There are five variants of the regulatory subunit: the three splice variants p85α, p55α, and p50α, p85β, and p55γ. There are also three variants of the p110 catalytic subunit designated p110α, β, or δ catalytic subunit.

Feb 1, 1998 · Here, we examine the Mn 2+ -dependent protein kinase activity of PI3Kα immunoprecipitated from normal resting or thrombin-stimulated platelets, and characterize p85/p110 phosphorylation, in vitro.

Mar 4, 2011 · The structure of a p110β/p85β complex identifies an inhibitory function for the C-terminal SH2 domain (cSH2) of the p85 regulatory subunit. Mutagenesis of a cSH2 contact residue activates downstream signaling in cells.

Feb 1, 1998 · Here, we examine the Mn(2+)-dependent protein kinase activity of PI3K alpha immunoprecipitated from normal resting or thrombin-stimulated platelets, and characterize p85/p110 phosphorylation, in vitro.

May 8, 2007 · According to the “free p85” model, the expression of non-p110-bound p85 is preferentially reduced in p85 knockout (KO) cells, allowing enhanced access of heterodimeric p85/p110 to pY binding sites, resulting in increased PI3K signaling and hypersensitivity in response to insulin (23–26, 30).

Jul 14, 2020 · Free p85 suppresses insulin signalling by competing with the p85/p110 complex and IRS-1 for pTyr binding sites on activated receptors. p85 mediated activation of JNK also suppresses signalling through IRS-1/PI3K.

Jun 30, 2020 · FOXM1D binds to p85 in its junction region between iSH2 and cSH2 via its exon II- and III-encoding region, while binds to p110 kinase domain via its exon VIII-encoding region; therefore, the...

We propose a novel model for the regulation of the p85/p110α phosphatidylinositol 3′-kinase. In insect cells, the p110α catalytic subunit is active as a monomer but its activity is decreased by coexpression with the p85 regulatory subunit.

Feb 1, 1998 · Here, we examine the Mn2+-dependent protein kinase activity of PI3Kα immunoprecipitated from normal resting or thrombin-stimulated platelets, and characterize p85/p110 phosphorylation, in vitro.

We propose a novel model for the regulation of the p85/pl10alpha phosphatidylinositol 3'-kinase. In insect cells, the p110alpha catalytic subunit is active as a monomer but its activity is decreased by coexpression with the p85 regulatory subunit.