R&D Systems now offers an anti-human Phospho-STAT3 (S727) polyclonal antibody (Catalog # AF4934 ). Signal transducer and activator of transcription 3 (STAT3) is a member of the STAT family of transcription factors. It is phosphorylated at serine 727 (S727) following the activation of several kinases including mTor, PKC, and MAPK. In contrast to STAT3 phosphorylation at tyrosine 705, which mediates homodimerization and heterodimerization with STAT1, S727 phosphorylation promotes interactions with Pin1 and p300. <table border="0" cellspacing="1" cellpadding="3" style="border: solid thin #0f4b8c;"> <tr> <td><img src="/f_img/RSD/6257.jpg"></td> </tr> <tr> <td style="font-family:verdana;font-size:12px">Detection of Phosphorylated STAT3 (S727) by Western Blot. A. Whole cell extracts from exponentially growing HepG2 human liver cells, untreated (-) or treated with IL-6 (+), were immunoblotted using anti-human Phospho-STAT3 (S727) polyclonal antibody (Catalog # AF4934). B. A blot using the same lysates was probed using a total anti-human STAT3 monoclonal antibody (Catalog # MAB1799). </td> </tr> </table>