat3 only when phosphorylated at tyrosine 705. This antibody does not cross-react with phospho-EGFR or the corresponding phospho-tyrosines of other Stat proteins. Stat3 (124H6) Mouse mAb detects endogenous levels of total Stat3 protein.

Source / Purification

Monoclonal antibodies are produced by immunizing animals with either a synthetic phosphopeptide corresponding to residues surrounding Tyr705 of mouse Stat3 or with a synthetic peptide corresponding to the sequence of mouse Stat3.

The Stat3 transcription factor is an important signaling molecule for many cytokines and growth factor receptors (1) and is required for murine fetal development (2). Research studies have shown that Stat3 is constitutively activated in a number of human tumors (3,4) and possesses oncogenic potential (5) and anti-apoptotic activities (3). Stat3 is activated by phosphorylation at Tyr705, which induces dimerization, nuclear translocation, and DNA binding (6,7). Transcriptional activation seems to be regulated by phosphorylation at Ser727 through the MAPK or mTOR pathways (8,9). Stat3 isoform expression appears to reflect biological function as the relative expression levels of Stat3α (86 kDa) and Stat3β (79 kDa) depend on cell type, ligand exposure, or cell maturation stage (10). It is notable that Stat3β lacks the serine phosphorylation site within the carboxy-terminal transcriptional activation domain (8).

1.  Heim, M.H. (1999) J Recept Signal Transduct Res 19, 75-120.

2.  Takeda, K. et al. (1997) Proc Natl Acad Sci U S A 94, 3801-4.

3.  Catlett-Falcone, R. et al. (1999) Immunity 10, 105-15.

4.  Garcia, R. and Jove, R. (1998) J Biomed Sci 5, 79-85.

5.  Bromberg, J.F. et al. (1999) Cell 98, 295-303.

6.  Darnell, J.E. et al. (1994) Science 264, 1415-21.

7.  Ihle, J.N. (1995) Nature 377, 591-4.

8.  Wen, Z. et al. (1995) Cell 82, 241-50.

9.  Yokogami, K. et al. (2000) Curr Biol 10, 47-50.

10.  Biethahn, S. et al. (1999) Exp Hematol 27, 885-94.

Entrez-Gene Id 6774
Swiss-Prot Acc. P40763

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PhosphoPlus® Stat3 (Tyr705) Antibody Kit