| First Author | Wang X | Year | 2013 |
| Journal | Diabetes | Volume | 62 |
| Issue | 2 | Pages | 444-56 |
| PubMed ID | 23086038 | Mgi Jnum | J:208611 |
| Mgi Id | MGI:5563761 | Doi | 10.2337/db12-0244 |
| Citation | Wang X, et al. (2013) PAQR3 modulates insulin signaling by shunting phosphoinositide 3-kinase p110alpha to the Golgi apparatus. Diabetes 62(2):444-56 |
| abstractText | Phosphoinositide 3-kinase (PI3K) mediates insulin actions by relaying signals from insulin receptors (IRs) to downstream targets. The p110alpha catalytic subunit of class IA PI3K is the primary insulin-responsive PI3K implicated in insulin signaling. We demonstrate here a new mode of spatial regulation for the p110alpha subunit of PI3K by PAQR3 that is exclusively localized in the Golgi apparatus. PAQR3 interacts with p110alpha, and the intracellular targeting of p110alpha to the Golgi apparatus is reduced by PAQR3 downregulation and increased by PAQR3 overexpression. Insulin-stimulated PI3K activity and phosphoinositide (3,4,5)-triphosphate production are enhanced by Paqr3 deletion and reduced by PAQR3 overexpression in hepatocytes. Deletion of Paqr3 enhances insulin-stimulated phosphorylation of AKT and glycogen synthase kinase 3beta, but not phosphorylation of IR and IR substrate-1 (IRS-1), in hepatocytes, mouse liver, and skeletal muscle. Insulin-stimulated GLUT4 translocation to the plasma membrane and glucose uptake are enhanced by Paqr3 ablation. Furthermore, PAQR3 interacts with the domain of p110alpha involved in its binding with p85, the regulatory subunit of PI3K. Overexpression of PAQR3 dose-dependently reduces the interaction of p85alpha with p110alpha. Thus, PAQR3 negatively regulates insulin signaling by shunting cytosolic p110alpha to the Golgi apparatus while competing with p85 subunit in forming a PI3K complex with p110alpha. |
