A motoneuron-selective stop signal in the synaptic protein S-laminin

Neuron. 1995 Mar;14(3):549-59. doi: 10.1016/0896-6273(95)90311-9.

Abstract

Motor axons preferentially reinnervate original synaptic sites on denervated muscle fibers. We have shown that components of synaptic basal lamina direct this selectivity, and we identified a protein, s-laminin, that is concentrated in synaptic basal lamina. Here, we report that a recombinant s-laminin fragment inhibits neurite outgrowth promoted by laminin. A tripeptide sequence in this fragment, Leu-Arg-Glu (LRE), contributes to this inhibition and is itself sufficient to inhibit outgrowth. LRE-mediated inhibition is selective for motoneuron-like cells and is observed in mixtures with several, but not all, outgrowth-promoting substrates. Growth cones extending on laminin stop for up to several hours upon contacting deposits of the s-laminin fragment. Thus, LRE may serve as a cell type-selective and context-dependent target-derived signal that plays a role in synapse formation.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Cell Division / drug effects
  • Chick Embryo
  • Ganglia, Parasympathetic / cytology
  • Ganglia, Parasympathetic / physiology
  • Laminin / biosynthesis
  • Laminin / pharmacology*
  • Molecular Sequence Data
  • Motor Neurons / cytology
  • Motor Neurons / drug effects*
  • Motor Neurons / physiology
  • Neurites / drug effects
  • Neurites / physiology*
  • Neurites / ultrastructure
  • Oligodeoxyribonucleotides
  • Peptide Fragments / pharmacology*
  • Recombinant Fusion Proteins / biosynthesis
  • Recombinant Proteins / pharmacology
  • Signal Transduction

Substances

  • Laminin
  • Oligodeoxyribonucleotides
  • Peptide Fragments
  • Recombinant Fusion Proteins
  • Recombinant Proteins
  • laminin beta2