%0 Journal Article %T Alix, a protein regulating endosomal trafficking, is involved in neuronal death. %+ Neurodegenerescence et Plasticite %A Trioulier, Yaël %A Torch, Sakina %A Blot, Béatrice %A Cristina, Nadine %A Chatellard-Causse, Christine %A Verna, Jean-Marc %A Sadoul, Rémy %Z This work was supported in part by INSERM, the University Joseph Fourier, grants from the Association pour la Recherche contre le Cancer and the Association Franc¸aise contre les Myopathies. %< avec comité de lecture %@ 0021-9258 %J Journal of Biological Chemistry %I American Society for Biochemistry and Molecular Biology %V 279 %N 3 %P 2046-52 %8 2004-01-16 %D 2004 %R 10.1074/jbc.M309243200 %M 14585841 %Z Life Sciences [q-bio]/Biochemistry, Molecular Biology %Z Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]Journal articles %X Alix/AIP1 is a cytoplasmic protein, which was first characterized as an interactor of ALG-2, a calcium-binding protein necessary for cell death. Alix has also recently been defined as a regulator of the endo-lysosomal system. Here we have used post-mitotic cerebellar neurons to test Alix function in caspase-dependent and -independent cell death. Indeed, these neurons survived when cultured in 25 mm potassium-containing medium but underwent apoptosis soon after the extracellular potassium was lowered to 5 mm. In agreement with other studies, we show that caspases are activated after K+ deprivation, but that inhibition of these proteases, using the pancaspase inhibitor boc-aspartyl(OMe)-fluoromethylketone, has no effect on cell survival. Transfection experiments demonstrated that Alix overexpression is sufficient to induce caspase activation, whereas overexpression of its C-terminal half, Alix-CT, blocks caspase activation and cell death after K+ deprivation. We also define a 12-amino acid PXY repeat of the C-terminal proline-rich domain necessary for binding ALG-2. Deletion of this domain in Alix or in Alix-CT abolished the effects of the overexpressed proteins on neuronal survival, demonstrating that the ALG-2-binding region is crucial for the death-modulating function of Alix. Overall, these findings define the Alix/ALG-2 complex as a regulator of cell death controlling both caspase-dependent and -independent pathways. They also suggest a molecular link between the endo-lysosomal system and the effectors of the cell death machinery. %G English %2 https://inserm.hal.science/inserm-00381892/document %2 https://inserm.hal.science/inserm-00381892/file/Trioulier_2004.pdf %L inserm-00381892 %U https://inserm.hal.science/inserm-00381892 %~ INSERM %~ UGA %~ UNIV-GRENOBLE1