Functional Dissection of the Interactions of Stonin 2 with the Adaptor Complex AP-2 and Synaptotagmin

• Published in: Proceedings of the National Academy of Sciences - PNAS 2004-01, Vol.101 (4), p.964-969
• Main Authors: Walther, Kristin, Diril, M. Kasim, Jung, Nadja, Haucke, Volker
• Format: Article
• Language: English
• Subjects: Adaptor Protein Complex 2 - metabolism; Adaptor Protein Complex alpha Subunits - metabolism; Adaptor Proteins, Vesicular Transport; Amino Acid Sequence; Amino acids; Animals; Biological Sciences; Brain - metabolism; Calcium-Binding Proteins; Carrier Proteins - chemistry; Carrier Proteins - metabolism; Cell Line; Cell membranes; Cellular biology; Endocytosis; Freight; Humans; Internalization; Membrane Glycoproteins - metabolism; Membrane Proteins - chemistry; Membrane Proteins - metabolism; Molecular Sequence Data; Mutagenesis, Site-Directed; Mutation; Nerve Tissue Proteins - metabolism; Neurons; Plasma; Plasma interactions; Protein Binding; Proteins; Synaptotagmin I; Synaptotagmins; Transferrin - metabolism; Transferrins; Vesicular Transport Proteins
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.0307862100

Synaptic vesicle recycling is in part mediated by clathrin-mediated endocytosis. This process involves the coordinated assembly of clathrin and adaptor proteins and the concomitant selection of cargo proteins. Here, we demonstrate that the endocytotic protein stonin 2 localizes to axonal vesicle clusters through its µ-homology domain. Interaction of this domain with synaptotagmin I is sufficient to recruit stonin 2 to the plasmalemma. The N-terminal domain of stonin 2 harbors multiple AP-2-interaction motifs that bind to the clathrin adaptor complex AP-2. These motifs with the consensus sequence WVxF are capable of binding to the α-adaptin ear domain and to µ2. Mutation of the tyrosine motif-binding pocket of µ2 abolishes recognition of the WVxF peptide, suggesting that association with stonin 2 renders AP-2 incompetent to sort tyrosine motif-containing cargo proteins. We hypothesize that stonin 2 may function as an AP-2-dependent sorting adaptor for synaptic vesicle recycling.