login

Regulation of the activity of the transcription factor Runx2 by two homeobox proteins, Msx2 and Dlx5

Genes to CellsPublished 1 October 2001Open access
Kyoko Shirakabe, Kazuya Terasawa, Katsuyoshi Miyama, Hiroshi Shibuyà, Eisuke Nishida
Citations180
SJR quartileQ2
SJR score0.69
SNIP0.48
View PDF

TL;DR

Runx2, formerly called PEBP2αA or Cbfa1, is a transcription factor whose deletion causes a complete lack of ossification and directly regulates the expression of osteoblast‐specific genes through the osteobasts specific cis‐acting element found in the promoter region of these genes.

Abstract

BACKGROUND: Runx2, formerly called PEBP2alphaA or Cbfa1, is a transcription factor whose deletion causes a complete lack of ossification. It directly regulates the expression of osteoblast-specific genes through the osteoblast-specific cis-acting element found in the promoter region of these genes. RESULTS: In this study, we have found conditions in which induction of the expression of Runx2 is not accompanied by expression of an osteoblast-specific gene, osteocalcin in C2C12 cells. This finding suggests the existence of a repressor of the activity of Runx2. We have then found that the homeobox protein Msx2 is able to repress the transcription activity of Runx2 by interacting with it. Furthermore, our results have shown that the other homeobox protein Dlx5 has an activity which interferes with both abilities of Msx2 to interact with Runx2 and repress its transcription activity. It has previously been shown that a missense mutation of Msx2 (P148H) causes Boston-type craniosynostosis in humans. Interestingly, while this mutant form of Msx2 was able to bind to Runx2 and repress its activity, these abilities of Msx2 (P148H) were not subject to regulation by Dlx5. CONCLUSION: These results suggest that regulation of the activity of Runx2 by Msx2 and Dlx5 plays an important role in the mammalian skull development.

Keywords

Biochemistry, Genetics and Molecular Biology