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Neuroligin 1 is dynamically exchanged at postsynaptic sites

Authors

  • I.U. Schapitz
  • B. Behrend
  • Y. Pechmann
  • C. Lappe-Siefke
  • S.J. Kneussel
  • K.E. Wallace
  • A.V. Stempel
  • F. Buck
  • S.G.N. Grant
  • M. Schweizer
  • D. Schmitz
  • J.R. Schwarz
  • E.L.F. Holzbaur
  • M. Kneussel

Journal

  • Journal of Neuroscience

Citation

  • J Neurosci 30 (38): 12733-12744

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.


DOI

doi:10.1523/JNEUROSCI.0896-10.2010