C-type lectin-like domain (CTLD) of the type found in human thrombomodulin(TM), Endosialin, C14orf27, and C1qR
CLECT_thrombomodulin_like: C-type lectin-like domain (CTLD) of the type found in human thrombomodulin(TM), Endosialin, C14orf27, and C1qR. CTLD refers to a domain homologous to the carbohydrate-recognition domains (CRDs) of the C-type lectins. In these thrombomodulin-like proteins the residues involved in coordinating Ca2+ in the classical MBP-A CTLD are not conserved. TM exerts anti-fibrinolytic and anti-inflammatory activity. TM also regulates blood coagulation in the anticoagulant protein C pathway. In this pathway, the procoagulant properties of thrombin (T) are lost when it binds TM. TM also plays a key role in tumor biology. It is expressed on endothelial cells and on several type of tumor cell including squamous cell carcinoma. Loss of TM expression correlates with advanced stage and poor prognosis. Loss of function of TM function may be associated with arterial or venous thrombosis and with late fetal loss. Soluble molecules of TM retaining the CTLD are detected in human plasma and urine where higher levels indicate injury and/or enhanced turnover of the endothelium. C1qR is expressed on endothelial cells and stem cells. It is also expressed on monocots and neutrophils, where it is subject to ectodomain shedding. Soluble forms of C1qR retaining the CTLD is detected in human plasma. C1qR modulates the phagocytosis of apoptotic cells in vivo. C1qR-deficient mice are defective in clearance of apoptotic cells in vivo. The cytoplasmic tail of C1qR, C-terminal to the CTLD of CD93, contains a PDZ binding domain which interacts with the PDZ domain-containing adaptor protein, GIPC. The juxtamembrane region of this tail interacts with the ezrin/radixin/moesin family. Endosialin functions in the growth and progression of abdominal tumors and is expressed in the stroma of several tumors.