Access

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

login

Log in to your personal account or through your institution.

Phosphoinositide Binding and Phosphorylation Act Sequentially in the Activation Mechanism of Ezrin

Bruno T. Fievet, Alexis Gautreau, Christian Roy, Laurence Del Maestro, Paul Mangeat, Daniel Louvard and Monique Arpin
The Journal of Cell Biology
Vol. 164, No. 5 (Mar. 1, 2004), pp. 653-659
Stable URL: http://www.jstor.org/stable/1621990
Page Count: 7
  • More info
  • Cite this Item
Phosphoinositide Binding and Phosphorylation Act Sequentially in the Activation Mechanism of Ezrin
Preview not available

Abstract

Ezrin, a membrane-actin cytoskeleton linker, which participates in epithelial cell morphogenesis, is held inactive in the cytoplasm through an intramolecular interaction. Phosphatidylinositol 4,5-bisphosphate ( PIP2) binding and the phosphorylation of theonine 567 (T567) are involved in the activation process that unmasks both membrane and actin binding sites. Here, we demonstrate that ezrin binding to PIP2 through its NH2-terminal domain, is required for T567 phosphorylation and thus for the conformational activation of ezrin in vivo. Furthermore, we found that the T567D mutation mimicking T567 phosphorylation bypasses the need for PIP2 binding for unmasking both membrane and actin binding sites. However, PIP2 binding and T567 phosphorylation are both necessary for the correct apical localization of ezrin and for its role in epithelial cell morphogenesis. These results establish that PIP2 binding and T567 phosphorylation act sequentially to allow ezrin to exert its cellular functions.

Page Thumbnails

  • Thumbnail: Page 
653
    653
  • Thumbnail: Page 
654
    654
  • Thumbnail: Page 
655
    655
  • Thumbnail: Page 
656
    656
  • Thumbnail: Page 
657
    657
  • Thumbnail: Page 
658
    658
  • Thumbnail: Page 
659
    659