Phospho-Stat5 (Tyr694) rabbit mAb Antibody

Stat5 activation occurs in response to many ligands including prolactin, IL-2, growth hormone, and GM-CSF. Tyr694 phosphorylation is obligatory activation of Stat5 (1,2), and is mediated by Src upon erythropoietin stimulation (3) . Phospho Stat5 is constitutively active in some leukemic cell types (4), and phospho Stat5 is found in some endothelial cells when treated with IL-3, suggesting its involvement in cell motility and angiogenesis (5) . Stat5 has been shown to be encoded by two separate genes, Stat5a and Stat5b, which share over 90% amino acid sequence identity. In different cell types, Stat5a and Stat5b are independently regulated and activated. For example, interferon treatment predominantly activates Stat5a in U937 cells and Stat5b in HeLa cells (6) .