Recombinant Mouse Thrombopoietin R Fc Chimera Protein, CF

Thrombopoietin receptor (Tpo R), also known as myeloproliferative leukemia protein (c-mpl), is a type I membrane protein that is a member of the hematopoietin/cytokine receptor superfamily. Thrombopoietin (Tpo) is a key regulator of megakaryocytopoiesis and thrombopoiesis in vitro and in vivo. Receptor dimerization occurs upon ligand binding. Downstream signaling cascades utilize the Ras/MAP and JAK/STAT pathways (1). In humans, variations at the 3’ end on the molecule result in the formation of 3 distinct mRNA species, a P-form, a K-form, and a potentially secreted form. The predominant form in humans is the P-form, which encodes a full length receptor. In mouse, mRNA for a full length form, a potentially secreted form, and a form lacking 8 amino acids in the extra-cytoplasmic domain has been detected (2). The human and mouse receptors share approximately 81% amino acid identity. Tpo R is expressed at low levels in various cell types including hematopoietic progenitor cells, megakaryocytes and platelets.