Figure 1

Extracellular matrix proteins and their interaction with each other and with cell surface matrix receptors. Decorin, fibromodulin, and types IX and XI collagen all interact with type II collagen and regulate collagen fiber assembly and structure. Types II and VI collagen bind matrix receptors (integrins). Type II collagen can also bind to anchorin CII, whereas fibronectin binds to integrins. A large proteoglycan aggregate forms when multiple aggrecan molecules bind to a long strand of hyaluronic acid, which, in turn, is anchored to the cell by CD44. Additional matrix proteins shown include thrombospondin and cartilage oligomeric protein (COMP).