2v1y
From Proteopedia
Structure of a phosphoinositide 3-kinase alpha adaptor-binding domain (ABD) in a complex with the iSH2 domain from p85 alpha
Structural highlights
Function[PK3CA_BOVIN] Phosphoinositide-3-kinase (PI3K) that phosphorylates PtdIns (Phosphatidylinositol), PtdIns4P (Phosphatidylinositol 4-phosphate) and PtdIns(4,5)P2 (Phosphatidylinositol 4,5-bisphosphate) to generate phosphatidylinositol 3,4,5-trisphosphate (PIP3). PIP3 plays a key role by recruiting PH domain-containing proteins to the membrane, including AKT1 and PDPK1, activating signaling cascades involved in cell growth, survival, proliferation, motility and morphology. Participates in cellular signaling in response to various growth factors. Involved in the activation of AKT1 upon stimulation by receptor tyrosine kinases ligands such as EGF, insulin, IGF1, VEGFA and PDGF. Involved in signaling via insulin-receptor substrate (IRS) proteins. Essential in endothelial cell migration during vascular development through VEGFA signaling, possibly by regulating RhoA activity. Required for lymphatic vasculature development, possibly by binding to RAS and by activation by EGF and FGF2, but not by PDGF. Regulates invadopodia formation in breast cancer cells through the PDPK1-AKT1 pathway. Participates in cardiomyogenesis in embryonic stem cells through a AKT1 pathway. Participates in vasculogenesis in embryonic stem cells through PDK1 and protein kinase C pathway (By similarity). Has also serine-protein kinase activity: phosphorylates PIK3R1 (p85alpha regulatory subunit), EIF4EBP1 and HRAS.[1] [2] [P85A_HUMAN] Binds to activated (phosphorylated) protein-Tyr kinases, through its SH2 domain, and acts as an adapter, mediating the association of the p110 catalytic unit to the plasma membrane. Necessary for the insulin-stimulated increase in glucose uptake and glycogen synthesis in insulin-sensitive tissues. Plays an important role in signaling in response to FGFR1, FGFR2, FGFR3, FGFR4, KITLG/SCF, KIT, PDGFRA and PDGFRB. Likewise, plays a role in ITGB2 signaling.[3] [4] [5] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedMany human cancers involve up-regulation of the phosphoinositide 3-kinase PI3Kalpha, with oncogenic mutations identified in both the p110alpha catalytic and the p85alpha regulatory subunits. We used crystallographic and biochemical approaches to gain insight into activating mutations in two noncatalytic p110alpha domains-the adaptor-binding and the helical domains. A structure of the adaptor-binding domain of p110alpha in a complex with the p85alpha inter-Src homology 2 (inter-SH2) domain shows that oncogenic mutations in the adaptor-binding domain are not at the inter-SH2 interface but in a polar surface patch that is a plausible docking site for other domains in the holo p110/p85 complex. We also examined helical domain mutations and found that the Glu545 to Lys545 (E545K) oncogenic mutant disrupts an inhibitory charge-charge interaction with the p85 N-terminal SH2 domain. These studies extend our understanding of the architecture of PI3Ks and provide insight into how two classes of mutations that cause a gain in function can lead to cancer. Mechanism of two classes of cancer mutations in the phosphoinositide 3-kinase catalytic subunit.,Miled N, Yan Y, Hon WC, Perisic O, Zvelebil M, Inbar Y, Schneidman-Duhovny D, Wolfson HJ, Backer JM, Williams RL Science. 2007 Jul 13;317(5835):239-42. PMID:17626883[6] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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Categories: Bovin | Human | Phosphatidylinositol-4,5-bisphosphate 3-kinase | Backer, J M | Hon, W C | Inbar, Y | Miled, N | Perisic, O | Schneidman-Duhovny, D | Williams, R L | Wolfson, H J | Yan, Y | Zvelebil, M | Cancer | Disease mutation | Host-virus interaction | Kinase | Oncogenic mutation | Phosphoinositide | Phosphoinositide 3-kinase | Phospholipid | Phospholipid signalling | Phosphorylation | Sh2 domain | Sh3 domain | Signal transduction | Transferase
