Semaphorin4F interacts with the synapse-associated protein SAP90/PSD-95

J Neurochem. 2001 Aug;78(3):482-9. doi: 10.1046/j.1471-4159.2001.00447.x.

Abstract

Semaphorins are a family of secreted and membrane-associated proteins involved in growth cone guidance during development. Here, we describe the interaction of Semaphorin4F (Sema4F) with the post-synaptic density protein SAP90/PSD-95. Using the yeast two-hybrid system and coprecipitation assays we were able to show an interaction between the extreme C-terminus of Sema4F and the PDZ domains of SAP90/PSD-95. Heterologous coexpression of a chimeric EphrinB1/Semaphorin4F protein with SAP90/PSD-95 in COS cells leads to translocation of SAP90/PSD-95 from the cytosol to the membrane. Deletion analysis shows that this translocation activity of Sema4F is completely dependent on the presence of the last three C-terminal amino acids. In addition, Sema4F immunoreactivity is present in synaptosome fractions and enriched in post-synaptic density fractions. Consistently, in cultured hippocampal neurons, we demonstrate punctate colocalization of Sema4F and SAP90/PSD-95 in dendrites, furthermore we found colocalization of Sema4F with synapsin1 suggesting a synaptic localization. Our data implicate a new functional context for semaphorins at glutamatergic synapses.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • COS Cells
  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism
  • Cell Fractionation
  • Cells, Cultured
  • Ephrin-B1
  • Hippocampus / cytology
  • Humans
  • Membrane Proteins / chemistry
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism*
  • Microscopy, Fluorescence
  • Molecular Sequence Data
  • Nerve Growth Factors / genetics
  • Nerve Growth Factors / metabolism*
  • Nerve Tissue Proteins / chemistry
  • Nerve Tissue Proteins / genetics
  • Nerve Tissue Proteins / metabolism*
  • Neurons / metabolism*
  • Protein Structure, Tertiary
  • Rats
  • Rats, Wistar
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • SAP90-PSD95 Associated Proteins
  • Sequence Alignment
  • Transfection
  • Two-Hybrid System Techniques

Substances

  • Carrier Proteins
  • Ephrin-B1
  • Membrane Proteins
  • Nerve Growth Factors
  • Nerve Tissue Proteins
  • Recombinant Fusion Proteins
  • SAP90-PSD95 Associated Proteins
  • SEMA4F protein, human
  • Sema3f protein, mouse
  • Sema4f protein, mouse