Cadherin-5, or VE-cadherin (vascular endothelial cadherin), also known as CD144 (Cluster of Differentiation 144), is a type of cadherin. It is encoded by the human gene CDH5. [5]
VE-cadherin is a classical cadherin from the cadherin superfamily and the gene is located in a six-cadherin cluster in a region on the long arm of chromosome 16 that is involved in loss of heterozygosity events in breast and prostate cancer. The encoded protein is a calcium-dependent cell–cell adhesion glycoprotein composed of five extracellular cadherin repeats, a transmembrane region and a highly conserved cytoplasmic tail. Functioning as a classic cadherin by imparting to cells the ability to adhere in a homophilic manner, the protein may play an important role in endothelial cell biology through control of the cohesion and organization of the intercellular junctions. [6]
Integrity of intercellular junctions is a major determinant of permeability of the endothelium, and the VE-cadherin-based adherens junction is thought to be particularly important. VE-cadherin is known to be required for maintaining a restrictive endothelial barrier – early studies using blocking antibodies to VE-cadherin increased monolayer permeability in cultured cells [7] and resulted in interstitial edema and hemorrhage in vivo. [8] A recent study has shown that TNFAIP3 (A20, a dual-ubiquitin editing enzyme) is essential for stability and expression of VE-cadherin. Deubiquitinase function of A20 was shown to remove ubiquitin chains from VE-cadherin, thereby prevented loss of VE-cadherin expression at the endothelial adherens junctions. [9]
VE-cadherin is indispensable for proper vascular development – there have been two transgenic mouse models of VE-cadherin deficiency, both embryonic lethal due to vascular defects. [10] [11] Further studies using one of these models revealed that although vasculogenesis occurred, nascent vessels collapsed or disassembled in the absence of VE-cadherin. [12] Therefore, it was concluded that VE-cadherin serves the purpose of maintaining newly formed vessels.
VE-cadherin has been shown to interact with:
VE-cadherin may serve as a biomarker for radiation exposure. [20]
Cell adhesion is the process by which cells interact and attach to neighbouring cells through specialised molecules of the cell surface. This process can occur either through direct contact between cell surfaces such as cell junctions or indirect interaction, where cells attach to surrounding extracellular matrix, a gel-like structure containing molecules released by cells into spaces between them. Cells adhesion occurs from the interactions between cell-adhesion molecules (CAMs), transmembrane proteins located on the cell surface. Cell adhesion links cells in different ways and can be involved in signal transduction for cells to detect and respond to changes in the surroundings. Other cellular processes regulated by cell adhesion include cell migration and tissue development in multicellular organisms. Alterations in cell adhesion can disrupt important cellular processes and lead to a variety of diseases, including cancer and arthritis. Cell adhesion is also essential for infectious organisms, such as bacteria or viruses, to cause diseases.
Cadherins (named for "calcium-dependent adhesion") are cell adhesion molecules important in forming adherens junctions that let cells adhere to each other. Cadherins are a class of type-1 transmembrane proteins, and they depend on calcium (Ca2+) ions to function, hence their name. Cell-cell adhesion is mediated by extracellular cadherin domains, whereas the intracellular cytoplasmic tail associates with numerous adaptors and signaling proteins, collectively referred to as the cadherin adhesome.
Cell junctions or junctional complexes, are a class of cellular structures consisting of multiprotein complexes that provide contact or adhesion between neighboring cells or between a cell and the extracellular matrix in animals. They also maintain the paracellular barrier of epithelia and control paracellular transport. Cell junctions are especially abundant in epithelial tissues. Combined with cell adhesion molecules and extracellular matrix, cell junctions help hold animal cells together.
Catenins are a family of proteins found in complexes with cadherin cell adhesion molecules of animal cells. The first two catenins that were identified became known as α-catenin and β-catenin. α-Catenin can bind to β-catenin and can also bind filamentous actin (F-actin). β-Catenin binds directly to the cytoplasmic tail of classical cadherins. Additional catenins such as γ-catenin and δ-catenin have been identified. The name "catenin" was originally selected because it was suspected that catenins might link cadherins to the cytoskeleton.
