Send to

Choose Destination
See comment in PubMed Commons below
J Biol Chem. 2006 Jun 2;281(22):15121-8. Epub 2006 Mar 29.

Up-regulation of the KLF2 transcription factor by fluid shear stress requires nucleolin.

Author information

  • 1Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267, USA.


We have previously characterized the regulation of the KLF2 transcription factor gene by describing an induction complex that binds to and regulates its promoter. In the present study, by using DNA affinity chromatography and mass spectrometry, we have identified nucleolin as an additional protein that binds to a palindromic response region in the KLF2 promoter. The presence of nucleolin on the KLF2 promoter in macrophages was verified by electrophoretic mobility shift assays. Interestingly, in mouse and human endothelial cell lines, electrophoretic mobility shift assays and chromatin immunoprecipitation analyses indicated that nucleolin binds the KLF2 promoter only upon application of fluid shear stress. Pretreatment of the endothelial cells with LY294002, a specific inhibitor of phosphatidylinositol 3-kinase (PI3K), blocked the shear stress-induced binding of nucleolin to the promoter, demonstrating its PI3K-dependent regulation. Additionally, nucleolin exhibited dynamic flow-specific, PI3K-dependent alterations in size. Anti-nucleolin antibodies interacted with a 110-kDa form in static endothelial cells and with several catalytic forms that changed in abundance after the application of shear stress. Immunoprecipitation experiments demonstrated that fluid flow induced the interaction of nucleolin with the p85 regulatory subunit of PI3K. Finally, introduction of small interfering RNAs targeting the nucleolin genetic sequence selectively reduced nucleolin expression and was sufficient to block the induction of KLF2 by shear stress. These data support a general role for nucleolin in gene regulation and identify it as a novel factor involved in regulation of KLF2 expression.

[PubMed - indexed for MEDLINE]
Free full text

LinkOut - more resources

Full Text Sources

Other Literature Sources

PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire
    Loading ...
    Support Center