Role of Runx Proteins in Chondrogenesis

The mammalian RUNX protein family comprises three transcription factors—RUNX1, RUNX2, and RUNX3. RUNX1 is involved in hematopoiesis, RUNX2 has multiple roles in osteogenesis and RUNX3 is associated with neural and gut development. In addition, all RUNX proteins are expressed during chondrogenesis, the process by which cartilage is formed. This review describes the involvement of Runx proteins in chondrogenesis, delineating their expression pattern and emphasizing their active roles in mesenchymal condensation, chondrocyte proliferation, and chondrocyte maturation. It also highlights how Runx proteins regulate transcription of target genes and how Runx proteins are regulated in the cartilaginous skeleton.