Negatively regulates periodontal ligament (PDL) differentiation and mineralization to ensure that the PDL is not ossified and to maintain homeostasis of the tooth-supporting system. Inhibits BMP2-induced cytodifferentiation of PDL cells by preventing its binding to the BMP receptor-IB (BMPR-IB), resulting in inhibition of BMP-dependent activation of SMAD proteins (By similarity). Critical regulator of TGF-beta in articular cartilage and plays an essential role in cartilage homeostasis and osteoarthritis (OA) pathogenesis. Negatively regulates chondrogenesis in the articular cartilage by blocking the TGF-beta/receptor interaction on the cell surface and inhibiting the canonical TGF-beta/Smad signal. Binds calcium and plays a role in osteoblast-driven collagen biomineralization activity.
Interacts with TGFB1, TGFB2 and TGFB3. DCN, BGN, and FMOD inhibit binding to TGFB1. Interacts with BMP2. Interacts in vitro with type II collagen (By similarity). Interacts with type I collagen. DCN can inhibit collagen binding.