First Author | Lin CF | Year | 2007 |
Journal | J Cell Sci | Volume | 120 |
Issue | Pt 16 | Pages | 2935-43 |
PubMed ID | 17666435 | Mgi Jnum | J:124996 |
Mgi Id | MGI:3723327 | Doi | 10.1242/jcs.03473 |
Citation | Lin CF, et al. (2007) GSK-3beta acts downstream of PP2A and the PI 3-kinase-Akt pathway, and upstream of caspase-2 in ceramide-induced mitochondrial apoptosis. J Cell Sci 120(Pt 16):2935-43 |
abstractText | The signaling of glycogen synthase kinase-3beta (GSK-3beta) has been implicated in stress-induced apoptosis. However, the pro-apoptotic role of GSK-3beta is still unclear. Here, we show the involvement of GSK-3beta in ceramide-induced mitochondrial apoptosis. Ceramide induced GSK-3beta activation via protein dephosphorylation at serine 9. We previously reported that ceramide induced caspase-2 and caspase-8 activation, Bid cleavage, mitochondrial damage, and apoptosis. In this study, we found that caspase-2 activation and the subsequent apoptotic events were abolished by the GSK-3beta inhibitors lithium chloride and SB216763, and by GSK-3beta knockdown using short interfering RNA. We also found that ceramide-activated protein phosphatase 2A (PP2A) indirectly caused GSK-3beta activation, and that the PP2A-regulated PI 3-kinase-Akt pathway was involved in GSK-3beta activation. These results indicate a role for GSK-3beta in ceramide-induced apoptosis, in which GSK-3beta acts downstream of PP2A and the PI 3-kinase-Akt pathway, and upstream of caspase-2 and caspase-8. |