title: PI3K is negatively regulated by PIK3IP1, a novel p110 interacting protein.
abstract: 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.
authors.affiliation: Department of Pathology, University of Pittsburgh, Pittsburgh, PA 15261, USA.
authors.forename: Zhenqi
authors.initials: Z
authors.lastname: Zhu
authors.forename: Xin
authors.initials: X
authors.lastname: He
authors.forename: Carla
authors.initials: C
authors.lastname: Johnson
authors.forename: John
authors.initials: J
authors.lastname: Stoops
authors.forename: Amanda E
authors.initials: AE
authors.lastname: Eaker
authors.forename: David S
authors.initials: DS
authors.lastname: Stoffer
authors.forename: Aaron
authors.initials: A
authors.lastname: Bell
authors.forename: Reza
authors.initials: R
authors.lastname: Zarnegar
authors.forename: Marie C
authors.initials: MC
authors.lastname: DeFrances
mesh_terms: D000595:Amino Acid Sequence; D020134:Catalytic Domain; D002460:Cell Line; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D018082:Kringles; D008565:Membrane Proteins / Q000502:physiology*; D008969:Molecular Sequence Data; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism*; D011485:Protein Binding; D021122:Protein Subunits; D015398:Signal Transduction
chemical_list: D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D019869:Phosphatidylinositol 3-Kinases; D021122:Protein Subunits; C521076:PIK3IP1 protein, human