Neuroligin 1 is dynamically exchanged at postsynaptic sites

J Neurosci. 2010 Sep 22;30(38):12733-44. doi: 10.1523/JNEUROSCI.0896-10.2010.

Abstract

Neuroligins are postsynaptic cell adhesion molecules that associate with presynaptic neurexins. Both factors form a transsynaptic connection, mediate signaling across the synapse, specify synaptic functions, and play a role in synapse formation. Neuroligin dysfunction impairs synaptic transmission, disrupts neuronal networks, and is thought to participate in cognitive diseases. Here we report that chemical treatment designed to induce long-term potentiation or long-term depression (LTD) induces neuroligin 1/3 turnover, leading to either increased or decreased surface membrane protein levels, respectively. Despite its structural role at a crucial transsynaptic position, GFP-neuroligin 1 leaves synapses in hippocampal neurons over time with chemical LTD-induced neuroligin internalization depending on an intact microtubule cytoskeleton. Accordingly, neuroligin 1 and its binding partner postsynaptic density protein-95 (PSD-95) associate with components of the dynein motor complex and undergo retrograde cotransport with a dynein subunit. Transgenic depletion of dynein function in mice causes postsynaptic NLG1/3 and PSD-95 enrichment. In parallel, PSD lengths and spine head sizes are significantly increased, a phenotype similar to that observed upon transgenic overexpression of NLG1 (Dahlhaus et al., 2010). Moreover, application of a competitive PSD-95 peptide and neuroligin 1 C-terminal mutagenesis each specifically alter neuroligin 1 surface membrane expression and interfere with its internalization. Our data suggest the concept that synaptic plasticity regulates neuroligin turnover through active cytoskeleton transport.

Publication types

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

MeSH terms

  • Animals
  • Biotinylation
  • Cell Adhesion Molecules, Neuronal / metabolism*
  • Cells, Cultured
  • Cytoskeleton / metabolism
  • Dendritic Spines / metabolism*
  • Disks Large Homolog 4 Protein
  • Dyneins / metabolism
  • Electrophysiology
  • Guanylate Kinases
  • Hippocampus / cytology
  • Hippocampus / metabolism*
  • Immunohistochemistry
  • Immunoprecipitation
  • Intracellular Signaling Peptides and Proteins / metabolism
  • Long-Term Potentiation / physiology
  • Long-Term Synaptic Depression / physiology
  • Mass Spectrometry
  • Membrane Proteins / metabolism
  • Mice
  • Mice, Transgenic
  • Neurons / metabolism
  • Synapses / metabolism*
  • Synaptic Transmission / physiology*
  • Transfection

Substances

  • Cell Adhesion Molecules, Neuronal
  • Disks Large Homolog 4 Protein
  • Dlg4 protein, mouse
  • Intracellular Signaling Peptides and Proteins
  • Membrane Proteins
  • neuroligin 1
  • Guanylate Kinases
  • Dyneins