Anti-Bacillus anthracis (Anthrax) Toxin Receptor (ATR, TEM8, Tumor Endothelial Marker 8)

The Anthrax toxin receptor (ATR) was initially discovered as the tumor endothelial marker 8 (TEM8) (1). This protein, which exists in three isoforms (36, 40, and 60kD), is highly expressed in tumor vessels as well as in the vasculature of developing embryos, suggesting that it may normally play a role in angiogenesis. However, it also acts as the receptor for anthrax toxin (2). Following the binding of this protein by the protective antigen (PA) of anthrax, PA is cleaved and heptamerizes to form the binding site for both edema factor (EF) and lethal factor (LF) (3). This complex is then endocytosed by the cell, acidification in endosomes allows the release of EF and LF into the cytoplasm where they interfere with MAPK signaling and induce apoptosis (4). Applications: Can be used for detection of ATR by Western blot at 0.5 to 1ug/ml. Storage and Stability: May be stored at 4°C for short-term only. For long-term storage and to avoid repeated freezing and thawing, aliquot and add glycerol (40-50%). Store at -20°C or colder. Aliquots are stable for at least 12 months at -20°C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.