Necessary for cellular interactions with laminin and the extracellular matrix. (Microbial infection) Receptor for the protective antigen (PA) of B.anthracis (PubMed:12700348, PubMed:15243628, PubMed:15326297). Binding of PA leads to heptamerization of the receptor-PA complex (PubMed:12700348, PubMed:15243628, PubMed:15326297). Upon binding of the PA of B.anthracis, the complex moves to glycosphingolipid-rich lipid rafts, where it is internalized via a clathrin-dependent pathway (PubMed:12551953, PubMed:15337774). In the endosomal membrane, at pH under 7, the complex then rearranges and forms a pore allowing the other components of anthrax toxin to escape to the cytoplasm (PubMed:12551953, PubMed:15337774). Binds laminin, and possibly also collagen type IV. (Microbial infection) Interacts (via VWFA domain) with the protective antigen (PA) of B.anthracis. Expressed at the cell surface. Expressed predominantly within the endoplasmic reticulum and not at the plasma membrane. Expressed in prostate, thymus, ovary, testis, pancreas, colon, heart, kidney, lung, liver, peripheral blood leukocytes, placenta, skeletal muscle, small intestine and spleen. The disease is caused by variants affecting the gene represented in this entry. May be produced at very low levels due to a premature stop codon in the mRNA, leading to nonsense-mediated mRNA decay. Belongs to the ATR family. Truncated N-terminus. Extended N-terminus.