Matrilin-3

Matrilin-3 is a protein that in humans is encoded by the MATN3 gene. It is linked to the development of many types of cartilage, and part of the Matrilin family, which includes Matrilin-1, Matrilin-2, Matrilin-3, and Matrilin-4, a family of filamentous-forming adapter oligomeric extracellular proteins that are linked to the formation of cartilage and bone, as well as maintaining homeostasis after development. It is considered an extracellular matrix protein that functions as an adapter protein where the Matrilin-3 subunit can form both homo-tetramers and hetero-oligomers with subunits from Matrilin-1 which is the cartilage matrix protein. This restricted tissue has been strongly expressed in growing skeletal tissue as well as cartilage and bone.

Each member of the Matrilin family consist of one or two Von Willebrand Factor A (vWFA) domains, several epidermal growth factor (EGF)- like domains, and an alpha-helical coiled-coil domain. Matrilin-3 does not contain the second vWFA -like domain that is present in the rest of the members of the Matrilin family. It is considered the shortest and least complex member of the family, consisting of only one Von Willebrand Factor A domain, four epidermal growth factor domains, and a C-terminal coiled-coil domain. The Matrilin-3 protein is considered a multimeric protein that can form bonds to triple helix collagens, decorin and biglycan, as it plays an important role as a linker molecule in the formation of the articular cartilage network.