124,63 kb, 8 Exon at least.

The transcription of the RUNX2 gene is regulated by two different promoters. The larger P1 transcript gives rise to a protein starting with the amino acid sequence MASNS (Runx2-type II or OSF2/CBFA1a, 521 amino acids), whereas the P2 gives rise to a protein starting with MRIPV (Runx2-type I or isoform c, 507 amino acids). Transcript variants of this protein have been reported as well due to alternative splicing.

Runx2 is a transcription factor belonging to Runx family. This family is characterized by a highly conserved region of 128 amino acids, termed the Runt domain. The Runt domain is responsible for DNA binding and heterodimerization with CBFB (PEBP2b), which increases its DNA-binding affinity and also stabilizes RUNX proteins against proteolytic degradation. The C-terminal portion is rich in proline, serine and threonine (PST region) and contains functional domains acting to regulate transcription.

Runx2 expression is largely restricted to osteoblasts and mesenchymal condensations forming bones, cartilages and teeth.

Nuclear

Runx2 is an osteoblast-specific transcription factor that plays a central role in osteoblast differentiation, chondrocyte maturation, bone formation and remodeling. Moreover, it is a key target of mechanical signals that affect bone biology.

RUNX family.

Heterozygous mutations (frameshift, nonsense, missense, splicing mutations) of the Runx2 gene have been identified in patients with Cleidocranial dysplasia (CCD).