ALG-2 interacting protein-X (Alix) is essential for clathrin-independent endocytosis and signaling

Vincent Mercier; Marine H Laporte; Olivier Destaing; Béatrice Blot; Cédric M Blouin; Karin Pernet-Gallay; Christine Chatellard; Yasmina Saoudi; Corinne Albiges-Rizo; Christophe Lamaze; Sandrine Fraboulet; Anne Petiot; Rémy Sadoul

doi:10.1038/srep26986

ALG-2 interacting protein-X (Alix) is essential for clathrin-independent endocytosis and signaling

Sci Rep. 2016 May 31:6:26986. doi: 10.1038/srep26986.

Authors

Vincent Mercier^{1

2}, Marine H Laporte^{1

2}, Olivier Destaing^{3

4

5}, Béatrice Blot^{1

2}, Cédric M Blouin^{6

7

8}, Karin Pernet-Gallay^{1

2}, Christine Chatellard^{1

2}, Yasmina Saoudi^{1

2}, Corinne Albiges-Rizo^{3

4

5}, Christophe Lamaze^{6

7

8}, Sandrine Fraboulet^{1

2}, Anne Petiot^{1

2}, Rémy Sadoul^{1

2}

Affiliations

¹ Institut National de la Santé et de la Recherche Médicale (INSERM), Unité 1216, F-38042 Grenoble, France.
² Université Grenoble Alpes, Institut des Neurosciences, F-38042 Grenoble, France.
³ INSERM U1209, Grenoble, F-38042, France.
⁴ Université Grenoble Alpes, Institut Albert Bonniot, F-38000 Grenoble, France.
⁵ CNRS UMR 5309, F-38000 Grenoble, France.
⁶ Institut Curie, PSL Research University, Membrane Dynamics and Mechanics of Intracellular Signaling Laboratory, Paris, France.
⁷ INSERM, U1143, Paris, France.
⁸ CNRS, UMR 3666, Paris, France.

Abstract

The molecular mechanisms and the biological functions of clathrin independent endocytosis (CIE) remain largely elusive. Alix (ALG-2 interacting protein X), has been assigned roles in membrane deformation and fission both in endosomes and at the plasma membrane. Using Alix ko cells, we show for the first time that Alix regulates fluid phase endocytosis and internalization of cargoes entering cells via CIE, but has no apparent effect on clathrin mediated endocytosis or downstream endosomal trafficking. We show that Alix acts with endophilin-A to promote CIE of cholera toxin and to regulate cell migration. We also found that Alix is required for fast endocytosis and downstream signaling of the interleukin-2 receptor giving a first indication that CIE is necessary for activation of at least some surface receptors. In addition to characterizing a new function for Alix, our results highlight Alix ko cells as a unique tool to unravel the biological consequences of CIE.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Acyltransferases / genetics
Acyltransferases / metabolism*
Animals
B-Lymphocytes / cytology
B-Lymphocytes / drug effects
B-Lymphocytes / metabolism
Calcium-Binding Proteins / genetics
Calcium-Binding Proteins / metabolism*
Cell Cycle Proteins / genetics
Cell Cycle Proteins / metabolism*
Cell Line, Tumor
Cell Movement / drug effects
Cholera Toxin / metabolism
Cholera Toxin / toxicity
Clathrin / genetics
Clathrin / metabolism
Embryo, Mammalian
Endocytosis / genetics*
Endosomal Sorting Complexes Required for Transport / genetics
Endosomal Sorting Complexes Required for Transport / metabolism*
Endosomes / drug effects
Endosomes / metabolism*
Fibroblasts / cytology
Fibroblasts / drug effects
Fibroblasts / metabolism
Gene Expression
Humans
Mice
Mice, Knockout
Neurons / cytology
Neurons / drug effects
Neurons / metabolism
Primary Cell Culture
Protein Binding
Receptors, Interleukin-2 / genetics
Receptors, Interleukin-2 / metabolism*
Signal Transduction

Substances

Calcium-Binding Proteins
Cell Cycle Proteins
Clathrin
Endosomal Sorting Complexes Required for Transport
PDCD6IP protein, human
Pdcd6ip protein, mouse
Receptors, Interleukin-2
Cholera Toxin
Acyltransferases
2-acylglycerophosphate acyltransferase