Abstract
We examined the interaction between ephrins and metabotropic glutamate (mGlu) receptors in the developing brain and cultured neurons. EphrinB2 coimmunoprecipitated with mGlu1a receptors, in all of the brain regions examined, and with mGlu5 receptors in the corpus striatum. In striatal slices, activation of ephrinB2 by a clustered form of its target receptor, EphB1, amplified the mGlu receptor-mediated stimulation of polyphosphoinositide (PI) hydrolysis. This effect was abolished in slices treated with mGlu1 or NMDA receptor antagonists but was not affected by pharmacological blockade of mGlu5 receptors. An interaction among ephrinB2, mGlu1 receptor, and NMDA was supported by the following observations: (1) the NR1 subunit of NMDA receptors coimmunoprecipitated with mGlu1a receptors and ephrinB2 in striatal lysates; (2) clustered EphB1 amplified excitatory amino acid-stimulated PI hydrolysis in cultured granule cells grown under conditions that favored the expression of mGlu1a receptors; and (3) clustered EphB1 amplified the enhancing effect of mGlu receptor agonists on NMDA toxicity in cortical cultures, and its action was sensitive to mGlu1 receptor antagonists. Finally, fluorescence resonance energy transfer and coclustering analysis in human embryonic kidney 293 cells excluded a physical interaction between ephrinB2 and mGlu1a (or mGlu5 receptors). A functional interaction between ephrinB and mGlu1 receptors, which likely involves adaptor or scaffolding proteins, might have an important role in the regulation of developmental plasticity.
Publication types
-
Comparative Study
-
Research Support, Non-U.S. Gov't
MeSH terms
-
Analysis of Variance
-
Animals
-
Animals, Newborn
-
Astrocytes / drug effects
-
Astrocytes / metabolism
-
Blotting, Western / methods
-
Brain / cytology*
-
Brain / growth & development
-
Brain / metabolism*
-
Carrier Proteins / metabolism
-
Cells, Cultured
-
Coculture Techniques / methods
-
Dose-Response Relationship, Drug
-
Drug Interactions
-
Embryo, Mammalian
-
Enzyme Activation / drug effects
-
Excitatory Amino Acid Agonists / pharmacology
-
Excitatory Amino Acid Antagonists / pharmacology
-
Fluorescence Resonance Energy Transfer / methods
-
Glial Fibrillary Acidic Protein / metabolism
-
Homer Scaffolding Proteins
-
Humans
-
Hydrolysis / drug effects
-
Immunoprecipitation / methods
-
Luminescent Proteins / metabolism
-
Mice
-
Mice, Inbred C57BL
-
Mice, Knockout
-
Neurons / drug effects
-
Neurons / physiology*
-
Peptide Fragments / pharmacology
-
Phosphatidylinositol Phosphates / metabolism
-
Potassium / pharmacology
-
Protein Structure, Tertiary / physiology
-
Quisqualic Acid / pharmacology
-
RGS Proteins
-
Rats
-
Rats, Sprague-Dawley
-
Receptor, Metabotropic Glutamate 5
-
Receptors, Dopamine D1 / metabolism
-
Receptors, Eph Family / chemistry
-
Receptors, Eph Family / metabolism*
-
Receptors, Metabotropic Glutamate / deficiency
-
Receptors, Metabotropic Glutamate / metabolism*
-
Repressor Proteins / metabolism
-
Spectrometry, Fluorescence / methods
-
Time Factors
-
Transfection / methods
-
Tritium / metabolism
Substances
-
Carrier Proteins
-
Excitatory Amino Acid Agonists
-
Excitatory Amino Acid Antagonists
-
Glial Fibrillary Acidic Protein
-
Homer Scaffolding Proteins
-
Luminescent Proteins
-
Peptide Fragments
-
Phosphatidylinositol Phosphates
-
RGS Proteins
-
Receptor, Metabotropic Glutamate 5
-
Receptors, Dopamine D1
-
Receptors, Metabotropic Glutamate
-
Repressor Proteins
-
Rgs3 protein, rat
-
metabotropic glutamate receptor type 1
-
Tritium
-
Quisqualic Acid
-
Receptors, Eph Family
-
Potassium