The 43A3 antibody reacts with CD105 (endoglin), an ~180 kDa cell surface glycoprotein which is a disulfide-bonded homodimer of ~90 kDa type I transmembrane subunits. CD105 is a component of the TGF-β receptor complex and is expressed by vascular endothelial smooth muscle cells, syncytiotrophoblasts of placenta and activated macrophages, and at relatively low levels by stromal fibroblasts. Its expression is also observed in some types of tumors, and levels are up-regulated on the endothelium during angiogenesis. In concert with signaling receptors, CD105 binds to TGF-β1 and TGF-β3 with high affinity, but does not bind TGF-β2. Other ligands reportedly include Activin A, BMP-2, and BMP-7. CD105 has important roles in angiogenesis, cardiovascular development, and vascular remodeling, and the protein serves a regulatory role in cytoskeletal reorganization by modulating the sites of focal adhesion and cellular migration. Certain mutations in CD105 result in the autosomal dominant disorder hereditary hemorrhagic telangiectasia.

This antibody clone has been verified for labeling human mesenchymal cells grown in MesenCult™ Proliferation Kit (Human; Catalog #05411) and MesenCult™-XF Medium