The extracellular glycosphingolipid-binding motif of Fas defines its internalization route, mode and outcome of signals upon activation by ligand.
Selective compartmentalization and internalization have been shown as a means for regulating specific signals of cell surface receptors to correspond to cellular requirements and conditions. Here, we present a conserved extracellular glycosphingolipid-binding motif of Fas as one of the regulatory elements in the selection of its internalization route and consequently the signals transmitted upon ligand binding. This motif is required for clathrin-mediated internalization of Fas, which allows the transduction of its cell death signal. The loss of function of the motif drives the activated receptor to an alternative internalization route that is independent of clathrin and cholesterol-dependent rafts but dependent on ezrin, and thereby extinguishing its cell death signal while promoting its non-death functions. Through biochemical, biophysical, and genetic approaches, we present a protein/lipid-based mechanism as a key to the versatility of the signal transduction by the multifunctional Fas receptor-ligand system.
Chakrabandhu
K
K
Equipe labelisée La Ligue, Institute of Developmental Biology and Cancer Research, CNRS UMR 6543, Nice, France. chakraba@unice.fr
Huault
S
S
Garmy
N
N
Fantini
J
J
Stebe
E
E
Mailfert
S
S
Marguet
D
D
Hueber
A-O
AO
D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D000818:Animals; D019556:COS Cells; D016923:Cell Death; D002462:Cell Membrane / Q000378:metabolism; D002522:Chlorocebus aethiops; D002784:Cholesterol / Q000378:metabolism; D002966:Clathrin / Q000378:metabolism; D003598:Cytoskeletal Proteins / Q000378:metabolism; D053418:Death Domain Receptor Signaling Adaptor Proteins / Q000378:metabolism; D004705:Endocytosis; D005110:Extracellular Space / Q000378:metabolism*; D006028:Glycosphingolipids / Q000378:metabolism*; D006801:Humans; D008024:Ligands; D021962:Membrane Microdomains / Q000378:metabolism; D051379:Mice; D008969:Molecular Sequence Data; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D015398:Signal Transduction; D013329:Structure-Activity Relationship; D019014:fas Receptor / Q000737:chemistry* / Q000378:metabolism*; D000099149:Ezrin
D002784:Cholesterol; D002966:Clathrin; D003598:Cytoskeletal Proteins; D053418:Death Domain Receptor Signaling Adaptor Proteins; D006028:Glycosphingolipids; D008024:Ligands; D019014:fas Receptor; D000099149:Ezrin; C491899:Fas protein, mouse