Protein kinase D2 and heat shock protein 90 beta are required for BCL6-associated zinc finger protein mRNA stabilization induced by vascular endothelial growth factor-A

Angiogenesis. 2013 Jul;16(3):675-88. doi: 10.1007/s10456-013-9345-x. Epub 2013 Mar 21.


Vascular endothelial growth factor (VEGF) is a major angiogenic factor that activates pro-angiogenic molecules to generate new vessels. Recently, we identified a VEGF-A-induced pro-angiogenic gene, BCL-6 associated zinc finger protein (BAZF), in endothelial cells. BAZF interacts with CBF1, a transcriptional regulator of Notch signaling, and downregulates Notch signaling by inducing the degradation of CBF1. A signal inhibition assay with a combination of chemical inhibitors and siRNA revealed that the protein kinase D (PRKD) family, mainly PRKD2, mediated BAZF gene expression by VEGF-A stimulation. A luciferase reporter assay showed that the promoter activity of the BAZF gene was unchanged by VEGF-A stimulation. However, we found that the stability of BAZF mRNA increased in a VEGF-A/PRKD2-dependent manner. In further studies to investigate the underlying mechanism, we successfully identified heat shock protein 90 beta (HSP90β) as a molecule that interacts with and stabilizes BAZF mRNA following VEGF-A/PRKD2 activation. These data suggest that HSP90β may positively regulate angiogenesis, not only as a protein chaperone, but also as an mRNA stabilizer for pro-angiogenic genes, such as BAZF, in a PRKD2 activity-dependent manner.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Blotting, Western
  • Electrophoresis, Gel, Two-Dimensional
  • Gene Expression Regulation / physiology*
  • HSP90 Heat-Shock Proteins / metabolism*
  • Human Umbilical Vein Endothelial Cells
  • Humans
  • Immunoglobulin J Recombination Signal Sequence-Binding Protein / metabolism
  • Luciferases
  • Protein Kinase C / metabolism
  • Protein Kinases / metabolism*
  • RNA Interference
  • RNA Stability / drug effects
  • RNA Stability / physiology*
  • Real-Time Polymerase Chain Reaction
  • Receptors, Notch / metabolism
  • Repressor Proteins / metabolism
  • Repressor Proteins / physiology*
  • Reverse Transcriptase Polymerase Chain Reaction
  • Signal Transduction / drug effects
  • Vascular Endothelial Growth Factor A / pharmacology


  • BCL6B protein, human
  • HSP90 Heat-Shock Proteins
  • HSP90AB1 protein, human
  • Immunoglobulin J Recombination Signal Sequence-Binding Protein
  • RBPJ protein, human
  • Receptors, Notch
  • Repressor Proteins
  • Vascular Endothelial Growth Factor A
  • Luciferases
  • Protein Kinases
  • protein kinase D2
  • protein kinase D
  • Protein Kinase C