Collagen of articular cartilage.
The extracellular framework and two-thirds of the dry mass of adult articular cartilage are polymeric collagen. Type II collagen is the principal molecular component in mammals, but collagens III, VI, IX, X, XI, XII and XIV all contribute to the mature matrix. In developing cartilage, the core fibrillar network is a cross-linked copolymer of collagens II, IX and XI. The functions of collagens IX and XI in this heteropolymer are not yet fully defined but, evidently, they are critically important since mutations in COLIX and COLXI genes result in chondrodysplasia phenotypes that feature precocious osteoarthritis. Collagens XII and XIV are thought also to be bound to fibril surfaces but not covalently attached. Collagen VI polymerizes into its own type of filamentous network that has multiple adhesion domains for cells and other matrix components. Collagen X is normally restricted to the thin layer of calcified cartilage that interfaces articular cartilage with bone.
Eyre
David
D
Orthopaedic Research Laboratories, Department of Orthopaedics and Sports Medicine, University of Washington, Seattle, Washington 98195-6500, USA. deyre@u.washington.edu
D002358:Cartilage, Articular / Q000378:metabolism* / Q000648:ultrastructure; D019902:Chondrocytes / Q000378:metabolism / Q000648:ultrastructure; D005109:Extracellular Matrix / Q000378:metabolism* / Q000648:ultrastructure; D024022:Fibrillar Collagens / Q000145:classification / Q000378:metabolism* / Q000648:ultrastructure; D010003:Osteoarthritis / Q000378:metabolism
D024022:Fibrillar Collagens