A portion of amino acids 308-337 from the human protein was used as the immunogen for this EPR1 antibody.
Cellular receptors for blood proteases regulate chemotaxis, extracellular proteolysis, and growth behavior of normal and malignant cells. Effector cell protease receptor-1 (EPR1) is a receptor for the coagulation protease factor Xa. EPR1 is characterized by a cysteine-rich extracellular module, a single membrane-spanning domain, and a serine-rich cytoplasmic tail featuring at least 15 potential phosphorylation sites. EPR1 also contains 2 N-linked glycosylation sites, 4 O-linked glycosylation sites, and a chondroitin sulfate attachment site, which may provide anchoring for carbohydrate chains, EPR1 transfectants bind to factor Xa in a specific and saturable manner, and in the absence of factor V/Va promote prothrombin activation in a factor Xa concentration-dependent reaction. Activated platelets and megakaryocytes express EPR1. Both EPR1 and membrane-bound factor Va are thought to be required to mediate factor Xa binding to the activated platelet to form a functional prothrombinase complex.
