title: MICAL-like1 mediates epidermal growth factor receptor endocytosis.
abstract: Small GTPase Rabs are required for membrane protein sorting/delivery to precise membrane domains. Rab13 regulates epithelial tight junction assembly and polarized membrane transport. Here we report that Molecule Interacting with CasL (MICAL)-like1 (MICAL-L1) interacts with GTP-Rab13 and shares a similar domain organization with MICAL. MICAL-L1 has a calponin homology (CH), LIM, proline rich and coiled-coil domains. It is associated with late endosomes. Time-lapse video microscopy shows that green fluorescent protein-Rab7 and mcherry-MICAL-L1 are present within vesicles that move rapidly in the cytoplasm. Depletion of MICAL-L1 by short hairpin RNA does not alter the distribution of a late endosome/lysosome-associated protein but affects the trafficking of epidermal growth factor receptor (EGFR). Overexpression of MICAL-L1 leads to the accumulation of EGFR in the late endosomal compartment. In contrast, knocking down MICAL-L1 results in the distribution of internalized EGFR in vesicles spread throughout the cytoplasm and promotes its degradation. Our data suggest that the N-terminal CH domain associates with the C-terminal Rab13 binding domain (RBD) of MICAL-L1. The binding of Rab13 to RBD disrupts the CH/RBD interaction, and may induce a conformational change in MICAL-L1, promoting its activation. Our results provide novel insights into the MICAL-L1/Rab protein complex that can regulate EGFR trafficking at late endocytic pathways.
authors.affiliation: Laboratory of Membrane Trafficking, DSV/iBiTec-S-URA2096 CNRS, CEA Saclay, 91191 Gif/Yvette, France.
authors.forename: Nancy
authors.initials: N
authors.lastname: Abou-Zeid
authors.forename: Rudy
authors.initials: R
authors.lastname: Pandjaitan
authors.forename: Lucie
authors.initials: L
authors.lastname: Sengmanivong
authors.forename: Violaine
authors.initials: V
authors.lastname: David
authors.forename: Gwenaelle
authors.initials: G
authors.lastname: Le Pavec
authors.forename: Jean
authors.initials: J
authors.lastname: Salamero
authors.forename: Ahmed
authors.initials: A
authors.lastname: Zahraoui
mesh_terms: D008841:Actin Cytoskeleton / Q000378:metabolism; D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D015815:Cell Adhesion Molecules / Q000378:metabolism; D002460:Cell Line; D003598:Cytoskeletal Proteins / Q000235:genetics / Q000378:metabolism*; D004285:Dogs; D004705:Endocytosis; D066246:ErbB Receptors / Q000378:metabolism*; D055785:Gene Knockdown Techniques; D006801:Humans; D060588:LIM Domain Proteins / Q000235:genetics / Q000378:metabolism*; D052118:Lysosomal-Associated Membrane Protein 1 / Q000378:metabolism; D008840:Microfilament Proteins; D006899:Mixed Function Oxygenases; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D021381:Protein Transport; D034622:RNA Interference; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism*; D020798:Two-Hybrid System Techniques; D020691:rab GTP-Binding Proteins / Q000378:metabolism; D000096985:Calponins
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D015815:Cell Adhesion Molecules; D003598:Cytoskeletal Proteins; D066246:ErbB Receptors; D060588:LIM Domain Proteins; D052118:Lysosomal-Associated Membrane Protein 1; D008840:Microfilament Proteins; D006899:Mixed Function Oxygenases; D011993:Recombinant Fusion Proteins; D020691:rab GTP-Binding Proteins; C455272:MICAL1 protein, human; D000096985:Calponins; C085485:RAB13 protein, human