Plakoglobin, also known as junction plakoglobin or gamma-catenin, is a protein that in humans is encoded by the JUP gene. Plakoglobin is a member of the catenin protein family and homologous to β-catenin. Plakoglobin is a cytoplasmic component of desmosomes and adherens junctions structures located within intercalated discs of cardiac muscle that function to anchor sarcomeres and join adjacent cells in cardiac muscle. Mutations in plakoglobin are associated with arrhythmogenic right ventricular dysplasia.
α-Catenin (alpha-catenin) functions as the primary protein link between cadherins and the actin cytoskeleton. It has been reported that the actin binding proteins vinculin and α-actinin can bind to alpha-catenin. It has been suggested that alpha-catenin does not bind with high affinity to both actin filaments and the E-cadherin-beta-catenin complex at the same time. It has been observed that when α-catenin is not in a molecular complex with β-catenin, it dimerizes and functions to regulate actin filament assembly, possibly by competing with Arp2/3 protein. α-Catenin exhibits significant protein dynamics. However, a protein complex including a cadherin, actin, β-catenin and α-catenin has not been isolated.
Kinase insert domain receptor also known as vascular endothelial growth factor receptor 2 (VEGFR-2) is a VEGF receptor. KDR is the human gene encoding it. KDR has also been designated as CD309. KDR is also known as Flk1.
Cadherin-2 also known as Neural cadherin (N-cadherin), is a protein that in humans is encoded by the CDH2 gene. CDH2 has also been designated as CD325 . Cadherin-2 is a transmembrane protein expressed in multiple tissues and functions to mediate cell–cell adhesion. In cardiac muscle, Cadherin-2 is an integral component in adherens junctions residing at intercalated discs, which function to mechanically and electrically couple adjacent cardiomyocytes. Alterations in expression and integrity of Cadherin-2 has been observed in various forms of disease, including human dilated cardiomyopathy. Variants in CDH2 have also been identified to cause a syndromic neurodevelopmental disorder.
p120 catenin, or simply p120, also called catenin delta-1, is a protein that in humans is encoded by the CTNND1 gene.
Junctional adhesion molecule A is a protein that in humans is encoded by the F11R gene. It has also been designated as CD321.
Cadherin-3, also known as P-Cadherin, is a protein that in humans is encoded by the CDH3 gene.
Homeobox protein Hox-A5 is a protein that in humans is encoded by the HOXA5 gene.
Receptor-type tyrosine-protein phosphatase beta or VE-PTP is an enzyme specifically expressed in endothelial cells that in humans is encoded by the PTPRB gene.
Receptor-type tyrosine-protein phosphatase mu is an enzyme that in humans is encoded by the PTPRM gene.
Membrane-associated guanylate kinase, WW and PDZ domain-containing protein 1 is an enzyme that in humans is encoded by the MAGI1 gene.
Serine/threonine-protein kinase SMG1 is an enzyme that in humans is encoded by the SMG1 gene. SMG1 belongs to the phosphatidylinositol 3-kinase-related kinase protein family.
Protocadherin-12 is a protein that in humans is encoded by the PCDH12 gene.
Cadherin-1 or Epithelial cadherin(E-cadherin), is a protein that in humans is encoded by the CDH1 gene. Mutations are correlated with gastric, breast, colorectal, thyroid, and ovarian cancers. CDH1 has also been designated as CD324. It is a tumor suppressor gene.
αE-catenin, also known as Catenin alpha-1 is a protein that in humans is encoded by the CTNNA1 gene. αE-catenin is highly expressed in cardiac muscle and localizes to adherens junctions at intercalated disc structures where it functions to mediate the anchorage of actin filaments to the sarcolemma. αE-catenin also plays a role in tumor metastasis and skin cell function.
Elisabetta Dejana is an Italian cell biologist and an expert on regulation of vascular system development. She has published widely and is frequently cited for her work. She has received several important awards. Dejana is a full professor at the University of Milan and has also been appointed full professor at the Department of Immunology, Genetics and Pathology at Uppsala University in Sweden.
This article incorporates text from the United States National Library of Medicine, which is in the public domain.