Growth Differentiation Factor 5 (GDF-5)

GDF-5 belongs to TGFβ superfamily. GDF-5 is essential for cartilage development and homeostasis, and GDF-5 deficiency is associated with osteoarthritis (OA). Specifically, GDF-5 has high binding affinity to BMPR-IB, BMPR-II and Activin type II receptors. Upon binding to the receptors, the signalling cascade of GDF-5 activates the downstream Smad pathway. The phosphorylated Smad 1/5/8 then forms the complex with Smad 4 and translocates into the nucleus, thereby regulating cellular processes, such as proliferation, differentiation and synthesis of the ECM^[1]. GDF-5 can modulate the initial stages of chondrogenesis (the mesenchymal condensations by increasing cell adhesion), or increase chondrocyte proliferation during skeletal development^[2]. Human GDF-5 shares about 91% aa sequence identity with mouse.

References: