First Author | Povsic TJ | Year | 2003 |
Journal | J Biol Chem | Volume | 278 |
Issue | 51 | Pages | 51334-9 |
PubMed ID | 14534298 | Mgi Jnum | J:87275 |
Mgi Id | MGI:2683996 | Doi | 10.1074/jbc.M309968200 |
Citation | Povsic TJ, et al. (2003) Beta-arrestin1 mediates insulin-like growth factor 1 (IGF-1) activation of phosphatidylinositol 3-kinase (PI3K) and anti-apoptosis. J Biol Chem 278(51):51334-9 |
abstractText | beta-arrestins (1 and 2) are widely expressed cytosolic proteins that play central roles in G protein-coupled receptor signaling. beta-arrestin1 is also recruited to the insulin-like growth factor 1 (IGF-1) receptor, a receptor tyrosine kinase, upon agonist binding. Here we report that, in response to IGF-1 stimulation, beta-arrestin1 mediates activation of phosphatidylinositol 3-kinase in a pathway that leads to the subsequent activation of Akt and anti-apoptosis. This process is independent of both Gi and ERK activity. The pathway fails in mouse embryo fibroblasts lacking both beta-arrestins and is restored by stable transfection of beta-arrestin1. Remarkably, this pathway is insensitive to chemical inhibition of IGF-1 receptor tyrosine kinase activity. These results suggest that, in addition to their roles in G protein-coupled receptor signaling, beta-arrestins couple the IGF-1 receptor tyrosine kinase to the phosphatidylinositol 3-kinase system and suggest that this mechanism is operative independently of the tyrosine kinase activity of the receptor. |