Junctional Adhesion Molecule C (JAM-C) Antibody – Mouse Monoclonal

Tight junctions represent one mode of cell-to-cell adhesion in epithelial or endothelial cell sheets, forming continuous seals around cells and serving as a physical barrier to prevent solutes and water from passing freely through the paracellular space. The protein encoded by this immunoglobulin superfamily gene member is localized in the tight junctions between high endothelial cells. Unlike other proteins in this family, the this protein is unable to adhere to leukocyte cell lines and only forms weak homotypic interactions. The encoded protein is a member of the junctional adhesion molecule protein family and acts as a receptor for another member of this family. A mutation in an intron of this gene is associated with hemorrhagic destruction of the brain, subependymal calcification, and congenital cataracts. Alternative splicing results in multiple transcript variants.[provided by RefSeq, Apr 2011]

Function: Participates in cell-cell adhesion. It is a counter-receptor for ITGAM, mediating leukocyte-platelet interactions and is involved in the regulation of transepithelial migration of polymorphonuclear neutrophils (PMN). The soluble form is a mediator of angiogenesis. Ref.3 Ref.12 Ref.16

Subunit structure: Interacts with JAM2. Interacts with ITGAM. Ref.1 Ref.3 Ref.12

Subcellular location: Cell membrane; Single-pass type I membrane protein

Potential. Cell junction › desmosome. Secreted › extracellular space. Note: In epithelial cells, it is expressed at desmosomes but not at tight junctions. Localizes at the cell surface of endothelial cells; treatment of endothelial cells with vascular endothelial growth factor stimulates recruitment of JAM3 to cell-cell contacts. Ref.12 Ref.13 Ref.16

Tissue specificity: Highest expression in placenta, brain and kidney. Significant expression is detected on platelets. Expressed in intestinal mucosa cells. Expressed in the vascular endothelium. Found in serum (at protein level). Also detected in the synovial fluid of patients with rheumatoid arthritis, psoriatic arthritis or ostearthritis (at protein level). Ref.1 Ref.3 Ref.4 Ref.12 Ref.13 Ref.16

Post-translational modification: Proteolytically cleaved from endothelial cells surface into a soluble form by ADAM10 and ADAM17; the release of soluble JAM3 is increased by proinflammatory factors. Ref.16

Involvement in disease: Hemorrhagic destruction of the brain with subependymal calcification and cataracts (HDBSCC) [MIM:613730]: A syndrome characterized by congenital cataracts and severe brain abnormalities apparently resulting from hemorrhagic destruction of the brain parenchyma, including the cerebral white matter and basal ganglia. Patients manifest profound developmental delay, and other neurologic features included seizures, spasticity, and hyperreflexia. The clinical course is very severe resulting in death in infancy. Brain imaging shows multifocal intraparenchymal hemorrhage with associated liquefaction and massive cystic degeneration, and calcification in the subependymal region and in brain tissue.Note: The disease is caused by mutations affecting the gene represented in this entry. Ref.15 Ref.18

Sequence similarities: Belongs to the immunoglobulin superfamily.Contains 1 Ig-like C2-type (immunoglobulin-like) domain.Contains 1 Ig-like V-type (immunoglobulin-like) domain.

Sequence caution: The sequence CAC94776.1 differs from that shown. Reason: Erroneous initiation.