Semaphorin4F interacts with the synapse-associated protein SAP90/PSD-95.
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.
Schultze
W
W
Department of Molecular Neurobiochemistry, Ruhr-University Bochum, Bochum, Germany.
Eulenburg
V
V
Lessmann
V
V
Herrmann
L
L
Dittmar
T
T
Gundelfinger
E D
ED
Heumann
R
R
Erdmann
K S
KS
D000595:Amino Acid Sequence; D000818:Animals; D019556:COS Cells; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D002458:Cell Fractionation; D002478:Cells, Cultured; D036387:Ephrin-B1; D006624:Hippocampus / Q000166:cytology; D006801:Humans; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008856:Microscopy, Fluorescence; D008969:Molecular Sequence Data; D009414:Nerve Growth Factors / Q000235:genetics / Q000378:metabolism*; D009419:Nerve Tissue Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D009474:Neurons / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D051381:Rats; D017208:Rats, Wistar; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D000074407:SAP90-PSD95 Associated Proteins; D016415:Sequence Alignment; D014162:Transfection; D020798:Two-Hybrid System Techniques
D002352:Carrier Proteins; D036387:Ephrin-B1; D008565:Membrane Proteins; D009414:Nerve Growth Factors; D009419:Nerve Tissue Proteins; D011993:Recombinant Fusion Proteins; D000074407:SAP90-PSD95 Associated Proteins; C118124:SEMA4F protein, human; C491229:Sema3f protein, mouse; C485552:Sema4f protein, mouse