Proteoglycans and dental biology: the first review.

Proteoglycans (PGs) are proteins which are vital components located in the extracellular matrix, cell surface or intracellular granules. They are linked to polysaccharides called glycosaminoglycans. There are several aspects associated with PGs, such as cell signaling and organization of the extracellular matrix (ECM), making them pivotal participants in many tissue compositions.