MICAL-like1 mediates epidermal growth factor receptor endocytosis

Mol Biol Cell. 2011 Sep;22(18):3431-41. doi: 10.1091/mbc.E11-01-0030. Epub 2011 Jul 27.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actin Cytoskeleton / metabolism
  • Adaptor Proteins, Signal Transducing / genetics
  • Adaptor Proteins, Signal Transducing / metabolism*
  • Animals
  • Cell Adhesion Molecules / metabolism
  • Cell Line
  • Cytoskeletal Proteins / genetics
  • Cytoskeletal Proteins / metabolism*
  • Dogs
  • Endocytosis*
  • ErbB Receptors / metabolism*
  • Gene Knockdown Techniques
  • Humans
  • LIM Domain Proteins / genetics
  • LIM Domain Proteins / metabolism*
  • Lysosomal-Associated Membrane Protein 1 / metabolism
  • Microfilament Proteins
  • Mixed Function Oxygenases
  • Protein Binding
  • Protein Structure, Tertiary
  • Protein Transport
  • RNA Interference
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism*
  • Two-Hybrid System Techniques
  • rab GTP-Binding Proteins / metabolism

Substances

  • Adaptor Proteins, Signal Transducing
  • Cell Adhesion Molecules
  • Cytoskeletal Proteins
  • LIM Domain Proteins
  • Lysosomal-Associated Membrane Protein 1
  • Microfilament Proteins
  • Recombinant Fusion Proteins
  • MICAL1 protein, human
  • Mixed Function Oxygenases
  • ErbB Receptors
  • RAB13 protein, human
  • rab GTP-Binding Proteins