Anti-Human Bit1 (Intermediate Domain) (B461-GRP)

Adhesion to extracellular matrix regulates cell survival through both integrin engagement and appropriate cell spreading. Anoikis is the molecular mechanism of apop-tosis induced by integrin detachment.1 Bit1 (Bcl-2 inhibitor of transcription 1) was recently identified as being involved in this process.2 Bit1 is a mitochondrial protein that is released into the cytoplasm upon onset of apoptosis where it forms a complex with AES, a small Groucho/transducin-like enhancer of split (TLE) protein and induces caspase-independent apoptosis. Both AES and TLE proteins are transcriptional co-repressors that play important roles in neurogenesis, segmentation, and sex determination.3 It has been suggested that Bit1-AES complexes turn off a survival-promoting gene transcription program controlled by TLE.2 Interestingly, apoptosis of cells transfected with Bit1 and AES could be inhibited if the cells were allowed to attach to fibronectin through the α5β1 integrin suggesting that the Bit1-AES pathway contributing to anoikis is regulated by integrins, and in particular, the α5β1 integrin.2