Phosphoinositide 3-kinases and membrane traffic

• Published in: Trends in cell biology 1996-03, Vol.6 (3), p.92-97
• Main Authors: Shepherd, Peter R., Reaves, Barbara J., Davidson, Howard W.
• Format: Article
• Language: English
• ISSN: 0962-8924; 1879-3088
• DOI: 10.1016/0962-8924(96)80998-6

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 3phosphoinositides 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.