RUNX2 Gene: Function, Mutations, and Associated Diseases | Biomedical SEO

RUNX2 (Runt-related transcription factor 2) is a master regulator of osteoblast differentiation and skeletal morphogenesis. It belongs to the RUNX family of transcription factors, characterized by a conserved runt domain that mediates DNA binding and heterodimerization with CBFB. RUNX2 controls the expression of multiple bone-specific genes, including osteocalcin, collagen type I, and alkaline phosphatase. It is essential for osteoblast maturation, chondrocyte hypertrophy, and bone mineralization. Mutations in RUNX2 cause cleidocranial dysplasia (CCD), a rare autosomal dominant disorder. Additionally, RUNX2 is implicated in cancer progression, particularly in breast, prostate, and lung cancers, where it promotes metastasis and tumor growth.

Tissue Expression

Cell Line Expression

Hotspot Mutations

Mutation functional classification

• Osteoblast differentiation pathway

• Wnt signaling pathway

• TGF-beta signaling pathway

• BMP signaling pathway

• PTH signaling pathway

RUNX2 is a 521-amino acid transcription factor with a conserved Runt domain (amino acids 103-204) that binds to the consensus sequence 5'-PYGPYGGT-3' on DNA. It heterodimerizes with CBFB, which enhances DNA binding affinity. The protein contains a nuclear localization signal, a proline/serine/threonine-rich region, and a C-terminal transcriptional activation domain. RUNX2 regulates target genes involved in osteoblast maturation, including SP7 (Osterix), COL1A1, SPP1 (Osteopontin), and BGLAP (Osteocalcin). Post-translational modifications such as phosphorylation and acetylation modulate its activity. In cancer, RUNX2 can act as an oncogene or tumor suppressor depending on context.