详细描述：
Endoglin, also known as CD105, is a Type I integral membrane glycoprotein with a large, disulfide-linked, extracellular region and a short, constitutively phosphorylated, cytoplasmic tail. Two splice variants of human endoglin, the S-endoglin and L-endoglin that differ in the length of their cytoplasmic tails have been identified. Endoglin is highly expressed on vascular endothelial cells, chondrocytes, and syncytiotrophoblasts of term placenta. It is also found on activated monocytes, bone marrow pro-erythroblasts, and leukemic cells of lymphoid and myeloid lineages. Human and mouse endoglin share approximately 70% and 97% amino acid sequence identity in their extracellular and intracellular domains, respectively. Endoglin is an accessory receptor for the TGF-( superfamily ligands. It binds TGF-( 1 and TGF-( 3 but not TGF-( 2 efficiently by associating with TGF-( type II receptor (T(RII). It interacts with Activin-A, BMP-2 and BMP-7 using either the activin type II or type IIB receptors. In the case of BMP-2 which binds directly to the type I but not the type II BMP receptor, endoglin binds via either BMPR-IA (ALK-3) or BMPR-1B (ALK-6). Although the consequence of endoglin interactions on the functions of TGF-( family ligands is poorly understood, endoglin has clearly been shown to be required for angiogenesis and to play a key role in heart development. Mutations in human endoglin or ALK-1 (another type I serine/threonine receptor) lead to the vascular disorder hereditary hemorrhagic telangiectasia (HHT). Mice heterozygous for endoglin have been developed as disease models for HHT. Endoglin has been shown to be a powerful marker of neovascularization. It is also useful as a functional marker that defines long-term repopulating hematopoietic stem cells. Human Endoglin is a disulfide-linked homodimeric protein. Based on Nterminal sequence analysis, the primary structure of recombinant mature Endoglin starts at Glu
26. |Human recombinant CD105 extracellular domain produced in E. coli is a single, glycosylated polypeptide of 151 amino acids (26-176) having a molecular mass of 43 kDa.
