Rab11-FIP2, an adaptor protein connecting cellular components involved in internalization and recycling of epidermal growth factor receptors.
Rab11-FIP2 is a member of a newly identified family of Rab11-binding proteins that have been implicated in the function of recycling endosomes. Here we show that Rab11-FIP2 may also be involved with the process of receptor-mediated endocytosis. First we demonstrate that Rab11-FIP2 contains an NPF motif that allows it to bind Reps1, a member of a family of EH domain proteins involved in endocytosis. We also show that Rab11-FIP2 associates with the alpha-adaptin subunit of AP-2 complexes, which are known to recruit receptors into clathrin-coated vesicles. Finally, we find that overexpression of Rab11-FIP2 suppresses the internalization of epidermal growth factor receptors, but not transferrin receptors, through binding sites that promote complex formation with Rab11, Reps1, and alpha-adaptin. These findings suggest that Rab11-FIP2 may participate in the coupling of receptor-mediated endocytosis to the subsequent sorting of receptor-containing vesicles in endosomes.
Pubmed ID: 12364336 RIS Download
3T3 Cells | Adaptor Protein Complex 2 | Adaptor Protein Complex alpha Subunits | Amino Acid Motifs | Amino Acid Sequence | Animals | Binding Sites | COS Cells | Carrier Proteins | Endocytosis | Endosomes | Glutathione Transferase | Membrane Proteins | Mice | Models, Biological | Molecular Sequence Data | Peptides | Plasmids | Precipitin Tests | Protein Binding | Protein Structure, Tertiary | Receptor, Epidermal Growth Factor | Sequence Homology, Amino Acid | Software | Spectrometry, Fluorescence | Transfection | Two-Hybrid System Techniques | rab GTP-Binding Proteins