Merck, 05-495, Anti-phospho-STAT5A/B (Tyr694/699) Antibody, clone 8-5-2

General description
STAT (Signal Transducers and Activators of Transcription) are a family of conserved transcription factors that transduce high-fidelity signals for the cytokine family of ligands and receptors as the principle substrates of JAK kinases (1,2). In resting cells, the STATs exist in an inactive state in the cytoplasm until activated. Activators include cytokines, growth factors, and some peptides. These activate JAK kinases, which when activated, bind to the STAT SH2 (Src homology domain-2) domain resulting in phosphorylation of STAT (1). Upon activation, STAT1, -3, -4, -5A, and -5B all form homodimers. STAT1 and STAT2, as well as STAT1 and STAT3 form heterodimers, and several STATs form tetramers, depending on the variables of the activating ligand (1). After dimerization, the STATs accumulate in the nucleus by way of nuclear transport (1). STAT5A and STAT5B appear to be most important to the function of growth hormone and prolactin and play critical roles in milk production (1,2,3). The phosphorylation of Tyrosine 694/699 is a hallmark of activated STAT5.
STAT5A (94 kDa) and STAT5B (92 kDa)
Immunogen
Epitope: Tyr694/699
KLH-conjugated, synthetic phosphopeptide (KAVDG[pY]VKPQIK) corresponding to amino acids 689-700 of STAT5A and 694-705 of STAT5B. Clone 8-5-2.
Application
Anti-phospho-STAT5A/B (Tyr694/699) Antibody, clone 8-5-2 is a mouse monoclonal antibody for detection of phospho-STAT5A/B (Tyr694/699) also known as signal transducer & activator of transcription 5A/B & has been validated in WB.
Biochem/physiol Actions
Specific for the phosphorylated tyrosine residue 694 of STAT5A (94kDa) and 699 of STAT5B (92kDa). Unidentified proteins may be detected in some lysates.
Physical form
Format: Purified
Purified mouse monoclonal IgG in buffer containing PBS. Frozen solution at -20°C.
Analysis Note
Control
IFN-α induced HeLa cells or GM-CSF treated TF-1 cells
Routinely evaluated by Western Blot on 3T3/A31 cells stimulated with PDGF or HeLa cells stimulated with interferon-α.

Western Blot Analysis: 0.5-2 μg/mL of this lot detected phosphorylated STAT5A/B in lysates from 3T3/NIH cells stimulated with PDGF. 0.5-2 μg/mL of a previous lot detected phosphorylated STAT5A/B in lysates from 3T3/A31 cells stimulated with PDGF and from HeLa cells stimulated with interferon-a (IFN-a).
Other Notes
Concentration: Please refer to the Certificate of Analysis for the lot-specific concentration.
Legal Information
UPSTATE is a registered trademark of Merck KGaA, Darmstadt, Germany