1. MICAL-like1 mediates epidermal growth factor receptor endocytosis.
- Author
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Abou-Zeid N, Pandjaitan R, Sengmanivong L, David V, Le Pavec G, Salamero J, and Zahraoui A
- Subjects
- Actin Cytoskeleton metabolism, Adaptor Proteins, Signal Transducing genetics, Animals, Cell Adhesion Molecules metabolism, Cell Line, Cytoskeletal Proteins genetics, Dogs, Gene Knockdown Techniques, Humans, LIM Domain Proteins genetics, Lysosomal-Associated Membrane Protein 1 metabolism, Microfilament Proteins, Mixed Function Oxygenases, Protein Binding, Protein Structure, Tertiary, Protein Transport, RNA Interference, Recombinant Fusion Proteins genetics, Two-Hybrid System Techniques, rab GTP-Binding Proteins metabolism, Adaptor Proteins, Signal Transducing metabolism, Cytoskeletal Proteins metabolism, Endocytosis, ErbB Receptors metabolism, LIM Domain Proteins metabolism, Recombinant Fusion Proteins metabolism
- 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.
- Published
- 2011
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