title: Proteoglycans of the extracellular environment: clues from the gene and protein side offer novel perspectives in molecular diversity and function.
abstract: This review focuses on the extracellular proteoglycans. Special emphasis is placed on the structural features of their protein cores, their gene organization, and their transcriptional control. A simplified nomenclature comprising two broad groups of extracellular proteoglycans is offered: the small leucine-rich proteoglycans or SLRPs, pronounced "slurps, " and the modular proteoglycans. The first group encompasses at least five distinct members of a gene family characterized by a central domain composed of leucine-rich repeats flanked by two cysteine-rich regions. The second group consists of those proteoglycans whose unifying feature is the assembly of various protein modules in a relatively elongated and often highly glycosylated structure. This group is quite heterogeneous and includes a distinct family of proteoglycans, the "hyalectans," that bind hyaluronan and contain a C-type lectin motif that is likely to bind carbohydrates, and a less distinct group that contains structural homologies but lacks hyaluronan-binding properties or lectin-like domains.
authors.affiliation: Department of Pathology, Anatomy, and Cell Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA.
authors.forename: R V
authors.initials: RV
authors.lastname: Iozzo
authors.forename: A D
authors.initials: AD
authors.lastname: Murdoch
mesh_terms: D000818:Animals; D050260:Carbohydrate Metabolism; D006133:Growth Substances / Q000378:metabolism; D006801:Humans; D006820:Hyaluronic Acid / Q000378:metabolism; D011506:Proteins / Q000378:metabolism; D011509:Proteoglycans / Q000737:chemistry / Q000235:genetics / Q000502:physiology; D009626:Terminology as Topic
chemical_list: D006133:Growth Substances; D011506:Proteins; D011509:Proteoglycans; D006820:Hyaluronic Acid