Alix differs from ESCRT proteins in the control of autophagy.
Alix/AIP1 is a cytosolic protein that regulates cell death through mechanisms that remain unclear. Alix binds to two protein members of the so-called Endosomal Sorting Complex Required for Transport (ESCRT), which facilitates membrane fission events during multivesicular endosome formation, enveloped virus budding and cytokinesis. Alix itself has been suggested to participate in these cellular events and is thus often considered to function in the ESCRT pathway. ESCRT proteins were recently implicated in autophagy, a process involved in bulk degradation of cytoplasmic constituents in lysosomes, which can also participate in cell death. In this study, we shown that, unlike ESCRT proteins, Alix is not involved in autophagy. These results strongly suggest that the capacity of several mutants of Alix to block both caspase-dependent and independent cell death does not relate to their capacity to modulate autophagy. Furthermore, they reinforce the conclusion of other studies demonstrating that the role of Alix is different from that of classical ESCRT proteins.
Petiot
Anne
A
INSERM U836, Grenoble Institute of Neuroscience, F-38042 Grenoble, France. remy.sadoul@ujf-grenoble.fr
Strappazzon
Flavie
F
Chatellard-Causse
Christine
C
Blot
Béatrice
B
Torch
Sakina
S
Verna
Jean-Marc
JM
Sadoul
Rémy
R
D000818:Animals; D001343:Autophagy / Q000235:genetics; D002135:Calcium-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D006224:Cricetinae; D056827:Endosomal Sorting Complexes Required for Transport; D011992:Endosomes / Q000378:metabolism*; D006801:Humans; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D009154:Mutation; D014617:Vacuoles / Q000378:metabolism
D002135:Calcium-Binding Proteins; D018797:Cell Cycle Proteins; D056827:Endosomal Sorting Complexes Required for Transport; D008869:Microtubule-Associated Proteins; C117020:PDCD6IP protein, human