Vesicle Clustering in a Living Synapse Depends on a Synapsin Region that Mediates Phase Separation

Cell Rep. 2020 Feb 25;30(8):2594-2602.e3. doi: 10.1016/j.celrep.2020.01.092.


Liquid-liquid phase separation is an increasingly recognized mechanism for compartmentalization in cells. Recent in vitro studies suggest that this organizational principle may apply to synaptic vesicle clusters. Here we test this possibility by performing microinjections at the living lamprey giant reticulospinal synapse. Axons are maintained at rest to examine whether reagents introduced into the cytosol enter a putative liquid phase to disrupt critical protein-protein interactions. Compounds that perturb the intrinsically disordered region of synapsin, which is critical for liquid phase organization in vitro, cause dispersion of synaptic vesicles from resting clusters. Reagents that perturb SH3 domain interactions with synapsin are ineffective at rest. Our results indicate that synaptic vesicles at a living central synapse are organized as a distinct liquid phase maintained by interactions via the intrinsically disordered region of synapsin.

Keywords: SH3 domain interaction; accessory proteins; phase separation; synapse; synapsin; synaptic vesicle.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Action Potentials
  • Adaptor Proteins, Vesicular Transport / metabolism
  • Amino Acid Sequence
  • Animals
  • Antibodies / metabolism
  • Cluster Analysis
  • Female
  • Intrinsically Disordered Proteins / chemistry
  • Intrinsically Disordered Proteins / metabolism
  • Lampreys
  • Male
  • Nerve Tissue Proteins / metabolism
  • Protein Binding
  • Protein Domains
  • Recombinant Fusion Proteins / metabolism
  • Synapsins / chemistry*
  • Synapsins / metabolism*
  • Synaptic Vesicles / metabolism*
  • Synaptic Vesicles / ultrastructure


  • Adaptor Proteins, Vesicular Transport
  • Antibodies
  • Intrinsically Disordered Proteins
  • Nerve Tissue Proteins
  • Recombinant Fusion Proteins
  • Synapsins
  • intersectin 1
  • amphiphysin