Class II phosphoinositide 3-kinase defines a novel signaling pathway in cell migration

Maffucci, T., Cooke, F. T., Foster, F. M., Traer, C. J., Fry, M. J. and Falasca, M. (2005) Class II phosphoinositide 3-kinase defines a novel signaling pathway in cell migration. Journal of Cell Biology, 169 (5). pp. 789-799. ISSN 0021-9525 doi: 10.1083/jcb.200408005

Abstract/Summary

The lipid products of phosphoinositide 3-kinase (PI3K) are involved in many cellular responses such as proliferation, migration, and survival. Disregulation of PI3K-activated pathways is implicated in different diseases including cancer and diabetes. Among the three classes of PI3Ks, class I is the best characterized, whereas class II has received increasing attention only recently and the precise role of these isoforms is unclear. Similarly, the role of phosphatidylinositol-3-phosphate (PtdIns-3-P) as an intracellular second messenger is only just beginning to be appreciated. Here, we show that lysophosphatidic acid (LPA) stimulates the production of PtdIns-3-P through activation of a class II PI3K (PI3K-C2β). Both PtdIns-3-P and PI3K-C2β are involved in LPA-mediated cell migration. This study is the first identification of PtdIns-3-P and PI3K-C2β as downstream effectors in LPA signaling and demonstration of an intracellular role for a class II PI3K. Defining this novel PI3K-C2β- PtdIns-3-P signaling pathway may help clarify the process of cell migration and may shed new light on PI3K-mediated intracellular events.