Postsynaptic membrane addition depends on the discs-large-interacting t-SNARE Gtaxin

David Gorczyca, James Ashley, Sean Speese, Norberto Gherbesi, Ulrich Thomas, Eckart Gundelfinger, L. Sian Gramates, Vivian Budnik

Research output: Contribution to journalArticlepeer-review

38 Scopus citations


Targeted membrane addition is a hallmark of many cellular functions. In the nervous system, modification of synaptic membrane size has a major impact on synaptic function. However, because of the complex shape of neurons and the need to target membrane addition to very small and polarized synaptic compartments, this process is poorly understood. Here, we show that Gtaxin (GTX), a Drosophilat-SNARE (target-soluble N-ethylmaleimide-sensitive factor attachment protein receptor), is required for expansion of postsynaptic membranes during new synapse formation. Mutations in gtx lead to drastic reductions in postsynaptic membrane surface, whereas gtx upregulation results in the formation of complex membrane structures at ectopic sites. Postsynaptic GTX activity depends on its direct interaction with Discs-Large (DLG), a multidomain scaffolding protein of the PSD-95(postsynaptic density protein-95) family with key roles in cell polarity and formation of cellular junctions as well as synaptic protein anchoring and trafficking. We show that DLG selectively determines the postsynaptic distribution of GTX to type I, but not to type II or type III boutons on the same cell, thereby defining sites of membrane addition to this unique set of glutamatergic synapses. We provide a mechanistic explanation for selective targeted membrane expansion at specific synaptic junctions.

Original languageEnglish (US)
Pages (from-to)1033-1044
Number of pages12
JournalJournal of Neuroscience
Issue number5
StatePublished - Jan 31 2007
Externally publishedYes


  • Discs-large
  • Drosophila
  • Membrane addition
  • Neuromuscular junction
  • Postsynaptic plasticity

ASJC Scopus subject areas

  • Neuroscience(all)


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