YOUR CART
Signal transducers and activators of transcription (STAT) proteins are latent transcription factors that are activated by phosphorylation via tyrosine kinases. Over 35 different extracellular polypeptides activate Janus kinase associated receptors, leading to phosphorylation of Janus kinases and the subsequent phosphorylation of STAT proteins. Upon phosphorylation, the STAT proteins dimerize and migrate to the nucleus where they exert transcriptional activation. Phosphorylation of a single tyrosine localized around residue 700 is crucial for activation of each STAT family member. STAT1 is involved in the activation of IFNα and IFNγ genes, STAT2 in the activation of IFNα genes, STAT4 and STAT6 in T-helper cell development and STAT5 in milk production. Disruption of STAT functions in mouse leads to several defects such as immune deficiency (STAT1), embryonic lethality (STAT2), lack of gastrulation (STAT3), T-helper 1 cell dysfunction (STAT4), lack of lactation (STAT5A, 5B) and T-helper 2 cell dysfunction (STAT6). The disruption of STAT signaling blocks neoplastic transformation, thus making inhibitors of STAT proteins candidates for the treatment of cancer.
The FACE™ Method
In FACE, cells are cultured in 96-well plates and stimulated to induce the pathway of interest. Following stimulation, the cells are fixed rapidly, which preserves activation-specific protein modifications. Each well is then incubated with a primary antibody specific for the activated protein of interest. Subsequent incubation with secondary HRP-conjugated antibody and developing solution provides a colorimetric or chemiluminescent readout that is quantitative and reproducible (Figure 1). The number of cells in each well can be normalized easily with the provided Crystal Violet solution. FACE Kits also contain primary antibody specific for the native inactive protein, so you can monitor both native and activated protein levels in the same experiment. FACE eliminates cellular extractions, radioactive kinase assays, time-consuming Westerns and inefficient epitope interactions that occur on membranes. FACE is a highly sensitive high-throughput assay designed for detecting activated proteins within mammalian cells.
