Phospho-ATF2 (Thr71) cellular kit

Mouse NIH3T3 cells were seeded at different cell densities in 96-well microplates, then stimulated with increasing concentrations of anisomycin for 30 minutes. Following the 2-plate assay protocol, 16 µL of lysate were transferred into a 384-well low volume white microplate before the addition of 4 µL of the HTRF phospho-ATF2 (Thr71) detection reagents. The HTRF signal was recorded after an overnight incubation.

Human HEK293A suspension cells were seeded at 100,000 cells/well in a 96 well half area plate, and incubated for 24h at 37°C, 5% CO2. Then cells were stimulated with different concentrations of anisomycin for 15, 30 & 60 minutes. After lysis, 16 µL of lysate were transferred into a 384-well low volume white microplate and 4 µL of the HTRF phospho-ATF2 (Thr71) detection reagents were added. The HTRF signal was recorded after an overnight incubation.

The human NIH3T3 cell line was seeded in a T175 flask and incubated a 37°C, 5% CO2 until confluency.

Serial dilutions of the cell lysate were performed in the supplemented lysis buffer, and 16 µL of each dilution were transferred into a low volume white microplate before the addition of 4 µL of HTRF phospho-ATF2 detection reagents. Equal amounts of lysates were used for a side by side comparison between HTRF and Western Blot.

Using the HTRF Phospho-ATF2 T71 assay, 3,000 cells/well were sufficient to detect a signal while 6,125 cells were needed using Western Blot with an ECL detection. These results demonstrate that the HTRF phospho-ATF2 assay is 2 times more sensitive than the Western Blot.

In response to cellular stress, such as exposure to genotoxic agents, cytokines, or UV irradiation, SAPK/JNK and p38 MAP kinases are activated and phosphorylate the transcription factor ATF-2 on residues Thr69 and Thr71. Once in the nucleus, phospho-ATF2 binds to cAMP response element (CRE) or to Activator Protein-1 (AP-1) response elements, and regulates the transcription of genes involved in cell growth, survival, and DNA damage response.