P46379

BAT3 (HLA-B associated transcript 3), also known as G3, scythe, BAG6 or D6S52E, is a proline-rich nuclear protein with an important role as an apoptotic regulator. BAT3 contains one ubiquitin-like domain at its N-terminus and two nuclear localization signals at its C-terminus. Specifically, BAT3 interacts with and stabilizes AIF (apoptosis inducing factor), thereby sensitizing the cell to apoptosis mediated by endoplasmic reticulum (ER) stress. Upon ricin treatment, BAT3 is cleaved by caspase-3 and its C-terminal fragment displays pro-apoptotic activities. The apoptotic activities executed include nuclear condensation, phosphatidlyserine externalization, cell rounding and shrinkage. Mice that are deficient in BAT3 exhibit pronounced defects in lung, brain and kidney development and in the regulation of proliferation and apoptosis. These defects ultimately result in perinatal or midgestational lethality.