Caspase-3 cleavage of dishevelled induces elimination of postsynaptic structures

Dev Cell. 2014 Mar 31;28(6):670-84. doi: 10.1016/j.devcel.2014.02.009. Epub 2014 Mar 13.

Abstract

During the development of vertebrate neuromuscular junction (NMJ), agrin stabilizes, whereas acetylcholine (ACh) destabilizes AChR clusters, leading to the refinement of synaptic connections. The intracellular mechanism underlying this counteractive interaction remains elusive. Here, we show that caspase-3, the effector protease involved in apoptosis, mediates elimination of AChR clusters. We found that caspase-3 was activated by cholinergic stimulation of cultured muscle cells without inducing cell apoptosis and that this activation was prevented by agrin. Interestingly, inhibition of caspase-3 attenuated ACh agonist-induced dispersion of AChR clusters. Furthermore, we identified Dishevelled1 (Dvl1), a Wnt signaling protein involved in AChR clustering, as the substrate of caspase-3. Blocking Dvl1 cleavage prevented induced dispersion of AChR clusters. Finally, inhibition or genetic ablation of caspase-3 or expression of a caspase-3-resistant form of Dvl1 caused stabilization of aneural AChR clusters. Thus, caspase-3 plays an important role in the elimination of postsynaptic structures during the development of NMJs.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetylcholine / metabolism
  • Adaptor Proteins, Signal Transducing / antagonists & inhibitors
  • Adaptor Proteins, Signal Transducing / genetics
  • Adaptor Proteins, Signal Transducing / metabolism*
  • Agrin / physiology
  • Animals
  • Caspase 3 / metabolism*
  • Cells, Cultured
  • Dishevelled Proteins
  • Electrophysiology
  • Embryo, Mammalian / cytology
  • Embryo, Mammalian / metabolism
  • Image Processing, Computer-Assisted
  • Immunoenzyme Techniques
  • Mice
  • Mice, Knockout
  • Motor Neurons / cytology
  • Motor Neurons / metabolism
  • Muscle, Skeletal / cytology
  • Muscle, Skeletal / metabolism*
  • Neuromuscular Junction / physiology*
  • Phosphoproteins / antagonists & inhibitors
  • Phosphoproteins / genetics
  • Phosphoproteins / metabolism*
  • RNA, Small Interfering / genetics
  • Rats
  • Rats, Sprague-Dawley
  • Receptors, Cholinergic / metabolism
  • Signal Transduction
  • Synaptic Potentials / physiology*
  • Synaptic Transmission*

Substances

  • Adaptor Proteins, Signal Transducing
  • Agrin
  • Dishevelled Proteins
  • Dvl1 protein, mouse
  • Dvl1 protein, rat
  • Phosphoproteins
  • RNA, Small Interfering
  • Receptors, Cholinergic
  • Caspase 3
  • Acetylcholine