Calmodulin-dependent kinase II regulates osteoblast differentiation through regulation of Osterix

Biochem Biophys Res Commun. 2013 Mar 8;432(2):248-55. doi: 10.1016/j.bbrc.2013.02.005. Epub 2013 Feb 10.

Abstract

Osterix (Osx), a zinc-finger transcription factor, is required for osteoblast differentiation and new bone formation during embryonic development. Calmodulin-dependent kinase II (CaMKII) acts as a key regulator of osteoblast differentiation. However, the precise molecular signaling mechanisms between Osterix and CaMKII are not known. In this study, we focused on the relationship between Osterix and CaMKII during osteoblast differentiation. We examined the role of the CaMKII pathway in the regulation of protein levels and its transcriptional activity on Osterix. We showed that CaMKII interacts with Osterix by increasing the protein levels and enhancing the transcriptional activity of Osterix. Conversely, CaMKII inhibitor KN-93 decreases the protein levels and increases the stability of Osterix. The siRNA-mediated knockdown of CaMKII decreased the protein levels and transcriptional activity of Osterix. These results suggest that Osterix is a novel target of CaMKII and the activity of Osterix can be modulated by a novel mechanism involving CaMKII during osteoblast differentiation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Benzylamines / pharmacology
  • Calcium-Calmodulin-Dependent Protein Kinase Type 2 / antagonists & inhibitors
  • Calcium-Calmodulin-Dependent Protein Kinase Type 2 / metabolism*
  • Cell Differentiation*
  • Cell Line
  • HEK293 Cells
  • Humans
  • Mice
  • Osteoblasts / cytology*
  • Osteoblasts / metabolism
  • Osteogenesis / genetics
  • Osteogenesis / physiology*
  • Protein Kinase Inhibitors / pharmacology
  • Sp7 Transcription Factor
  • Sulfonamides / pharmacology
  • Transcription Factors / genetics
  • Transcription Factors / metabolism*
  • Transcription, Genetic

Substances

  • Benzylamines
  • Protein Kinase Inhibitors
  • Sp7 Transcription Factor
  • SP7 protein, human
  • Sulfonamides
  • Transcription Factors
  • KN 93
  • CAMK2A protein, human
  • Calcium-Calmodulin-Dependent Protein Kinase Type 2