What is PECAM1?
Platelet endothelial cell adhesion molecule (PECAM-1), also known as CD31 antigen,
It is a type I transmembrane glycoprotein, belonging to the immunoglobulin superfamily. It was first proposed by Newman et al in 1990. At the 2015 ASCO meeting, Michael j. Birrer, MD team, in conjunction with their study, presented CD31 as a potential marker for the efficacy of bevacizumab in ovarian cancer.
The Structure of PECAM1
CD31, encoded by 75kb gene located at the end of the long arm of chromosome 17, is a type I transmembrane glycoprotein with relative molecular weight of 130kDa. The protein varies slightly in different cell types due to glycosylation.
Human CD31 protein contains three domains: extracellular domain, transmembrane domain and intracellular domain. Among them, extracellular domain and intracellular domain are the main functional areas.
Extracellular domain: the extracellular domain of CD31 consists of 574 amino acids. Except for the signal peptide, the remaining amino acids form a homologous region composed of 6 immunoglobulin subunits, each of which contains about 100 amino acid residues.
The transmembrane domain contains 19 hydrophobic amino acids.
Intracellular domain: the intracellular domain contains 118 amino acids. The structure of the cytoplasmic domain was determined by two-dimensional nuclear magnetic resonance, and is characterized by two lipid-associated regions separated by a large unstructured region. The domain consists of 8 exons.
The intracellular domain of CD31 contains two immune receptor tyrosine inhibitory motifs (ITIM), which has a specific SHP-2 mooring site. The combination of SHP-2 and phosphorylated tyrosine triggers feedback inhibitory signal transduction, which has a variety of physiological effects.
The Expression of PECAM1
PECAM1 is mainly expressed on the surface of vascular endothelial cells, circulating platelets, macrophages, kuffer cells, granulocytes, T/NK cells, lymphocytes, megakaryocytes, osteoclasts, neutrophils and monocytes.
CD31 in circulating platelets and leukocytes restricts cell activation by regulating the phosphorylation order of their intracellular domains and usually acts as an inhibitory receptor. CD31 expressed between endothelial cells acts as a mechanical sensor, which regulates leukocyte transport and maintains the integrity of endothelial cell connections.
CD31 expressed between endothelial cells acts as a mechanical sensor, which regulates leukocyte transport and maintains the integrity of endothelial cell connections.
In addition, the expression of CD31 was also found in some tumors, such as epithelioid hemangioendothelioma, epithelioid sarcomatoid hemangioendothelioma, histiocytic malignant tumor and plasma cells.
The Function of PECAM1
The main functions of CD31 include leukocyte migration, angiogenesis and integrin activation. Most of its functions can be attributed to the interaction between homophile CD31-CD31.
CD31 can promote the binding of various leukocyte-associated integrins to ICAM/VCAM IgSF members and help peripheral blood leukocytes cross the endothelial barrier. CD31 plays a key role in clearing aging neutrophils in the body. In addition, the expression of CD31 is up-regulated by LPS stimulation, which may be a feedback negative regulator of macrophage LPS inflammatory response.
CD31 can be expressed in all leukocytes, including T cells, B cells and dendritic cells. The complex biological function of CD31 is mainly due to the integration of its adhesion and signal transduction functions in immune and vascular systems. Abnormal expression of CD31 can lead to a variety of diseases, such as atherosclerosis, inflammation and hematological diseases.
Latest Research Progress
PECAM-1 plays an important role in promoting the occurrence and development of endothelial cell inflammation in the context of disturbed flow. However, the mechanism of controlling the stability of PECAM-1 protein is still unclear.
A recent study identified PECAM-1 as a new substrate of APC/Cdh1 E3 ubiquitin ligase. Lentivirus-mediated Cdh1 depletion stabilizes PECAM-1 in endothelial cells. The overexpression of Cdh1 destroys the stability of PECAM-1.
This study reveals a new mechanism that the fluid flow pattern regulates the dynamic balance of endothelial cells through Cdh1-dependent ubiquitination and subsequent PECAM-1 degradation.
More Interesting read related CD31>>
CD31 Monoclonal Antibody (ELISA, WB, IHC, IF, FC) (CSB-MA017767A0m)
Positive WB detected in: Jurkat whole cell lysate, THP-1 whole cell lysate, Raji whole cell lysate
IHC image of CSB-MA017767A0m diluted at 1:100 and staining in paraffin-embedded human breast cancer performed on a Leica BondTM system.
Immunofluorescence staining of Hela cells with CD31 antibody at 1:100, counter-stained with DAPI.
Overlay histogram showing THP-1 cells stained with CD31 antibody (red line) at 1:250.
The following PECAM1 reagents supplied by CUSABIO are manufactured under a strict quality control system. Multiple applications have been validated and solid technical support is offered.