Transient Fcho1/2⋅Eps15/R⋅AP-2 Nanoclusters Prime the AP-2 Clathrin Adaptor for Cargo Binding

Dev Cell. 2016 Jun 6;37(5):428-43. doi: 10.1016/j.devcel.2016.05.003. Epub 2016 May 26.

Abstract

Clathrin-coated vesicles form by rapid assembly of discrete coat constituents into a cargo-sorting lattice. How the sequential phases of coat construction are choreographed is unclear, but transient protein-protein interactions mediated by short interaction motifs are pivotal. We show that arrayed Asp-Pro-Phe (DPF) motifs within the early-arriving endocytic pioneers Eps15/R are differentially decoded by other endocytic pioneers Fcho1/2 and AP-2. The structure of an Eps15/R⋅Fcho1 μ-homology domain complex reveals a spacing-dependent DPF triad, bound in a mechanistically distinct way from the mode of single DPF binding to AP-2. Using cells lacking FCHO1/2 and with Eps15 sequestered from the plasma membrane, we establish that without these two endocytic pioneers, AP-2 assemblies are fleeting and endocytosis stalls. Thus, distinct DPF-based codes within the unstructured Eps15/R C terminus direct the assembly of temporary Fcho1/2⋅Eps15/R⋅AP-2 ternary complexes to facilitate conformational activation of AP-2 by the Fcho1/2 interdomain linker to promote AP-2 cargo engagement.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Protein Complex 2 / chemistry
  • Adaptor Protein Complex 2 / metabolism*
  • Adaptor Proteins, Signal Transducing / chemistry
  • Adaptor Proteins, Signal Transducing / metabolism*
  • Amino Acid Motifs
  • Amino Acid Sequence
  • Animals
  • Clathrin / metabolism
  • Clathrin-Coated Vesicles / metabolism
  • Endocytosis
  • HeLa Cells
  • Humans
  • Membrane Proteins / metabolism*
  • Models, Biological
  • Models, Molecular
  • Protein Binding
  • Protein Domains
  • Protein Interaction Maps
  • Rats
  • Transfection

Substances

  • Adaptor Protein Complex 2
  • Adaptor Proteins, Signal Transducing
  • Clathrin
  • EPS15 protein, human
  • FCHO1 protein, human
  • FCHO2 protein, human
  • Membrane Proteins