Tandem arrangement of the clathrin and AP-2 binding domains in amphiphysin 1 and disruption of clathrin coat function by amphiphysin fragments comprising these sites.
Amphiphysin 1 and 2 are proteins implicated in the recycling of synaptic vesicles in nerve terminals. They interact with dynamin and synaptojanin via their COOH-terminal SH3 domain, whereas their central regions contain binding sites for clathrin and for the clathrin adaptor AP-2. We have defined here amino acids of amphiphysin ... 1 crucial for binding to AP-2 and clathrin. Overexpression in Chinese hamster ovary cells of an amphiphysin 1 fragment that binds both AP-2 and clathrin resulted in a segregation of clathrin, which acquired a diffuse distribution, from AP-2, which accumulated at patches also positive for Eps15. These effects correlated with a block in clathrin-mediated endocytosis. A fragment selectively interacting with clathrin produced a similar effect. These results can be explained by the binding of amphiphysin to the NH(2)-terminal domain of clathrin and by a competition with the binding of this domain to the beta-subunit of AP-2 and AP180. The interaction of amphiphysin 1 with either clathrin or AP-2 did not prevent its interaction with dynamin, supporting the existence of tertiary complexes between these proteins. Together with previous evidence indicating a direct interaction between amphiphysin and membrane lipids, these findings support a model in which amphiphysin acts as a multifunctional adaptor linking the membrane to coat proteins and coat proteins to dynamin and synaptojanin.
Mesh Terms:
Adaptor Protein Complex alpha Subunits, Adaptor Proteins, Vesicular Transport, Amino Acid Sequence, Animals, Binding Sites, Binding, Competitive, CHO Cells, Clathrin, Cricetinae, Glutathione Transferase, Humans, Membrane Proteins, Molecular Sequence Data, Monomeric Clathrin Assembly Proteins, Mutagenesis, Site-Directed, Nerve Tissue Proteins, Peptide Fragments, Recombinant Fusion Proteins, Transfection
Adaptor Protein Complex alpha Subunits, Adaptor Proteins, Vesicular Transport, Amino Acid Sequence, Animals, Binding Sites, Binding, Competitive, CHO Cells, Clathrin, Cricetinae, Glutathione Transferase, Humans, Membrane Proteins, Molecular Sequence Data, Monomeric Clathrin Assembly Proteins, Mutagenesis, Site-Directed, Nerve Tissue Proteins, Peptide Fragments, Recombinant Fusion Proteins, Transfection
J. Biol. Chem.
Date: Jun. 09, 2000
PubMed ID: 10748223
View in: Pubmed Google Scholar
Download Curated Data For This Publication
9398
Switch View:
- Interactions 5