Endosialin/CD248: Proteins and Enzymes

Endosialin, also known as CD248 and tumor endothelial marker 1 (Tem1), is a 165 kDa transmembrane O-glycosylated protein that contains one C-type lectin, one Sushi, one EGF-like domain and a mucin-like stalk in its extracellular domain (ECD). It is expressed on activated perivascular and stromal cells in embyronic and tumor neovasculature but is downregulated in quiescent vasculature. Endosialin regulates pericyte proliferation, migration, and adhesion to matrix Fibronectin and Collagens I and IV. It is also required for lymph node and spleen remodeling during immune responses. Within the ECD, mouse Endosialin shares 76% and 93% aa sequence identity with human and rat Endosialin, respectively.