We have characterized the role of Drosophila PI3K and AKT in ERK pathway activation involving insulin-induced proliferation using Drosophila Schneider cells. After insulin treatment, dPI3K and dAKT activities were both increased along with activation of the dERK pathway components dMEK and dERK. The insulin-induced activations of dERK and dAKT were blocked by LY294002, dPTEN, and by an AKT inhibitor, indicating involvement of dPI3K and dAKT in the insulin-induced dERK and dAKT activations. Proliferation and the G1 to S phase cell cycle progression due to insulin were also blocked by PI3K and AKT inhibitors, indicating that the Drosophila PI3K-AKT pathway involves insulin-mediated cell proliferation. The insulin-stimulated size increase was blocked by both LY294002 and AKT inhibitor, not by U0126, indicating that insulin-mediated size control by dPI3K and dAKT occurs independently of the ERK pathway. This study indicates that dPI3K and dAKT are involved in insulin-induced ERK pathway activation leading to proliferation in Drosophila Schneider cells.
Bibliographical noteFunding Information:
This work was supported by grants from The Molecular and Cellular BioDiscovery Research Program (M1-0311-00-0111), the Korea Research Foundation Grant (KRF-2003-2003-015-C00400), and the Korea Science and Engineering Foundation through the Protein Network Research Center at Yonsei University to K.Y. Choi.
All Science Journal Classification (ASJC) codes
- Cell Biology