Importin 13 regulates neurotransmitter release at the Drosophila neuromuscular junction

J Neurosci. 2009 Apr 29;29(17):5628-39. doi: 10.1523/JNEUROSCI.0794-09.2009.


In an unbiased genetic screen designed to isolate mutations that affect synaptic transmission, we have isolated homozygous lethal mutations in Drosophila importin 13 (imp13). Imp13 is expressed in and around nuclei of both neurons and muscles. At the larval neuromuscular junction (NMJ), imp13 affects muscle growth and formation of the subsynaptic reticulum without influencing any presynaptic structural features. In the absence of imp13, the probability of release of neurotransmitter and quantal content is increased, yet the abundance of the postsynaptic receptors and the amplitude of miniature excitatory junctional potentials are not affected. Interestingly, imp13 is required in the muscles to control presynaptic release. Thus, imp13 is a novel factor that affects neurotransmitter release at the fly NMJ. Its role in the context of synaptic homeostasis is discussed.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Drosophila Proteins / genetics
  • Drosophila Proteins / physiology*
  • Drosophila melanogaster
  • Karyopherins / genetics
  • Karyopherins / physiology*
  • Larva / genetics
  • Larva / physiology
  • Mutation
  • Neuromuscular Junction / genetics
  • Neuromuscular Junction / metabolism*
  • Neuromuscular Junction / ultrastructure
  • Neurotransmitter Agents / genetics
  • Neurotransmitter Agents / metabolism*


  • Drosophila Proteins
  • IPO13 protein, human
  • Karyopherins
  • Neurotransmitter Agents
  • cdm protein, Drosophila