- Cell adhesion molecule
These proteins are typically transmembrane receptors and are composed of three domains: an intracellular domain that interacts with the cytoskeleton, a transmembrane domain, and an extracellular domain that interacts either with other CAMs of the same kind (homophilic binding) or with other CAMs or the extracellular matrix (heterophilic binding).
Families of CAMs
One classification system involves the distinction between calcium-independent CAMs and calcium-dependent CAMs.
Immunoglobulin superfamily CAMs (IgSF CAMs) are either or heterophilic and bind integrins or different IgSF CAMs.
The Integrins are a family of heterophilic CAMs that bind IgSF CAMs or the extracellular matrix. They are heterodimers, called alpha and beta. Eighteen different alpha subunits that combine with 8 different beta subunits to form twenty-four known integrins; however not all combinations are observed.
The selectins are a family of heterophilic CAMs that bind fucosylated carbohydrates, e.g., mucins. The three family members are E-selectin (endothelial), L-selectin (leukocyte), and P-selectin (platelet). The best-characterized ligand for the three selectins is P-selectin glycoprotein ligand-1 (PSGL-1), which is a mucin-type glycoprotein expressed on all white blood cells.
- ^ MeSH Cell+Adhesion+Molecules
- ^ Brackenbury R, Rutishauser U, Edelman GM (January 1981). "Distinct calcium-independent and calcium-dependent adhesion systems of chicken embryo cells". Proc. Natl. Acad. Sci. U.S.A. 78 (1): 387–91. doi:10.1073/pnas.78.1.387. PMC 319058. PMID 6165990. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=319058.
Calcium-independentIgSF CAM Calcium-dependentClassicalUnconventional/ungrouped Other
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