Agonist-stimulated phosphatidylinositol-3,4,5-trisphosphate generation by scaffolded phosphoinositide kinases.

ABSTRACT: Generation of the lipid messenger phosphatidylinositol-3,4,5-trisphosphate (PtdIns(3,4,5)P₃) is crucial for development, cell growth and survival, and motility, and it becomes dysfunctional in many diseases including cancers. Here we reveal a mechanism for PtdIns(3,4,5)P₃ generation by scaffolded phosphoinositide kinases. In this pathway, class I phosphatidylinositol-3-OH kinase (PI(3)K) is assembled by IQGAP1 with PI(4)KIIIα and PIPKIα, which sequentially generate PtdIns(3,4,5)P₃ from phosphatidylinositol. By scaffolding these kinases into functional proximity, the PtdIns(4,5)P₂ generated is selectively used by PI(3)K for PtdIns(3,4,5)P₃ generation, which then signals to PDK1 and Akt that are also in the complex. Moreover, multiple re

SUBMITTER: Choi S 

PROVIDER: S-EPMC5679705 | biostudies-literature | 2016 Dec

REPOSITORIES: biostudies-literature