PI3K is negatively regulated by PIK3IP1, a novel p110 interacting protein

Biochem Biophys Res Commun. 2007 Jun 22;358(1):66-72. doi: 10.1016/j.bbrc.2007.04.096. Epub 2007 Apr 24.


Signaling initiated by Class Ia phosphatidylinositol-3-kinases (PI3Ks) is essential for cell proliferation and survival. We discovered a novel protein we call PI3K interacting protein 1 (PIK3IP1) that shares homology with the p85 regulatory PI3K subunit. Using a variety of in vitro and cell based assays, we demonstrate that PIK3IP1 directly binds to the p110 catalytic subunit and down modulates PI3K activity. Our studies suggest that PIK3IP1 is a new type of PI3K regulator.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Catalytic Domain
  • Cell Line
  • Humans
  • Intracellular Signaling Peptides and Proteins
  • Kringles
  • Membrane Proteins / physiology*
  • Molecular Sequence Data
  • Phosphatidylinositol 3-Kinases / metabolism*
  • Protein Binding
  • Protein Subunits
  • Signal Transduction


  • Intracellular Signaling Peptides and Proteins
  • Membrane Proteins
  • PIK3IP1 protein, human
  • Protein Subunits