Formation of an endophilin-Ca2+ channel complex is critical for clathrin-mediated synaptic vesicle endocytosis

Cell. 2003 Oct 3;115(1):37-48. doi: 10.1016/s0092-8674(03)00726-8.

Abstract

A tight balance between synaptic vesicle exocytosis and endocytosis is fundamental to maintaining synaptic structure and function. Calcium influx through voltage-gated Ca2+ channels is crucial in regulating synaptic vesicle exocytosis. However, much less is known about how Ca2+ regulates vesicle endocytosis or how the endocytic machinery becomes enriched at the nerve terminal. We report here a direct interaction between voltage-gated Ca2+ channels and endophilin, a key regulator of clathrin-mediated synaptic vesicle endocytosis. Formation of the endophlin-Ca2+ channel complex is Ca2+ dependent. The primary Ca2+ binding domain resides within endophilin and regulates both endophilin-Ca2+ channel and endophilin-dynamin complexes. Introduction into hippocampal neurons of a dominant-negative endophilin construct, which constitutively binds to Ca2+ channels, significantly reduces endocytosis-mediated uptake of FM 4-64 dye without abolishing exocytosis. These results suggest an important role for Ca2+ channels in coordinating synaptic vesicle recycling by directly coupling to both exocytotic and endocytic machineries.

Publication types

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

MeSH terms

  • Adaptor Proteins, Signal Transducing*
  • Animals
  • Binding Sites
  • Calcium / metabolism
  • Calcium Channels / genetics
  • Calcium Channels / metabolism*
  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism*
  • Cells, Cultured
  • Clathrin / metabolism*
  • Dynamins / metabolism
  • Electrophysiology
  • Endocytosis / physiology*
  • Humans
  • Macromolecular Substances
  • Neurons / cytology
  • Neurons / metabolism
  • Presynaptic Terminals / metabolism
  • Protein Structure, Tertiary
  • Rats
  • Rats, Sprague-Dawley
  • Recombinant Fusion Proteins / metabolism
  • Synaptic Transmission
  • Synaptic Vesicles / metabolism*
  • Two-Hybrid System Techniques

Substances

  • Adaptor Proteins, Signal Transducing
  • Calcium Channels
  • Carrier Proteins
  • Clathrin
  • Macromolecular Substances
  • Recombinant Fusion Proteins
  • SH3GL2 protein, human
  • Dynamins
  • Calcium