title: Phosphoinositide 3-kinases and membrane traffic.
abstract: Phosphoinositide 3-kinases (PI 3-kinases) and their 3-phosphoinositide products were identified initially as components of intracellular signalling pathways emanating from cell surface receptors. A new role for 3-phosphoinositides in the constitutive movement o f proteins from one intracellular compartment to another was proposed with the discovery of homology between the product of a yeast gene important for vacuolar sorting, Vps34p, and a mammalian PI 3-kinase. Recent studies have implicated PI 3-kinase as an essential component in membrane traffic at specific steps o f the trans-Golgi-network-endosomal pre-lysosomal system. Evidence largely emerging from the insulin-stimulated glucose transport system suggests that PI 3-kinase may also mediate the effects o f growth factors on membrane traffic events. These studies suggest a possible link between growth-factor-stimulated and constitutive membrane traffic in the endosomal system.
authors.affiliation: Dept of Biochemistry and Molecular Biology, University College London, Gower St, London, UK WC1 E 6BT.
authors.forename: P R
authors.initials: PR
authors.lastname: Shepherd
authors.forename: B J
authors.initials: BJ
authors.lastname: Reaves
authors.forename: H W
authors.initials: HW
authors.lastname: Davidson