Dual interaction of synaptotagmin with mu2- and alpha-adaptin facilitates clathrin-coated pit nucleation

EMBO J. 2000 Nov 15;19(22):6011-9. doi: 10.1093/emboj/19.22.6011.

Abstract

The synaptic vesicle protein synaptotagmin was proposed to act as a major docking site for the recruitment of clathrin coats implicated in endocytosis, including the recycling of synaptic vesicles. We show here that the C2B domain of synaptotagmin binds mu2- and alpha-adaptin, two of the four subunits of the endocytic adaptor complex AP-2. mu2 represents the major interacting subunit of AP-2 within this complex. Its binding to synaptotagmin is mediated by a site in subdomain B that is distinct from the binding site for tyrosine-based sorting motifs located in subdomain A. The presence of the C2B domain of synaptotagmin at the surface of liposomes enhances the recruitment of AP-2 and clathrin. Conversely, perturbation of the interaction between synaptotagmin and AP-2 by synprint, the cytoplasmic synaptotagmin-binding domain of N-type calcium channels, inhibits transferrin internalization in living cells. We conclude that a dual interaction of synaptotagmin with the clathrin adaptor AP-2 plays a key physiological role in the nucleation of endocytic clathrin-coated pits.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adaptor Protein Complex 1*
  • Adaptor Protein Complex 2*
  • Adaptor Protein Complex 3*
  • Adaptor Protein Complex alpha Subunits
  • Adaptor Protein Complex mu Subunits*
  • Adaptor Proteins, Vesicular Transport
  • Animals
  • Binding Sites
  • CHO Cells
  • Calcium-Binding Proteins*
  • Clathrin / chemistry
  • Clathrin / metabolism*
  • Coated Pits, Cell-Membrane / metabolism*
  • Cricetinae
  • In Vitro Techniques
  • Liposomes
  • Lysine / chemistry
  • Membrane Glycoproteins / chemistry
  • Membrane Glycoproteins / metabolism*
  • Membrane Proteins / chemistry
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism*
  • Mutation
  • Nerve Tissue Proteins / chemistry
  • Nerve Tissue Proteins / genetics
  • Nerve Tissue Proteins / metabolism*
  • Phosphoproteins / chemistry
  • Phosphoproteins / genetics
  • Phosphoproteins / metabolism*
  • Protein Subunits
  • Rats
  • Synaptic Vesicles / metabolism
  • Synaptotagmins
  • Tyrosine / chemistry

Substances

  • Adaptor Protein Complex 1
  • Adaptor Protein Complex 2
  • Adaptor Protein Complex 3
  • Adaptor Protein Complex alpha Subunits
  • Adaptor Protein Complex mu Subunits
  • Adaptor Proteins, Vesicular Transport
  • Ap3m2 protein, rat
  • Calcium-Binding Proteins
  • Clathrin
  • Liposomes
  • Membrane Glycoproteins
  • Membrane Proteins
  • Nerve Tissue Proteins
  • Phosphoproteins
  • Protein Subunits
  • adaptor protein complex 1, mu 2 subunit
  • adaptor protein complex 2, mu 2 subunit
  • Synaptotagmins
  • Tyrosine
  • Lysine